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The alkaline α-galactosidase AtAkαGal3 from Arabidopsis thaliana catalyzes the hydrolysis of α-D-galactose from galacto-oligosaccharides under alkaline conditions. A phylogenetic analysis based on sequence alignment classifies AtAkαGal3 as more closely related to the raffinose family of oligosaccharide (RFO) synthases than to the acidic α-galactosidases. Here, thin-layer chromatography is used to demonstrate that AtAkαGal3 exhibits a dual function and is capable of synthesizing stachyose using raffinose, instead of galactinol, as the galactose donor. Crystal structures of complexes of AtAkαGal3 and its D383A mutant with various substrates and products, including galactose, galactinol, raffinose, stachyose and sucrose, are reported as the first representative structures of an alkaline α-galactosidase. The structure of AtAkαGal3 comprises three domains: an N-terminal domain with 13 antiparallel β-strands, a catalytic domain with an (α/β)8-barrel fold and a C-terminal domain composed of β-sheets that form two Greek-key motifs. The WW box of the N-terminal domain, which comprises the conserved residues FRSK75XW77W78 in the RFO synthases, contributes Trp77 and Trp78 to the +1 subsite to contribute to the substrate-binding ability together with the (α/β)8 barrel of the catalytic domain. The C-terminal domain is presumably involved in structural stability. Structures of the D383A mutant in complex with various substrates and products, especially the natural substrate/product stachyose, reveal four complete subsites (–1 to +3) at the catalytic site. A functional loop (residues 329–352) that exists in the alkaline α-galactosidase AtAkαGal3 and possibly in RFO synthases, but not in acidic α-galactosidases, stabilizes the stachyose at the +2 and +3 subsites and extends the catalytic pocket for the transferase mechanism. Considering the similarities in amino-acid sequence, catalytic domain and activity between alkaline α-galactosidases and RFO synthases, the structure of AtAkαGal3 might also serve a model for the study of RFO synthases, structures of which are lacking.

A new polymorph of β-cyclodextrin (β-CD) was produced by optical trapping with a 1064 nm continuous wave laser beam in D2O solution. Upon optical trapping of β-CD in unsaturated solutions, a single...

We demonstrated the concept of anisotropic off-axis laser oscillator through stimulated Raman scattering and generated the octave-spanning supercontinuum, containing two spectral groups between 540~750 and 1095~1800 nm, in a monolithic KTP crystal.

We report generation of octave-spanning supercontinuum from a high-gain, ultra-broadband, and mirrorless Raman oscillator in a monolithic KTP crystal. The supercontinuum output contains two spectral groups between 540~750 and 1095~1800 nm.

Introduction: The aim of this study was to better understand the onset time and factors associated with cochlear obliteration following translabyrinthine approach (TLA) surgery for large cerebellopontine angle tumors. Methods: This retrospective cohort study included 117 patients with large cerebellopontine angle tumor (tumor diameter >2 cm) treated by TLA surgery from June 2011 to March 2019 in a single tertiary referral center. The Kaplan-Meier method with log-rank test was used to estimate cochlear patency survival and the association between survival and covariates, and the Cox proportional hazards regression analysis was used to identify possible factors associated with cochlear obliteration. Results: Of the 117 patients included in our analysis, the median follow-up was 24.8 months. There were 30 (25.6%) patients in the cochlear obliteration group, and 87 (74.4%) in the patent cochlear group. Various degrees of cochlear obliteration was found in 25.6% patients in final MRI scan, comprised of 50% grade I, 30% grade II, and 20% grade III. Cochlear patency survival curves showed 94.0% at 3 months, 73.0% at 18 months, which plateaued after 20 months with a survival rate of 71.6%. In the multivariate Cox proportional hazards model, patients presented with postoperative hyperintense T1W cochlear signal had poorer cochlear patency survival compared to isointense T1W (HR = 4.15). Similarly, postoperative deteriorated facial function (HR = 4.52) and full IAC involvement of tumor (HR = 2.33) demonstrated a higher risks of cochlear obliteration after TLA surgery. Conclusion: The 2-year estimated cochlear patency rate was 71.6% in patients that received TLA. Cochlear obliteration can develop as early as 3 months post-surgery, with no new obliteration 20 months after the surgery and half of these patients got severe obliteration. Three factors associated with cochlear obliteration were identified including full IAC involvement of tumor, postoperative facial function deterioration, and postoperative hyperintense T1W cochlear signal.

We report generation of a visible and near-infrared supercontinuum from a high-gain, ultra-broadband, and mirrorless Raman oscillator in a monolithic KTP crystal. The plane transverse to the pump axis resonates and traps off-axis Stokes waves and their frequency-upconverted components bouncing between two crystal surfaces via total internal reflection. The Raman gain is maximized with the Stokes polarization perpendicular to the plane of reflections. When pumped by a Q -switched Nd:YAG laser, the monolithic oscillator generates quasi-mode-locked Stokes pulses with octave-spanning spectral groups across the visible and near-infrared spectra between 540 and 1800 nm.

Two crystal structures of the histidine-containing phospho­transfer protein (HptB) and the receiver domain of the hybrid sensor histidine kinase PA1611 (PA1611REC) in the two-component regulatory system of Pseudomonas aeruginosa have been determined. With the modeled structure of the PA1611REC/HptB complex, the interactions and phospho­ryl group transfer between HptB and PA1611REC are elucidated., In Pseudomonas aeruginosa, an important opportunistic pathogen that causes numerous acute and chronic infections, the hybrid two-component system (TCS) regulates the swarming ability and biofilm formation with a multistep phospho­relay, and consists of hybrid-sensor histidine kinase (HK), histidine-containing phospho­transfer protein (Hpt) and response regulator (RR). In this work, two crystal structures of HptB and the receiver domain of HK PA1611 (PA1611REC) of P. aeruginosa have been determined in order to elucidate their interactions for the transfer of the phospho­ryl group. The structure of HptB folds into an elongated four-helix bundle – helices α2, α3, α4 and α5, covered by the short N-terminal helix α1. The imidazole side chain of the conserved active-site histidine residue His57, located near the middle of helix α3, protrudes from the bundle and is exposed to solvent. The structure of PA1611REC possesses a conventional (β/α)5 topology with five-stranded parallel β-sheets folded in the central region, surrounded by five α-helices. The divalent Mg2+ ion is located in the negatively charged active-site cleft and interacts with Asp522, Asp565 and Arg567. The HptB–PA1611REC complex is further modeled to analyze the binding surface and interactions between the two proteins. The model shows a shape complementarity between the convex surface of PA1611REC and the kidney-shaped HptB with fewer residues and a different network involved in interactions compared with other TCS complexes, such as SLN1-R1/YPD1 from Saccharomyces cerevisiae and AHK5RD/AHP1 from Arabidopsis thaliana. These structural results provide a better understanding of the TCS in P. aeruginosa and could potentially lead to the discovery of a new treatment for infection.

The protrusion domain (P-domain; MrNVPd) of Macrobrachium rosenbergii nodavirus (MrNV) exists in two conformations, parallel and X-shaped. We have performed a theoretical study to gain insight into the nature of the dimeric interactions involving the dimeric interfaces within parallel and X-shaped conformations of MrNVPd by applying the quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analyses in the framework of the density functional theory (DFT) approach. The results reveal that the dimer–dimer interfaces of MrNVPd have hydrogen bonds of common types. Leu255–Lys287, Tyr257–Lys287, Lys287–Ser253, Met294–Cys328, Asp295–Lys327, Ser298–Ser324, Ile326–Asp295, and Cys328–Met294 are the key residue pairs of the dimer–dimer interfaces to maintain the dimer–dimer structures of MrNVPd through charge–charge, charge–dipole, dipole–dipole, hydrophobic, and hydrogen bonding interactions. The strengths of these intermolecular dimer–dimer interactions in the parallel conformation are much greater than those in the X-shaped conformation. The parallel trimeric interface is held basically by electrostatic and hydrophobic interactions. The electrostatic interactions accompanying a strong hydrogen bond of Oγ1–Hγ1···Oγ1 in the Thr276 A–Thr276 D pair maintain the intermolecular interface of two X-shaped MrNVPd dimers.

In this paper, we propose to manipulate a nonrelativistic electron beam during its emission and acceleration to create nanobunched electrons. Specifically, we simulate the acceleration of a structured electron beam emitted from a multiring photocathode in a photoinjector and show that, after acceleration, such a transversely structured beam can be transformed into a hollow beam with a longitudinal density modulation in the petahertz frequency range. Our theoretical study shows that, in the far-field zone, the coherent radiation of the bunched hollow beam approaches that of a similarly bunched solid beam in the paraxial limit.

By exploiting the anisotropic radiation pattern of an elementary dipole in a laser material, we report a gain enhancement factor of 1.3104 for an off-axis Raman laser in a monolithic y-cut versus z-cut KTP crystal.

We report the generation of 82-kW and 117-kW peak powers at 5.7 THz external and internal to a Si prism coupler, respectively, of a pulsed KTP difference frequency generator with a line-shape beam profile.

A laser is meant to emit coherent radiation at a particular wavelength. Here, we demonstrate a laser that is prohibited to emit at a particular wavelength, called a dark line in the emission background of its gain spectrum. Specifically, we installed a 150 µm thick etalon mirror on an ytterbium-doped fiber laser. The laser suffers from 100% loss at the resonance of the etalon and generates a dark line in its emission spectrum. The interplay among the etalon resonance, homogenous gain broadening, and gain competition allows wavelength tuning and multiple-color emission from the laser.

Mnemiopsin 2 from a luminous ctenophore with two functional EF-hand motifs is a calcium-regulated photoprotein that is responsible for emitting a bright blue bioluminescence upon reacting with coelenterazine and calcium ions in Mnemiopsis leidyi. Synchrotron radiation-based Fourier-transform infrared (SR-FTIR) spectroscopy was applied to analyze the distribution of secondary structures, the conformational changes resulting from calcium binding and the structural stabilities in wild-type mnemiopsin 2, as well as its mutant type that possesses three EF-hand motifs. The distribution of secondary structures of these proteins indicates that mutant apo-mnemiopsin 2 has a more stable secondary structure than the wild-type. Analyses of the SR-FTIR spectra revealed that the conformational changes at the secondary structures of both mnemiopsin 2 depend on the calcium concentrations, such that the most noticeable changes in structures of wild-type and mutant mnemiopsin 2 occur at optimum concentrations 6 and 2 mM of calcium chloride, respectively. The addition of calcium to both proteins increases the proportions of their secondary structures in the amide I and II regions. The major amide I bands in the IR spectra of both mnemiopsin‑calcium complexes shift towards smaller wavenumbers, whereas their main amide II bands are identified at larger wavenumbers.

Compressed sensing (CS) is a newly developed research in multimedia compression studies. A large portion of papers in this field focuses on compression performance. In this paper, we aim at transmitting CS signals over lossy channels. We employ wavelet transform, and then apply compressed sensing to original image to obtain CS signals. Channel errors may cause severe effects to CS signals, leading to degradation to the reconstruction. We use multiple description coding (MDC) to protect CS signals beforehand, transmit the protected signals, and recover the reconstruction with the calculations from the compensations of MDC. Simulations have presented the alleviation of reconstructed image quality with proposed algorithm.

The protrusion-domain (P-domain) of Penaeus vannamei nodavirus (PvNV) exists as two dimer-dimer conformations: one is a protein dimer and the other is a protein tetramer. We undertook a theoretical study to gain a clear understanding of the nature of the stabilizing interactions at the dimeric interfaces of the dimeric and tetrameric conformations of the PvNV P-domain (PvNVPd) using the quantum theory of atoms in molecules (QTAIM) and natural-bond orbital (NBO) analyses in the framework of the density-functional theory (DFT) approach. The QTAIM analysis characterized the presence of multiple hydrogen bonds of common types with strength ranging from electrostatic to the covalent limit inside the PvNVPd dimer-dimer interfaces. Val257-Lys335, Phe294-Val330, Gln296-Thr328, Glu296-Thr329, Thr328-Gln297, Val330-Ala293, Lys335-Asp256 and Lys335-Val257 pairs are critical residue pairs of all three dimeric interfaces of PvNVPd. They preserve these dimeric interfaces through charge-charge, charge-dipole, dipole-dipole, hydrophobic and hydrogen bond interactions. The strongest intermolecular dimer–dimer interactions belong to the dimeric interface between subunits A and B of PvNVPd in the tetrameric conformation.

With the rapid development of information and Communication Technologies (ICTs) and a wide range of mobile devices, the government website must provide rich information to adopt multi-mobile devices and response the public questions quickly. In Taiwan, the National Development Council (NDC) has established the website-checking system, then help each government organization to improve the website service. Therefore, the purpose of this study is to apply the design research method. To solve the current issues of the old website design, the case study was discussed based on theories of four main operation performance indicators by NDC, ten major digital service designs by UK Government, as well as six main principles of the user-friendly web design. The case study of government website, the old website used the checking system was 88 score points, but the new website got 99 points, the only one item didn’t get is the website rank must under 1000 in Taiwan. The methodology developed by the process of this research provided appropriated solutions for the same issues, which county and municipal government may encounter with in the future. In response to the ever-changing web service, service innovations and future designs can be brought into institutions by applying it. In addition, it achieved goals, such as improving website performance, enhancing the transparency of government administrations, and strengthening the power of public supervision of governments.

We report tunable narrow-line high-power far-infrared radiation between 3-6 THz from off-axis parametric oscillators using lithium niobate and KTP as gain crystals. We measured tens of kW power at 5.7 THz in an ~80 ps width.

We report the detection of $> 70 -$kW radiation power at about $52 \mu$ m from a KTP off-axis THz parametric oscillator, when pumping it with 11.9-mJ energy in a 450-ps pulse from a single-frequency Nd:YAG laser and seeding it with a 7-μJ, 40-GHz-linewidth Stokes pulse from a synchronously pumped KTP parametric generator. With 63% coupling efficiency of the silicon prism, the seeded off-axis THz parametric oscillator has emitted $> 111 -$kW peak power radiation into the silicon prism.

The human hepatoma-derived growth factor (HDGF), containing the chromatin-associated N-terminal PWWP domain capable of binding the SMYD1 promoter, participates in various cellular processes and is involved in human cancers. We report the first crystal structures of the human HDGF PWWP domain (residues 1–100) in a complex with SMYD1 of 10 bp at 2.84 Å resolution and its apo form at 3.3 Å, respectively. The structure of the apo PWWP domain comprises mainly four β-strands and two α-helices. The PWWP domain undergoes domain swapping to dramatically transform its secondary structures, altering the overall conformation from monomeric globular folding into an extended dimeric structure upon DNA binding. The flexible loop2, as a hinge loop with the partially built structure in the apo PWWP domain, notably refolds into a visible and stable α-helix in the DNA complex. The swapped PWWP domain interacts with the minor grooves of the DNA through residues Lys19, Gly22, Arg79 and Lys80 in varied ways on loops 1 and 4 of the two chains, and the structure becomes more rigid than the apo form. These novel structural findings, together with physiological and activity assays of HDGF and the PWWP domain, provide new insights into the DNA-binding mechanism of HDGF during nucleosomal functions.

Building integrated photovoltaic (BIPV) systems are a promising strategy to integrate photovoltaic (PV) systems with building materials to reduce construction costs and add aesthetic features. In this study, a fire test in accordance with ISO 834-1:1999, CNS 14803-2010 and ISO 3008:2007 to provide the standard heating curve was carried out to investigate the fire-resistant characteristics based on the breaking behaviour and surface temperature distribution of type I and type II BIPV modules. The BIPV modules tested have both open and hidden junction-box (J-box) designs, with the aim of reducing fire risks. Our results show that the proposed type II BIPV module could resist the simulated room fire test for about 12 min without reducing any risk with regard to the J-box. Furthermore, the type II BIPV module could resist a fire test at temperatures of up to ∼1000℃ for 60 min with better compartment functionality when refractory glasses are employed. The BIPV fire test data reported in this study can help to improve the design and development of BIPV systems.

In previous studies, KTiOPO4 (KTP) shows higher laser damage resistance and larger figure of merit for THz parametric generation [1,2]. To generate high-power THz radiation, it is possible to perform pulsed difference frequency generation in a bulk KTP crystal [3]. Recently, we have also reported an off-axis THz parametric oscillator (OTPO) with unprecedented SPS gain in lithium niobate [4]. In this work, we employ a y-cut KTP slab crystal as an OTPO and seed it with a pulsed signal from a KTP THz parametric generator (TPG) to generate THz radiation with tens of kW power.

Using the superradiant Smith-Purcell radiation from a train of periodic electron-bunches interacting with a grating is an efficient way for generating terahertz radiation beyond the frequency region of traditional vacuum electron devices. The producing of a train of well-shaped electron bunches is essential for these radiation schemes. Here we design and simulate a photocathode DC-gun driven by train of laser pulses, aiming to generating train of sheet-shaped electron bunches for practices. The effects of main structural parameters and of laser properties on the performances of electron gun are investigated. It will set an important base for the development and improvement of practical electron guns in experiments.