Ultraviolet Photodissociation Spectroscopy of Cold K+•Calix[4]arene Complex in the Gas Phase

The cooling of ionic species in the gas phase greatly simplifies the UV spectrum, which is of special importance to study the electronic and geometric structures of large systems, such as bio-related molecules and host-guest complexes. Many efforts have been devoted to achieving the ion cooling with a cold quadrupole Paul ion trap (QIT), but one problem was insufficient cooling of ions (up to ~30 K) in the QIT. In this study, we construct a mass spectrometer for ultraviolet photodissociation (UVPD) spectroscopy of gas-phase cold ions. The instrument consists of an electrospray ion source, a QIT cooled with a He cryostat, and a time-of-flight mass spectrometer. Giving a great care for the cooling condition, we can achieve ~10 K for the vibrational temperature of ions in the QIT, which is estimated from UVPD spectra of the benzo-18-crown-6 (B18C6) complex with potassium ion, K+•B18C6. Using this setup, we measure a UVPD spectrum of cold calix[4]arene (C4A) complex with potassium ion, K+•C4A. The spectrum shows a very weak band and a strong one at 36018 and 36156 cm–1, respectively, accompanied by many sharp vibronic bands in the 36000–36600 cm–1 region. In the geometry optimization of the K+•C4A complex, we obtain three stable isomers: one endo and two exo forms. On the basis of the total energy and UV spectral patterns predicted by density functional theory calculations, we attribute the structure of the K+•C4A complex to the endo isomer (C2 symmetry), in which the K+ ion is located inside the cup of C4A. The vibronic bands of K+•C4A at 36018 and 36156 cm–1 are assigned to the S1(A)–S0(A) and S2(B)–S0(A) transitions of the endo isomer, respectively.This work is partly supported by the Japan Society for the Promotion of Science (JSPS) through the program “Strategic Young Researcher Overseas Visits Program for Accelerating Brain Circulation”

DanceDJ: A 3D Dance Animation Authoring System for Live Performance

Dance is an important component of live performance for expressing emotion and presenting visual context. Human dance performances typically require expert knowledge of dance choreography and professional rehearsal, which are too costly for casual entertainment venues and clubs. Recent advancements in character animation and motion synthesis have made it possible to synthesize virtual 3D dance characters in real-time. The major problem in existing systems is a lack of an intuitive interfaces to control the animation for real-time dance controls. We propose a new system called the DanceDJ to solve this problem. Our system consists of two parts. The first part is an underlying motion analysis system that evaluates motion features including dance features such as the postures and movement tempo, as well as audio features such as the music tempo and structure. As a pre-process, given a dancing motion database, our system evaluates the quality of possible timings to connect and switch different dancing motions. During run-time, we propose a control interface that provides visual guidance. We observe that disk jockeys (DJs) effectively control the mixing of music using the DJ controller, and therefore propose a DJ controller for controlling dancing characters. This allows DJs to transfer their skills from music control to dance control using a similar hardware setup. We map different motion control functions onto the DJ controller, and visualize the timing of natural connection points, such that the DJ can effectively govern the synthesized dance motion. We conducted two user experiments to evaluate the user experience and the quality of the dance character. Quantitative analysis shows that our system performs well in both motion control and simulation quality

Ultraviolet Photodissociation Spectroscopy of the Cold K⁺·Calix[4]arene Complex in the Gas Phase

The cooling of ionic species in the gas phase greatly simplifies the UV spectrum, which is of special importance when studying the electronic and geometric structures of large systems, such as biorelated molecules and host–guest complexes. Many efforts have been devoted to achieving ion cooling with a cold, quadrupole Paul ion trap (QIT), but one problem was the insufficient cooling of ions (up to ∼30 K) in the QIT. In this study, we construct a mass spectrometer for the ultraviolet photodissociation (UVPD) spectroscopy of gas-phase cold ions. The instrument consists of an electrospray ion source, a QIT cooled with a He cryostat, and a time-of-flight mass spectrometer. With great care given to the cooling condition, we can achieve ∼10 K for the vibrational temperature of ions in the QIT, which is estimated from UVPD spectra of the benzo-18-crown-6 (B18C6) complex with a potassium ion, K⁺·B18C6. Using this setup, we measure a UVPD spectrum of cold calix[4]­arene (C4A) complex with potassium ion, K⁺·C4A. The spectrum shows a very weak band and a strong one at 36018 and 36156 cm^–1, respectively, accompanied by many sharp vibronic bands in the 36000–36600 cm^–1 region. In the geometry optimization of the K⁺·C4A complex, we obtain three stable isomers: one endo and two exo forms. On the basis of the total energy and UV spectral patterns predicted by density functional theory calculations, we attribute the structure of the K⁺·C4A complex to the endo isomer (<i>C</i>₂ symmetry), in which the K⁺ ion is located inside the cup of C4A. The vibronic bands of K⁺·C4A at 36 018 and 36 156 cm^–1 are assigned to the S₁(A)–S₀(A) and S₂(B)–S₀(A) transitions of the endo isomer, respectively

Detection of regional low myocardial perfusion helps predict a response to cardiac resynchronization therapy in patients with non-ischemic cardiomyopathy: Results of the Find Index by Nuclear Imaging for Dyssynchrony (FIND) study

Background: The aim of this study was to investigate the use of imaging techniques to predict the response to cardiac resynchronization therapy (CRT) in patients with non-ischemic cardiomyopathy (NICM) by simultaneous assessment of left ventricular (LV) dyssynchrony and myocardial perfusion in a single nuclear scan of the heart. Methods: Patients indicated for CRT device implantation underwent a resting myocardial perfusion assessment with single photon emission computed tomography (MP-SPECT) examination using technetium-99 m methoxyisobutylisonitrile prior to device implantation. CardioGRAF and cardioBull software (FUJIFILM RI Pharma, Tokyo, Japan) were used to analyze the LV mechanical dyssynchrony and myocardial viability, respectively. Patient follow-ups were performed at 6 months after device implantation. CRT response was defined as a ≥10% decrease in the LV end systolic volume. Results: A total of 43 patients with NICM were analyzed. Using the cutoff points of 6.2 for the dyssynchrony index and 66% for LV myocardial perfusion, the combined indices predicted CRT response with a sensitivity of 77.8% and specificity of 91.2%. Conclusion: Combined assessment of MP-SPECT and a measure of LV mechanical dyssynchrony showed good predictive ability in patients with non-ischemic heart failure

Homologous Recombination but Not Nucleotide Excision Repair Plays a Pivotal Role in Tolerance of DNA-Protein Cross-links in Mammalian Cells*

DNA-protein cross-links (DPCs) are unique among DNA lesions in their unusually bulky nature. The steric hindrance imposed by cross-linked proteins (CLPs) will hamper DNA transactions, such as replication and transcription, posing an enormous threat to cells. In bacteria, DPCs with small CLPs are eliminated by nucleotide excision repair (NER), whereas oversized DPCs are processed exclusively by RecBCD-dependent homologous recombination (HR). Here we have assessed the roles of NER and HR for DPCs in mammalian cells. We show that the upper size limit of CLPs amenable to mammalian NER is relatively small (8–10 kDa) so that NER cannot participate in the repair of chromosomal DPCs in mammalian cells. Moreover, CLPs are not polyubiquitinated and hence are not subjected to proteasomal degradation prior to NER. In contrast, HR constitutes the major pathway in tolerance of DPCs as judged from cell survival and RAD51 and γ-H2AX nuclear foci formation. Induction of DPCs results in the accumulation of DNA double strand breaks in HR-deficient but not HR-proficient cells, suggesting that fork breakage at the DPC site initiates HR and reactivates the stalled fork. DPCs activate both ATR and ATM damage response pathways, but there is a time lag between two responses. These results highlight the differential involvement of NER in the repair of DPCs in bacterial and mammalian cells and demonstrate the versatile and conserved role of HR in tolerance of DPCs among species