対称Si-Cl伸縮振動の振動数におけるヘキサクロロジシランの異常性および振動の帰属

The symmetric Si-Cl stretching of hexachlorodisilane, 352 cm-1 is found to be anomously low when a comparison with those of some compounds containing SiCl3 groups is made. This anomaly seems due to irltensive coupling of symmetric SiCl3 deformation with symmetric Si-Cl stretching and/or Si-Si stretching mode. On the basis of the above consideration, the vibrational assignments of hexachlorodisilane are tentatively done

エタン,ジメチル・エ-テル,ジメチル・サルファイド,ジメチル・セレナイドおよびジメチル・テルライドの回転-振動スペクトルならびに構造

There are two possible configurations for H3C-X-CH3 (X=O,S,Se,Te), linear or bent C-X-C, the latter having C2v symmetry. For a linear model the methyl groups may be staggered, D3d or eclipsed, D3h. A bent model, C2v allows 21 fundamentals, all of which are active in Raman and 17 of which are active in infrared. This means that a C2v symmetry should have 17 coincidences between Raman and infrared spectra among 21 fundamental frequencies. The obtained spectra indicate the general simplicity of the spectra and the lack of coincidence between Raman and infrared frequencies. In addition, the rotation-vibrational band contours consist of a family of Q branches having an intensity alternation for degenerate infrared ones, which indicates the existence of C3 symmetry about the C-X-C axis of rotation. Consequently, the linear models are strongly supported for H3CXCH3 type molecules and, of the linear configurations, the eclipsed D3h form is eliminated, because a D3h symmetry should indicate the coincidence between Raman and infrared frequencies in E′species. Above all, it seems to the authors sufficient evidence to justify a linear skeleton for H3CXCH3 that an intensity alternation in Q branch sequence of perpendicular band(Eu) is observed. However the final decision must await the results of the further studies, because structure of H3CXCH3 type molecule has been determined from electron diffraction and microwave spectroscopy to be approximately C2v symmetry. The Raman spectra are recorded on JEOL JRS-S1B spectrophotometer using Ar+ laser and the infrared spectra are measured with Shimadzu IR-450 spectrometer, whose gas cell had a path of 10 cm and KRS-5 windows

メタノールの回転-振動スペクトルおよび構造

The authors obtain the infrared rotation-vibrational spectrum of gaseous methanol and the Raman spectrum of liquid one. Actually the infrared as well as the Raman spectrum of methanol has been analyzed on the basis of CS symmetry. However, the present observations show that the vibrational bands of methanol obtained can be explained according to C3v selection rule, that is, it is in agreement with theoretical expectations for C3v model that four parallel type bands are polarized in Raman and have P, Q, and R branches in infrared, whose P-R separations are observed to be 40 cm-1 and estimated to be 43 cm-1 on the basis of the parameters for C3v model. In addition, the obtained spectra of methanol resemble very closely those of acetonitrile, whose symmetry is C3

Retrieving Photorecombination Cross Sections of Atoms from High-Order Harmonic Spectra

We observe high-order harmonic spectra generated from a thin atomic medium, Ar, Kr, and Xe, by intense 800-nm and 1300-nm femtosecond pulses. A clear signature of a single-atom response is observed in the harmonic spectra. Especially in the case of Ar, a Cooper minimum, reflecting the electronic structure of the atom, is observed in the harmonic spectra. We successfully extract the photorecombination cross sections of the atoms in the field-free condition with the help of an accurate recolliding electron wave packet. The present protocol paves the way for exploring ultrafast imaging of molecular dynamics with attosecond resolution

Accurate Retrieval of Atomic Structures from High-Order Harmonic Spectra

We extracted the photorecombination cross sections from the high-order harmonic spectra generated from rare gases by intense femtosecond pulses. By taking the ratio between the observed high-order harmonic spectra and recolliding electron wave packets, we successfully obtained the photorecombination cross sections

Enzymatic and Immunological Studies of Prostatic Acid Phosphatase

Levels of serum acid phosphatase are elevated in prostatic cancer patients as compared with those of normal human. Prostatic cancer patients with bone metastasis show about 2 to 5 fold increased activities of serum acid phosphatase while patients without bone metastasis show slight increase (about 20%) of the activity. When we analysed serum acid phosphatase isozyme pattern with DEAE cellulose column chromatography, profiles of these enzymes of normal and prostatic cancer patients differ greatly. In normal human, three distinct isozymes I, II and III of serum acid phosphatase were observed. Acid phosphatase of prostatic adenoma tissue surgically removed from prostatic hypertrophy patients consists of two isozymes II and III which are chromatographically corresponding to those isozymes of serum acid phosphatase. Serological analyses and inhibitor- enzyme specificities led us to conclude that serum isozymes II and III are derived from prostatic gland. In cancer patients without bone metastasis, a greatly increased activity of isozyme III and normal level of isozyme II in serum acid phosphatase were observed. However in prostatic cancer patient with advanced bone metastasis, a huge increase of serum isozyme II activity was observed whereas isozyme III is at an undertectable level. These isozyme variations in serum acid phosphatase suggest that assay of each isozyme is a valuable approach for diagnosis and judgement of prognosis of prostatic cancer

Lynx1, a Cholinergic Brake, Limits Plasticity in Adult Visual Cortex

Experience-dependent brain plasticity typically declines after an early critical period during which circuits are established. Loss of plasticity with closure of the critical period limits improvement of function in adulthood, but the mechanisms that change the brain’s plasticity remain poorly understood. Here, we identified an increase in expression of Lynx1 protein in mice that prevented plasticity in the primary visual cortex late in life. Removal of this molecular brake enhanced nicotinic acetylcholine receptor signaling. Lynx1 expression thus maintains stability of mature cortical networks in the presence of cholinergic innervation. The results suggest that modulating the balance between excitatory and inhibitory circuits reactivates visual plasticity and may present a therapeutic target

Diastematomyelia: A Surgical Case with Long-Term Follow-Up

Few reports have described the involvement of syringomyelia associated with diastematomyelia in the etiology of neurological deficits. We reported a case with syringomyelia associated with diastematomyelia. A female patient with diastematomyelia was followed up clinically over 14 years. At the age of 8, she developed clubfoot deformity with neurological deterioration. Motor function of the right peroneus demonstrated grade 2 in manual muscle tests. Continuous intracanial bony septum and double cords with independent double dura were observed at upper thoracic spine. Magnetic resonance imaging revealed a tethering of the spinal cord and syringomyelia distal to the level of diastematomyelia. Extirpation of the osseum septum and duralplasty were performed surgically. She grew without neurological deterioration during 7 years postoperatively. A long-term followed up case with syringomyelia that was possibly secondary to the tethering of the spinal cord associated with diastematomyelia, and effective treatment with extirpation of the osseum septum and duralplasty was described

Longitudinal assessment of neuronal 3D genomes in mouse prefrontal cortex

Neuronal epigenomes, including chromosomal loopings moving distal cis-regulatory elements into proximity of target genes, could serve as molecular proxy linking present-day-behaviour to past exposures. However, longitudinal assessment of chromatin state is challenging, because conventional chromosome conformation capture assays essentially provide single snapshots at a given time point, thus reflecting genome organization at the time of brain harvest and therefore are non-informative about the past. Here we introduce ‘NeuroDam’ to assess epigenome status retrospectively. Short-term expression of the bacterial DNA adenine methyltransferase Dam, tethered to the Gad1 gene promoter in mouse prefrontal cortex neurons, results in stable G[superscriptmethyl]ATC tags at Gad1-bound chromosomal contacts. We show by NeuroDam that mice with defective cognition 4 months after pharmacological NMDA receptor blockade already were affected by disrupted chromosomal conformations shortly after drug exposure. Retrospective profiling of neuronal epigenomes is likely to illuminate epigenetic determinants of normal and diseased brain development in longitudinal context.United States. National Institutes of Healt