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Decompression surgery is the most common surgical treatment for lumbar spinal stenosis (LSS). Relatively low satisfaction rate was reported. Patients often complaint of residual numbness despite significant pain relief. We hypothesized that numbness had a significant impact on patient satisfaction, but had not been evaluated, which is associated with low satisfaction rate. This study aimed to examine how much numbness is associated with patient satisfaction. We retrospectively reviewed prospectively collected data from consecutive patients who underwent decompression without fusion for LSS. We evaluated the Numeric Rating Scale (NRS) scores of low back pain (LBP), leg pain, and leg numbness preoperatively and at the final follow-up visit. Improvement was evaluated using minimum clinically important differences (MCIDs). Patient satisfaction was evaluated using the question, "How satisfied are you with the overall result of your back operation?". There are four possible answers consisting of "very satisfied (4-point)", "somewhat satisfied (3-point)", "somewhat dissatisfied (2-point)", or "very dissatisfied (1-point)". Spearman correlation was used to evaluate the association between patient satisfaction and reaching MCIDs. A total of 116 patients were included. All three components had correlation with patient satisfaction with the correlation efficient of 0.30 in LBP, 0.22 in leg pain, and 0.33 in numbness. Numbness had greatest correlation efficient value. We showed that numbness has a greater impact than leg/back pain on patient satisfaction in patients undergoing decompression for LSS. We suggest not only LBP and leg pain but also numbness should be evaluated pre- and postoperatively.

Adolescent idiopathic scoliosis (AIS) is a serious health problem affecting 3% of live births all over the world. Many loci associated with AIS have been identified by previous genome wide association studies, but their biological implication remains mostly unclear. In this study, we evaluated the AIS-associated variants in the 7p22.3 locus by combining in silico, in vitro, and in vivo analyses. rs78148157 was located in an enhancer of UNCX, a homeobox gene and its risk allele upregulated the UNCX expression. A transcription factor, early growth response 1 (EGR1), transactivated the rs78148157-located enhancer and showed a higher binding affinity for the risk allele of rs78148157. Furthermore, zebrafish larvae with UNCX messenger RNA (mRNA) injection developed body curvature and defective neurogenesis in a dose-dependent manner. rs78148157 confers the genetic susceptibility to AIS by enhancing the EGR1-regulated UNCX expression. © 2022 American Society for Bone and Mineral Research (ASBMR).

Purpose: This study aimed to undertake a multidisciplinary characterization of the phenotype associated with SOX11 variants. Methods: Individuals with protein altering variants in SOX11 were identified through exome and genome sequencing and international data sharing. Deep clinical phenotyping was undertaken by referring clinicians. Blood DNA methylation was assessed using Infinium MethylationEPIC array. The expression pattern of SOX11 in developing human brain was defined using RNAscope. Results: We reported 38 new patients with SOX11 variants. Idiopathic hypogonadotropic hypogonadism was confirmed as a feature of SOX11 syndrome. A distinctive pattern of blood DNA methylation was identified in SOX11 syndrome, separating SOX11 syndrome from other BAFopathies. Conclusion: SOX11 syndrome is a distinct clinical entity with characteristic clinical features and episignature differentiating it from BAFopathies. (C) 2022 The Authors. Published by Elsevier Inc. on behalf of American College of Medical Genetics and Genomics.

Study Design: Retrospective observational study. Objectives: There is no consensus to predict improvement of lower back pain (LBP) in lumbar spinal stenosis after decompression surgery. The aim of this study was to evaluate the improvement of LBP and analyze the preoperative predicting factors for residual LBP. Methods: We retrospectively reviewed 119 patients who underwent lumbar decompression surgery without fusion and had a minimum follow-up of 1 year. LBP was evaluated using the numerical rating scale (NRS), Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) LBP score, and Roland-Morris Disability Questionnaire (RMDQ). All patients were divided into LBP improved group (group I) and LBP residual group (group R) according to the NRS score. Radiographic images were examined preoperatively and at the final follow-up. We evaluated spinopelvic radiological parameters and analyzed the differences between group I and group R. Results: LBP was significantly improved after decompression surgery (LBP NRS, 5.7 vs 2.6, P < .001; JOABPEQ LBP score, 41.3 vs 79.6, P < .001; RMDQ, 10.3 vs 3.6, P < .001). Of 119 patients, 94 patients were allocated to group I and 25 was allocated to group R. There was significant difference in preoperative thoracolumbar kyphosis between group I and group R. Conclusions: Most cases of LBP in lumbar spinal stenosis were improved after decompression surgery without fusion. Preoperative thoracolumbar kyphosis predicted residual LBP after decompression surgery.

We report the usefulness of revision balloon kyphoplasty (re-BKP) and vertebra-pediculoplasty using cannulated screws (VPCS) for osteoporotic vertebral fractures (OVF) following cement dislodgement of conventional BKP. Between 2015 and 2020, three patients with OVF developed symptomatic cement dislodgement following BKP and underwent re-BKP. All three patients showed a loose cemented mass and spinal instability. Balloon inflation was performed in the gap between the loosened cemented mass and the remaining cortical bone rim, and this extended gap was filled with cement. To prevent re-dislodgement of the cement mass, a cannulated screw was inserted into the cemented mass through the pedicle. All patients achieved early pain relief, and improved vertebral stability of the fractured vertebra and all related symptoms, with no perioperative complications. Re-BKP and VPCS are innovative concepts and could be an effective minimally invasive treatment for OVF following cement dislodgement of conventional BKP treatment.

Background The clinical outcomes of balloon kyphoplasty (BKP) for split-type osteoporotic vertebral fractures (OVF) are poor. These may be owing to the vertebral body bifurcating anteriorly and posteriorly when a load is applied and the filled cement being unstable. We report the usefulness of BKP combined with pediculoplasty using cannulated screws (vertebra-pediculoplasty) for OVF with a risk of cement dislodgement. Methods Between April 2020 and February 2021, this surgery was performed on 10 patients with split-type and delayed-union OVF. The diagnosis was made using imaging findings on preoperative computed tomography or intraoperative images during balloon inflation. Early postoperative ambulatory rehabilitation was performed, and clinical outcomes were evaluated. Results Early pain relief was obtained in all patients. The stability of the fractured vertebrae was demonstrated using both supine and seated radiographs from the early postoperative period, and good clinical results were obtained. The cement in this surgery was stabilized using a cannulated screw in the vertebral body, anteroposteriorly, and craniocaudally. The cement mass integrated with the cannulated screw was stabilized with the vertebral lamina and pedicle as a stopper. Conclusions Vertebra-pediculoplasty could be an effective method for managing OVF with a high risk of cement dislodgement, which has been difficult to treat using conventional BKP.

Decompression surgery is the standard treatment in lumbar spinal stenosis (LSS). Recent studies have shown that patient satisfaction following decompression surgery does not correspond well with outcomes measured by conventional patient-reported outcome measurements. Recent study reported that the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) is the most accurate outcome measurement to reflect patient satisfaction. Nevertheless, the JOABPEQ was not studied enough, especially along with the minimally clinically important differences (MCIDs), as JOABPEQ is relatively new questionnaire. The MCID is the minimum score change which patients perceive as beneficial. Thus, knowing the MCID is critical evaluating the efficacy of intervention. The aim of this study was to determine the MCIDs of the JOABPEQ for patients with LSS undergoing decompression surgery. Patients who underwent decompression surgery for LSS were consecutively enrolled if they had a complete set of questionnaires. We determined the MCIDs of each domain in the JOABPEQ using distribution-based and anchor-based methods. The MCIDs were determined to be 20.4 in low back pain, 15.6 in lumbar function, 16.8 in walking ability, 13.4 in social life function, and 9.4 in mental health by the distribution-based method. Using the anchor-based method, the MCIDs were determined to be 28.5, 16.5, 25.0, 21.5, and 14.5, respectively. The MCIDs of the JOABPEQ in LSS were slightly different from 20-point, which was proposed in the JOABPEQ user's manual. Our findings should be considered when evaluating LSS patients undergoing decompression surgery as JOABPEQ is not LSS specific.

Study Design: Retrospective cohort study. Objectives: Decompression without fusion is a standard surgical treatment for lumbar spinal stenosis (LSS) with reasonable surgical outcomes. Nevertheless, some studies have reported low patient satisfaction (PS) following decompression surgery. The cause of the discrepancy between reasonable clinical outcomes and PS is unknown; moreover, the factors associated with PS are expected to be complex, and little is known about them. This study aimed to identify satisfaction rate and to clarify the factors related to PS following decompression surgery in LSS patients. Methods: We retrospectively reviewed 126 patients who underwent lumbar decompression with a minimum follow-up of 1 year. Patients were divided into 2 groups based on the PS question. The Japanese Orthopaedic Association (JOA) scores, and the Numeric Rating Scale (NRS) scores of low back pain (LBP), leg pain, and leg numbness were compared between the 2 groups preoperatively and at the latest visit. To identify the prognostic factors for dissatisfaction, multiple logistic regression analysis was performed. Results: Overall satisfaction rate was 75%. The JOA recovery rate, NRS improvement, and Short Form–8 (SF-8) were significantly higher in the satisfied group. Postoperative NRS scores of LBP, leg pain, and leg numbness were significantly lower in the satisfied group. Multivariate logistic regression analysis showed that smoking and scoliosis were significant risk factors for dissatisfaction. Conclusions: Overall satisfaction rate was 75% in patients with LSS undergoing decompression surgery. This study found that smoking status and scoliosis were associated with patient dissatisfaction following decompression in LSS patients.

OBJECTIVEThe importance of global sagittal alignment is well known. Patients with lumbar spinal stenosis (LSS) generally tend to bend forward to relieve their neurological symptoms, i.e., they have a positive sagittal vertical axis (SVA). We hypothesized that the positive SVA associated with LSS is symptom related and should improve after surgery. However, little is known about the changes in sagittal alignment in LSS patients after decompression surgery. In this study the authors aimed to evaluate midterm radiographical changes in sagittal spinopelvic alignment after decompression surgery for LSS and to determine the factors influencing the improvement in sagittal spinopelvic alignment.METHODSThe authors retrospectively reviewed 89 patients who underwent lumbar decompression without fusion between January 2014 and September 2015 with a minimum follow-up of 2 years. Standing whole-spine radiographs at the preoperative stage and at the final follow-up were examined. We analyzed SVA, lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence (PI), thoracolumbar kyphosis (TLK), and thoracic kyphosis (TK).RESULTSLL and TK were significantly increased postoperatively. SVA and PI minus LL (PI-LL) were significantly decreased. There were no significant differences between the preoperative and postoperative PT, PI, SS, or TLK. Twenty-nine patients had preoperative sagittal malalignment with SVA > 50 mm. Thirteen of the 29 patients improved to SVA < 50 mm after decompression surgery. Lower ASA grade, preoperative higher LL, and lower PI-LL were related to patient improvement. A receiver operating characteristic curve for the preoperative PI-LL had an area under the curve value of 0.821, indicating moderate accuracy (p = 0.003). A cutoff value for preoperative PI-LL of 19.2° showed a sensitivity of 93.5% and a specificity of 71.4%.CONCLUSIONSLumbar decompression can lead to a reactive improvement in the lumbar and global sagittal alignment. However, some of the sagittal malalignment in LSS was irreversible. Preoperative PI-LL was a useful predictor to distinguish reversible from irreversible sagittal malalignment.

Objective Decompression surgery is the standard treatment for lumbar spinal stenosis (LSS); however, despite the good clinical outcomes reported for this procedure, a relatively high dissatisfaction rate has been reported. We hypothesized that the previously used outcome measures do not accurately reflect patient satisfaction (PS). This study aimed to examine which outcome measures reflect PS accurately in patients undergoing decompression for LSS. Patients and methods Patients with LSS treated with lumbar decompression surgery between January 2014 and March 2016 were enrolled if they had the preoperative and final follow-up questionnaires including the Numeric Rating Scale (NRS), Roland-Morris Disability Questionnaire (RMDQ), Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), and Short Form-8 (SF-8). PS was evaluated using the question, “How satisfied are you with the overall result of your back operation?”. There are four possible answers consisting of “very satisfied (4-point)”, “somewhat satisfied (3-point)”, “somewhat dissatisfied (2-point)”, or “very dissatisfied (1-point)”. The Spearman correlation coefficient between PS and each questionnaire was calculated. Results Postoperative JOABPEQ had strong correlation with PS (r > 0.6) whereas NRS, RMDQ and SF-8 had moderate correlation (0.4 Conclusion JOABPEQ reflected PS and therefore may be used as a main outcome measure in evaluating patients who underwent decompression surgery for LSS.

Study Design: Retrospective chart audit.Purpose: This study aimed to investigate the gender difference in pre- and postoperative health-related quality of life (HRQOL) in patients who have had decompression surgery for lumbar spinal stenosis (LSS).Overview of Literature: Gender differences may contribute to variations in disease presentations and health outcomes. The influence of gender on pre- and postoperative HRQOL in spinal disorders remains unclear.Methods: We reviewed 125 patients (79 men and 46 women) who had lumbar spinous process splitting laminectomy (LSPSL) for LSS. We assessed the following clinical information: Japanese Orthopedic Association (JOA) score; numerical rating scale (NRS) for low back pain (LBP), leg pain, and leg numbness; Zurich Claudication Questionnaire; JOA Back Pain Evaluation Questionnaire; Roland- Morris Disability Questionnaire (RMDQ); and Short Form 8 (SF-8) as HRQOL. We compared the HRQOLs of men and women pre- and postoperatively.Results: Although the preoperative NRS results for LBP were significantly higher in women (p

Objective Decompression surgery is a mainstay of surgical treatment for lumbar spinal stenosis (LSS). However, up to 30% of patients have low satisfaction due to residual symptoms. In the clinical setting, improvements in leg pain are more significant than those in leg numbness. Residual numbness could be related to the relatively low satisfaction rate. However, few studies have focused on numbness; thus, elucidating the risk factors and rate of residual numbness would benefit surgeons and patients. This study aimed to clarify the risk factors for and rate of residual numbness after decompression surgery. Patients and Methods We retrospectively reviewed prospectively collected data from consecutive patients who underwent lumbar decompression without fusion for LSS at a single institution between January 2014 and March 2016. Patients were included if preoperative and final follow-up questionnaires and radiographs were available. A minimum one-year follow-up was required. We evaluated the Numeric Rating Scale (NRS) scores of low back pain, leg pain, and leg numbness preoperatively and at the final follow-up visit. Residual numbness was defined as a postoperative NRS ≥ 1, whereas persistent numbness was defined as a postoperative NRS ≥ 5. We compared the clinical data of patients with or without residual numbness to those of patients with or without persistent numbness. Multivariate logistic regression analysis was performed to identify risk factors for residual and persistent numbness. Results A total of 116 patients (73 men, 43 women) were included. Of them, 60% had residual numbness with a mean follow-up period of 25 months. Only durotomy differed significantly between patients with and those without residual numbness. However, the significance did not persist after logistic regression analysis. A total of 16% had persistent numbness. Diabetes mellitus, intraoperative durotomy, and preoperative NRS of numbness were identified as risk factors. There were no differences in smoking status, presence of spondylolisthesis or scoliosis, or severity of stenosis. Conclusions We found three risk factors for persistent numbness following decompression surgery for LSS; diabetes mellitus and durotomy were modifiable, whereas preoperative numbness was not. Our findings would help surgeons minimize the incidence of persistent numbness by adequately controlling diabetes and avoiding durotomy during surgery. Providing information about the potential for residual numbness during the informed consent process is important to ensuring realistic patient expectations.

OBJECTIVEPatients with lumbar spinal stenosis (LSS) tend to bend forward to relieve neurological symptoms. They therefore have a positive sagittal vertical axis (SVA). The importance of the SVA value is well known in the field of adult spinal deformity; however, little is known about its impact on LSS. The authors sought to investigate the impact of sagittal spinopelvic alignment on clinical outcome and health-related quality of life (HRQOL) after decompression surgery for LSS.METHODSThe authors retrospectively reviewed 83 patients who underwent lumbar decompression without fusion between January 2014 and September 2015 with a minimum follow-up of 2 years. Standing whole-spine radiographs were examined preoperatively and at final follow-up. Based on the SVA, patients were allocated to a sagittal balance group (group B; SVA < 50 mm) or a sagittal imbalance group (group I; SVA ≥ 50 mm). The authors compared the groups using Japanese Orthopaedic Association (JOA), Zurich Claudication Questionnaire (ZCQ), Roland-Morris Disability Questionnaire (RMDQ), and the 8-item Short Form Health Survey (SF-8) scores.RESULTSPreoperative groups B (group pre-B) and I (group pre-I) included 58 and 25 patients, respectively. Preoperative sagittal malalignment had negative effects on the JOA score recovery rate, postoperative ZCQ physical function domain score, and numeric rating scale (NRS) score of postoperative low-back pain (LBP), but no significant effects were observed for RMDQ and SF-8 domain scores. Postoperatively, groups B (group post-B) and I (group post-I) included 60 and 23 patients, respectively. Group post-I had a significantly worse JOA score recovery rate, postoperative symptom severity domain score in the ZCQ, and NRS score for postoperative LBP. Similarly, the postoperative RMDQ score and the Physical Component Summary score of the SF-8 were significantly worse in group post-I.CONCLUSIONSPositive SVA had significantly negative effects on clinical outcome and HRQOL in LSS patients after lumbar decompression surgery.

Objective The influence of preoperative mental health on health-related quality of life (HRQOL) in patients with lumbar spinal stenosis (LSS) remains unclear. This study aims to investigate the influence of preoperative mental health HRQOL after laminectomy in patients with LSS. Patients and Methods We retrospectively reviewed 122 patients who had lumbar spinous process splitting laminectomy (LSPSL) for LSS. We assessed clinical information; Japanese Orthopedic Association (JOA) score; numerical rating scale (NRS) for low back pain, for leg pain, and for leg numbness; Zurich Claudication Questionnaire (ZCQ); JOA Back Pain Evaluation Questionnaire (JOABPEQ); Roland-Morris Disability Questionnaire (RMDQ); and Short Form 8 (SF-8) as patient reported outcomes. Patients were divided into two groups (Group L ≤ 36.2 points and Group NL > 36.2 points) based on the results of the preoperative mental health (MH) score in SF-8 to examine the influence of MH in LSS. We compared the HRQOL between the two groups postoperatively. Results The JOA score, NRS, and ZCQ score significantly improved after surgery. HRQOL outcomes including JOABPEQ, RMDQ, and SF-8 showed that the LSPSL improved not only the physical but also the mental function in patients with LSS. All HRQOL outcomes in Group L exhibited significantly worse scores preoperatively; however, no significant differences between two groups were found postoperatively. Conclusions LSPSL greatly reduced low back pain, leg pain, and leg numbness. LSPSL resulted in a significant improvement based on HRQOL questionnaires even in patients with preoperative depressive mood. Not only the physical status but also the mental health may improve after LSPSL even in patients with LSS with a depressive mood preoperatively.

A novel hybrid process of hydrothermal or supercritical water oxidation and TiO2 photocatalysis was developed to examine the degradation of chlorobenzene as a model of the oxidative decomposition of organic pollutants. Aqueous solutions of chlorobenzene containing H2O2 as the oxidizing agent and/or colloidal TiO2 nanoparticles as catalyst, were fed into the reactor with the temperature and the pressure controlled to be T = 25–400°C and P = 30 MPa, respectively. Chlorobenzene was considerably decomposed in the presence of H2O2 under hydrothermal conditions for T ≧ 300°C. It appeared that photocatalytic decomposition of chlorobenzene takes place at all temperatures by colloidal TiO2 nanoparticles under irradiation with near-UV light. We have realized the synergic decomposition of chlorobenzene by the coexistence of H2O2 and TiO2 in which maximum conversion is more than 80% under irradiation at T = 200°C.

Although many surgical procedures are available for treating osteoporotic vertebral fractures, there have been no comprehensive multicenter surveys in Japan focusing on surgical treatments for these fractures. This study aimed at (1) conducting a retrospective multicenter study to survey surgical treatments performed at referral center hospitals in various regions in Japan and (2) analyzing situations and problems related to the surgical treatments of osteoporotic vertebral fractures in Japanese hospitals.Among 738 patients who were hospitalized in 13 hospitals in various regions in Japan between 2005 and 2006 for osteoporotic vertebral fractures, 84 patients (11.4%) who underwent spinal surgery were enrolled. These patients were retrospectively analyzed regarding cause of injury, preoperative symptoms, preoperative neurological function, surgical procedures, periods of bed rest, length of hospital stay, and ambulatory status at discharge from hospital.As to the cause of spinal fracture, 38 patients (45% of the surgical patients) could not identify a specific cause of their spinal fracture. Preoperative neurological motor weakness in legs was observed in 41 (49%). With regard to surgical treatment, posterior spinal reconstruction surgery was performed in 50 patients (60%), vertebroplasty in 26 (31%), anterior reconstruction surgery in 6 (7%), anterior and posterior combined reconstruction surgery in 1, and posterior decompression alone in 1 patient. In all, 70 patients (83.3%), whose periods of hospital stay averaged 52.8 days, could walk by themselves at the time of discharge; 14 (16.7%), whose periods of hospital stay averaged 44.7 days, could not walk by themselves at the time of discharge.Even after a large variety of surgical procedures were tried to treat osteoporotic vertebral fractures and long hospital stays, about 17% of the patients were unable to walk by themselves at the time of discharge from hospital.

The results of the experimental and theoretical studies of the optical absorption properties of the composite metal/organic nanoparticles in colloidal solutions are reported. The nanoparticles consist of Ag-core coated with the J-aggregate of 3,3′-disulfopropyl-5,5′-dichlorothiacyanine sodium salt (TC). The absorption spectrum of the composite Ag/TC nanoparticles exhibits two peaks at λ = 395 and 480 nm, which originally come from the localized surface plasmon resonance of Ag nanoparticles and the electronic excitation of TC-dye, respectively. To explain the results obtained we calculate the extinction cross-section of such composite material on the basis of a model for the polarizability of two concentric spheres by taking into account complex frequency-dependent dielectric functions of Ag and the TC-dye and size-dependent effects. The model provides a good description of the main features in the measured absorbance. It is shown that for the core–shell nanoparticles under investigation the peak positions and their intensities are strongly dependent on their geometrical size and the thickness of the J-aggregate coating. This opens a possibility to controllable driving of the absorption properties of such composite materials.

We have synthesized small silver clusters in aqueous microemulsion droplets in supercritical carbon dioxide (sc-CO 2 ) solutions with fluorinated surfactants; ammonium carboxylate perfluoropolyether, PFPE-1, PFPE-2 and PFPE-3. Irradiation of water-in-sc-CO 2 (w/c) microemulsions of PFPE-1 containing concentrated AgClO 4 solution within the water core (local concentration [AgClO 4 ] = 5.0 M) at P = 36.3 MPa and T = 311 K with weak UV light resulted in the appearance of a broad absorption band in the λ = 320–400 nm range with a small peak around λ = 330 nm and a shoulder around λ = 370 nm in the UV–vis absorption spectra. Irradiation of the w/c microemulsions of PFPE-2 containing [AgClO 4 ] = 5.0 M with intense UV light brought about the development of almost the same absorption band at the early stage. Then a single broad peak bearing the absorbance as large as about 3.0 around λ = 340 nm developed after prolonged irradiation. Those spectral features would demonstrate the formation of small Ag clusters, Ag n , due to photoreduction of Ag + ions inside of water core of the w/c microemulsions. Although the absorption spectrum gradually changed during dark storage at P = 30 MPa and T = 311 K, there was no indication of the surface plasmon band even after 20 h storage, indicating that the growth of colloidal Ag nanoparticles, Ag c , by agglomeration of small Ag clusters does not proceed because microemulsions are separated each other in the sc-CO 2 . These observations would suggest that the w/c microemulsion is an excellent “nanoreactor” to confine the reaction field on the nanometer scale.

We have examined optical absorption properties of the composite nanoparticles consisting of Ag core coated with the J-aggregate of 3,3′-disulfopropyl-5,5′-dichlorothiacyanine sodium salt (TC) in aqueous suspensions and in self-assembled (SA) films on the quartz plates. Four kinds of SA films were fabricated by the alternate adsorption technique; the monolayer SA films in which Ag:TC composite nanoparticles were sparsely (S film) or densely (D film) packed on the surface, and the multilayer SA films composed of D films and thin (SAS film) or thick (SAL film) spacer layers. Based on the absorption spectra and the atomic force microscopic images of those films, the existence of electromagnetic interaction between densely packed Ag:TC nanoparticles in the single layers, as well as between adjacent layers incorporating those nanoparticles has been suggested.

N-doped TiO2 nanoparticles have been prepared by continuous or batch treatment of the colloidal TiO2 nanoparticles under hydrothermal conditions with formamide, nitric acid, ammonia or triethylamine. The optical absorption tail of the obtained photocatalysts near the band gap extended to the visible region around λ = 500 nm. The efficiency of nitrogen doping was strongly dependent on the kind of nitrogen compounds, treatment method as well as treatment temperature. The most effective N-doping could be accomplished by the batch treatment with a small amount of triethylamine, which showed the efficient photocatalytic activity for both the reduction of Ag+ ions and the degradation of methylene blue under visible light irradiation.

The photocatalytic reduction of Ag+ ions by TiO2 nanoparticles was examined in water under high-temperature high-pressure conditions of T = 25–400°C and P = 30 MPa. The analysis of the reaction by uv-vis absorption spectroscopy, the atomic absorption spectrometry, and TEM observations revealed that the efficient photocatalytic activity compared with that at room temperature remained even under hydrothermal and supercritical conditions. These results could open the way to new applications of TiO2 under extreme environments which have never been explored before.

Spectroscopic properties of the monolayer assemblies, S9(J) + S11(J), which incorporate the mixed J-aggregate (JA) of oxacyanine dye; N , N ′-dioctadecyl-oxacyanine perchlorate (S9) and thiacyanine dye; N , N ′-dioctadecyl-thiacyanine perchlorate (S11), have been studied in the wide temperature range of T = 6.0–293 K. The mole fraction X of S11, X = [S11]/([S9] + [S11]), in the S9(J) + S11(J) assemblies has been varied from 0 to 1. At room temperature, absorption and fluorescence spectra of the monolayer assemblies incorporating the individual dye aggregate, S9 J-aggregate (S9(J)) or S11 J-aggregate (S11(J)), are characterized by a distinct J-band and resonance fluorescence. The S9(J) + S11(J) assemblies with X = 0.1–0.9 display two absorption bands; shorter-wavelength (SW) band and longer-wavelength (LW) band and a single fluorescence band (LW-fluorescence). With lowering temperature, the blue shift and narrowing of the absorption bands are observed. The low-energy tails of the J-band of the S9(J) ( X = 0) and the S11(J) ( X = 1) assemblies, as well as the LW-band of the S9(J) + S11(J) assemblies obey the Urbach–Martienssen (U–M) rule. The steepness parameter σ versus T curves show characteristic changes caused by mutual mixing of S9 and S11, which would supply us with a supporting evidence for the formation of the homogeneous aggregate of persistence-type (HP-aggregate) in the S9(J) + S11(J) assemblies.

The monolayer assemblies incorporating two kinds of unsymmetric merocyanine dye aggregates (MC(X)/MC(Y), X = O, S, Se) have been fabricated by the Langmuir–Blodgett technique. The absorption spectra of the Langmuir–Blodgett films were measured in wide temperature range of T = 6.0–293 K. The absorption spectra of the MC(O)/MC(S) and the MC(O)/MC(Se) assemblies bear two absorption bands which are assigned to the MC(O) aggregate and the MC(S) J-aggregate or the MC(Se) J-aggregate, respectively. In contrast, the absorption spectrum of the MC(S)/MC(Se) assembly shows a single absorption band of the mixed J-aggregate. From detailed considerations of the low-energy tail of absorption spectra based on the Urbach–Martienssen rule, together with other spectroscopic properties, it is concluded that the MC(O)/MC(S) or the MC(O)/MC(Se) assembly forms a mosaic aggregate. The MC(S)/MC(Se) assembly can form high-quality homogeneous aggregate of amalgamation type.

The monolayer assemblies incorporating merocyanine J-aggregates, MC(S), MC(Se), 6-Me-MC(S), and their combinations have been fabricated by the Langmuir–Blodgett (LB) technique. At room temperature, absorption and fluorescence spectra of the monolayer assemblies: MC(S), MC(Se), 6-Me-MC(S), are characterized by a sharp J-band and resonance fluorescence. The monolayer assemblies incorporating two dyes: MC(S)/MC(Se), 6-Me-MC(S)/MC(S), 6-Me-MC(S)/MC(Se), bear a single absorption band and accompanying fluorescence band, which are assigned to the homogeneous aggregate of amalgamation type (HA-aggregate). Detailed spectroscopic measurements: absorption spectra in wide temperature range and the fluorescence decay curves, of the MC(S)/MC(Se) assembly have been carried out as a prototype of the HA-aggregate. The continuous shift of the absorption and fluorescence peak positions with increasing x , from x = 0 (MC(S) assembly) to x = 1 (MC(Se) assembly), would indicate that the doping of MC(Se) molecules into the MC(S) J-aggregate does not induce serious structure change. An observation that the fluorescence lifetime of the MC(S)/MC(Se) assembly lies between those of the MC(S) assembly and the MC(Se) assembly implies that the inclusion of MC(Se) molecules does not result in the formation of defect states which may promote non-radiative decay of molecular excitons. The usefulness of the Urbach–Martienssen (UM) rule for the analysis of the low energy tail of absorption spectra of the MC(S)/MC(Se) assembly has been examined.

The photoreduction of Ag+ ions at the surface of colloidal TiO2 nanoparticles has been investigated. Irradiation of an aqueous solution containing TiO2 and Ag+ ions with near-UV light brings about the growth of a sharp absorption band of colloidal silver in absorption spectrum. The photoreduction of Ag+ ions by TiO2 is optically sensitized by a simple cyanine dye, 3,3′-disulfopropyl-5,5′-dichloro-thiacyanine sodium salt (TC). TC molecules are adsorbed at the surface of TiO2 nanoparticles in the form of the J-aggregate (JA). Visible-light irradiation of the solution containing TiO2, Ag+ ions, and TC causes the growth of a broad absorption band of the colloidal silver and the decrease of whole absorption bands of TC. Experimental results have been interpreted in terms of electronic energy levels of the colloidal silver and the TC aggregate, as well as energy bands of TiO2. In the sensitized photoreduction, TiO2 could play the role of a medium to facilitate efficient electron transfer from the excited TC aggregate to Ag+ ions adsorbed at the surface.

Delocalization and energy transfer of the molecular exciton of the J-aggregate of oxacyanine dye, N,N'-dioctadecyl-oxacyanine perchlorate (S9) in LB films have been examined. Fluorescence lifetime of the S9 J-aggregate (S9(J)) appears to be ca. 1/20 of the isolated S9 molecules (S9(M)), which suggests that the coherent size of the J-aggregate, N cohe , is about 22 at room temperature. Quenching of resonance fluorescence of S9(J) by thiacyanine dye, N,N'-dioctadecyl-thiacyanine perchlorate (S11) obeys the Stern-Volmer relation with a Stern-Volmer constant of 1.2 x 10 3 nm 2 molecules -1 at room temperature, which is responsible to the incoherent size N inco of about 2000. The rate constant of energy transfer k ET amounts to 1.5 x 10 13 nm 2 molecules -1 s -1 .

Langmuir-Blodgett (LB) films incorporating unsymmetrical merocyanine dyes; MC(X) (X = O, S, Se), have been fabricated. The J-aggregates of MC(S) and MC(Se) are characterized by a sharp J-band and resonance fluorescence. The MC(O) aggregate has a broad absorption band and is non-fluorescent. We have examined the formation of mixed J-aggregates in the MC(X)/MC(Y) assemblies (X, Y = O, S, Se). It has been found that a homogeneous aggregate of amalgamation type (HA-aggregate) is formed in the MC(S)/ MC(Se) assembly. The mixed J-aggregate in the MC(O)/MC(S) and the MC(O)/MC(Se) assemblies are classified into a mosaic (M-)aggregate in a wide sense. Despite of similar molecular structure of MC(O) with both MC(S) and MC(Se), the growth of the MC(O) aggregate with a help of the J-aggregate of MC(S) or MC(Se) as a template may hinder the homogeneous mixing of dye molecules.

Subpicosecond fluorescence anisotropy decay curves have been measured using the fluorescence up-conversion technique to examine the rotational dynamics of coumarin 153 (C 153) in supercritical fluoroform (T = 302 and 310 K). For reduced densities (p, = ρ/ρ c ) above 0.9, the rotation times of C153 increase with density. For reduced densities lower than 0.9, the rotation times increase with decreasing density and has a maximum at a density near p, = 0.5. The comparison with the extrapolation of the data in polar aprotic solvents indicates that the local solvent density around the solute exceeds about 4 times the bulk density at a density near ρ r = 0.5, which is consistent with those obtained from the steady-state electronic spectral shifts.

Formation and aggregation of photolytic silver nanoparticles at the surface of silver salt of carboxymethylcellulose films (CMCAg films) have been investigated. Detailed X-ray photoelectron spectroscopy (XPS) study and field emission type scanning electron microscopy (FE-SEM) observation have been carried out to characterize silver nanoparticles at the film surface. When the CMCAg films were irradiated with UV light in wet air at room temperature for 30–60 min, silver nanoparticles of ca. 10 nm size were formed at the irradiated surface. According to the FE-SEM observation, the growth of the particle diameter and aggregation of nanoparticles took place after prolonged irradiation, and finally, the irradiated side of the film surface was densely covered with the silver nanoparticles of ca. 35 nm size. Chemical composition analysis by the XPS measurements has confirmed the increase in the atomic concentration of silver with irradiation time. It is suggested that silver atoms and clusters can move in the film and precipitate at the irradiated surface.

UV absorption spectra of benzene have been measured over the wide range of temperature and pressure from the ambient state to the supercritical state (T = 400 °C and P = 40 MPa). The analysis of the spectral shift of benzene in water relative to that in the gas indicates that at T = 380 and 390 °C the local solvent density around benzene is likely to be depressed below the bulk density for densities near the critical density. It is found that π-hydrogen bond between benzene and water becomes evident with lowering temperature below T = 340 °C.

CO 2 reforming of CH 4 was studied over Fe, Co and Ni catalysts supported on cerium oxide at atmospheric pressure. Ni catalyst gave the highest activity; equilibrium conversion of methane was attained under the conditions of 1123 K, 1 g h/mol, and CO 2 /CH 4 =1, and the composition of syngas formed was almost H 2 /CO=1. Carbon deposition was not observed, and the catalytic activity and the syngas selectivity were stable for 24 h over the catalyst. It was found that the high temperature treatment of the catalyst at 1123 K is important for such an excellent catalytic performance. Co catalyst exhibited an activity nearly equal to that of Ni catalyst when reduced sufficiently, whereas Fe catalyst showed a poor activity.

The fluorescence spectra of 4-dimethylamino(benzonitrile) (DMABN) have been measured for a mixture of supercritical CO2 and methanol at high pressures up to 15.5 MPa at 318 K. It is found that the addition of a small amount of methanol can stabilize the intramolecular charge transfer (ICT) state of DMABN in the supercritical fluid mixture. The spectral shift of the ICT band has been analysed on the basis of Onsager reaction field theory; a significant increase of the local composition of methanol around the DMABN molecule in the ICT state is demonstrated.

Sensitized photoreduction of Ag+ ions and subsequent formation of colloidal Ag nanoparticles take place when an aqueous solution of a mixture of AgClO4, sodium dodecylsulfate (SDS) and benzophenone (BP) is irradiated with near-UV light. In this study, the mechanism and kinetics of the reaction have been studied by means of nanosecond laser flash photolysis, time-resolved emission spectroscopy and also steady-state photolysis. Benzophenone ketyl radial (BPK) is formed by the hydrogen abstraction reaction of the benzophenone triplet (BPT) from SDS, which reduces Ag+ ions. It is found that the yield of colloidal Ag nanoparticle formation decreases remarkably with increasing concentration of Ag+ ions, indicating the efficient quenching process of BPT by Ag+ ions. Rate constants for the oxidation of BPK as well as the quenching of BPT by Ag+ ions in SDS micellar solution are considerably larger than those expected in the bulk solution, reflecting that Ag+ ions and BP molecules are concentrated in the SDS micelles. The rate of colloidal Ag nanoparticle formation, VAg, and BP photobleach, VBP, under steady-state irradiation with near-UV light (λ = 365 nm) were evaluated and the dependence of VAg and VBP on the concentration of Ag+ ions is interpreted quantitatively in terms of rate constants estimated by laser flash photolysis.

The layer-by-layer alternate assemblies incorporating two kinds of cyanine dyes have been fabricated by alternately adsorbing a cationic polyelectrolyte and anionic cyanine dyes on the quartz plate. A thiacyanine dye (dye I) was employed as the donor and two kinds of thiacarbocyanine dye having a meso-alkyl groupm-ethyl (dye II), m-methyl (dye III)as the acceptor. The mole fraction of the acceptor in the mixed J-aggregate, χ, was varied from 0 to 1. It is confirmed that these dye combinations form the mixed J-aggregate in the alternate assemblies. From steady-state fluorescence spectra of the molecular assemblies, excitation energy transfer from the donor J-aggregate to the acceptor J-aggregate is observed, whose kinetics obeys the Stern−Volmer relationship. The experimentally determined rate constant of energy transfer, kET, is fairly large, indicating efficient energy transfer due to exciton migration through the donor J-aggregate. The relative fluorescence quantum yield and the fluorescence lifetime of...

各種アルカリ土類金属とプラセオジムを複合させた酸化物を共沈法により調製し, これらの酸化物を触媒に用いて, メタンと二酸化炭素からのC2炭化水素合成反応を行った。Ca, Sr, BaとPrを複合化させると, Pr単独の触媒に比べC2選択率が向上し, Pr量基準ではC2収率も増加した。最も効果的であったのはSrであり, 1173KでのC2収率, 選択率はそれぞれ2.5%, 43%であった。Sr-Pr複合系では, 酸化物前駆体の水酸化物沈殿の生成条件により触媒の活性や選択性が変化した。

Conversion of methane and carbon dioxide into ethane and ethylene (C2 hydrocarbons) has been performed over terbium (Tb) oxide catalysts. Effectiveness of catalyst is influenced by precursor of the oxide; a Tb oxide prepared from the nitrate shows the highest C2 yield, whereas, an oxide from the oxalate gives the highest C2 selectivity. Since CO yield increases with increasing specific surface area of the Tb oxide, attributed to the successive oxidation of C2 hydrocarbons formed from CH4, lower specific surface area is favored for formation of C2. Examining the effects of reaction conditions on the performance of the catalyst from Tb nitrate, it was found that the highest C2 yield and selectivity are obtained at 1173K and 1073K, respectively, and higher C2 selectivity was observed at higher partial pressure of CH4.

Layer-by-layer alternate assemblies, which incorporate two kinds of cyanine dyes in the form of mixed J-aggregates, were fabricated by means of the alternate adsorption method. The excited-state dynamics of the mixed J-aggregates were examined by steady-state fluorescence spectroscopy and picosecond lifetime measurements. In these assemblies, the behavior of excitation energy transfer between the donor and acceptor J-aggregates obeyed Stern–Volmer kinetics in the low concentration region of the acceptor molecules. It was found that both the fluorescence lifetime and quantum yield of the acceptor aggregates decrease with increasing concentration of the acceptor molecules, which indicates that fluorescence self-quenching occurred in the acceptor aggregates.

We have fabricated multilayer assemblies consisting of cyanine dye and polyelectrolyte by means of alternate adsorption method. In this study we used two kinds of water soluble thiacyanine dyes and poly(diallyldimethylammonium chloride) (PDDA) as polycation. Anionic cyanine dye molecules were adsorbed onto the positively charged surface of PDDA layer, giving rise to the J-aggregate. The sequential alternate adsorption yielded the PDDA-(dye/PDDA)n assemblies (n, repeating number). UV-vis spectroscopy measurements indicated that peak absorbance at the J-band increased linearly with the increasing adsorption cycles. These results demonstrate the advantage of the alternate adsorption method for investigating J-aggregate-containing multilayer assemblies.

Sandwich-type monolayer assemblies, [donor/spacer/acceptor], consisting of the J-aggregates of two kinds of cyanine dyes, donor aggregate and acceptor aggregate, as well as inert spacer layers have been fabricated. A combination of cyanine dyes, 5,5′-dichloro-3,3′-diethyl-9-phenyl-thiacarbocyanine chloride (Thia()) + 3,3′-dimethyl-9-phenyl-4, 5,4′,5′-naphthothiacarbocyanine chloride (Nap()), has been focused on because this combination is capable of forming the homogeneous aggregate of the amalgamation-type (HA-aggregate) in the mixed assembly. Sensitization of resonance fluorescence of the acceptor aggregate (Nap()) occurs at the expense of quenching of the resonance fluorescence of the donor aggregate (Thia()) in the sandwich assembly. The critical distance of energy transfer, d0, in the exponential decay law is fairly large (d0 = 170 A).

Chitosan (CTO) films containing ammonium 1,1′-disulfopropyl-9-aminothiacarbocyanine (KP2) were fabricated by dropping an aqueous solution of CTO and KP2 on the quartz plate. Although KP2 molecules take a monomeric form in aqueous solutions, most dye molecules form the H-aggregate in the presence of CTO, as evidenced by an exceptionally sharp H-band. The formation of the H-aggregate was further promoted in the CTO films. In contrast, the formation of the H-aggregate reported thus far has been accompanied with the coexistence of large amounts of dye monomers and oligomers. We could devise, for the first time, a reproducible method for preferred formation of the H-aggregate in polymer films.

The J-aggregates of quinocyanine dyes (5,6,5'6'-dibenzo-1,1'-diethyl-2,2'-cyanine chloride (Sh) and 1-methyl-1'-octadecyl-2,2'-cyanine perchlorate (S120)) have been fabricated in a Langmuir trough and transferred onto quartz substrate. The formation of the J-aggregates has been studied by methods of conventional absorption and fluorescence time resolved spectroscopy. The mixed J-aggregate of S120 and Sh shows two distinct absorption bands and one fluorescence band intermediate between those of the J-aggregates of the individual component dyes. These results have some anomaly compared with the mixed J-aggregates of quinocyanine dyes and its benzothiazole or benzoselenazole derivative formed in solutions (Scheibe et al., Naturwissenschaften 29 474 (1937)) and in Langmuir-Blodgett films (Penner and Mobius, Thin Solid Films 132 185 (1985)).

The black lipid membranes (BLM) of soybean lecithin doped with an amphiphilic azobenzene derivative, 4-octyl-4′-(5-carboxypentamethyleneoxy) azobenzene (8A5), was fabricated, and the K+ ion permeation through the “quasi-channels”, as represented by the steady d.c. current signal across the membrane, was photochemically regulated. A transient photocurrent overlapping with the steady d.c. current due to photoisomerization of 8A5 was observed in the BLM cell filled with a diluted KCl solution for the first time. Dependence of the steady photocurrent on the molar concentration ratio of 8 A5 to lecithin, [8 A5] / [lecithin], was also examined. It has been found that the normalized conductivity change, δG/G(trans), is roughly proportional to the square of [8A5]/[lecithin]. The result would suggest that one “quasichannel” consists of two 8A5 molecules.

We prepared dispersions of composite particles of thiacarbocyanine dye and colloidal silver or gold and examined an effect of the composite on the third-order nonlinear susceptibility (χ(3)) measured by using degenerate four-wave mixing method. The χ(3) of the dispersion was enhanced about 3.5 times the sum of those of dye solution and colloidal metal dispersion. A new absorption band (Δ=600 nm) which was bathochromically shifted from monomer band (Δ=551 nm) was formed and this band was related to the enhancement of χ(3).

Polymer films containing cationic cyanine dye, 1,1′-diethyl-2,2′-cyanine chloride (PIC), were fabricated by dropping aqueous solutions of the dye and the water-soluble polymer on the quartz plate and drying. The aggregation state of PIC in thin polymer films was dependent on the kind of polymers. The aggregation state could be controlled by varying the amount of anionic sites on the polymer chain or by mixing two kinds of polymers.