Delayed fluorescence from inverted singlet and triplet excited states.

Hund's multiplicity rule states that a higher spin state has a lower energy for a given electronic configuration1. Rephrasing this rule for molecular excited states predicts a positive energy gap between spin-singlet and spin-triplet excited states, as has been consistent with numerous experimental observations over almost a century. Here we report a fluorescent molecule that disobeys Hund's rule and has a negative singlet-triplet energy gap of -11 ± 2 meV. The energy inversion of the singlet and triplet excited states results in delayed fluorescence with short time constants of 0.2 µs, which anomalously decrease with decreasing temperature owing to the emissive singlet character of the lowest-energy excited state. Organic light-emitting diodes (OLEDs) using this molecule exhibited a fast transient electroluminescence decay with a peak external quantum efficiency of 17%, demonstrating its potential implications for optoelectronic devices, including displays, lighting and lasers.

Mural infective endocarditis with a mass on the fossa ovalis in the right atrium.

Infective endocarditis (IE) is a life-threatening disease that affects the endocardial surface of the heart. Although heart valves are commonly involved in IE, in rare cases, vegetation is attached to the cardiac walls without valvular endocardial involvement, which is referred to as mural IE. In this case, a 60-year-old female presented with a seven-day history of fever associated with worsening pain in the right shoulder and left hip. Streptococcus dysgalactiae subsp. Equisimilis was detected in both blood and joint fluid cultures. Although transthoracic echocardiography revealed no mass, transesophageal echocardiography revealed a mobile mass in the fossa ovalis of the right atrium. She was subsequently diagnosed with mural IE and successfully treated with antibiotics without cardiac surgery. To our knowledge, only a few reports have described mural IE with vegetation in or around the fossa ovalis of the right atrium. This case highlights the importance of transesophageal echocardiography in diagnosing mural IE. The treatment strategy for mural IE should be discussed individually and in a multidisciplinary manner because current IE guidelines may not be applicable to mural IE cases due to differences in disease characteristics and clinical course between mural and valvular IE.

Use of Continuous Electrical Impedance Measurement for Accurate Nerve Block in Rabbits.

OBJECTIVE: To perform an effective and safe nerve block, the needle must be placed near the target nerve while avoiding nerve damage. Our objective was to conduct an animal study to determine whether changes in electrical impedance (EI) could be used to guide the needle and achieve a safe and accurate nerve block. METHODS: We measured the EI of rabbit tissues during ultrasound-guided sciatic nerve block using a bipolar needle via the in-plane needle approach. The EI values and needle track on the ultrasound monitor were video-recorded. When there was a change in the EI, the needle advancement was stopped, and a stained anesthetic was injected. Subsequently, the animals were euthanized, and the anesthetic-stained tissue was examined via dissection, while the other tissue was preserved at -80°C for microscopic analysis. RESULTS: The EI remained stable as the needle advanced through the muscle (extraneural); however, it markedly decreased when the needle tip contacted the nerve or slightly punctured the epineurium (paraneural). The mean extra- and paraneural EIs were 4.92 ± 1.31 kΩ (range, 2.39-9.67 kΩ) and 2.86 ± 0.96 kΩ (range, 1.66-5.13 kΩ), respectively. Examination of the dissections and cryostat sections showed anesthetic delivery around the nerve. CONCLUSIONS: EI values differed between extra- and paraneural sites, and monitoring these values allowed prediction of the needle tip location with respect to the target nerve. Real-time EI measurement could improve the nerve block.

Carbonic anhydrase 2 is a novel invasion-associated factor in urinary bladder cancers.

Rat bladder cancer is nearly always papillary non-invasive urothelial carcinoma (UC). To establish an animal model mimicking invasive UC that arises from papillary non-invasive UC in the bladder, male human c-Ha-ras proto-oncogene transgenic rats (Hras128) were treated with 0.05% N-butyl-N-(hydroxybutyl)nitrosameine (BBN) in their drinking water and/or 0.1% phenylethyl isothiocyanate (PEITC) in their diet as follows: BBN (8 weeks)→PEITC (8 weeks); PEITC (8 weeks)→BBN (8 weeks); BBN alone (16 weeks); PEITC alone (16 weeks); and no treatment. At the end of week 16, the highest incidence of invasive UC was observed in the BBN→PEITC group. Therefore, we used Hras128 rats treated with BBN followed by PEITC as a model of invasive bladder cancer to identify invasion-associated proteins. Proteome analysis was performed to compare the protein profiles of invasive and non-invasive UC in Hras128 rats. We identified 49 proteins that were either overexpressed or underexpressed in invasive UC but not in non-invasive UC. Immunohistochemical analysis of carbonic anhydrase 2 (CA2), an overexpressed protein, showed that the relative number of CA2-positive UC was significantly higher for invasive UC compared to non-invasive UC in rats. Moreover, the incidence of CA2-positive cancers was also significantly higher for human muscle-invasive bladder cancer (MIBC) compared to non-MIBC (NMIBC) and was positively associated with the progression of NMIBC. Our findings indicate that CA2 is an invasion-associated factor and suggest that it could serve as a potential therapeutic molecular target for bladder cancers.

Infection control of COVID-19 in operating theaters in a designated hospital for specified infectious diseases in Japan.

At the beginning of the COVID-19 pandemic in 2020, many hospitals around the world recommended stopping elective surgery as a precaution to stop the spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The number of elective surgeries was reduced in Japan due to several waves of the pandemic. This work describes the management of COVID-19 and actual polymerase chain reaction (PCR) screening in operating theaters at the National Center for Global Health and Medicine (NCGM), a designated hospital for specified infectious diseases in Japan. The following three steps for COVID-19 infection control were taken to maintain the operating theater: i) Do not bring COVID-19 into the operating theater, ii) Infection control for all medical staff, and iii) Surgical management of surgical patients with COVID-19. We introduced checklists for surgical patients, simulations of surgery on infected patients, screening PCR tests for all surgical patients, and use of a negative pressure room for infective or suspected cases. We determined the flow and timing of surgery for patients with COVID-19. However, many aspects of COVID-19 infection control measures in the operating theater are still unclear. Therefore, infection control measures require further advances in the future to manage new infections.

Compressive force stimulates the gene expression of IL-17s and their receptors in MC3T3-E1 cells.

During orthodontic tooth movement, cytokines released from periodontal ligament fibroblasts and alveolar bone osteoblasts can alter the process of bone remodeling. Recently, interleukin-17 (IL-17) was found to stimulate osteoclastic resorption through osteoblasts by inducing receptor activator of nuclear factor κB ligand (RANKL) expression. However, the relationship between mechanical stress and IL-17 production by osteoblasts is not clear. Therefore, we examined the effect of compressive force on the expressions of IL-17A, IL-17B, IL-17C, IL-17D, IL-17E, IL-17F, and their receptors (IL-17RA, IL-17RB, IL-17RC, IL-17RD, and IL-17RE) using MC3T3-E1 cells as osteoblast-like cells. We also examined the effect of IL-17A on the expression of IL-17Rs, RANKL, macrophage colony-stimulating factor (M-CSF), and osteoprotegerin (OPG). The cells were cultured with or without continuous compressive force (1.0 and 2.0 g/cm(2)) for up to 24 hr. The cells were also cultured with or without IL-17A (0.1, 1.0, or 10 ng/ml) for up to 72 hr. The mRNA expressions of IL-17s and their receptors were estimated by real-time polymerase chain reaction. The expression levels of IL-17s and their receptors increased depending on the compressive force. The addition of IL-17A increased the expression of IL-17RA, IL-17RB, IL-17RC, IL-17RE, RANKL, and M-CSF, whereas it decreased OPG expression. These results indicate that compressive force induces the expression of IL-17s and their receptors in osteoblast-like cells and that IL-17s and their receptors produced in response to compressive force may affect osteoclastogenesis through the expression of RANKL, M-CSF, and OPG.

Compressive force induces osteoclast differentiation via prostaglandin E(2) production in MC3T3-E1 cells.

In orthodontic tooth movement, prostaglandin E(2) (PGE(2)) released from osteoblasts can alter the normal process of bone remodeling. We previously showed that compressive force (CF) controls bone formation by stimulating the production of PGE(2) and Ep2 and/or Ep4 receptors in osteoblasts. The present study was undertaken to examine the effect of CF on the production of PGE(2), cyclooxygenase-2 (COX-2), macrophage colony-stimulating factor (M-CSF), receptor activator of NF-kappaB ligand (RANKL), and osteoprotegerin (OPG) using osteoblastic MC3T3-E1 cells and to examine the indirect effect of CF on osteoclast differentiation using RAW264.7 cells as osteoclast precursors. MC3T3-E1 cells were cultured with or without continuous CF (1.0 or 3.0 g/cm(2)) for 24 hr, and PGE(2) production was determined using ELISA. The expression of COX-2, M-CSF, RANKL, and OPG genes and proteins was determined using real-time PCR and ELISA, respectively. Osteoclast differentiation was estimated using tartrate-resistant acid phosphatase (TRAP) staining of RAW 264.7 cells cultured for 10 days with conditioned medium from CF-treated MC3T3-E1 cells and soluble RANKL. As CF increased, PGE(2) production and the expression of COX-2, M-CSF, and RANKL increased, whereas OPG expression decreased. The number of TRAP-positive cells increased as CF increased. Celecoxib, a specific inhibitor of COX-2, blocked the stimulatory effect of CF on TRAP staining and the production of PGE(2), M-CSF, RANKL, and OPG. These results suggest that CF induces osteoclast differentiation by increasing M-CSF production and decreasing OPG production via PGE(2) in osteoblasts.

Gastric lymphoma complicated by phlegmonous gastritis and Guillain-Barré syndrome: A case report.

INTRODUCTION: Complications such as severe infection may occur during the chemotherapy of malignant lymphoma. Phlegmonous gastritis (PG) is a rare acute bacterial infection associated with high mortality, requiring early diagnosis, and prompt management. In addition, Guillain-Barré syndrome (GBS) occasionally requires early treatment and intensive care management due to the occurrence of severe neuropathy and respiratory failure. PATIENT CONCERNS: A 70-year-old male was diagnosed with primary gastric diffuse large B-cell lymphoma (DLBCL) after the detection of several polypoid tumors with ulcers. The patient underwent chemotherapy for DLBCL and exhibited adverse effects (i.e., fever, vomiting, epigastric pain, and neutropenia). Computed tomography indicated widespread thickening in the gastric wall. Furthermore, approximately 2 weeks later, the patient presented with gradual symmetric lower extremity weakness and respiratory failure due to paralysis of the respiratory muscle. DIAGNOSES: DLBCL was diagnosed through a gastric tumor biopsy. On the basis of the computed tomography findings, a culture of gastric juice, nerve conduction studies, and clinical symptoms, this case of gastric lymphoma was complicated with PG and GBS. INTERVENTIONS: The patient was treated with antimicrobial therapy and administration of granulocyte colony-stimulating factor for PG, and with intravenous immunoglobulin and intensive care management for GBS. OUTCOMES: Despite the aggressive progress of the condition, the patient improved without relapse of DLBCL. CONCLUSION: PG was regarded as a precedent infection of GBS. In this article, we present the first reported case of gastric lymphoma complicated with PG and GBS.

Exciplex emissions derived from exceptionally long-distance donor and acceptor molecules.

Intermolecular electron-hole coupling in organic semiconductor excited states plays important roles in organic light-emitting diodes and organic photovoltaics, and the distance of the coupling is typically only on the order of a few nanometers. Here, we report exceptionally long-distance coupled exciplex emissions between electron-donor and electron-acceptor molecules even with a 70 nm-thick spacer layer. Donor/spacer (∼70 nm)/acceptor-type stacked films showed a low-energy band emission, which is not ascribed to the emission of the donor, spacer, and acceptor themselves, but well corresponds to the energy difference between the highest occupied molecular orbital of the donor and the lowest unoccupied molecular orbital of the acceptor. Delayed transient photoluminescence (PL) and electroluminescence (EL) decays and PL quenching by oxygen at the low-energy band were observed and are consistent with the characteristics of the exciplex species.

Protective effects of the Francisella tularensis ΔpdpC mutant against its virulent parental strain SCHU P9 in Cynomolgus macaques.

Tularemia is a severe infectious zoonotic disease caused by Francisella tularensis. Although F. tularensis is considered to be a potential biological weapon due to its high infectivity and mortality rate, no vaccine has been currently licensed. Recently, we reported that F. tularensis SCHU P9 derived ΔpdpC strain lacking the pathogenicity determinant protein C gene conferred stable and good protection in a mouse lethal model. In this study, the protective effect of ΔpdpC was evaluated using a monkey lethal model. Two cynomolgus macaques (Macaca fascicularis) intratracheally challenged with the virulent strain SCHU P9 were euthanized on 7 and 11 days post-challenge after the development of severe clinical signs. The bacterial replication in alveolar macrophages and type II epithelial cells in the lungs would cause severe pneumonia accompanied by necrosis. Conversely, two animals subcutaneously immunized with ΔpdpC survived 3 weeks after SCHU P9 challenge. Though one of the two animals developed mild symptoms of tularemia, bacterial replication was limited in the respiratory organs, which may be due to a high level of humoral and cellular immune responses against F. tularensis. These results suggest that the ΔpdpC mutant would be a safe and promising candidate as a live attenuated tularemia vaccine.

Identification of a novel endochitinase from a marine bacterium Vibrio proteolyticus strain No. 442.

Chitin binding proteins prepared from Vibrio proteolyticus were purified and the N-terminal amino-acid sequence of a protein from a 110-kDa band on SDS-PAGE was found to be 85-90% identical to the 22nd-41st residues of the N-termini of chitinase A precursor proteins from other vibrios. We cloned the corresponding gene, which encodes a putative protein of 850 amino acids containing a 26-residue signal sequence. The chitinase precursor from V. proteolyticus was 78-80% identical to those from Vibrio parahaemolyticus, Vibrio alginolyticus and Vibrio carchariae. However, the proteolytic cleavage site for C-terminal processing between R597 and K598 in the chitinase precursor of other vibrios was not observed in the amino acid sequence of V. proteolyticus, which instead had the sequence R600 and A601. Subsequently, full-length and truncated chitinases were generated in Escherichia coli. The specific activity of full-length chitinase expressed in E. coli was 17- and 20-folds higher for colloidal and alpha-chitins (insoluble substrate), respectively, than that of the C-terminal truncated enzyme. However, both recombinants showed similar hydrolysis patterns of hexa-N-acetyl-chitohexaose (soluble substrate), producing di-N-acetyl-chitobiose as major product on TLC analysis. We showed that the C-terminus of the V. proteolyticus chitinase A was important for expression of high specific activity against insoluble chitins.

Compressive force stimulates the expression of osteogenesis-related transcription factors in ROS 17/2.8 cells.

OBJECTIVE: To determine how compressive force affects the expression of osteogenesis-related transcription factors in osteoblasts. DESIGN: Cells of ROS 17/2.8, a typical osteoblastic cell line, were cultured with or without continuous compressive force (0.5-2.0 g/cm(2)). Expression of mRNA encoding the osteogenesis-related transcription factors Runx2, Osterix, Msx2, Dlx5 and AJ18 was measured using real-time polymerase chain reaction. Protein expression of these transcription factors was determined by Western blotting. RESULTS: A compressive force of 1.0 g/cm(2) significantly increased mRNA and protein expression of Runx2, Osterix, Msx2 and Dlx5, which are critical for osteoblast differentiation. In contrast, mRNA and protein expression of AJ18, which downregulates osteoblast differentiation, were decreased with 1.0 g/cm(2) of compressive force. CONCLUSIONS: A compressive force of 1.0 g/cm(2), which was considered optimal for bone formation under the present experimental conditions, stimulates osteoblastic differentiation via the modulation of osteogenesis-related transcription factors.

Effect of compressive force on the expression of inflammatory cytokines and their receptors in osteoblastic Saos-2 cells.

OBJECTIVE: In orthodontic tooth movement, some cytokines released from periodontal ligament fibroblasts and alveolar bone osteoblasts on the pressure side can alter the normal processes of bone remodelling, resulting in physiological bone resorption. We examined the effect of compressive force and interleukin (IL)-1 type I receptor antagonist (IL-1ra) on the expression of inflammatory cytokines that promote osteoclast formation, as well as on their receptors, in osteoblastic Saos-2 cells. DESIGN: The cells were cultured in Dulbecco's modified Eagle medium containing 10% fetal bovine serum with or without continuous compressive force (0.5-3.0 g/cm(2)) and/or IL-1ra for up to 24h. The gene expression levels of the cytokines and their receptors were estimated by determining mRNA levels using real-time PCR; the protein levels were determined using ELISA or immunohistochemical staining. RESULTS: The expression of IL-1beta, IL-1 receptor, IL-6, IL-6 receptor, IL-8 receptor, IL-11 and tumor necrosis factor-alpha (TNFalpha) increased depending on the strength and duration of the compressive force, whereas the expression of IL-8, IL-11 receptor and TNFalpha receptor did not change with the application of compressive force. The expression of cytokines and their receptors produced by 3.0 g/cm(2) of compressive force decreased with the simultaneous addition of IL-1ra and the decrease was remarkable in IL-8 receptor, IL-11 and TNFalpha. CONCLUSION: These results indicate that mechanical stress induces the production of inflammatory cytokines and their receptors in osteoblasts and the phenomenon is enhanced by the autocrine action of IL-1beta, which is increased in amount by mechanical stress.

Atomic and Isomeric Separation of Thiolate-Protected Alloy Clusters.

Techniques to control the chemical compositions and geometric structures of alloy clusters are indispensable to understand the correlation between the structures and physical/chemical properties of alloy clusters. In this study, we established a method to separate thiolate-protected 25-atom gold-silver alloy clusters (Au25- xAg x(SR)18) according to their chemical composition and structural isomer. Furthermore, using this method, we revealed that an isomeric distribution of the products exists in Au25- xAg x(SR)18 ( x ≥ 2) and that the distribution of these isomers depends on the synthesis method and standing time in solution. In this study, it was also demonstrated that the continuous discretization of the electronic structure is induced by the Ag substitution. This method can also be used to separate mixtures of [Au24M(SR)18]0 (M = Au, Pt, or Pd) and other Au-Ag alloy clusters ([Au36- xAg x(SR)24]0 and [Au38- xAg x(SR)24]0). This method is expected to be used to obtain comprehensive knowledge of the structural-property correlation of alloy clusters.

Autonomous Positioning of Eye Surgical Robot Using the Tool Shadow and Kalman Filtering.

Vitreoretinal surgery is one of the most difficult surgical operations, even for experienced surgeons. Thus, a master-slave eye surgical robot has been developed to assist the surgeon in safely performing vitreoretinal surgeries; however, in the master-slave control, the robotic positioning accuracy depends on the surgeon's coordination skills. This paper proposes a new method of autonomous robotic positioning using the shadow of the surgical instrument. First, the microscope image is segmented into three regions-namely, a micropipette, its shadow, and the eye ground-using a Gaussian mixture model (GMM). The tips of the micropipette and its shadow are then extracted from the contour lines of the segmented regions. The micropipette is then autonomously moved down to the simulated eye ground until the distance between the tips of micropipette and its shadow in the microscopic image reaches a predefined threshold. To handle possible occlusions, the tip of the shadow is estimated using a Kalman filter. Experiments to evaluate the robotic positioning accuracy in the vertical direction were performed. The results show that the autonomous positioning using the Kalman filter enhanced the accuracy of robotic positioning.

Effects of compressive force on the differentiation of pluripotent mesenchymal cells.

The purpose of this study was to determine the effect of mechanical stress on the differentiation of the pluripotent mesenchymal cell line C2C12. C2C12 cells were cultured continuously under compressive force (0.25-2.0 g/cm(2)). After mechanical stress loading, the levels of expression of mRNAs and proteins for phenotype-specific markers of osteoblasts (Runx2, Msx2, Dlx5, Osterix, AJ18), chondroblasts (Sox5, Sox9), myoblasts (MyoD), and adipocytes (PPAR gamma) were measured by real-time polymerase chain reaction analysis and Western blot analysis, respectively. The expression of activated p38 mitogen-activated protein kinase (p38 MAPK) was measured by Western blotting and/or ELISA. Loading 0.5 g/cm(2) of compressive force significantly increased the expression levels of Runx2, Msx2, Dlx5, Osterix, Sox5, and Sox9. In contrast, the expression levels of AJ18, MyoD, and PPAR gamma were decreased by exposure to 0.5 g/cm(2) of compressive force. Loading 0.5 g/cm(2) of compressive force also induced the phosphorylation of p38 MAPK. SB203580, which is a specific inhibitor of p38 MAPK, inhibited the compressive force-induced phosphorylation of p38 MAPK and partially blocked compressive force-induced Runx2 mRNA expression. These results demonstrate that compressive force stimulation directs the differentiation pathway of C2C12 cells into the osteoblast and chondroblast lineage via activated phosphorylation of p38 MAPK.

Late-onset severe biliary bleeding after endoscopic pigtail plastic stent insertion.

Here, we report our experience with a case of severe biliary bleeding due to a hepatic arterial pseudoaneurysm that had developed 1 year after endoscopic biliary plastic stent insertion. The patient, a 78-year-old woman, presented with hematemesis and obstructive jaundice. Ruptured hepatic arterial pseudoaneurysm was diagnosed, which was suspected to have been caused by long-term placement of an endoscopic retrograde biliary drainage (ERBD) stent. This episode of biliary bleeding was successfully treated by transarterial embolization (TAE). Pseudoaneurysm leading to hemobilia is a rare but potentially fatal complication in patients with long-term placement of ERBD. TAE is a minimally invasive procedure that offers effective treatment for biliary bleeding.

Osteopontin deficiency suppresses high phosphate load-induced bone loss via specific modulation of osteoclasts.

Phosphate (Pi) plays a critical role in the maintenance of mineralized tissues and signaling in the intracellular environment. Although extracellular phosphate concentration is maintained at fixed levels, physiological machineries involved in phosphate homeostasis in bone, which is the largest phosphate storage site, have not yet been fully elucidated. Here we examined the role of osteopontin (OPN) in a high-Pi diet load-induced bone loss. A high-Pi diet significantly reduced bone mineral density as well as bone mass in wild type. In contrast, OPN deficiency totally prevented reduction in bone mineral density and bone mass. Analyses of bone turnover-related components revealed that bone formation parameters (bone formation rate and mineral apposition rate) were enhanced by high-Pi diet load similarly in wild-type and OPN-deficient mice. In sharp contrast, bone resorption parameters (osteoclast number and osteoclast surface) were enhanced by high-Pi diet load in wild type but not at all in OPN-deficient mice. Bone marrow cell cultures revealed no major effects of OPN deficiency on high-Pi diet modulation of mineralized nodule formation in culture. On the other hand, tartrate-resistant acid phosphatase-positive multinucleated cell development in cultures were enhanced by high-Pi diet load in wild-type cells, but such effects of high Pi-diet were totally abolished in the absence of OPN. These data indicated that OPN is needed for osteoclastic activity to resorb bone on high phosphate loading.

Optimal compressive force induces bone formation via increasing bone morphogenetic proteins production and decreasing their antagonists production by Saos-2 cells.

Orthodontic tooth movement induced alveolar bone resorption and formation around the teeth applied mechanical force. Although mechanical force can promote bone formation, the molecular mechanism that underlies this phenomenon is not fully understood. The purposes of this study were to determine how mechanical stress affects the osteogenic response of human osteoblastic cells (Saos-2), and also to examine the optimal compressive force for osteogenesis in vitro. Saos-2 cells were cultured with or without continuously compressive force (0.5-3.0 g/cm2). The expression of bone morphogenetic proteins (BMPs), their antagonists, and transcription factors which involved in osteogenesis were measured using real-time PCR and/or Western blot analysis. Phosphorylation of Smad1 was determined by Western blot. Loading with 1.0 g/cm2 of compressive force significantly increased the expression of BMPs, Runx2 and osterix. In contrast, the expression of BMP antagonists and AJ18 was decreased with 1.0 g/cm2 of compressive force. Loading with 1.0 g/cm2 of compressive force also induced phosphorylation of Smad1. Noggin inhibited the compressive force-induced phosphorylation of Smad1 markedly, and also partially blocked compressive force-induced Runx2 mRNA expression. Moreover, the conditioned medium from 1.0 g/cm2 of compressive force applied cells apparently increased calcium content in mineralized nodules of Saos-2 culture. This study demonstrates that an optimal compressive force stimulates in vitro mineralization via increasing BMPs production and decreasing their antagonists production.