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[32](1,4)Naphthalenophanes, bearing carbon-bridge chains (syn- and anti-NPs) and nitrogen-bridge chains (syn- and anti-ANPs), were synthesized, and their X-ray structures and photoreactions were investigated. The intramolecular separation distance between the naphthalene cores for ANPs was shorter than that for NPs, suggesting that intramolecular interactions between the naphthalene rings were more efficient for ANPs compared to NPs. Upon photoirradiation at 300 nm, anti-NP, syn-ANP and anti-ANP produced the corresponding intramolecular [π4s + π4s] cycloadducts, whereas syn-NP gave an unidentified complex product mixture. Quantum yields for the photo-consumption (ΦPC) of NPs and ANPs were evaluated to quantitatively compare their photoreactivity. The ΦPC values of ANPs were approximately two-fold higher than those of ANPs.Noteworthily, the ΦPC value of syn-ANP was estimated to be unity. Based on these results we discuss the effects of the alignments of the naphthalene cores (anti vs. syn) and the bridging elements (C-bridge vs. N-bridge) on the photoreaction efficiencies of [32](1,4)naphthalenophanes.
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BACKGROUND: In the treatment of peripheral nerve injuries with nerve defects, second-generation collagen-based conduits, such as Renerve® (Nipro, Osaka, Japan), have shown the potential for promoting nerve regeneration. However, there is concern related to the weak material properties. No previous studies have addressed the strength of the bridging model using collagen conduits. This study aimed to investigate the tensile strength and failure patterns in nerve defect models bridged with Renerve® conduits through biomechanical research. METHODS: Using fresh chicken sciatic nerves, we examined the maximum failure load of four groups: bridging models using Renerve® with one suture (group A), with two sutures (group B), with three sutures (group C), and end-to-end neurorrhaphy models with two sutures (group N). Each group had eight specimens. We also evaluated failure patterns of the specimens. RESULTS: Group N showed a significantly higher maximum failure load (0.96 ± 0.13 N) than groups A (0.23 ± 0.06 N, p < 0.0001), B (0.29 ± 0.05 N, p < 0.0001), and C (0.40 ± 0.10 N, p < 0.0001). Regarding failure patterns, all specimens in group A showed nerve end dislocation from the conduit. Two specimens in group B and three specimens in group C failed due to circumferential cracks in the conduit. Six specimens in group B and five specimens in group C exhibited cutting out of sutures from the conduit. CONCLUSION: This study suggests that the number of sutures in synthetic collagen nerve conduits has little effect on the maximum failure load. To take advantage of its biomaterial benefits, a period of postoperative range of motion restriction may be required.
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BACKGROUND: Biodegradable synthetic nerve conduits have become widely used for peripheral nerve injuries. Recently, bioabsorbable collagen conduits filled with collagen fibers (Renerve®) are commercially available in Japan. We investigated the clinical efficacy and safety of Renerve® conduits for digital nerve repair. PATIENTS AND METHODS: We retrospectively reviewed data of patients who underwent digital nerve repair using Renerve® conduits between August 2017 and February 2022 at our hospital and were followed up for at least 12 months. Seventeen patients (20 nerves) with a median age of 46.5 years (interquartile rage: 26-48 years) were included in the analysis. We analyzed sensory nerve function recovery and residual pain or uncomfortable tingling, as well as safety outcomes. The relationship between nerve defect length and sensory function data was assessed using Spearman's rank correlation. RESULTS: Sensory nerve function at 12 months postoperatively was excellent in six, good in 10, and poor in four nerves, and that at the final follow-up (median period, 24 months; range, 12-30 months) was excellent in nine, good in 10, and poor in one nerve. All nerves with a defect length of <12 mm had excellent or good sensory outcomes. At 12 months postoperatively, the correlation coefficients between nerve defect length and Semmes-Weinstein monofilament test results, static two-point discrimination, and dynamic two-point discrimination were 0.35 (p = 0.131), 0.397 (p = 0.0827), and 0.451 (p = 0.0461), respectively. Residual pain or tingling sensation were observed in four nerves at the final follow-up. No postoperative complications were observed in any of the patients. CONCLUSIONS: This study demonstrated the clinical efficacy and safety of Renerve® conduits for digital nerve repair. Our results will be useful in clinical practice because of the scarcity of real-world data on the use of Renerve® conduits for digital nerve repair.
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BACKGROUND: The purpose of this study is to justify the result of the modified Stand-Up test (MSUT) in Little League baseball players and to clarify the association with sports related disorders in the elbow. METHODS: A total of 245 (240 boys and 5 girls) Little League baseball players aged 9 to 12 underwent physical examination, elbow ultrasonography and questionnaires during a routine medical checkup. In addition, the MSUT, based on the Japanese Orthopaedic Association (JOA)'s original Stand-Up test to evaluate the risk of Locomotive syndrome, was performed. RESULTS: Seventeen osteochondritis dissecans (OCD) of capitellum and 4 medial epicondylar fragmentation (MEF) cases were diagnosed with ultrasonography in 242 players. Based on the MSUT, five boys could not stand up from 40 cm platform with the single leg stance, two of whom complained of current elbow pain, three of whom diagnosed with a positive finding with ultrasonography. Odds ratio (95% confidence limits) of risk factors for failing to the 40 cm-MSUT with the single leg stance were: incidence of current elbow pain 5.7 (0.9-35.5); OCD (Grade 1b and 2) 8.2 (0.8-83); and MEF 19.5 (1.7-230). CONCLUSION: Two percent of Little League baseball players were unable to stand up from a 40 cm high platform/stool with the single leg stance by the MSUT and it was associated with an increase in MEF or OCD diagnosis by ultrasonography and presence of elbow pain. These results suggest that players who failed to the 40 cm-MSUT with the single leg stance are at risk of elbow disorders. Also, these results are consistent with previous research on throwing injuries that have associated poor control in the legs or trunk with pain and injury involving the upper extremities. MSUT, a relatively simple procedure, may be a helpful adjunct for screening to estimate readiness for resuming general physical activity in Little League baseball players.
Subject(s)
Baseball , Elbow Joint , Osteochondritis Dissecans , Male , Female , Humans , Elbow , Baseball/injuries , Elbow Joint/diagnostic imaging , Pain , Arthralgia , Osteochondritis Dissecans/diagnostic imaging , Osteochondritis Dissecans/epidemiologyABSTRACT
BACKGROUND: The standard chemotherapy regimens for soft tissue sarcoma are doxorubicin-based. This retrospective study aimed to assess the efficacy and safety of pirarubicin, ifosfamide, and etoposide combination therapy for patients with this disease. METHODS: Between 2008 and 2017, 25 patients with soft tissue sarcoma were treated with pirarubicin (30 mg/m2, 2 days), ifosfamide (2 g/m2, 5 days), and etoposide (100 mg/m2, 3 days) every 3 weeks. The primary endpoint was overall response, and the secondary endpoint was adverse events of this regimen. RESULTS: Responses to this regimen according to RECIST criteria were partial response (n = 9, 36%), stable disease (n = 9, 36%) and progressive disease (n = 7, 28%). During the treatment phase, frequent grade 3 or worse adverse events were hematological toxicities including white blood cell decreases (96%), febrile neutropenia (68%), anemia (68%), and platelet count decreases (48%). No long-term adverse events were reported during the study period. CONCLUSION: This regimen was comparable to previously published doxorubicin-based combination chemotherapy in terms of response rate. Although there were no long-lasting adverse events, based on our results, severe hematological toxicity should be considered.
Subject(s)
Doxorubicin/analogs & derivatives , Etoposide/administration & dosage , Ifosfamide/administration & dosage , Sarcoma/drug therapy , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Disease-Free Survival , Doxorubicin/administration & dosage , Doxorubicin/adverse effects , Drug-Related Side Effects and Adverse Reactions/classification , Drug-Related Side Effects and Adverse Reactions/pathology , Etoposide/adverse effects , Female , Humans , Ifosfamide/adverse effects , Leukopenia/chemically induced , Leukopenia/pathology , Male , Middle Aged , Sarcoma/pathology , Thrombocytopenia/chemically induced , Thrombocytopenia/pathologyABSTRACT
We prepared amide-heterocycle (HC) compounds having various aromatic π-electron systems (Ar), such as phenyl, naphthyl, furyl, thienyl and phenanthryl moieties, and converted them as ligands to difluoroboronated complexes, Ar@HCs. Blue fluorescence from Ar@HCs was observed in solution and the solid state, and the fluorescence quantum yields (Φf) and lifetimes (τf) were determined. The Φf values in CHCl3 were as small as 0.1 except for the phenanthrene derivatives (0.4-0.6). Observation of the triplet-triplet absorption upon laser flash photolysis of Ar@HCs in solution indicated that the fluorescence process competes with intersystem crossing to the triplet state. Blue fluorescence in the solid state was observed with the Φf values of 0.3-0.7. Based on the crystallographic data, the relationship between the crystal structures and emission features of Ar@HCs in the solid state is discussed.
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The absorption and fluorescence spectra of a series of 1,8-naphthalimide derivatives incorporating the amino functionality at the 2-, 3- and 4-positions of the naphthalene ring (2APNI, 3APNI and 4APNI, respectively) were systematically investigated in various solvents and in the solid state. The fluorescence spectra of 2APNI were insensitive to solvent polarity and intermolecular hydrogen-bonding even in a protic medium such as methanol. Thus, 2APNI displayed blue fluorescence with a moderate fluorescence quantum yield (λFmax = 420-445 nm, ΦF 0.2-0.3) in the solvents investigated. In contrast, the fluorescence spectra of 3APNI and 4APNI were strongly solvent dependent showing positive solvatofluorochromism with large Stokes shifts. Upon increasing the solvent polarity, the fluorescence colours changed from blue in hexane (λFmax = 429 nm) to orange-yellow in methanol (λFmax = 564 nm) for 3APNI, and from blue in hexane (λFmax = 460 nm) to yellow in methanol (λFmax = 538 nm) for 4APNI. The fluorescence quantum yields of 3APNI and 4APNI decreased with increasing solvent polarity. In the solid state, APNIs displayed red-shifted fluorescence emission compared to that in solution (λFmax = 541 nm for 2APNI, 575 nm for 3APNI, and 561 nm for 4APNI) and the fluorescence quantum yields in the solid state were lower than those in solution.
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BACKGROUND: Recurrence after wide excision or residual tumor after an unplanned excision of a malignant soft tissue sarcoma (STS) is a complex problem, due to a higher recurrence rate and poorer survival rate compared with primary resection. Regional hyperthermia was used, with the expectation that it will enhance the anti-tumor effects of chemotherapy and radiotherapy. This study aimed to assess the efficacy of neoadjuvant concomitant radiotherapy, hyperthermia, and chemotherapy (RHC) for salvage of recurrent or residual malignant STS. METHODS: We identified 64 patients with recurrent or residual STS treated between 1994 and 2013. After excluding those with low-grade malignancy, with recurrent bone tumor in the soft tissues, with truncal STS, and who declined to participate, 23 patients (7 with recurrence and 16 with residual tumor) underwent RHC. The histologic diagnoses were undifferentiated pleomorphic sarcoma (n = 11), synovial sarcoma (n = 3), leiomyosarcoma and myxoid liposarcoma (n = 2 each), and other histologic types. As primary outcomes, the 5-year overall survival (OS), distant metastasis-free survival (D-MFS), and local control (LC) rates were evaluated by Kaplan-Meier analysis. RESULTS: The median follow-up period was 112.3 months. The 5-year OS, D-MFS, and LC were 86.4%, 77.4%, and 86.7%, respectively. In the univariate analysis, tumor depth was considered as a negative prognostic factor for OS and D-MFS, and a positive margin was also a negative prognostic factor for OS, D-MFS LC with retained on Cox proportional hazards model in OS, and D-MFS. CONCLUSION: RHC is an effective option for salvage treatment of recurrent and residual STS.
Subject(s)
Salvage Therapy/methods , Soft Tissue Neoplasms/drug therapy , Soft Tissue Neoplasms/radiotherapy , Female , Humans , Male , Middle Aged , Neoplasm Recurrence, Local , Soft Tissue Neoplasms/mortality , Soft Tissue Neoplasms/pathology , Survival Rate , Treatment OutcomeABSTRACT
BACKGROUND: Although aneurysmal bone cysts (ABCs) are benign tumours, they have the potential to be locally aggressive. Various treatment approaches, such as en bloc resection, open curettage, radiotherapy, sclerotherapy, and embolization have been proposed, but the most appropriate treatment should be selected after considering the risk of tumour recurrence and treatment complications. Endoscopic curettage (ESC) may be a less invasive alternative to open curettage for ABC treatment. We aimed to describe the use of ESC for the treatment of ABCs and to report our clinical outcomes, including the incidence rate of recurrence, radiological appearance at final follow-up, time to solid union, complications, and postoperative function. METHODS: Between 1998 and 2015, 30 patients (18 men and 12 women; mean age, 17.4 years) underwent ESC for the treatment of primary ABCs at our hospital (mean postoperative follow-up, 55 months). ESC was performed under arthroscopic guidance for direct visualization, and curettage extended until normal bone was observed in the medullary cavity. To investigate bone healing after ESC, we evaluated the consolidation of cysts at the final evaluation (based on the modified Neer classification) and time to solid union after surgery, which was defined as sufficient cortical bone thickness to prevent fracture and allow physical activities. RESULTS: Recurrence was identified in 3 cases (10%). Curative outcomes were obtained after repeated ESC or open curettage. A log-rank analysis indicated that age < 10 years (p = 0.004) and contact of the tumour with the physis (p = 0.01) increased the risk of tumour recurrence. Residual tumours were identified in 9 cases (30%); these lesions remained inactive over the extended follow-up period. The average time to solid union after endoscopic curettage was 3.2 months. Transient radial nerve palsy was identified in 1 case. Good postoperative functional recovery occurred in all cases. CONCLUSIONS: ESC is a minimally invasive technique for the treatment of ABCs, and the tumour recurrence rate is comparable to that of other standard procedures. However, the application of this method should be carefully considered, especially for patients < 10 years and when the tumour comes in contact with the physis.
Subject(s)
Bone Cysts, Aneurysmal/diagnostic imaging , Bone Cysts, Aneurysmal/surgery , Curettage/methods , Endoscopy/methods , Adolescent , Adult , Child , Child, Preschool , Female , Follow-Up Studies , Humans , Male , Minimally Invasive Surgical Procedures/methods , Treatment Outcome , Young AdultABSTRACT
We prepared a variety of coumarin derivatives having expanded π-electron systems along the direction crossing the C3-C4 bond of the coumarin skeleton via a photochemical cyclization process and investigated their photophysical features as a function of the number (n) of the added benzene rings based on emission and transient absorption measurements. Upon increasing n, the fluorescence quantum yields of the π-extended coumarins increased. Expanding the π-electron system on the C3-C4 bond of the coumarin skeleton was found to be efficient for increasing the fluorescence ability more than that on the C7-C8 bond. Introducing the methoxy group at the 7-position was also efficient for enhancing the fluorescence quantum yield and rate of the expanded coumarins. The non-radiative process from the fluorescence state was not substantially influenced by the expanded π-electron system. The competitive process with the fluorescence was found to be intersystem crossing to the triplet state based on the observations of the triplet-triplet absorption. The effects of the expanded π-electron systems on the fluorescence ability were investigated with the aid of TD-DFT calculations.
Subject(s)
Coumarins/chemistry , Cyclization , Electrons , Phenanthrenes/chemistry , Quantum Theory , Solvents/chemistry , Spectrometry, FluorescenceABSTRACT
We studied the photoproducts of 1-(n-phenanthryl)-2-(m-phenanthryl)ethenes (nEm; n, m = 1, 3 and 9) for understanding photocyclization patterns based on NMR spectroscopy. The crystal structures of the photoproducts were analyzed by X-ray crystallography, and the photophysical features of the photocyclized molecules were investigated based on emission and transient absorption measurements. Phenanthrene derivatives substituted at the 1- and 3-positions were prepared for synthesizing nEm by photocyclization of stilbene derivatives. We obtained four types of primary photoproducts (n@m) from the corresponding nEm. Two of them were found to have racemic molecular structures in the single crystal determined by X-ray crystallography. Besides the primary photoproducts, two types of secondary photoproducts (n@mPP) were isolated. Fluorescence quantum yields and lifetimes of the obtained photoproducts were determined in solution whereas the definite fluorescence quantum yields were obtained in the powder. Observation of the triplet-triplet absorption spectra in solution by laser photolysis techniques showed that intersystem crossing to the triplet state competes with the fluorescence process.
ABSTRACT
Small molecules having intense luminescence properties are required to promote biological and organic material applications. We prepared five types of benzamides having pyridine, pyridazine, pyrazine, and pyrimidine rings and successfully converted them into three types of the difluoroboronated complexes, Py@BAs, as novel blue fluorophores. Py@BA having a pyridine moiety (2-Py@BA) showed no fluorescence in solution, whereas Py@BAs of pyridazine and pyrazine moieties (2,3-Py@BA and 2,5-Py@BA, respectively) emitted blue fluorescence with quantum yields of ca. 0.1. Transient absorption measurements using laser flash photolysis of the Py@BAs revealed the triplet formation of 2,3- and 2,5-Py@BAs, while little transient signal was observed for 2-Py@BA. Therefore, the deactivation processes from the lowest excited singlet state of fluorescent 2,3- and 2,5-Py@BAs consist of fluorescence and intersystem crossing to the triplet state while that of the nonfluorescent Py@BA is governed almost entirely by internal conversion to the ground state. Conversely, in the solid state, 2-Py@BA emitted intense fluorescence with a fluorescence quantum yield as high as 0.66, whereas 2,3- and 2,5-Py@BAs showed fluorescence with quantum yields of ca. 0.2. The crystal structure of 2-Py@BA took a herringbone packing motif, whereas those for 2,3- and 2,5-Py@BAs were two-dimensional sheetlike. On the basis of the difference in crystal structures, the emission mechanism in the solid state was discussed.
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BACKGROUND: Recently several authors have reported on the quantitative evaluation of the pivot-shift test using cutaneous fixation of inertial sensors. Before utilizing this sensor for clinical studies, it is necessary to evaluate the accuracy of cutaneous sensor in assessing rotational knee instability. To evaluate the accuracy of inertial sensors, we compared cutaneous and transosseous sensors in the quantitative assessment of rotational knee instability in a cadaveric setting, in order to demonstrate their clinical applicability. METHODS: Eight freshly frozen human cadaveric knees were used in this study. Inertial sensors were fixed on the tibial tuberosity and directly fixed to the distal tibia bone. A single examiner performed the pivot shift test from flexion to extension on the intact knees and ACL deficient knees. The peak overall magnitude of acceleration and the maximum rotational angular velocity in the tibial superoinferior axis was repeatedly measured with the inertial sensor during the pivot shift test. Correlations between cutaneous and transosseous inertial sensors were evaluated, as well as statistical analysis for differences between ACL intact and ACL deficient knees. RESULTS: Acceleration and angular velocity measured with the cutaneous sensor demonstrated a strong positive correlation with the transosseous sensor (r = 0.86 and r = 0.83). Comparison between cutaneous and transosseous sensor indicated significant difference for the peak overall magnitude of acceleration (cutaneous: 10.3 ± 5.2 m/s2, transosseous: 14.3 ± 7.6 m/s2, P < 0.01) and for the maximum internal rotation angular velocity (cutaneous: 189.5 ± 99.6 deg/s, transosseous: 225.1 ± 103.3 deg/s, P < 0.05), but no significant difference for the maximum external rotation angular velocity (cutaneous: 176.1 ± 87.3 deg/s, transosseous: 195.9 ± 106.2 deg/s, N.S). CONCLUSIONS: There is a positive correlation between cutaneous and transosseous inertial sensors. Therefore, this study indicated that the cutaneous inertial sensors could be used clinically for quantifying rotational knee instability, irrespective of the location of utilization.
Subject(s)
Anterior Cruciate Ligament/physiopathology , Joint Instability/diagnosis , Knee Joint , Physical Examination/instrumentation , Physical Examination/methods , Aged , Aged, 80 and over , Cadaver , Evaluation Studies as Topic , Female , Humans , Male , Reproducibility of Results , RotationABSTRACT
We investigated the photophysical properties of difluoroboronated ß-diketones (BF2DK) with chrysene and pyrene skeletons (ChB and PyB, respectively) in solution and in the solid state. Acetylchrysenes, as the key precursors to ChBs, were photochemically prepared from the corresponding (acetylphenyl)naphthylethenes by means of a modified photocyclization method. The absorption and emission spectra of the BF2DKs were obtained in chloroform and acetonitrile, and the quantum yields and lifetimes of the fluorescence were determined. Excimeric fluorescence from PyB was absent even in highly concentrated solution. Based on the Lippert-Mataga analysis of the absorption and fluorescence features, the photophysical properties of the ChBs were discussed in comparison with those of PyB. The fluorescence states of the studied BF2DKs are shown to be of a charge-transfer character. The fluorescence quantum yields decrease with increasing the solvent polarity due to the enhanced internal conversion process. The fluorescence quantum yields in the solid state of the studied BF2DKs were determined, and it was found that PyB is fluorescent, whereas the fluorescence quantum yields of the ChBs depend on the substituted position of the chrysene moiety.
Subject(s)
Chrysenes/chemistry , Pyrenes/chemistry , Acetonitriles/chemistry , Chrysenes/chemical synthesis , Cyclization , Pyrenes/chemical synthesis , Quantum Theory , Solvents/chemistry , Spectrometry, Fluorescence , X-Ray DiffractionABSTRACT
Six difluoroboronated ß-diketones having the phenanthrene skeleton (Phe@Ar) are prepared. Based on the measurements of the fluorescence quantum yields, lifetimes and transient absorption, the photophysical features of Phe@Ar are studied in comparison with those of difluoroboronated diketones having phenyl, naphthyl and anthryl moieties. ß-Diketones having 1-, 2-, 3- and 9-phenanthryl moieties (PheDKAr) were prepared as the precursor to Phe@Ar. 1-Acetylphenanthrene was synthesized by the photocyclization method as the key building block of PheDKAr having the 1-phenanthryl moiety. The counter aromatic moieties (Ar) of the prepared PheDKAr are varied with phenyl, furyl and thienyl rings (Ar = Ph, F and T, respectively) to investigate the effects of π-conjugation on the fluorescence properties. The prepared Phe@Ars are fluorescent with appreciable fluorescence quantum yields which depend on the substitution position of the phenanthrene moiety. 3-Phe@Ph having the 3-phenanthryl moiety provides the largest fluorescence quantum yield (0.81) in acetonitrile among the Phe@Ars whereas 2-Phe@Ph having the 2-phenanthryl moiety shows the smallest fluorescence quantum yield (0.07) in acetonitrile. All the Phe@Ars show fluorescence also in the solid state, and the fluorescence spectra and quantum yields were determined. Transient absorption measurement using laser flash photolysis of the Phe@Ars revealed the triplet formation. DFT and TD-DFT calculations of Phe@Ars rationalize the dependency of the fluorescence quantum yields on the substitution position of the phenanthrene skeleton in terms of difference in the oscillator strength for the HOMO-LUMO transition.
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A series of amino-2,3-naphthalimide derivatives having the amino functionality at 1-, 5- and 6-positions (, and , respectively) were prepared, and their photophysical properties were systematically investigated based on the measurements of steady-state absorption and fluorescence spectra, fluorescence lifetimes as well as transient absorption spectra. The s efficiently fluoresced in solution, and the emission spectra appreciably shifted depending on the solvent polarity. displayed only a slight fluorescence red-shift upon increasing the solvent polarity. In contrast, and showed marked positive solvatofluorochromism with large Stokes shifts displaying multicolour fluorescence; the fluorescence colours of and varied from violet-blue in hexane to orange-red in methanol. and , thus, serve as micro-environment responding fluorophores. In methanol, the intensity of the fluorescence emission band of and significantly reduced. Based on the fluorescence quantum yields and lifetimes, and transient absorption measurements, it has been revealed that internal conversion from the S1 state of s to the ground state was accelerated by the protic medium, resulting in a reduction in their fluorescence efficiency, while intersystem crossing from the S1 state to a triplet state was not responsible for the decrease of fluorescence intensity.
Subject(s)
Naphthalimides/chemistry , Solvents/chemistry , Methanol/chemistry , Quantum Theory , Spectrometry, FluorescenceABSTRACT
Efforts to identify and develop new superconducting materials continue apace, motivated by both fundamental science and the prospects for application. For example, several new superconducting material systems have been developed in the recent past, including calcium-intercalated graphite compounds, boron-doped diamond and-most prominently-iron arsenides such as LaO(1-x)F(x)FeAs (ref. 3). In the case of organic superconductors, however, no new material system with a high superconducting transition temperature (T(c)) has been discovered in the past decade. Here we report that intercalating an alkali metal into picene, a wide-bandgap semiconducting solid hydrocarbon, produces metallic behaviour and superconductivity. Solid potassium-intercalated picene (K(x)picene) shows T(c) values of 7 K and 18 K, depending on the metal content. The drop of magnetization in K(x)picene solids at the transition temperature is sharp (<2 K), similar to the behaviour of Ca-intercalated graphite. The T(c) of 18 K is comparable to that of K-intercalated C(60) (ref. 4). This discovery of superconductivity in K(x)picene shows that organic hydrocarbons are promising candidates for improved T(c) values.
ABSTRACT
Photophysical and photochemical features of [3n]cyclophanes (3nCPs) (n = 2-6) in solution were investigated by emission and transient absorption measurements. The studied 3nCPs show excimer fluorescence without locally excited fluorescence whereas some of them emit excimer phosphorescence in rigid glass at 77 K. The probability of excimeric phosphorescence from transannular π-electron systems was shown to strictly depend on the symmetric molecular structures. A feature of intersystem crossing from an excimeric fluorescence state to the excimeric triplet state was observed. Transient absorption spectra obtained upon laser flash photolysis of 3nCP revealed formation of the triplet excimer states. Triplet sensitization of 33CP using xanthone as the sensitizer demonstrated formation of triplet 33CP via triplet energy transfer whereas from the xanthone ketyl radical formation, it was inferred that triplet xanthone undergoes H atom abstraction from 32CP, providing a benzylic 32CP radical as the counter species. Based on kinetic and spectroscopic data obtained upon laser flash photolysis, differences in photochemical reactions of triplet xanthone between 32CP and 33CP were discussed.
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BACKGROUND: Low-grade osteosarcoma, including low-grade central osteosarcoma and parosteal osteosarcoma, is an extremely rare variant, and the diagnosis is occasionally difficult. In this article we present cases of low-grade osteosarcomas that should be reviewed by a clinical oncologist. PATIENTS AND METHODS: Nine cases of histologically diagnosed Broder grade 1 osteosarcoma were retrospectively reviewed. The pathological diagnoses included parosteal osteosarcoma, low-grade central osteosarcoma, and low-grade chondroblastic osteosarcoma in four, four, and one cases, respectively. RESULTS: Duration from initial surgical intervention including biopsy to final diagnosis as low-grade osteosarcoma was a mean of 9.4 months. The initial benign diagnoses on biopsy specimens included fibrous dysplasia in three cases, chondroblastoma in one case, and a giant cell tumor in one case. The average number of histological examinations was 1.8. Low-grade osteosarcomas are well suited for biological reconstruction: seven cases were reconstructed by frozen autografts, distraction osteogenesis, or vascularized bone grafts. CONCLUSION: Low-grade osteosarcomas can be misdiagnosed as benign lesions, especially fibrous dysplasia. If the diagnosis of a low-grade osteosarcoma is not established on the basis of radiologic findings, care should be exercised, even when a biopsy suggests a benign lesion. Low-grade osteosarcomas should be treated with wide excision, even after an intralesional excision. Biological reconstruction might be a better option for low-grade osteosarcomas.
Subject(s)
Biomarkers, Tumor/biosynthesis , Bone Neoplasms , Osteosarcoma , Adult , Aged , Biopsy , Bone Neoplasms/diagnosis , Bone Neoplasms/pathology , Cyclin-Dependent Kinase 4/biosynthesis , Female , Gene Expression Regulation, Neoplastic , Humans , Male , Middle Aged , Neoplasm Grading , Osteosarcoma/diagnosis , Osteosarcoma/pathology , Proto-Oncogene Proteins c-mdm2/biosynthesisABSTRACT
A 70-year-old man underwent nephrectomy for renal cell carcinoma followed by 3 cycles of pembrolizumab as adjuvant chemotherapy. Three months later, he complained of appetite loss. He was diagnosed with secondary adrenal insufficiency and pancreatic tumor. Amylase and immunoglobulin G (IgG) 4 levels were normal. The differential diagnosis poses challenges in distinguishing pancreatic cancer, renal cell carcinoma metastasis, and autoimmune pancreatitis, necessitating tumor resection surgery. A histological examination revealed IgG4-related sclerosing pancreatitis. Postoperatively, there was no recurrence of pancreatitis. It is essential to consider the potential development of IgG4-related diseases after the administration of immune checkpoint inhibitors.