Mass, Spectroscopy, and Two-Neutron Decay of ^{16}Be

The structure and decay of the most neutron-rich beryllium isotope, ^{16}Be, has been investigated following proton knockout from a high-energy ^{17}B beam. Two relatively narrow resonances were observed for the first time, with energies of 0.84(3) and 2.15(5) MeV above the two-neutron decay threshold and widths of 0.32(8) and 0.95(15) MeV, respectively. These were assigned to be the ground (J^{π}=0^{+}) and first excited (2^{+}) state, with E_{x}=1.31(6)  MeV. The mass excess of ^{16}Be was thus deduced to be 56.93(13) MeV, some 0.5 MeV more bound than the only previous measurement. Both states were observed to decay by direct two-neutron emission. Calculations incorporating the evolution of the wave function during the decay as a genuine three-body process reproduced the principal characteristics of the neutron-neutron energy spectra for both levels, indicating that the ground state exhibits a strong spatially compact dineutron component, while the 2^{+} level presents a far more diffuse neutron-neutron distribution.

First observation of 28O

Subjecting a physical system to extreme conditions is one of the means often used to obtain a better understanding and deeper insight into its organization and structure. In the case of the atomic nucleus, one such approach is to investigate isotopes that have very different neutron-to-proton (N/Z) ratios than in stable nuclei. Light, neutron-rich isotopes exhibit the most asymmetric N/Z ratios and those lying beyond the limits of binding, which undergo spontaneous neutron emission and exist only as very short-lived resonances (about 10-21 s), provide the most stringent tests of modern nuclear-structure theories. Here we report on the first observation of 28O and 27O through their decay into 24O and four and three neutrons, respectively. The 28O nucleus is of particular interest as, with the Z = 8 and N = 20 magic numbers1,2, it is expected in the standard shell-model picture of nuclear structure to be one of a relatively small number of so-called 'doubly magic' nuclei. Both 27O and 28O were found to exist as narrow, low-lying resonances and their decay energies are compared here to the results of sophisticated theoretical modelling, including a large-scale shell-model calculation and a newly developed statistical approach. In both cases, the underlying nuclear interactions were derived from effective field theories of quantum chromodynamics. Finally, it is shown that the cross-section for the production of 28O from a 29F beam is consistent with it not exhibiting a closed N = 20 shell structure.

Demonstration of a spherical plasma mirror for the counter-propagating kilojoule-class petawatt LFEX laser system

A counter-propagating laser-beam platform using a spherical plasma mirror was developed for the kilojoule-class petawatt LFEX laser. The temporal and spatial overlaps of the incoming and redirected beams were measured with an optical interferometer and an x-ray pinhole camera. The plasma mirror performance was evaluated by measuring fast electrons, ions, and neutrons generated in the counter-propagating laser interaction with a Cu-doped deuterated film on both sides. The reflectivity and peak intensity were estimated as ∼50% and ∼5 × 10¹⁸ W/cm², respectively. The platform could enable studies of counter-streaming charged particles in high-energy-density plasmas for fundamental and inertial confinement fusion research.

Ticagrelor versus Clopidogrel in the Dual Antiplatelet Regimen for Intracranial Stenting or Flow-Diverter Treatment for Unruptured Cerebral Aneurysms: A Single-Center Cohort Study

BACKGROUND AND PURPOSE

Ticagrelor is a novel P2Y12 antagonist, and little is known about its efficacy and safety in the endovascular treatment of aneurysms. This study evaluated the efficacy and safety of ticagrelor versus clopidogrel for stent-assisted coiling or flow-diversion treatment in patients with unruptured cerebral aneurysms.

MATERIALS AND METHODS

From November 2003 to February 2019, two hundred one patients (mean age, 57.5 years; 156 women) with 233 unruptured aneurysms underwent stent-assisted coiling or flow-diversion treatment. All patients received antiplatelet therapy of aspirin plus clopidogrel (clopidogrel group, 121 patients with 140 aneurysms) or aspirin plus ticagrelor (ticagrelor group, 80 patients with 93 aneurysms). The clinical and radiologic data in each group were retrospectively reviewed and compared.

RESULTS

Two hundred thirty-six procedures were performed, including stent-assisted coiling (n = 101) and flow diversion (n = 135). At 90 days, the primary outcome-a composite of any stroke and death-occurred in 9.9% of the clopidogrel group and 8.6% of the ticagrelor group (P = .822). Ischemic stroke occurred in 10 (7.0%) of the clopidogrel group and 7 (7.5%) of the ticagrelor group (P > .999). Disabling stroke occurred in 4 (2.8%) in the clopidogrel group and in 4 (4.3%) in the ticagrelor group (P = .716). Ninety-day death occurred in 3 (2.1%) in the clopidogrel group and 1 (1.1%) in the ticagrelor group (P > .999). Any bleeding at 90 days occurred in 13 (9.2%) in the clopidogrel group and 6 (6.5%) in the ticagrelor group (P = .479).

CONCLUSIONS

Ticagrelor appears to be as effective and safe as clopidogrel in stent-assisted coiling or flow-diversion treatment for unruptured cerebral aneurysms.

Electron Kinetics Induced by Ultrafast Photoexcitation of Warm Dense Matter in a 30-nm-Thick Foil

We report on the study of electron kinetics induced by intense femtosecond (fs) laser excitation of electrons in the 5d band of Au. Changes in the electron system are observed from the temporal evolution of ac conductivity and conduction electron density. The results reveal an increase of electron thermalization time with excitation energy density, contrary to the Fermi-liquid behavior of the decrease of thermalization time associated with the heating of conduction electrons. This is attributed to the severe mitigation of photoexcitation by Auger decay. The study also uncovers the shortening of 5d hole lifetime with the increase of photoexcitation rates. These unique findings provide valuable insights for understanding electron kinetics under extreme nonequilibrium conditions.

Quasifree Neutron Knockout Reaction Reveals a Small s-Orbital Component in the Borromean Nucleus ^{17}B

A kinematically complete quasifree (p,pn) experiment in inverse kinematics was performed to study the structure of the Borromean nucleus ^{17}B, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for 1s_{1/2} and 0d_{5/2} orbitals, and a surprisingly small percentage of 9(2)% was determined for 1s_{1/2}. Our finding of such a small 1s_{1/2} component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in ^{17}B. The present work gives the smallest s- or p-orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of s or p orbitals is not a prerequisite for the occurrence of a neutron halo.

Surface Localization of the Dineutron in ^{11}Li

The formation of a dineutron in the ^{11}Li nucleus is found to be localized to the surface region. The experiment measured the intrinsic momentum of the struck neutron in ^{11}Li via the (p,pn) knockout reaction at 246  MeV/nucleon. The correlation angle between the two neutrons is, for the first time, measured as a function of the intrinsic neutron momentum. A comparison with reaction calculations reveals the localization of the dineutron at r∼3.6  fm. The results also support the density dependence of dineutron formation as deduced from Hartree-Fock-Bogoliubov calculations for nuclear matter.

Angioscopic evaluation of vascular healing at 1 and 12 months after drug-coated stent implantation

Background

Polymer- and carrier-free Biolimus-A9-coated stent (DCS) is expected better vascular healing compared with conventional durable polymer drug-eluting stents (DES). Moreover, DCS had been demonstrated in clinical trials to allow one-month short dual antiplatelet therapy, which might achieve sufficient healing at only 1 month after implantation. However, the process of vascular healing after DCS implantation has not been elucidated by angioscopic observation.

Purpose

To evaluate the process of vascular healing at 1 month and 12 months after DCS implantation.

Methods

This study included 57 patients treated with DCS or durable polymer everolimus-eluting stents (EES) in our hospital from April 2017 to April 2019. Firstly, the angioscopic findings of DCS at 1 month (n=16) and 12 months (n=14) after implantation were respectively compared with EES at 12 months after implantation (EES-12, n=35) as a standard healing status of DES. Secondary, angioscopic findings of DCS at 1 month and 12 months after implantation were compared among the serially observed eight patients. Neointimal coverage (NIC) grade, yellow colour grade, and the presence of thrombus were evaluated. NIC grade was classified as grade 0 (no neointimal coverage), grade 1 (struts were bulged into lumen but covered), grade 2 (struts were embedded in the neointima but visible), or grade 3 (struts were fully embedded and invisible). Yellow colour grade was classified as grade 0 (white), grade 1 (light yellow), grade 2 (yellow), or grade 3 (intensive yellow).

Results

At 1 month after DCS implantation, dominant NIC grade was lower (0.3±0.5 vs. 1.5±0.7, p<0.001) and the frequency of thrombus was higher (38% vs. 6%, p=0.008) than EES-12. On the other hands, at 12 months after DCS implantation, dominant NIC grade was higher (2.1±0.6 vs. 1.5±0.7, p=0.013) and the frequency of thrombus was not different (7% vs. 6%, p=1.000) in comparison with EES-12. By serial observation of DCS, dominant NIC grade was higher at 12 months than at 1 month (2.3±0.5 vs. 0.4±0.5, p<0.001), while yellow colour grade (1.0±0.5 vs. 1.5±1.2, p=0.227) and the frequency of thrombus adhesion (0% vs. 38%, p=0.200) were not different.

Conclusion

Compared with EES-12, vascular healing of DCS was inferior at 1 month but superior at 12 months.

Figure 1

Funding Acknowledgement

Type of funding source: None

Relativistic magnetic reconnection in laser laboratory for testing an emission mechanism of hard-state black hole system

Magnetic reconnection in a relativistic electron magnetization regime was observed in a laboratory plasma produced by a high-intensity, large energy, picoseconds laser pulse. Magnetic reconnection conditions realized with a laser-driven several kilotesla magnetic field is comparable to that in the accretion disk corona of black hole systems, i.e., Cygnus X-1. We observed particle energy distributions of reconnection outflow jets, which possess a power-law component in a high-energy range. The hardness of the observed spectra could explain the hard-state x-ray emission from accreting black hole systems.

Active terahertz time differentiator using piezoelectric micromachined ultrasonic transducer array

The rapid growth of information technology is closely linked to our ability to modulate and demodulate a signal, whether in the frequency or in the time domain. Recent demonstrations of terahertz (THz) modulation involve active semiconductor metamaterial surfaces or use of a grating-based micromirror for frequency offset tuning. However, a wideband and active differentiator in the THz frequency band is yet to be demonstrated. Here, we propose a simple method to differentiate a THz pulse by inducing tiny phase changes on the THz beam path using a piezoelectric micromachined ultrasonic transducer array. We precisely demonstrate that the modulated THz signal detected after the piezoelectric device is proportional to the first-order derivative of the THz pulse. The proposed technique will be able to support a wide range of THz applications, such as peak detection schemes for telecommunication systems.

SAT0010 ANTI-CD30 IMMUNOTHERAPY AMELIORATES BONE AND CARTILAGE DESTRUCTION IN EXPERIMENTAL MODEL OF RHEUMATOID ARTHRITIS IN MICE

Background:

CD30 is a member of the TNF-receptor family and commonly expressed on lymphocytes of Hodgkin lymphoma and anaplastic large cell lymphoma. It has been reported that levels of soluble CD30 in serum and joint fluid is significantly elevated in rheumatoid arthritis (RA). Although RA patients may develop lymphoproliferative disorders (LPD) as a result of immunosuppression by MTX or bDMARDs, safety medications after the regression of LPD for RA have not yet been established.

Objectives:

To explore the potential of CD30 targeting therapy for RA.

Methods:

(1) Immuno-histological staining of CD30 was performed for fresh synovial tissues of RA and osteoarthritis (OA). In addition, double immunofluorescence staining of CD30 with CD3, CD20, CD68, CD138 were performed on RA synovial tissue. (2) Brentuximab vedotin (BV) is an anti-CD30 antibody conjugated with monomethyl auristatin E, designed to induce apoptosis of CD30 expressing cells. A multiple myeloma cell line (RPMI8226) was used as a non-lymphoma cell line and plasma cell-like cell line. Immuno-cytological staining for CD30 was performed on RPMI8226. Cells were cultured and harvested on days 0, 1, and 3 to evaluate the effects of BV (50 μl / ml per well). Cytospin specimens were stained by May-Grunwald-Giemsa (MGG) staining for cell counting and by FIFC-terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining for detection of apoptosis. (3) Collagen antibody induced arthritis (CAIA) was induced in DBA/1 mice by arthritogenic cocktail of monoclonal antibodies against type II collagen. BV was administered to the treatment groups (30mg/kg and 70mg/kg n=4 each) and evaluated clinical score, histological findings and levels of SAA, IL-6, and TNFα in serum by ELISA. Student’st-test (two-tailed) was used to determine statistical significance for analysis of synovial tissues and cell line assay. Two way ANOVA with Dunnett’s post hoc analysis was used for multiple comparisons of mice model.

Results:

(1) The number of CD30-positive cells was significantly higher in RA synovial tissue than in OA synovial tissue (p<0.01) (Fig. 1). CD30-positive cells were detected around the lymphoid follicles. Double immunofluorescence showed CD30 and CD138 double-positive cells in the synovial tissue of RA, suggesting CD30 is predominantly expressed by plasma cells. (2) RPMI8226 cells expressed CD30. BV caused apoptosis of RPMI8226 cells, and the number of cells treated with BV decreased to 95% compared to controls. (3) All control mice (n=4) developed severe arthritis, and their scores reached a peak (score: 13.3) on day 10. In the mice of treatment group of 30 mg/kg, paw swelling was slightly decreased, their clinical score reached a peak (score: 9.3) on day 10. In contrast, paw swelling was significantly reduced in the 70 mg/kg treatment group. The peak of the clinical score was 4.3 on day 10 (Fig.2). Histological score evaluated synovitis with infiltration of inflammatory cells, pannus formation, and erosion of bone and cartilage. Histological score of hind paws were 3.0 ± 0.8 for the control group, 2.7 ± 1.0 for 30 mg/kg group, and 0.7 ± 1.1 for 70 mg/kg group (p<0.01), respectively. The serum levels of SAA and IL-6 of treatment group were lower than those of no treatment group (p<0.01).

Conclusion:

We showed the expression of CD30 on synovial tissue of RA and the expression of CD30 on plasma cells. In addition, the current study provides the first evidence that BV depletion of CD30-positive cells suppressed arthritis and osteochondral destruction in CAIA mice. Our results may provide an important clue for the development of an effective treatment for RA with iatrogenic immunodeficiency-related LPD.

Disclosure of Interests:

Minami Matsuhashi: None declared, Keiichiro Nishida Grant/research support from: K. Nishida has received scholarship donation from CHUGAI PHARMACEUTICAL Co., Eisai Co., Mitsubishi Tanabe Pharma and AbbVie GK., Speakers bureau: K. Nishida has received speaking fees from CHUGAI PHARMACEUTICAL Co., Eli Lilly, Janssen Pharmaceutical K.K., Eisai Co. and AYUMI Pharmaceutical Corporation., Yoshihisa Nasu: None declared, Ryuichi Nakahara: None declared, Masahito Watanabe: None declared, Yoshifumi Hotta: None declared, Toshifumi Ozaki: None declared

SAT0068 THE RECENT INCIDENCE OF SURGICAL SITE INFECTION AND DELAYED WOUND HEALING AFTER ELECTIVE ORTHOPAEDIC SURGERIES FOR PATIENTS WITH RHEUMATOID ARTHRITIS WHO TREATED WITH B/TSDMARDS

Background:

In Japan, Methotrexate (MTX) has been approved in 1999, the first biologic DMARD (bDAMRD) in 2003, and the Janus kinase (JAK) inhibitors have been used since 2013. Although it is expected that the recent advancement of drug therapy would contribute the decrease in the incidence of orthopaedic surgeries by preventing structural damages1, 2), we are still facing a considerable number of patients who require surgical interventions3).

Objectives:

To investigate the recent trends of patient’s background who underwent the orthopaedic surgery for rheumatoid arthritis, number of orthopaedic intervention, and the type of the surgery.

Methods:

We reviewed the records of 1569 patients with RA who underwent orthopedic surgeries between 2004 and 2019 in our institution. The mean age of patients was 62.8 (22-88) years-old with disease duration of 20.9 (0.5-64) years. Data of these patients such as age, disease duration, medication (Glucocorticoid; GC, MTX, b/tsDMARD), type of surgeries (total joint replacement; TJR, hand surgery, foot surgery, spine surgery, and others), and preoperative serum CRP level were collected. We analyzed the annual change of these demographic and clinical data. Then, we compared them between CRP negative (<1.5g/l) and CRP positive group. Cochran-Armitage trend test,χ square test, or unpaired T-test was performed for statistical analysis. P <0.05 was considered significant.

Results:

Among all cases, 426 cases (27.2%) were treated with b/tsDMARDs at the time of operation. MTX and GC were used in 937 cases (59.7%) and 1015 cases (64.7%), respectively. The mean age and disease duration of RA showed an increasing trend, although the CRP level was dramatically decreased during the study period. While the rate of MTX use has not changed significantly (p=0.102), the number of cases treated by b/ts DMARD increased significantly to 46.7% (p<0.001). In contrast, the rate of GC use dicreased significantly (p<0.001). Although the annual number of surgeries have not changed, the proportion of cases who performed TJR decreased dramatically (59.6% in 2011, 29.5% in 2019), and the surgeries for hand and foot increased significantly (p<0.001) (Fig 1). The annual mean preoperative CRP level also decreased from 18.8±1.95 to 4.89±0.81 (Fig2). Compared to CRP positive group (n=1,113), the patients in CRP negative group (n=446) showed significantly younger age(p<0.001), shorter disease duration (p=0.031), lower late of GC use, and a higher rate of b/tsDAMRD use. The proportion of patients who underwent TJR was significantly higher in CRP positive group (p<0.001).

Conclusion:

Along with the increasing use of b/tsDMARD, the preoperative disease control of RA, as well as the type of demanded surgeries have dramatically changed.

References:

[1] Yamanaka H, Tanaka E, Nakajima A, et al. A large observational cohort study of rheumatoid arthritis, IORRA: Providing context for today’s treatment options.Mod Rheumatol2020;30:1-6.

[2] Matsumoto T, Nishino J, Izawa N, et al. Trends in Treatment, Outcomes, and Incidence of Orthopedic Surgery in Patients with Rheumatoid Arthritis: An Observational Cohort Study Using the Japanese National Database of Rheumatic Diseases.J Rheumatol2017;44:1575-82.

[3] Momohara S, Tanaka S, Nakamura H, et al. Recent trends in orthopedic surgery performed in Japan for rheumatoid arthritis.Mod Rheumatol2011;21:337-42.

Disclosure of Interests:

Yoshifumi Hotta: None declared, Yoshihisa Nasu: None declared, Keiichiro Nishida Grant/research support from: K. Nishida has received scholarship donation from CHUGAI PHARMACEUTICAL Co., Eisai Co., Mitsubishi Tanabe Pharma and AbbVie GK., Speakers bureau: K. Nishida has received speaking fees from CHUGAI PHARMACEUTICAL Co., Eli Lilly, Janssen Pharmaceutical K.K., Eisai Co. and AYUMI Pharmaceutical Corporation., Minami Matsuhashi: None declared, Masahito Watanabe: None declared, Ryuichi Nakahara: None declared, Toshifumi Ozaki: None declared

SAT0023 THE ROLE OF ADAM12 UPREGULATED PROLIFERATION OF SYNOVIAL MEMBRANE IN RHEUMATOID ARTHRITIS

Background:

ADAM12 is a member of a disintegrin and metalloproteinase family and has been reported to participate in the development of a variety of tumors by degrading ECM and shed precursors, thus promoting cell proliferation, invasion, and metastasis1). Additionally, ADAM12 is involved in chondrocyte differentiation from osteoarthritis (OA) patients by regulation of TGFβ1-induced IGF-1 and RUNX-2 expressions2). However, there is no report on the role of ADAM12 for rheumatoid arthritis (RA).

Objectives:

To investigate the expression and role of ADAM12 in the synovial tissue of RA.

Methods:

(1) The expression of ADAM12 in synovial tissues from RA (18 cases), OA (5 cases) and healthy control (HC) (3 cases) was examined by immunohistochemistry. The synovial tissues of HC were obtained during surgery of hemiarthroplasty for bone tumors. Three researchers evaluated the positive cell ratio. The samples were scored according to the percentage of positive staining: 0 points (weak positive, positive expression was less than 5%), 1 point (moderate positive, positive expression was between 5% and 50%) and 2 points (strong positive, positive expression was greater than 50%). In addition, the samples were scored according to the staining intensity: 0 points (weak intensity), 1 point (moderate intensity) and 2 points (high intensity). (2) The cultured synovial fibroblasts obtained from RA patients at the surgery (RASF) were stimulated by TNFα (1, 5, 10 ng/mL), TGFβ1 (1, 5, 10 ng/mL), PDGF-BB (1, 5, 10 ng/mL) and TNFα+TGFβ1+PDGF-BB (all 10 ng/mL), and the expression levels of ADAM12 relative mRNA was examined by real-time PCR. (3) siADAM12 was transfected in RASF, and the proliferation was examined by WST-1 assay, and the expression of ADAM12 protein was examined by western blotting.

Results:

(1) ADAM12 positive cells were found in synovial lining cells, plasma cells, and vascular endothelial cells. ADAM12 was highly expressed in RA synovial tissues. The immunostaining scores of RA, OA, and HC were 3.9±0.01, 1.9±0.27, and 0.8±0.18, respectively. (2) Stimulation by TNFα, TGFβ1, and PDGF-BB resulted in the upregulation of the expression of ADAM12 relative mRNA in RASF, and TGFβ1 stimulation notably tended to increase the expression by about 5 to 6 times. (3) siADAM12 successfully suppressed the expression of ADAM12 protein and simultaneously suppressed the proliferation of RASF.

Conclusion:

ADAM12 might be involved in the pathogenesis of RA, promoting the cell proliferation of RASF.

References:

[1] Kyeiborg M, Albrechtsen R, Couchman J, et al., Cellular roles of ADAM12 in health and disease, Int J Biochem Cell Biol, 2008

[2] Masahiro H, Keiichiro N, Joe H, et al., Involvement of ADAM12 in Chondrocyte Differentiation by Regulation of TGF-beta1-Induced IGF-1 and RUNX-2 Expressions, Calcif Tissue Int, 2019

Disclosure of Interests:

Masahito Watanabe: None declared, Keiichiro Nishida Grant/research support from: K. Nishida has received scholarship donation from CHUGAI PHARMACEUTICAL Co., Eisai Co., Mitsubishi Tanabe Pharma and AbbVie GK., Speakers bureau: K. Nishida has received speaking fees from CHUGAI PHARMACEUTICAL Co., Eli Lilly, Janssen Pharmaceutical K.K., Eisai Co. and AYUMI Pharmaceutical Corporation., Yoshihisa Nasu: None declared, Ryuichi Nakahara: None declared, Minami Matsuhashi: None declared, Yoshifumi Hotta: None declared, Toshifumi Ozaki: None declared

SAT0047 RISK FACTORS FOR THE POSTOPERATIVE DELAYED WOUND HEALING IN PATIENTS WITH RHEUMATOID ARTHRITIS TREATED WITH A BIOLOGICAL AGENT

Background:

It has been suggested that perioperative use of biological disease-modifying anti-rheumatic drugs (bDMARDs) in rheumatoid arthritis (RA) patients carries risks for the surgical-site infection and the delayed wound healing (DWH); however, the risk of DWH with perioperative use of bDMARDs has not reached a general consensus.

Objectives:

This retrospective study aimed to investigate the risk factors associated with DWH after orthopedic surgery in RA patients treated with bDMARDs.

Methods:

We reviewed medical records of 277 orthopedic procedures for 188 RA patients treated with bDMARDs between from 2014 to 2017 in Niigata Rheumatic Center. As preoperative nutritional status assessment, we evaluated body mass index (BMI), prognostic nutritional index (PNI), and CONtrolling NUTritional status (CONUT). In addition, we evaluated DAS28-CRP, DAS28-ESR, face scale for pain, global health (GH), and Health Assessment Questionnaire-Disability Index (HAQ-DI) to assess the disease activity. Univariate and multivariate logistic regression analyses were performed to evaluate the risk factor for DWH.

Results:

The major characteristics of the patients in 277 procedures were mean age of 63.2 years old and mean disease duration of 18.2 years. Surgical site were hand and wrist (145 procedures), foot and ankle (76), hip and knee (31), elbow and shoulder (24), and spine (1). Seventy-four patients were treated with tocilizumab, 62 with etanercept, 55 with golimumab, 49 with abatacept, 16 with infliximab, 15 with adalimumab, and 6 with certolizumab. According to nutritional assessment in PNI and CONUT, 63% (n=175) and 47% (n=130) were normal nourished patients, respectively.

In 277 procedures, DWH were identified in 24 patients (8.6%). The following variables were significant in the univariate analyses: disease duration (OR 1.053; 95% CI 1.010–1.099; p=0.016), foot and ankle surgery (OR 7.091; 95% CI 2.130–23.603; p=0.001), tocilizumab (OR 0.286; 95% CI 0.093–0.881; p=0.029) (Table 1). These variables were entered into a multivariate model, and it was revealed that pre-operative use of tocilizumab (OR 0.265; 95% CI 0.074–0.953; p=0.042) and procedures in the foot and ankle (OR 6.915; 95% CI 1.914–24.976; p=0.003) were associated with an increased risk of DWH (Table 1).

Conclusion:

As previous study on tocilizumab described, the current retrospective study suggested that pre-operative use of tocilizumab and procedures in the foot and ankle were risk factors for DWH. Pre-operative disease activity and nutritional status were not independent risk factors for an increase in the prevalence of DWH.

References:

[1] Momohara S, Hashimoto J, Tsuboi H et al. Analysis of perioperative clinical features and complications after orthopaedic surgery in rheumatoid arthritis patients treated with tocilizumab in a real-world setting: Results from the multicentre tocilizumab in perioperative period (TOPP) study. Modern rheumatology. 2013, 23: 440-9.

Disclosure of Interests:

Shunji Okita: None declared, Hajime Ishikawa: None declared, Asami Abe: None declared, Satoshi Ito Speakers bureau: Abbvie,Eisai, Akira Murasawa: None declared, Keiichiro Nishida Grant/research support from: K. Nishida has received scholarship donation from CHUGAI PHARMACEUTICAL Co., Eisai Co., Mitsubishi Tanabe Pharma and AbbVie GK., Speakers bureau: K. Nishida has received speaking fees from CHUGAI PHARMACEUTICAL Co., Eli Lilly, Janssen Pharmaceutical K.K., Eisai Co. and AYUMI Pharmaceutical Corporation., Toshifumi Ozaki: None declared

FRI0523 THE RECENT TREND OF ORTHOPAEDIC SURGERIES FOR RHEUMATOID ARTHRITIS. AN ANALYSIS OF 1569 CASES FROM 2004 TO 2019

Background:

In Japan, Methotrexate (MTX) has been approved in 1999, the first biologic DMARD (bDAMRD) in 2003, and the Janus kinase (JAK) inhibitors have been used since 2013. Although it is expected that the recent advancement of drug therapy would contribute the decrease in the incidence of orthopaedic surgeries by preventing structural damages1, 2), we are still facing a considerable number of patients who require surgical interventions3).

Objectives:

To investigate the recent trends of patient’s background who underwent the orthopaedic surgery for rheumatoid arthritis, number of orthopaedic intervention, and the type of the surgery.

Methods:

We reviewed the records of 1569 patients with RA who underwent orthopedic surgeries between 2004 and 2019 in our institution. The mean age of patients was 62.8 (22-88) years-old with disease duration of 20.9 (0.5-64) years. Data of these patients such as age, disease duration, medication (Glucocorticoid; GC, MTX, b/tsDMARD), type of surgeries (total joint replacement; TJR, hand surgery, foot surgery, spine surgery, and others), and preoperative serum CRP level were collected. We analyzed the annual change of these demographic and clinical data. Then, we compared them between CRP negative (<1.5g/l) and CRP positive group. Cochran-Armitage trend test,χ square test, or unpaired T-test was performed for statistical analysis. P <0.05 was considered significant.

Results:

Among all cases, 426 cases (27.2%) were treated with b/tsDMARDs at the time of operation. MTX and GC were used in 937 cases (59.7%) and 1015 cases (64.7%), respectively. The mean age and disease duration of RA showed an increasing trend, although the CRP level was dramatically decreased during the study period. While the rate of MTX use has not changed significantly (p=0.102), the number of cases treated by b/ts DMARD increased significantly to 46.7% (p<0.001). In contrast, the rate of GC use dicreased significantly (p<0.001). Although the annual number of surgeries have not changed, the proportion of cases who performed TJR decreased dramatically (59.6% in 2011, 29.5% in 2019), and the surgeries for hand and foot increased significantly (p<0.001) (Fig 1). The annual mean preoperative CRP level also decreased from 18.8±1.95 to 4.89±0.81 (Fig 2). Compared to CRP positive group (n=1,113), the patients in CRP negative group (n=446) showed significantly younger age(p<0.001), shorter disease duration (p=0.031), lower late of GC use, and a higher rate of b/tsDAMRD use. The proportion of patients who underwent TJR was significantly higher in CRP positive group (p<0.001).

Conclusion:

Along with the increasing use of b/tsDMARD, the preoperative disease control of RA, as well as the type of demanded surgeries have dramatically changed.

References:

[1] Yamanaka H, Tanaka E, Nakajima A, et al. A large observational cohort study of rheumatoid arthritis, IORRA: Providing context for today’s treatment options.Mod Rheumatol2020;30:1-6.

[2] Matsumoto T, Nishino J, Izawa N, et al. Trends in Treatment, Outcomes, and Incidence of Orthopedic Surgery in Patients with Rheumatoid Arthritis: An Observational Cohort Study Using the Japanese National Database of Rheumatic Diseases.J Rheumatol2017;44:1575-82.

[3] Momohara S, Tanaka S, Nakamura H, et al. Recent trends in orthopedic surgery performed in Japan for rheumatoid arthritis.Mod Rheumatol2011;21:337-42.

Disclosure of Interests:

Yoshifumi Hotta: None declared, Yoshihisa Nasu: None declared, Keiichiro Nishida Grant/research support from: K. Nishida has received scholarship donation from CHUGAI PHARMACEUTICAL Co., Eisai Co., Mitsubishi Tanabe Pharma and AbbVie GK., Speakers bureau: K. Nishida has received speaking fees from CHUGAI PHARMACEUTICAL Co., Eli Lilly, Janssen Pharmaceutical K.K., Eisai Co. and AYUMI Pharmaceutical Corporation., Minami Matsuhashi: None declared, Masahito Watanabe: None declared, Ryuichi Nakahara: None declared, Toshifumi Ozaki: None declared

AB0216 POWER DOPPLER SCORE IS USEFUL TO PREDICT JOINT DESTRUCTION OF HAND AND WRIST JOINT IN RHEUMATOID ARTHRITIS PATIENTS

Background:

Several studies demonstrated that total power Doppler (PD) signal can predict radiographic progression as a change in total van der Heijde-modified total Sharp score (mTSS) in rheumatoid arthritis (RA) patients. However, in some studies, radiographic progression was observed in a different joint compared with the site of a positive PD signal at baseline in many cases.

Objectives:

The aim of this study was to identify the clinical factor of RA patients in association with radiographic progression of hands and wrists and to investigate which joint showed radiographic progression in RA patients. We focused on the correlation of the site of a positive PD signal and the site of radiographic progression.

Methods:

We examined retrospectively of 70 RA patients (67 women, three men) who underwent ultrasonography (US) examination at 32 regions on bilateral hands and wrists from 2014 to 2016. Radiographs of the hands were taken at baseline and at least one year after US (mean, 19.9 months), and radiographic progression was assessed using mTSS system. We performed multivariate logistic regression analysis to investigate the association between baseline factors and radiographic progression. The relationships between radiographic progression of the individual joint and total/each joint PD score were assessed by ROC analysis and Fisher’s exact test.

Results:

Nineteen patients (37.3%) experienced progression of mTSS of hands and wrists. DAS28-CRP (P=0.02) and total PD score (P=0.01) were associated with radiographic progression, and total PD score was significantly associated with radiographic progression (OR 1.22; 95% CI 1.04-1.36; P=0.006) by multivariate logistic regression analysis (Table 1).

Table 1.

Association between the demographic and clinical findings at baseline and radiographic progression over 12 months

a.univariate analysisNo radiographicprogression(n = 51)Radiographicprogression(n = 19)P-valueAge, years63.4 ± 12.758.1 ± 10.60.61Duration of RA, years24.4 ± 13.620.0 ± 5.00.28Usage of Bio, %42.240.40.57Amount of MTX, mg/week4.8 ± 3.34.5 ± 4.30.77Amount of PSL, mg1.5 ± 2.11.8 ± 2.20.73DAS28-CRP2.5 ± 0.72.9 ± 0.60.02*CRP, mg/dl0.4 ± 0.50.7 ± 0.70.10Total PD score2.4 ± 3.36.6 ± 6.10.01*b.multivariate analysisodds ratio95% CIP-valueDAS28-CRP1.630.72 - 3.710.238Total PD score1.191.04 - 1.360.010*

Predictive performance of total PD score was good for radiographic progression of MCP joint (AUC-ROC 0.91) and wrist joint (AUC-ROC 0.85), although poor for PIP joint (AUC-ROC 0.57).

PD score of wrist joint, MCP joint, and PIP joint were significantly associated with radiographic progression of each joint (P<0.01). The sensitivity, specificity, positive predictive value, and negative predictive value of wrist joint PD score were 100%, 57.0%, 8.0%, and 100%, MCP joint PD score were 85.7%, 90.5%, 8.0%, 99.8%, and 8.3%, and PIP joint PD score were 30.0%, 97.2%, 13.6%, and 99.0%, respectively.

Conclusion:

Total PD score of hands and wrists was a strong predictor of radiographic progression, especially in MCP and wrist joint. Evaluation of PD signal in individual joint is a clinically useful method to predict radiographic progression of the same joint, however there are some differences in sensitivity and specificity.

References:

[1]Brown AK, et al. Arthritis & Rheumatism. 2008;58:2958-2967.

[2]McQueen F, et al. Annals of the Rheumatic Diseases. 2011;70:241-244.

Disclosure of Interests:

Shunji Okita: None declared, Ryuichi Nakahara: None declared, Minami Matsuhashi: None declared, Masahito Watanabe: None declared, Yoshihisa Nasu: None declared, Keiichiro Nishida Grant/research support from: K. Nishida has received scholarship donation from CHUGAI PHARMACEUTICAL Co., Eisai Co., Mitsubishi Tanabe Pharma and AbbVie GK., Speakers bureau: K. Nishida has received speaking fees from CHUGAI PHARMACEUTICAL Co., Eli Lilly, Janssen Pharmaceutical K.K., Eisai Co. and AYUMI Pharmaceutical Corporation., Toshifumi Ozaki: None declared

Extending the Southern Shore of the Island of Inversion to ^{28}F

Detailed spectroscopy of the neutron-unbound nucleus ^{28}F has been performed for the first time following proton/neutron removal from ^{29}Ne/^{29}F beams at energies around 230  MeV/nucleon. The invariant-mass spectra were reconstructed for both the ^{27}F^{(*)}+n and ^{26}F^{(*)}+2n coincidences and revealed a series of well-defined resonances. A near-threshold state was observed in both reactions and is identified as the ^{28}F ground state, with S_{n}(^{28}F)=-199(6)  keV, while analysis of the 2n decay channel allowed a considerably improved S_{n}(^{27}F)=1620(60)  keV to be deduced. Comparison with shell-model predictions and eikonal-model reaction calculations have allowed spin-parity assignments to be proposed for some of the lower-lying levels of ^{28}F. Importantly, in the case of the ground state, the reconstructed ^{27}F+n momentum distribution following neutron removal from ^{29}F indicates that it arises mainly from the 1p_{3/2} neutron intruder configuration. This demonstrates that the island of inversion around N=20 includes ^{28}F, and most probably ^{29}F, and suggests that ^{28}O is not doubly magic.

Petapascal Pressure Driven by Fast Isochoric Heating with a Multipicosecond Intense Laser Pulse

Fast isochoric laser heating is a scheme to heat matter with a relativistic intensity (>10^{18}  W/cm^{2}) laser pulse for producing an ultrahigh-energy-density (UHED) state. We have demonstrated an efficient fast isochoric heating of a compressed dense plasma core with a multipicosecond kilojoule-class petawatt laser and an assistance of externally applied kilotesla magnetic fields for guiding fast electrons to the dense plasma. A UHED state of 2.2 PPa is achieved experimentally with 4.6 kJ of total laser energy that is one order of magnitude lower than the energy used in the conventional implosion scheme. A two-dimensional particle-in-cell simulation confirmed that diffusive heating from a laser-plasma interaction zone to the dense plasma plays an essential role to the efficient creation of the UHED state.

Fragmentation of Single-Particle Strength around the Doubly Magic Nucleus ^{132}Sn and the Position of the 0f_{5/2} Proton-Hole State in ^{131}In

Spectroscopic factors of neutron-hole and proton-hole states in ^{131}Sn and ^{131}In, respectively, were measured using one-nucleon removal reactions from doubly magic ^{132}Sn at relativistic energies. For ^{131}In, a 2910(50)-keV γ ray was observed for the first time and tentatively assigned to a decay from a 5/2^{-} state at 3275(50) keV to the known 1/2^{-} level at 365 keV. The spectroscopic factors determined for this new excited state and three other single-hole states provide first evidence for a strong fragmentation of single-hole strength in ^{131}Sn and ^{131}In. The experimental results are compared to theoretical calculations based on the relativistic particle-vibration coupling model and to experimental information for single-hole states in the stable doubly magic nucleus ^{208}Pb.

P92 A novel method of correcting the left ventricular stroke volume by Doppler echocardiography: comparison with multidetector computed tomography

Background

Although transthoracic Doppler echocardiography is widely used for estimating left ventricular stroke volume (SV), accelerated blood flow in the left ventricular (LV) outflow tract may lead to overestimation. SV can be calculated accurately from left ventricular end-systolic and end-diastolic volume determined by multi-detector computed tomography (MDCT). However, radiation exposure as well as the use of contrast medium hampers its routine use.

Purpose

The purpose of this study was to examine whether the correction of SV measured by pulsed wave Doppler echocardiography (SVdop) can accurately predicts SV obtained by MDCT (SVct).

Methods： We enrolled consecutive 61 patients who underwent both MDCT and transthoracic echocardiography. Patients with moderate or severe valvular diseases and valve replacement surgery were excluded. Correction of SV was explored with SVct as a reference.

Results： Univariate analysis showed that SVdop (r = 0.42, P = 0.0007) and patient age (r=-0.50, P &lt; 0.0001) were significantly correlated with SVct. On the other hand, left ventricular ejection fraction calculated by Teicholz method (EFteich) (r = 0.19, P = 0.14), systolic blood pressure (r = 0.07, P = NS), and LV mass index (r=-0.02, P = NS) were not correlated with SVct. Multivariate analysis showed that SVdop, patient age and EFteich were the independent predictive factors for SVct (R2 = 0.49, P &lt; 0.0001). Based on these correlations, we postulated SV as: corrected SV = SVdop × 0.40 + EFteich × 0.46 – age × 0.67 + 44.77. As expected, the correlation between corrected SV and SVct significantly improved (r = 0.70, P &lt; 0.0001). Bland-Altman plot analysis showed that corrected SV significantly reduced the variation between SVdop and SVct, and diminished the overestimation of SVdop (Figure).

Conclusion： The new correction formula of SVdop may correct the overestimation of SV obtained by pulsed wave Doppler echocardiography, although the formula remains to be validated in a separate cohort of patients.

Abstract P92 Figure

Proposal of patient-specific growth plate cartilage xenograft model for FGFR3 chondrodysplasia

OBJECTIVE

FGFR3 chondrodysplasia is caused by a gain-of-function mutation of the FGFR3 gene. The disease causes abnormal growth plate cartilage and lacks effective drug treatment. We sought to establish an in vivo model for the study of FGFR3 chondrodysplasia pathology and drug testing.

DESIGN

We created cartilage from human induced pluripotent stem cells (hiPSCs) and transplanted the cartilage into the subcutaneous spaces of immunodeficient mice. We then created cartilage from the hiPSCs of patients with FGFR3 chondrodysplasia and transplanted them into immunodeficient mice. We treated some mice with a FGFR inhibitor after the transplantation.

RESULTS

Xenografting the hiPSC-derived cartilage reproduced human growth plate cartilage consisting of zones of resting, proliferating, prehypertrophic and hypertrophic chondrocytes and bone in immunodeficient mice. Immunohistochemistry of xenografts using anti-human nuclear antigen antibody indicated that all chondrocytes in growth plate cartilage were human, whereas bone was composed of human and mouse cells. The pathology of small hypertrophic chondrocytes due to up-regulated FGFR3 signaling in FGFR3 skeletal dysplasia was recapitulated in growth plate cartilage formed in the xenografts of patient-specific hiPSC-derived cartilage. The mean diameters of hypertrophic chondrocytes between wild type and thanatophoric dysplasia were significantly different (95% CI: 13.2-26.9; n = 4 mice, one-way analysis of variance (ANOVA)). The pathology was corrected by systemic administration of a FGFR inhibitor to the mice.

CONCLUSION

The patient-specific growth plate cartilage xenograft model for FGFR3 skeletal dysplasia indicated recapitulation of pathology and effectiveness of a FGFR inhibitor for treatment and warrants more study for its usefulness to study disease pathology and drug testing.

Observation of crossover from intraband to interband nonlinear terahertz optics

In this Letter, we investigate the nonlinear effects of extremely intense few-cycle terahertz (THz) pulses (generated from the organic crystal 4-NN, NN-dimethylamino-4^'4^'-N^'N^'-methyl-stilbazolium 2, 4, 6 trimethylbenzenesulfonate, with peak electrical fields of a few MV/cm) on the carrier dynamics in n-doped semiconductor thin film In_0.53Ga_0.47As. By performing open-aperture Z-scan measurements and recording the transmitted THz energy through semiconductor sample, we observed a strong THz absorption bleaching effect at high fields, followed by an absorption enhancement at even higher fields. We attribute our observations to a crossover from pure intraband carrier dynamics to an interplay between intraband carrier heating and interband carrier generations.

Mid-term results of alumina ceramic unlinked total elbow arthroplasty with cement fixation for patients with rheumatoid arthritis

Aims

The aim of this study was to report the mid-term clinical outcome of cemented unlinked J-alumina ceramic elbow (JACE) arthroplasties when used in patients with rheumatoid arthritis (RA).

Patients and Methods

We retrospectively reviewed 87 elbows, in 75 patients with RA, which was replaced using a cemented JACE total elbow arthroplasty (TEA) between August 2003 and December 2012, with a follow-up of 96%. There were 72 women and three men, with a mean age of 62 years (35 to 79). The mean follow-up was nine years (2 to 14). The clinical condition of each elbow before and after surgery was assessed using the Mayo Elbow Performance Index (MEPI, 0 to 100 points). Radiographic loosening was defined as a progressive radiolucent line of >1 mm that was completely circumferential around the prosthesis.

Results

The mean MEPI scores significantly improved from 40 (10 to 75) points preoperatively to 95 (30 to 100) points at final follow-up (p < 0.0001). Complications were noted in ten elbows (ten patients; 11%). Two had an intraoperative humeral fracture which was treated by fixation and united. One had a postoperative fracture of the olecranon which united with conservative treatment and one had a radial neuropathy which resolved. Further surgery was required for one with a dislocation, three with an ulnar neuropathy and one with a postoperative humeral fracture. Revision with removal of the components was performed in one elbow due to deep infection. There was no radiographic evidence of loosening around the components.With any revision surgery or revision with implant removal as the endpoint, the rates of survival up to 14 years were 93% (95% confidence interval (CI), 83.9 to 96.6) and 99% (95% CI 91.9 to 99.8), respectively, as determined by Kaplan-Meier analysis.

Conclusion

With the appropriate indications, the mid-term clinical performance of the cemented JACE TEA is reliable and comparable to other established TEAs in the management of the elbow in patients with RA.

Cite this article: Bone Joint J 2018;100-B:1066–73.

Harmonic Generation from Neutral Manganese Atoms in the Vicinity of the Giant Autoionization Resonance

High harmonics from laser-ablated plumes are mostly generated from ionic species. We demonstrate that with ultrashort infrared (∼1.82  μm) driving lasers, high harmonics from laser-ablated manganese are predominantly generated from neutral atoms, a transition metal atom with an ionization potential of 7.4 eV. Our results open the possibility to advance laser-ablation technique to study the dynamics of neutral atoms of low ionization potential. Moreover, as manganese contains giant autoionizing resonance, intense and broadband high harmonics have been demonstrated from this resonance at energies from 49 to 53 eV. This opens the possibility to generate intense attosecond pulses directly from the giant resonances, as well as to study these resonances using high-harmonic spectroscopy.

Medial meniscus extrusion correlates with disease duration of the sudden symptomatic medial meniscus posterior root tear

INTRODUCTION

Medial meniscus posterior root tear (MMPRT) leads to abnormal biomechanics of the knee by inducing the medial meniscus extrusion (MME). However, a time-dependent increase of the MME is not fully elucidated in patients suffering from the acute MMPRT. The aim of this study was to investigate the relationships among disease duration of the MMPRT and severity of the MME. We hypothesized that MME measurement correlates with disease duration after a sudden onset of the minor traumatic MMPRT during the short-term follow-up period.

MATERIALS AND METHODS

Forty-six patients who had an accurate episode of the posteromedial painful popping were investigated. All the patients were diagnosed having a symptomatic MMPRT with magnetic resonance imaging (MRI) examinations. Absolute MME was measured using MRI scans within 12 months after painful popping events. A correlation coefficient between duration from injury to MRI examination and absolute MME was evaluated.

RESULTS

Mean absolute MME was 4.5±1.6mm (range, 1.1-8.8mm) on MRI measurements. A good correlation was observed between MME measurement and duration from injury to MRI examination (R²=0.612). The best-fit equation for predicting each value was: MME=0.014×disease duration+3.288mm.

DISCUSSION

This study demonstrated that absolute MME increases progressively within the short duration after the onset of symptomatic MMPRT. Our results suggest that preoperative MME assessment may be important in determining disease duration and treatment strategy of the MMPRT.

LEVEL OF EVIDENCE

Retrospective cohort study level IV.

Giant self-induced transparency of intense few-cycle terahertz pulses in n-doped silicon

The results of high-field terahertz transmission experiments on n-doped silicon (carrier concentration of 8.7×10¹⁶  cm^-3) are presented. We use terahertz pulses with electric field strengths up to 3.1  MV cm^-1 and a pulse duration of 700 fs. A huge transmittance enhancement of ∼90 times is observed with increasing of the terahertz electric field strengths within the range of 1.5-3.1  MV cm^-1.

High-order harmonic generation from the dressed autoionizing states

In high-order harmonic generation, resonant harmonics (RH) are sources of intense, coherent extreme-ultraviolet radiation. However, intensity enhancement of RH only occurs for a single harmonic order, making it challenging to generate short attosecond pulses. Moreover, the mechanism involved behind such RH was circumstantial, because of the lack of direct experimental proofs. Here, we demonstrate the exact quantum paths that electron follows for RH generation using tin, showing that it involves not only the autoionizing state, but also a harmonic generation from dressed-AIS that appears as two coherent satellite harmonics at frequencies ±2Ω from the RH (Ω represents laser frequency). Our observations of harmonic emission from dressed states open the possibilities of generating intense and broadband attosecond pulses, thus contributing to future applications in attosecond science, as well as the perspective of studying the femtosecond and attosecond dynamics of autoionizing states.

High-energy photons in XUV range and attosecond pulses are generated from infrared laser pulses through high harmonic generation in gases and solids. Here, the authors demonstrate the microscopic origin of resonant harmonic generation involving the autoionizing states of Sn in plasma plumes.

A new aiming guide can create the tibial tunnel at favorable position in transtibial pullout repair for the medial meniscus posterior root tear

INTRODUCTION

Injuries to the medial meniscus (MM) posterior root lead to accelerated cartilage degeneration of the knee. An anatomic placement of the MM posterior root attachment is considered to be critical in transtibial pullout repair of the medial meniscus posterior root tear (MMPRT). However, tibial tunnel creation at the anatomic attachment of the MM posterior root is technically difficult using a conventional aiming device. The aim of this study was to compare two aiming guides. We hypothesized that a newly-developed guide, specifically designed, creates the tibial tunnel at an adequate position rather than a conventional device.

MATERIALS AND METHODS

Twenty-six patients underwent transtibial pullout repairs. Tibial tunnel creation was performed using the Multi-use guide (8 cases) or the PRT guide that had a narrow twisting/curving shape (18 cases). Three-dimensional computed tomography images of the tibial surface were evaluated using the Tsukada's measurement method postoperatively. Expected anatomic center of the MM posterior root attachment and tibial tunnel center were evaluated using the percentage-based posterolateral location on the tibial surface. Percentage distance between anatomic center and tunnel center was calculated.

RESULTS

Anatomic center of the MM posterior root footprint located at a position of 78.5% posterior and 39.4% lateral. Both tunnels were anteromedial but tibial tunnel center located at a more favorable position in the PRT group: percentage distance was significantly smaller in the PRT guide group (8.7%) than in the Multi-use guide group (13.1%).

DISCUSSION

The PRT guide may have great advantage to achieve a more anatomic location of the tibial tunnel in MMPRT pullout repair.

LEVEL OF EVIDENCE

III.

Suppression of Trapped Energetic Ions Driven Resistive Interchange Modes with Electron Cyclotron Heating in a Helical Plasma

The resistive interchange mode destabilized by the resonant interaction with the trapped energetic ions is fully suppressed when the injected power of electron cyclotron heating exceeds a certain threshold. It is shown for the first time that the complete stabilization of the energetic-particle-driven mode without relaxing the energetic particle (EP) pressure gradient is possible by reducing the radial width of the eigenmodes δ_{w}, especially when δ_{w} narrows to a small enough value relative to the finite orbit width of EP.

Aligned copper nanorod arrays for highly efficient generation of intense ultra-broadband THz pulses

We demonstrate an intense broadband terahertz (THz) source based on the interaction of relativistic-intensity femtosecond lasers with aligned copper nanorod array targets. For copper nanorod targets with a length of 5 μm, a maximum 13.8 times enhancement in the THz pulse energy (in ≤20 THz spectral range) is measured as compared to that with a thick plane copper target under the same laser conditions. A further increase in the nanorod length leads to a decrease in the THz pulse energy at medium frequencies (≤20 THz) and increase of the electromagnetic pulse energy in the high-frequency range (from 20–200 THz). For the latter, we measure a maximum energy enhancement of 28 times for the nanorod targets with a length of 60 μm. Particle-in-cell simulations reveal that THz pulses are mostly generated by coherent transition radiation of laser produced hot electrons, which are efficiently enhanced with the use of nanorod targets. Good agreement is found between the simulation and experimental results.

Pullout repair of a medial meniscus posterior root tear using a FasT-Fix® all-inside suture technique

A medial meniscus posterior root tear (MMPRT) may increase the tibiofemoral contact pressure by decreasing the tibiofemoral contact area. Meniscal dysfunction induced by posterior root injury may lead to the development of osteoarthritic knees. Repair of a MMPRT can restore medial meniscus (MM) function and prevent knee osteoarthritis progression. Several surgical procedures have been reported for treating a MMPRT. However, these procedures are associated with several technical difficulties. Here, we describe a technique to stabilize a torn MM posterior root using the FasT-Fix^® all-inside meniscal suture device and a new aiming device. The uncut free-end of the FasT-Fix^® suture can be used as a thread for transtibial pullout repair. Our procedure might help overcome the technical difficulties in arthroscopic treatment of a MMPRT.