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.

Observation of the Exotic 0_{2}^{+} Cluster State in ^{8}He

We report here the first observation of the 0_{2}^{+} state of ^{8}He, which has been predicted to feature the condensatelike α+^{2}n+^{2}n cluster structure. We show that this state is characterized by a spin parity of 0^{+}, a large isoscalar monopole transition strength, and the emission of a strongly correlated neutron pair, in line with theoretical predictions. Our finding is further supported by the state-of-the-art microscopic α+4n model calculations. The present results may lead to new insights into clustering in neutron-rich nuclear systems and the pair correlation and condensation in quantum many-body systems under strong interactions.

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.

Multiple Mechanisms in Proton-Induced Nucleon Removal at ∼100 MeV/Nucleon

We report on the first proton-induced single proton- and neutron-removal reactions from the neutron-deficient ^{14}O nucleus with large Fermi-surface asymmetry S_{n}-S_{p}=18.6  MeV at ∼100  MeV/nucleon, a widely used energy regime for rare-isotope studies. The measured inclusive cross sections and parallel momentum distributions of the ^{13}N and ^{13}O residues are compared to the state-of-the-art reaction models, with nuclear structure inputs from many-body shell-model calculations. Our results provide the first quantitative contributions of multiple reaction mechanisms including the quasifree knockout, inelastic scattering, and nucleon transfer processes. It is shown that the inelastic scattering and nucleon transfer, usually neglected at such energy regime, contribute about 50% and 30% to the loosely bound proton and deeply bound neutron removal, respectively. These multiple reaction mechanisms should be considered in analyses of inclusive one-nucleon removal cross sections measured at intermediate energies for quantitative investigation of single-particle strengths and correlations in atomic nuclei.

Extended p_{3/2} Neutron Orbital and the N=32 Shell Closure in ^{52}Ca

The one-neutron knockout from ^{52}Ca in inverse kinematics onto a proton target was performed at ∼230  MeV/nucleon combined with prompt γ spectroscopy. Exclusive quasifree scattering cross sections to bound states in ^{51}Ca and the momentum distributions corresponding to the removal of 1f_{7/2} and 2p_{3/2} neutrons were measured. The cross sections, interpreted within the distorted-wave impulse approximation reaction framework, are consistent with a shell closure at the neutron number N=32, found as strong as at N=28 and N=34 in Ca isotopes from the same observables. The analysis of the momentum distributions leads to a difference of the root-mean-square radii of the neutron 1f_{7/2} and 2p_{3/2} orbitals of 0.61(23) fm, in agreement with the modified-shell-model prediction of 0.7 fm suggesting that the large root-mean-square radius of the 2p_{3/2} orbital in neutron-rich Ca isotopes is responsible for the unexpected linear increase of the charge radius with the neutron number.

Pairing Forces Govern Population of Doubly Magic ^{54}Ca from Direct Reactions

Direct proton-knockout reactions of ^{55}Sc at ∼220  MeV/nucleon were studied at the RIKEN Radioactive Isotope Beam Factory. Populated states of ^{54}Ca were investigated through γ-ray and invariant-mass spectroscopy. Level energies were calculated from the nuclear shell model employing a phenomenological internucleon interaction. Theoretical cross sections to states were calculated from distorted-wave impulse approximation estimates multiplied by the shell model spectroscopic factors, which describe the wave function overlap of the ^{55}Sc ground state with states in ^{54}Ca. Despite the calculations showing a significant amplitude of excited neutron configurations in the ground-state of ^{55}Sc, valence proton removals populated predominantly the ground state of ^{54}Ca. This counterintuitive result is attributed to pairing effects leading to a dominance of the ground-state spectroscopic factor. Owing to the ubiquity of the pairing interaction, this argument should be generally applicable to direct knockout reactions from odd-even to even-even nuclei.

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.

Sequential Nature of (p,3p) Two-Proton Knockout from Neutron-Rich Nuclei

Twenty-one two-proton knockout (p,3p) cross sections were measured from neutron-rich nuclei at ∼250  MeV/nucleon in inverse kinematics. The angular distribution of the three emitted protons was determined for the first time, demonstrating that the (p,3p) kinematics are consistent with two sequential proton-proton collisions within the projectile nucleus. Ratios of (p,3p) over (p,2p) inclusive cross sections follow the trend of other many-nucleon removal reactions, further reinforcing the sequential nature of (p,3p) in neutron-rich nuclei.

SAT0222 CLINICAL SPECTRUM AND LONG TERM FOLLOWUP OF SYSTEMIC LUPUS ERYTHEMATOSUS-ASSOCIATED MACROPHAGE ACTIVATION SYNDROME

Background:

Systemic lupus erythematosus (SLE) patients present with variable clinical features ranging from mild joint and skin involvement to life-threatening organ involvement such as nephritis, neuropsychiatric involvement, diffuse alveolar hemorrhage, and hemophagocytic lymphohistiocytosis (HLH). HLH is rare, but fatal complication of SLE. Recently, European League Against Rheumatism, the American College of Rheumatology, and the Pediatric Rheumatology International Trials Organization was to develop a set of classification criteria for MAS complicating systemic juvenile idiopathic arthritis (PRINTO criteria) [1]. Sung Soo Ahn and his colleagues reported PRINTO criteria predicted mortality of adult SLE patient, but they followed only one year [2].

Objectives:

To reveal association PRINTO criteria with long term mortalities in SLE patient in our Hospital.

Methods:

We performed a retrospective analysis of SLE patients who received moderate dose glucocorticoid therapy (>0.4mg/kg/d) in our hospital between April 2008 and April 2019. Patients were evaluated for HLH using the 2016 PRINTO classification criteria for MAS. Clinical features and laboratory findings were compared and overall survival rate was analyzed.

Results:

Among 164 episode (144 patients) with SLE, 31 episode (31 patients) 5.2% were considered to have MAS on admission.

The overall survival rate was significantly lower in patients with MAS than without MAS (86.2% vs. 95.3%, p = 0.048). Interestingly, SLEDAI had no association with mortality, relapse rate, and MAS complication. SLEDAI more focused on renal and neuropsychiatric symptoms than hematologic features. So SLEDAI might not be associated with MAS secondary to SLE. Furthermore, we observed no death patient with MAS after one year, and only 1 case relapse in MAS patient. So MAS might have fatal but less relapsing property compared with other lupus cases.

Conclusion:

PRINTO criteria may be useful to differentiated fatal MAS patients from others. Further investigations are required to confirm our findings.

Limitation:

The main limitations of our study include its retrospective design, single center site, and that the number of admitted patients with SLE was small.

Limitation:

Limitation The main limitations of our study include its retrospective design, single center site, and that the number of admitted patients with SLE was small.

References:

[1]Wulffraat N, Schneider R, Filipovic L, et al. 2016 Classification Criteria for Macrophage Activation Syndrome Complicating Systemic Juvenile Idiopathic Arthritis. Ann Rheum Dis 2016;75:481–9.

[2]Ahn SS, Yoo BW, Jung SM, et al. In-hospital mortality in febrile lupus patients based on 2016 EULAR/ACR/PRINTO classification criteria for macrophage activation syndrome. Semin Arthritis Rheum 2017;47:216–21.

Disclosure of Interests:

None declared

Halo Structure of the Neutron-Dripline Nucleus ^{19}B

The heaviest bound isotope of boron ^{19}B has been investigated using exclusive measurements of its Coulomb dissociation, into ^{17}B and two neutrons, in collisions with Pb at 220  MeV/nucleon. Enhanced electric dipole (E1) strength is observed just above the two-neutron decay threshold with an integrated E1 strength of B(E1)=1.64±0.06(stat)±0.12(sys)  e^{2} fm^{2} for relative energies below 6 MeV. This feature, known as a soft E1 excitation, provides the first firm evidence that ^{19}B has a prominent two-neutron halo. Three-body calculations that reproduce the energy spectrum indicate that the valence neutrons have a significant s-wave configuration and exhibit a dineutronlike correlation.

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.

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.

Quasifree Neutron Knockout from ^{54}Ca Corroborates Arising N=34 Neutron Magic Number

Exclusive cross sections and momentum distributions have been measured for quasifree one-neutron knockout reactions from a ^{54}Ca beam striking on a liquid hydrogen target at ∼200  MeV/u. A significantly larger cross section to the p_{3/2} state compared to the f_{5/2} state observed in the excitation of ^{53}Ca provides direct evidence for the nature of the N=34 shell closure. This finding corroborates the arising of a new shell closure in neutron-rich calcium isotopes. The distorted-wave impulse approximation reaction formalism with shell model calculations using the effective GXPF1Bs interaction and ab initio calculations concur our experimental findings. Obtained transverse and parallel momentum distributions demonstrate the sensitivity of quasifree one-neutron knockout in inverse kinematics on a thick liquid hydrogen target with the reaction vertex reconstructed to final state spin-parity assignments.

Prominence of Pairing in Inclusive (p,2p) and (p,pn) Cross Sections from Neutron-Rich Nuclei

Fifty-five inclusive single nucleon-removal cross sections from medium mass neutron-rich nuclei impinging on a hydrogen target at ∼250  MeV/nucleon are measured at the RIKEN Radioactive Isotope Beam Factory. Systematically higher cross sections are found for proton removal from nuclei with an even number of protons as compared to odd-proton number projectiles for a given neutron separation energy. Neutron removal cross sections display no even-odd splitting, contrary to nuclear cascade model predictions. Both effects are understood through simple considerations of neutron separation energies and bound state level densities originating in pairing correlations in the daughter nuclei. These conclusions are supported by comparison with semimicroscopic model predictions, highlighting the enhanced role of low-lying level densities in nucleon-removal cross sections from loosely bound nuclei.

How Robust is the N=34 Subshell Closure? First Spectroscopy of ^{52}Ar

The first γ-ray spectroscopy of ^{52}Ar, with the neutron number N=34, was measured using the ^{53}K(p,2p) one-proton removal reaction at ∼210  MeV/u at the RIBF facility. The 2_{1}^{+} excitation energy is found at 1656(18) keV, the highest among the Ar isotopes with N>20. This result is the first experimental signature of the persistence of the N=34 subshell closure beyond ^{54}Ca, i.e., below the magic proton number Z=20. Shell-model calculations with phenomenological and chiral-effective-field-theory interactions both reproduce the measured 2_{1}^{+} systematics of neutron-rich Ar isotopes, and support a N=34 subshell closure in ^{52}Ar.

First Observation of ^{20}B and ^{21}B

The most neutron-rich boron isotopes ^{20}B and ^{21}B have been observed for the first time following proton removal from ^{22}N and ^{22}C at energies around 230  MeV/nucleon. Both nuclei were found to exist as resonances which were detected through their decay into ^{19}B and one or two neutrons. Two-proton removal from ^{22}N populated a prominent resonancelike structure in ^{20}B at around 2.5 MeV above the one-neutron decay threshold, which is interpreted as arising from the closely spaced 1^{-},2^{-} ground-state doublet predicted by the shell model. In the case of proton removal from ^{22}C, the ^{19}B plus one- and two-neutron channels were consistent with the population of a resonance in ^{21}B 2.47±0.19  MeV above the two-neutron decay threshold, which is found to exhibit direct two-neutron decay. The ground-state mass excesses determined for ^{20,21}B are found to be in agreement with mass surface extrapolations derived within the latest atomic-mass evaluations.

Extraction of the Landau-Migdal Parameter from the Gamow-Teller Giant Resonance in ^{132}Sn

The key parameter to discuss the possibility of the pion condensation in nuclear matter, i.e., the so-called Landau-Migdal parameter g^{'}, was extracted by measuring the double-differential cross sections for the (p,n) reaction at 216  MeV/u on a neutron-rich doubly magic unstable nucleus, ^{132}Sn with the quality comparable to data taken with stable nuclei. The extracted strengths for Gamow-Teller (GT) transitions from ^{132}Sn leading to ^{132}Sb exhibit the GT giant resonance (GTR) at the excitation energy of 16.3±0.4(stat)±0.4(syst)  MeV with the width of Γ=4.7±0.8  MeV. The integrated GT strength up to E_{x}=25  MeV is S_{GT}^{-}=53±5(stat)_{-10}^{+11}(syst), corresponding to 56% of Ikeda's sum rule of 3(N-Z)=96. The present result accurately constrains the Landau-Migdal parameter as g^{'}=0.68±0.07, thanks to the high sensitivity of the GTR energy to g^{'}. In combination with previous studies on the GTR for ^{90}Zr and ^{208}Pb, the result of this work shows the constancy of this parameter in the nuclear chart region with (N-Z)/A=0.11 to 0.24 and A=90 to 208.

Erratum: Persistence of the Z=28 Shell Gap Around ^{78}Ni: First Spectroscopy of ^{79}Cu [Phys. Rev. Lett. 119, 192501 (2017)]

This corrects the article DOI: 10.1103/PhysRevLett.119.192501.

Abstract PD2-06: Preoperative diagnosis of sentinel lymph node metastasis using computed tomography lymphography for early breast cancer patients

Background: Sentinel lymph nodes (SLN) biopsy has been established as a standard of care in the treatment of early breast cancer. This technique represents a minimally invasive, highly accurate method of axillary staging and is an alternative to conventional axillary lymph node dissection. However, an indication of SLN navigation to metastatic disease may lead to misdiagnosis for staging. Recently, SLN identification using computed tomography lymphography (CTLG) has been reported in Japan. This study investigated the value of CTLG for preoperative prediction of SLN status in early breast cancer patients.

Patients and method: Between January 2013 and August 2016, 350 breast cancer patients without clinical evidence of lymph node metastasis were treated. On the day before the operation, CTLG was performed using 64-row multidetector helical CT scanner. Patients were placed in a supine position with their arms positioned in a cranial direction with CT guidelineattached to the skin at the axilla. We performed an intradermal injection in the periareolar area, using 4 ml of iopamidolwith 1 ml of local anesthetic. The contrasted lymph route and SLN were identified in reconstructed three-dimensional imaging. The SLN spot was indicated by CT laser light navigator system. We established typical pattern of the lymphography: stain defect of SLN, stagnation of lymphatic route for preoperative diagnosis of metastatic SLN. SLN biopsy was performed using the fluorescence imaging system, Photpdynamic Eye (pde-neo, Hamamatsu Photonics Co., Japan) referring to the point by axillary compression technique by plastic device. Intraoperative pathological analysis of SLN was examined, and an axillary lymph node dissection was performed in patients with SLN metastasis pathologically.

Results: The median age of the 350 patients was 59 (range 28 – 90) years old. One patient was male and others were female. CTLG were safely performed in all patients. CTLG could visualize lymphatic route and accurately identify SLN in 336 (96.0 %) and 343 (98.0 %) cases, respectively. Lymphatic routes of CTLG were completely consistent with those of fluorescence imaging. The mean number of SLN identified by CTLG was 1.1. Fifty of 350 patients had metastatic SLN pathologically, and 11 of them had micrometastases of SLNs. The accuracy for metastatic diagnosis of SLN using CTLG without micrometastasis was 84.1 %, sensitivity was 82.1 % and specificity was 84.3 %. The positive predictive value was 40.5 % and negative predictive value was 97.3 %. There were no complications associated with SLN identification.

Conclusion: CTLG in SLN biopsy has some advantages in that this method is simple and quite useful for obtaining accurate anatomic images of the SLN, lymph vessels, and tumor. CTLG could select the candidate with truly node negative cases in early breast cancer patients, because it predicts lymph node metastasis preoperatively from natural status of the lymphographic image.

Citation Format: Abe H, Teramoto A, Tanaka M, Yamasaki K, Yoneda K. Preoperative diagnosis of sentinel lymph node metastasis using computed tomography lymphography for early breast cancer patients [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD2-06.

Persistence of the Z=28 Shell Gap Around ^{78}Ni: First Spectroscopy of ^{79}Cu

In-beam γ-ray spectroscopy of ^{79}Cu is performed at the Radioactive Isotope Beam Factory of RIKEN. The nucleus of interest is produced through proton knockout from a ^{80}Zn beam at 270  MeV/nucleon. The level scheme up to 4.6 MeV is established for the first time and the results are compared to Monte Carlo shell-model calculations. We do not observe significant knockout feeding to the excited states below 2.2 MeV, which indicates that the Z=28 gap at N=50 remains large. The results show that the ^{79}Cu nucleus can be described in terms of a valence proton outside a ^{78}Ni core, implying the magic character of the latter.

Abstract P2-01-17: The combination of preoperative computed tomography lymphography and intraoperative fluorescence imaging navigation for sentinel lymph node biopsy of early breast cancer patients

Background: Sentinel lymph nodes (SLN) biopsy has been established as a standard of care in the treatment of early breast cancer. This technique represents a minimally invasive, highly accurate method of axillary staging and is an alternative to conventional axillary lymph node dissection. The combination of the radioisotope and dye-staining methods is the most accurate way to identify SLN. We had reported feasibility and safety of a new technique of SLN identification using fluorescence imaging of indocyanine green (ICG) injection without any need for training. Recently, SLN identification using computed tomography lymphography (CTLG) has been reported in Japan. This study investigated a usefulness of the combination of CTLG and fluorescence imaging for SLN biopsy of early breast cancer patients.

Patients and method: Between January 2013 and March 2016, 296 breast cancer patients without clinical evidence of lymph node metastasis were treated. On the day before the operation, CTLG was performed using 64-row multidetector CT. We performed an intradermal injection in the periareolar area, using 4 ml of contrast agent with 1 ml of local anesthetic. The contrasted lymph route and SLN were identified in reconstructed three-dimensional imaging. The SLN spot was indicated by CT laser light navigator system. We established typical pattern of the lymphography: stain defect of SLN, stagnation of lymphatic route for preoperative diagnosis of metastatic SLN. During the operation, fluorescence images were obtained using the fluorescence imaging system, Photpdynamic Eye (pde-neo, Hamamatsu Photonics Co., Japan). After 0.5 ml dye mixed indigocarmin and ICG was injected intradermally into the periareolar skin, lymphatic route was observed with fluorescence images. SLN biopsy was performed referring to the point by axillary compression technique by plastic device. Intraoperative pathological analysis of SLN was examined.

Results: The median age of the 296 patients was 59 (range 28 – 90) years old. One patient was male and others were female. CTLG and fluorescence imaging were safely performed in all patients. CTLG could visualize lymphatic route and accurately identify SLN in 284 (95.9 %) and 290 (98.0 %) cases, respectively, whereas fluorescence imaging identified successfully lymphatic route and SLN in all patients. Lymphatic routes of CTLG were completely consistent with those of fluorescence imaging. The number of SLN identified by CTLG was significantly lower than that by fluorescence imaging (1.1 vs. 1.6, p<0.01). Thirty-nine of 296 patients had metastatic SLN pathologically, and 10 of them had micrometastases of SLNs. The accuracy for metastatic diagnosis of SLN using CTLG without micrometastasis was 83.9 %, sensitivity was 82.1 % and specificity was 84.1 %. The positive predictive value was 35.9 % and negative predictive value was 97.7 %.

Conclusion: The combination of CTLG and fluorescence imaging revealed easy and effective to detect SLN. The fluorescence imaging was more high detection rate and number of SLN than CTLG. Otherwise, preoperative diagnosis of SLN metastasis using CTLG would be useful to detect negative SLNs.

Citation Format: Abe H, Teramoto A, Yamasaki K, Yoneda K, Ogawa M, Kawasaki M, Kameyama M. The combination of preoperative computed tomography lymphography and intraoperative fluorescence imaging navigation for sentinel lymph node biopsy of early breast cancer patients [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-01-17.

Nucleus ^{26}O: A Barely Unbound System beyond the Drip Line

The unbound nucleus ^{26}O has been investigated using invariant-mass spectroscopy following one-proton removal reaction from a ^{27}F beam at 201  MeV/nucleon. The decay products, ^{24}O and two neutrons, were detected in coincidence using the newly commissioned SAMURAI spectrometer at the RIKEN Radioactive Isotope Beam Factory. The ^{26}O ground-state resonance was found to lie only 18±3(stat)±4(syst)  keV above threshold. In addition, a higher lying level, which is most likely the first 2^{+} state, was observed for the first time at 1.28_{-0.08}^{+0.11}  MeV above threshold. Comparison with theoretical predictions suggests that three-nucleon forces, pf-shell intruder configurations, and the continuum are key elements to understanding the structure of the most neutron-rich oxygen isotopes beyond the drip line.

Abstract P3-01-02: A comparison of significance with indocyanine green fluorescence imaging method and computed tomography-lymphography in sentinel lymph node identification for early breast cancer patients

Background: Sentinel lymph nodes (SLN) biopsy has been established as a standard of care in the treatment of early breast cancer. This technique represents a minimally invasive, highly accurate method of axillary staging and is an alternative to conventional axillary lymph node dissection. The combination of the radioisotope and dye-staining methods is the most accurate way to identify sentinel lymph nodes. We had reported feasibility and safety of a new technique of SLN identification using fluorescence imaging of indocyanine green (ICG) injection without any need for training. Recently, SLN identification using computed tomography-lymphography (CTLG) has been reported in Japan. This study investigated the comparison of significance with fluorescence imaging method and CTLG.

Patients and method: Between January 2013 and May 2015, 213 breast cancer patients without clinical evidence of lymph node metastasis were treated. On the day before the operation, CTLG was performed using 64-row multidetector CT. We performed an intradermal injection in the periareolar area, using 4 ml of contrast agent with 1 ml of local anesthetic. The contrasted lymph flow and SLN were identified in reconstructed three-dimensional imaging. The SLN spot was indicated by CT laser light navigator system. During the operation, fluorescence images were obtained using the fluorescence imaging system, Photpdynamic Eye (pde-neo, Hamamatsu Photonics Co., Japan). After 5 mg / 0.3ml ICG was injected intradermally in to the periareolar skin, lymphatic drainage was observed with fluorescence images. SLN biopsy was performed referring to the point by axillary compression technique by plastic device.

Results: The median age of the 213 patients was 59 (range 28 – 87) years old. CTLG and fluorescence imaging was safely performed in all patients. CTLG could visualize lymphatic flow and accurately identify SLN in 189 (89 %) and 196 (92 %) cases, respectively, whereas fluorescence imaging identified successfully lymphatic flow and SLN in all patients. Fluorescence imaging with axillary compression technique was visually easy to identify the location of SLN on the axillary skin even in obese patients. Lymphatic flows of CTLG were completely consistent with those of fluorescence imaging. The number of SLN identified by CTLG was significantly lower than that by fluorescence imaging (1.1 vs. 1.6, p<0.01). Twenty seven patients (13%) were found to have lymph node metastases pathologically, and 7 of them had micrometastases of lymph node. In case of partial enhancement of SLN with CTLG, the rate of positive metastasis was significant higher compared to the cases of whole enhancement (p<0.01), however, even if enhancement is poor, about 70 % cases without metastasis are present.

Conclusion: Both of fluorescence imaging and CTLG revealed easy and effective to detect SLN. The fluorescence imaging with fluorescence mapping showed strong fluorescence from all parts of the surgical field, which hindered identification of SLNs, and fluorescence imaging was more high detection rate of SLN.

Citation Format: Abe H, Yamasaki K, Teramoto A, Yoneda K, Ogawa M, Kawasaki M, Kameyama M. A comparison of significance with indocyanine green fluorescence imaging method and computed tomography-lymphography in sentinel lymph node identification for early breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-01-02.

Extension of the N=40 Island of Inversion towards N=50: Spectroscopy of (66)Cr, (70,72)Fe

We report on the measurement of the first 2(+) and 4(+) states of (66)Cr and (70,72)Fe via in-beam γ-ray spectroscopy. The nuclei of interest were produced by (p,2p) reactions at incident energies of 260  MeV/nucleon. The experiment was performed at the Radioactive Isotope Beam Factory, RIKEN, using the DALI 2γ-ray detector array and the novel MINOS device, a thick liquid hydrogen target combined with a vertex tracker. A low-energy plateau of 2(1)(+) and 4(1)(+) energies as a function of the neutron number was observed for N≥38 and N≥40 for even-even Cr and Fe isotopes, respectively. State-of-the-art shell model calculations with a modified Lenzi-Nowacki-Poves-Sieja (LNPS) interaction in the pfg(9/2)d(5/2) valence space reproduce the observations. Interpretation within the shell model shows an extension of the island of inversion at N=40 for more neutron-rich isotopes towards N=50.

The Cornified Cell Envelope: Loricrin and Transglutaminases

The cornified cell envelope (CE) of terminally differentiated human epidermis is a complex structure consisting of several defined protein constituents. The CE is the most insoluble component of the epidermis due to crosslinking by disulfide bonds as well as isodipeptide bonds that are formed by the action of transglutaminases (TGases). We have recently determined that loricrin is the major component of CE. We now have isolated and characterized its gene and showed that it has a simple structure with a single intron. We also show that the loricrin gene maps to position 1q21, which, coincidentally, is similar to the location of the profilaggrin and involucrin genes. Human loricrin in 26 kDa and consists of three long glycine-serine-cysteine rich sequence domains that contain quasi-repeating peptides and which form the novel glycine loop motif. These are interspersed by lysine+glutamine rich domains involved in isodipeptide crosslinks. The glycine loops are thought to be involved in organization of epidermal proteins and maintenance of the flexibility of the epidermis. By use of PCR analyses, we have found that human loricrin consists of two allelic size variants, due to sequence variations in the second glycine loop domain only, and these variants segregate in the human population by normal Mendelian mechanisms. Furthermore, there are multiple sequence variants within these two size class alleles due to various deletions of 12 bp (4 amino acids) in the major loop of this glycine loop domain. In order to study the expression and role of TGases in the formation of CE, we have isolated and sequenced cDNA and genomic clones encoding the TGase1 enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)

Observation of a p-wave one-neutron halo configuration in (37)Mg

Cross sections of 1n-removal reactions from the neutron-rich nucleus (37)Mg on C and Pb targets and the parallel momentum distributions of the (37)Mg residues from the C target have been measured at 240  MeV/nucleon. A combined analysis of these distinct nuclear- and Coulomb-dominated reaction data shows that the (37)Mg ground state has a small 1n separation energy of 0.22(-0.09)(+0.12)  MeV and an appreciable p-wave neutron single-particle strength. These results confirm that (37)Mg lies near the edge of the "island of inversion" and has a sizable p-wave neutron halo component, the heaviest such system identified to date.

Deformation-driven p-wave halos at the drip line: 31Ne

The halo structure of 31Ne is studied using 1n-removal reactions on C and Pb targets at 230  MeV/nucleon. A combined analysis of the cross sections of these nuclear and Coulomb dominated reactions that feed directly the 30Ne ground-state reveals 31Ne to have a small neutron separation energy, 0.15(-0.10)(+0.16)  MeV, and spin-parity 3/2-. Consistency of the data with reaction and large-scale shell-model calculations identifies 31Ne as deformed and having a significant p-wave halo component, suggesting that halos are more frequent occurrences at the neutron drip line.

Abstract IA20: Linking tumor genomics to patient outcomes through a large-scale patient-derived xenograft (PDX) platform

Background: Preclinical models have generally proven suboptimal for directing clinical application of new anti-cancer therapies. Here we detail an integrated research platform engaging core resources at JAX-WEST and the clinical research and genomics facilities at UCDCCC. Pilot studies using this platform are focusing on non-small cell lung cancer (NSCLC) due to molecular targets of interest, such as epidermal growth factor receptor (EGFR), heterogeneity in NSCLC tumor biology and the complexity of related cancer signaling pathways.

Methods: Clinically and demographically annotated cancer patients (pt) seen at UCDCCC and collaborating facilities undergo tumor biopsy of various types which are implanted into JAX Nod Scid Gamma (NSG) mice to develop PDXs. Pt tumors and subsequent PDXs are assessed by histomorphology, clinically applicable molecular biomarkers, gene expression arrays and genome-wide technologies (NGS). NSCLC PDXs are grouped as panels (EGFR mutant (MT), KRAS MT ALK+). PDX panels of interest undergo multi-regimen drug testing for differential efficacy, together with pre- and post-therapy NGS and timed tumor pharmacodynamics (PD) assessment, to determine mechanisms of primary and acquired resistance in individual PDX models and how to overcome them.

Results: As of November 2013 over 1,200 cancer pt tumors have been xenotransplanted into NSG mice (~175 from NSCLC), including successful PDX formation from small FNA and, cell pellets and transportability of specimens by overnight shipping for implantation. NSCLC PDXs show excellent histomorphologic, gene expression and mutational fidelity to host pt tumors, including mutation status for KRAS, EGFR and gene expression levels. Pilot studies in a panel of EGFR MT PDXs with TKI-acquired resistance demonstrate differential drug activity which mimics that of the host pt to the same therapy, and tumor PD at baseline and timed intervals post-therapy provide the basis for subgrouping resistance mechanisms

Conclusion: This UCDCCC-JAX collaboration has established a large resource applicable to multi-drug testing and tumor PD in a wide range of clinically and genomically characterized tumors, including PDX panels for representative oncogene-driven NSCLCs. An EGFR-directed pilot project supports the feasibility of systematically integrating data derived from these models in order to optimize drug development and treatment strategies to address drug resistance mechanisms. This approach to PDX development and testing will be prospectively integrated into a developing multi-institution clinical trial of the Southwest Oncology Group (S1403), designed to advance understanding of differences in inter- and intra-patient tumor biology and hasten the transition to personalized cancer therapy.

Citation Format: David R. Gandara, T. Li, P.N. Lara, K. Kelly, D.T. Cooke, R. Gandour-Edwards, K. Yoneda, N. Goodwin, S. Kuslak-Meyer, P. Mack. Linking tumor genomics to patient outcomes through a large-scale patient-derived xenograft (PDX) platform. [abstract]. In: Proceedings of the AACR-IASLC Joint Conference on Molecular Origins of Lung Cancer; 2014 Jan 6-9; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2014;20(2Suppl):Abstract nr IA20.

In-beam γ-ray spectroscopy of ^34,36,38Mg: merging the N=20 and N=28 shell quenching

Neutron-rich N=22, 24, 26 magnesium isotopes were studied via in-beam γ-ray spectroscopy at the RIKEN Radioactive Isotope Beam Factory following secondary fragmentation reactions on a carbon target at ≈200 MeV/nucleon. In the one- and two-proton removal channels from 39Al and 40Si beams, two distinct γ-ray transitions were observed in 38Mg, while in the one-proton removal reaction from 37Al a new transition was observed in addition to the known 2(1)(+)→0(g.s.)(+) decay. From the experimental systematics and comparison to theoretical predictions it is concluded that the transitions belong to the 2(1)(+)→0(g.s.)(+) and 4(1)(+)→2(1)(+) decays in 36Mg and 38Mg, respectively. For 34Mg, previously reported 2(1)(+) and 4(1)(+) level energies were remeasured. The deduced E(4(1)(+))/E(2(1)(+)) ratios for 34,36,38Mg of 3.14(5), 3.07(5), and 3.07(5) are almost identical and suggest the emergence of a large area of deformation extending from the N=20 to the N=28 shell quenching.

A peptide that inhibits function of Myristoylated Alanine-Rich C Kinase Substrate (MARCKS) reduces lung cancer metastasis

Myristoylated Alanine-Rich C Kinase Substrate (MARCKS), a substrate of protein kinase C, is a key regulatory molecule controlling mucus granule secretion by airway epithelial cells as well as directed migration of leukocytes, stem cells and fibroblasts. Phosphorylation of MARKCS may be involved in these responses. However, the functionality of MARCKS and its related phosphorylation in lung cancer malignancy have not been characterized. This study demonstrated elevated levels of MARCKS and phospho-MARCKS in highly invasive lung cancer cell lines and lung cancer specimens from non-small-cell lung cancer patients. siRNA knockdown of MARCKS expression in these highly invasive lung cancer cell lines reduced cell migration and suppressed PI3K (phosphatidylinositol 3'-kinase)/Akt phosphorylation and Slug level. Interestingly, treatment with a peptide identical to the MARCKS N-terminus sequence (the MANS peptide) impaired cell migration in vitro and also the metastatic potential of invasive lung cancer cells in vivo. Mechanistically, MANS peptide treatment resulted in a coordination of increase of E-cadherin expression, suppression of MARCKS phosphorylation and AKT/Slug signalling pathway but not the expression of total MARCKS. These results indicate a crucial role for MARCKS, specifically its phosphorylated form, in potentiating lung cancer cell migration/metastasis and suggest a potential use of MARCKS-related peptides in the treatment of lung cancer metastasis.