Solid 4He and the Supersolid Phase: from Theoretical Speculation to the Discovery of a New State of Matter? A Review of the Past and Present Status of Research

The possibility of a supersolid state of matter, i.e., a crystalline solid exhibiting superfluid properties, first appeared in theoretical studies about forty years ago. After a long period of little interest due to the lack of experimental evidence, it has attracted strong experimental and theoretical attention in the last few years since Kim and Chan (Penn State, USA) reported evidence for nonclassical rotational inertia effects, a typical signature of superfluidity, in samples of solid 4He. Since this "first observation", other experimental groups have observed such effects in the response to the rotation of samples of crystalline helium, and it has become clear that the response of the solid is extremely sensitive to growth conditions, annealing processes, and 3He impurities. A peak in the specific heat in the same range of temperatures has been reported as well as anomalies in the elastic behaviour of solid 4He with a strong resemblance to the phenomena revealed by torsional oscillator experiments. Very recently, the observation of unusual mass transport in hcp solid 4He has also been reported, suggesting superflow. From the theoretical point of view, powerful simulation methods have been used to study solid 4He, but the interpretation of the data is still rather difficult; dealing with the question of supersolidity means that one has to face not only the problem of the coexistence of quantum coherence phenomena and crystalline order, exploring the realm of spontaneous symmetry breaking and quantum field theory, but also the problem of the role of disorder, i.e., how defects, such as vacancies, impurities, dislocations, and grain boundaries, participate in the phase transition mechanism.Comment: Published on J. Phys. Soc. Jpn., Vol.77, No.11, p.11101

Aluminum Nanoparticles with Hot Spots for Plasmon-Induced Circular Dichroism of Chiral Molecules in the UV Spectral Interval

Plasmonic nanocrystals with hot spots are able to localize optical energy in small spaces. In such physical systems, near-field interactions between molecules and plasmons can become especially strong. This paper considers the case of a nanoparticle dimer and a chiral biomolecule. In our model, a chiral molecule is placed in the gap between two plasmonic nanoparticles, where the electromagnetic hot spot occurs. Since many important biomolecules have optical transitions in the UV, we consider the case of Aluminum nanoparticles, as they offer strong electromagnetic enhancements in the blue and UV spectral intervals. Our calculations show that the complex composed of a chiral molecule and an Al-dimer exhibits strong CD signals in the plasmonic spectral region. In contrast to the standard Au- and Ag-nanocrystals, the Al system may have a much better spectral overlap between the typical biomolecule's optical transitions and the nanocrystals' plasmonic band. Overall, we found that Al nanocrystals used as CD antennas exhibit unique properties as compared to other commonly studied plasmonic and dielectric materials. The plasmonic systems investigated in this study can be potentially used for sensing chirality of biomolecules, which is of interest in applications such as drug development.Comment: 31 pages, 7 figure

Universal imprinting of chirality with chiral light by employing plasmonic metastructures

Chirality, either of light or matter, has proved to be very practical in biosensing and nanophotonics. However, the fundamental understanding of its temporal dynamics still needs to be discovered. A realistic setup for this are the so-called metastructures, since they are optically active and are built massively, hence rendering an immediate potential candidate. Here we propose and study the electromagnetic-optical mechanism leading to chiral optical imprinting on metastructures. Induced photothermal responses create anisotropic permittivity modulations, different for left or right circularly polarized light, leading to temporal-dependent chiral imprinting of hot-spots, namely imprinting of chirality. The above effect has not been observed yet, but it is within reach of modern experimental approaches. The proposed nonlinear chiroptical effect is general and should appear in any anisotropic material; however, we need to design a particular geometry for this effect to be strong. These new chiral time-dependent metastructures may lead to a plethora of applications.Comment: Main (29 pages, 6 figures) and supplemental (46 pages, 35 figures

The tumour bank at the children's hospital at westmead: An Australian paediatric cancer biorepository

© 2018 The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC-BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. See http://creativecommons.org/licenses/by/4.0/. The Tumor Bank at The Children's Hospital at Westmead was established in 1998 with the purpose of facilitating research into childhood malignancy through the active provision of well annotated, ethically collected tissue samples and providing a pathway for the Children Hospital at Westmead to engage in leading research initiatives, supporting international investigations and clinical trials. Within 20 years practice as a single institute biorepository, The Tumour Bank has established standard operating procedures for collection of tissue, blood and bone marrow that were integrated into routine patient management systems. In addition, three main operational areas have been developed: collection of biospecimens and written consent; management of clinical data and biospecimen inventory database; and implementation of an open access policy to support childhood cancer research around the world. Regulatory oversight is provided by the Tumour Bank Committee, Human Research Ethics Committee and Governance Department. This concerted effort has resulted in collecting 20340 specimens from 3788 patients within 20 years, and The Tumour bank has supported over 108 national and international research projects, and contributed to over 70 peer-reviewed publications to date, with a mean time-to-publication of 19.1 ± 9.0 months and average Impact Factor of 6.11 ± 4.53. In conclusion, the Children's Hospital at Westmead Tumour Bank has demonstrated a sustained single institutional biorepository model for facilitating translational research of rare cancer. It has provided strong evidence that integration of a single institutional biobank into standard clinical practices would be the long-term pathway of valuable bio-resource for rare cancer research

Research in progress: report on the ICAIL 2017 doctoral consortium

This paper arose out of the 2017 international conference on AI and law doctoral consortium. There were five students who presented their Ph.D. work, and each of them has contributed a section to this paper. The paper offers a view of what topics are currently engaging students, and shows the diversity of their interests and influences

Hot electrons and electromagnetic effects in the broadband Au, Ag, and Ag-Au nanocrystals: The UV, visible, and NIR plasmons

Energetic and optical properties of plasmonic nanocrystals strongly depend on their sizes, shapes, and composition. Whereas using plasmonic nanoparticles in biotesting has become routine, applications of plasmonics in energy are still early in development. Here, we investigate hot electron (HE) generation and related electromagnetic effects in both mono- and bi-metallic nanorods (NRs) and focus on one promising type of bi-metallic nanocrystals - core-shell Au-Ag nanorods. The spectra of the NRs are broadband, highly tunable with their geometry, and have few plasmon resonances. In this work, we provide a new quantum formalism describing the HE generation in bi-metallic nanostructures. Interestingly, we observe that the HE generation rate at the UV plasmon resonance of Au-Ag NRs appears to be very high. These HEs are highly energetic and suitable for carbon-fuel reactions. Simultaneously, the HE generation at the longitudinal plasmon (L-plasmon) peaks, which can be tuned from the yellow to near-IR, depends on the near-field and electromagnetic Mie effects, limiting the HE efficiencies for the long and large NRs. These properties of the L-plasmon relate to all kinds of NRs (Au, Ag, and Au-Ag). We also consider the generation of the interband d-holes in Au and Ag, since the involvement of the d-band is crucial for the energetic properties of UV plasmons. The proposed formalism is an important development for the description of bi-metallic (or tri-metallic, or more complex) nanostructures, and it paves the way to the efficient application of the plasmonic HEs and hot holes in sensing, nanotechnology, photocatalysis, and electrophotochemistry

Expression heterogeneity of ABC-transporter family genes and chemosensitivity genes in gastric tumor, carcinomatosis and lymph node metastases

Introduction. Metastatic tumors (particularly gastric cancer) have been found to be characterized by heterogeneity between the primary tumor and metastases. This type of heterogeneity comes to the fore when treating primary-metastatic forms of tumor and is an important reason for the low effectiveness of their treatment. In this regard, comparative analysis of ABC-transporter gene expression and chemosensitivity genes will allow to characterize to a certain extent the resistance and sensitivity of primary tumor, carcinomatosis and metastases to therapy and provide the basis for personalized treatment approach.Aim. To evaluate expression heterogeneity of ABC-transporter genes and chemosensitivity genes in gastric tumor, carcinomatosis and lymph node metastases.Materials and methods. Overall 41 patients with disseminated gastric cancer stage IV with carcinomatosis of peritoneum were included in the investigation. All patients underwent surgery according to Roux palliative gastrectomy. After surgery patients underwent chemotherapy depending on indications. RNA was isolated using RNeasy Plus mini kit (Qiagen, Germany). The expression level of ABC transporter genes (ABCB1, ABCC1, ABCC2, ABCC5, ABCG1, ABCG2) and chemosensitivity genes (BRCA1, RRM1, ERCC1, TOP1, TOP2α, TUBβ3, TYMS, GSTP1) was assessed by reverse transcription polymerase chain reaction (RT-PCR) in primary tumor, carcinomatosis and lymph node metastases.Results. The expression levels of the genes under study were shown to vary widely. For ABC transporter genes, ABCG1 (3.1 ± 1.1; max 32.0), ABCG2 (7.9 ± 2.3; max 54.1), ABCG2 (9.6 ± 3.8; max 101.0) were the most expressed genes in gastric tumor tissue, carcinomatosis and lymph node metastasis, respectively. Hyperexpression among chemosensitivity genes at all three sites was characteristic only of TOP2α (17.2 ± 6.0; max. 161.9; 10.8 ± 4.1; max. 105.1; 35.3 ± 0.8; max. 439.6, respectively). We found that TOP2α and BRCA1 gene expression levels were higher in lymph node metastasis compared with gastric tumor tissue and carcinomatosis (at p = 0.005 and p = 0.001). Whereas ABCC1 gene expression was statistically significantly higher in carcinomatosis (p = 0.03).Conclusion. Thus, a high level of expression heterogeneity is observed in gastric cancer, which affects the expression patterns of various genes in different localizations. The expression profile can be used to determine the level of heterogeneity and approach to personalized therapy tactics

Efficacy and predictors of response to somatostatin analogues in patients with ectopic ACTH syndrome

Aim. To study the immediate efficacy, tolerability and predictors of response to prolonged-acting somatostatin analogues (SSAs) in patients with ectopic ACTH syndrome (EAS). Materials and methods. A multicenter, observational study with a retrospective analysis. The effectiveness of treatment was evaluated every 12–24 weeks by the activity of hypercortisolism, clinical symptoms of the disease, control of tumor growth. Patients were conditionally divided into “responders” and “non-responders” at time points of 6, 12 and 24 months. Radiological efficacy was performed according to the RECIST 1.1. Statistical data processing was carried out by using IBM SPSS Statistics 23. Results. The study included 46 patients (26 women, 20 men). The median follow-up period was 71 months [32; 122]. Localized tumor process (T1-3N0M0) – in 19 (41.3%) patients, locally widespread (T1-3N1M0, T4N0-1M0) – in 15 (32.6%), generalized (T1-4N0-1M1) – in 12 (26.1%) cases. Surgical treatment was performed in 33 (71.7%) patients. SSAs were the first-line therapy for all 46 patients. The average duration of SSAs use was 34 months (Me 27.5 [13.8; 41]). Dose escalation was required in 39.4% cases, the period before the first dose escalation was on average 9 months. 13 (48.1%) patients achieved drug-induced remission of the disease. Normalization of cortisol in 24hUFC or its decrease ≥50% from the baseline level by the 6th month of treatment was achieved in 46.4%, by the 12th month – in 61.9%, “eluding” from the effect of therapy was observed in 3 patients. Objective response was evaluated in 30 patients. There was no complete response to the treatment. In 4 (13.3%) cases – a partial response, in 15 (50%) – disease stabilization, in 11 (36.7%) – disease progression. The best therapeutic efficacy of SSAs is associated with bronchial NET (HR 0.078, 95% CI 0.010–0.633; p=0.017), and resistance to treatment is associated with negative expression of SSTR5 (HR 6.532, 95% CI 1.019–41.878; p=0.048). Conclusion. SSAs are the drugs of choice for the first-line treatment of patients with EAS, allowing for long-term effective control of hypercortisolism and tumor progression in more than 60% of patients. Significant factors determining the response to SSAs after 6 months of treatment are expression status of SSTR5 and NET localization

Combined modality treatment of patients with stage IV gastric cancer with peritoneal carcinomatosis

Peritoneal carcinomatosis is associated with poor prognosis in gastric cancer patients. Stage IV gastric cancer (GC) is diagnosed in 39.8 % of patients; local metastases without evidence of distant metastases occur only in 18–20 % of stage IV gastric cancer patients.The purpose of the study was to estimate the efficacy of personalized chemotherapy in the combined modality treatment of patients with stage IV GC with peritoneal carcinomatosis.Material and Methods. Cytoreductive surgery was performed in 70 patients with GC with peritoneal dissemination. The control group patients (n=35) received postoperative chemotherapy with the FOLFOX regimen. The study group patients (n=35) received personalized systemic and intraperitoneal chemotherapy based on the expression of chemosensitivity and resistance genes.Results. The median survival time (18.7 months) in the study group patients was higher than that in the control group and in studies described in the world literature (CRS + HIPEC). Personalized chemotherapy improved median progressionfree survival (PFS) by 4.6 months (29.1 %) and median overall survival (OS) by 6 months (32 %) compared to FOLFOX regimen chemotherapy. In the study group, the 1-, 2and 3-year survival rates were observed in 35 (100 %), 9 (27 %) and 1 (3 %) patients, respectively.Conclusion. Personalized chemotherapy in the combined modality treatment can improve long-term treatment outcomes (longer median PFS and OS) in GC patients with peritoneal dissemination