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We synthesised a novel family of liquid crystalline 1,4-phenylene bis(4-alkylthio benzoates), of which homologues with different alkyl chain lengths of 1-8 were designed, to investigate the structure-property relationship. The mesogenic incidence and tendency were found to be strongly dependent on the carbon numbers in the terminal alkyl chains. Even members formed widely monotropic or enantiotropic nematic (N) phases compared to odd members that showed either none or monotropic-narrower ones. The temperature dependence of birefringence (Δn) for the hexylthio homologue was evaluated and compared to that for a hexyloxy counterpart. It was found that the hexylthio homologue exhibited higher Δn values than the hexyloxy counterpart over the entire range of near TIN-T. In addition, wide-angle X-ray diffraction measurements, using magnetically aligned specimens, found enhanced cybotactic nematic tendency with smectic (Sm) A-like temperature dependence for the hexylthio analogue, due to the intermolecular attractive S···S interaction, in comparison with the hexyloxy analogue exhibiting N phase with clear Sm C-type clusters. We revealed the actual benefits of alkylthio groups in the fluid N phase. [ABSTRACT FROM AUTHOR]

In this study, we offer a new family of alkylthio-containing diphenylacetylene-based liquid crystalline molecules (the so-called tolanes) showing nematic phases stable down to room temperature and high birefringence, with insights into the role for terminal alkyl chains in mesogenic incidence and tendency. A number of asymmetric tolane homologues having various alkyl chain lengths in the alkylthio and alkyl groups at each p-, p’-position were synthesised, and their phase transition behaviour was investigated by polarising optical microscope observation, differential scanning calorimetry and wide-angle X-ray diffraction measurement. Consequently, several homologues exhibited monotropic nematic or highly ordered smectic (soft crystal) phases stable down to room temperature. It is found that a long alkyl group on the side opposite to an alkylthio group is prerequisite for mesogenic incidence. In addition, a nematogenic homologue exhibited a higher birefringence value of 0.20 compared to that of 0.19 for an alkoxy counterpart. [ABSTRACT FROM AUTHOR]

Germline genetic variants influence development of pediatric B cell acute lymphoblastic leukemia (B-ALL). Genome-wide association studies (GWAS) have identified several pediatric B-ALL susceptibility loci. IKZF1 and PAX5, transcription factors involved in B cell development, have been reported as susceptibility genes for B-ALL development. Therefore, we hypothesized that rare variants of genes involved in B cell development would be candidate susceptibility loci for pediatric B-ALL. Thus, we sequenced TCF3, a key transcription factor gene involving in B cell development. Saliva DNA from 527 pediatric patients with pediatric B-ALL in remission who were registered with the Tokyo Children's Cancer Study Group (TCCSG) were examined. As a TCF3 gene-based evaluation, the numbers of rare deleterious germline TCF3 sequence variants in patients with pediatric B-ALL were compared with those in cancer-free individuals using data in public databases. As a TCF3 single-variant evaluation, the frequencies of rare deleterious germline TCF3 sequence variants in patients with pediatric B-ALL were also compared with those in control data. TCF3 gene-based analysis revealed significant associations between rare deleterious variants and pediatric B-ALL development. In addition, TCF3 variant-based analysis showed particularly strong association between variant rs372168347 (three in 521 TCCSG and three in the 15780 gnomAD whole genome analysis cohort, p = 0.0006) and pediatric B-ALL development. TCF3 variants are known to influence B cell maturation and may increase the risk of preleukemic clone emergence. [ABSTRACT FROM AUTHOR]

Relatively high-molecular-weight linear one- and two-armed and star-shaped four-armed poly( l-lactide) and poly( d-lactide) are synthesized and the multiplicate effects of arm-number (branching architecture, coinitiator moiety), crystallization temperature ( Tc), and number-average molecular weight ( Mn) on stereocomplex (SC)- and homo-crystallization and phase-transition behavior are investigated. For nonisothermal and isothermal crystallization, in addition to SC crystallites, homo-crystallites are formed in the blends with higher Mn values, irrespective of arm number. For isothermal crystallization, the transition Tc ranges below which in addition to SC crystallites, homo-crystallites are formed depended on Mn per one arm-determining melting temperature or thickness of homo-crystallites. The transition Mn ranges above which in addition to SC crystallites, homo-crystallites are formed are not affected by arm number. The high molecular weight disturbs the change of crystalline growth mechanism of one- and two-armed blends, whereas the branching architecture inhibits the change of crystalline growth mechanism of four-armed blends. [ABSTRACT FROM AUTHOR]

Dislocations are one-dimensional lattice defects in crystalline materials, and unique atomic configurations at their core can affect functional properties of materials. Here we report on a [012] dislocation having a nonstoichiometric core structure in strontium titanate (SrTiO 3 ). TEM and STEM observations showed that a (001) low-angle tilt grain boundary consists of two types of dislocations. One is a [001] edge dislocation that compensates a tilt angle of the boundary as found in previous studies. The other is a [012] dislocation with both edge and screw component. This dislocation is considered to be formed to compensate a slight twist angle of the boundary. It is interesting that the [012] dislocations have a specific core structure with the dissociation into three partial dislocations of b = 1/2 [011], [001] and 1/2 [011]. At stacking faults formed with the dissociation, two (001) Ti-O layers were located to be neighbors across the stacking fault plane due to missing of a (001) Sr-O layer. In addition, the energy of the stacking fault was estimated to be 0.4 J/m 2 from the separation distances between partial dislocations. It is suggested that the [012] dislocation is formed due to presence of the nonstoichiometric stacking fault structure with low energy. [ABSTRACT FROM AUTHOR]

In order to reveal the effect of fluorine substitutions on the refractive index properties for calamitic nematic materials, we carried out a comparative study with respect to non-fluorinated and two types of laterally fluorinated 1,4-bis[4-(hexyloxy)phenyl]ethynylbenzene molecules. Phase transition behaviours were investigated by differential scanning calorimetry and polarised optical microscopy. Additionally, extraordinary and ordinary refractive index and birefringence were evaluated from each single component system. All the analogues exhibited high birefringence values beyond 0.3 at 550 nm, of which an analogue with a fluorine substitution at the central benzene ring showed the highest Δn-value of 0.43. With respect to an analogue with the highest level of fluorination, Δnas well asneandnovalues were declined due to decreased order parameter and diluted molecular density. Not only the mesomorphic behaviours but also optical properties strongly relied on the manner of fluorine substitution including the number and position. [ABSTRACT FROM AUTHOR]

The article reports on a study that explored the origin and evolutionary process of the sequential relationship between Langerhans cell histiocytosis (LCH) and acute lymphoblastic leukemia (ALL). Topics discussed include the comprehensive genomic analysis of the dynamics of clonal architecture for one case and the genomic analysis performed for another 2 ALL cases that subsequently developed LCH. The derivation of LCH from a founding clone with genomic alterations common to ALL is mentioned.

Purpose: Minimally invasive surgery (MIS) has become widely accepted as a technique for abdominal neuroblastoma resection. However, the indications for MIS are still controversial. The aim of this study was to evaluate image-defined risk factors (IDRFs), complications, and oncologic outcomes in patients with abdominal neuroblastomas treated with MIS.Methods: Between August 1998 and February 2016, MIS was planned for 20 children with abdominal neuroblastomas. Clinical data were retrospectively reviewed and compared between the IDRF-negative and IDRF-positive patients.Results: On the basis of the latest IDRF guidelines, five patients were classified as IDRF-positive and four of them had operative complications; namely, partial infarction of the ipsilateral kidney or open conversion. Concerning the two patients who needed open conversion, the primary reason for open conversion was difficulty in dissection of the tumor from the vena cava. Preoperative images of these cases showed either deformation or subtotal encasement of the vena cava. Relapse occurred in three high-risk patients and in none of the low/intermediate-risk patients. No complication occurred in the IDRF-negative cases.Conclusions: IDRF-negative might be a good indication for MIS for abdominal neuroblastoma. However, deformation or subtotal encasement of the vena cava should be considered as IDRF-positive for MIS. [ABSTRACT FROM AUTHOR]

The formation of the nematic to twist-bend nematic (NTB) phase has emerged as a fascinating phenomenon in the field of supramolecular chemistry, based on complex intermolecular interactions. Through a careful analysis of molecular structures and dynamics, we elucidate how these intermolecular interactions drive the complex twist-bend modulation observed in the NTB. The study employs broadband dielectric spectroscopy spanning frequencies from 10 to 2 × 109 Hz to investigate the molecular orientational dynamics within the glass-forming thioether-linked cyanobiphenyl liquid crystal dimers, namely, CBSC7SCB and CBSC7OCB. The experimental findings align with theoretical expectations, revealing the presence of two distinct relaxation processes contributing to the dielectric permittivity of these dimers. The low-frequency relaxation mode is attributed to an "end-over-end rotation" of the dipolar groups parallel to the director. The high-frequency relaxation mode is associated with precessional motions of the dipolar groups about the director. Various models are employed to describe the temperature-dependent behavior of the relaxation times for both modes. Particularly, the critical-like description via the dynamic scaling model seems to give not only quite good numerical fittings, but also provides a consistent physical picture of the orientational dynamics in accordance with findings from infrared (IR) spectroscopy. Here, as the longitudinal correlations of dipoles intensify, the m1 mode experiences a sudden upsurge in enthalpy, while the m2 mode undergoes continuous changes, displaying critical mode coupling behavior. Interestingly, both types of molecular motion exhibit a strong cooperative interplay within the lower temperature range of the NTB phase, evolving in tandem as the material's temperature approaches the glass transition point. Consequently, both molecular motions converge to determine the glassy dynamics, characterized by a shared glass transition temperature, Tg. [ABSTRACT FROM AUTHOR]

The article discusses the pediatric case of a girl diagnosed with acute megakaryotic leukemia with double chimeric transcripts. The study found the chimeric transcript in leukemic cells and the biological mechanism and clinical significance of the second chimera. Results of the positron emission tomography, bone marrow examination and karyotype analysis performed on the patient are discussed. The treatment approach is described including azacitidine (AZA) and cord blood transplant (CBT).

We report the synthesis, phase transitions, and mesomorphic behavior of alkylthio-appended azobenzenes. Various symmetric and asymmetric azobenzenes bearing alkylthio and alkyl groups (m S–AZO–S m and m S–AZO– n , respectively, where m and n denote the numbers of carbon atoms in the alkyl chains of alkylthio and alkyl groups, respectively, and are equal to 1, 6, or 10). Symmetric alkylthio m S–AZO–S m and asymmetric m S–AZO–1 with the shortest methyl group do not exhibit practical liquid crystal (LC) phases. Among them, polarized optical microscopy indicated that 6S–AZO–1 formed the elusive monotropic nematic (N) phase only in its supercooled isotopic-phase parts. By contrast, asymmetric m S–AZO–6 with a relatively longer hexyl group at the azobenzene core terminal opposite to the alkylthio-appended terminal form well-defined LC phases. As the length of the alkyl chains of the alkylthio groups increases, the LC phase changes from a non-layered N phase to a layered smectic A phase to a highly ordered orthogonal phase; moreover, the LC phases transform from monotropic to enantiotropic. Asymmetric substitution with a relatively longer alkyl chain at the core terminal opposite to the alkylthio group is beneficial for inducing LC phases in alkylthio azobenzenes. [Display omitted] • Symmetric and asymmetric alkylthio- and alkyl-bearing azobenzenes (mS–AZO–Sm and mS–AZO–n, respectively) are synthesized. • Symmetric mS–AZO–Sm and asymmetric mS–AZO–1 with the shortest methyl group do not exhibit practical LC phases. • Asymmetric mS–AZO–6 with a longer hexyl group at the other end opposite to the alkylthio group form well-defined LC phases. • As the alkyl chain length increases, the LC phase changes from non-layered to layered and from monotropic to enantiotropic. [ABSTRACT FROM AUTHOR]