Metal-Halide Covalency, Exchange Coupling, and Slow Magnetic Relaxation in Triangular (CpiPr5)3U3X6 (X = Cl, Br, I) Clusters.

The actinide elements are attractive alternatives to transition metals or lanthanides for the design of exchange-coupled multinuclear single-molecule magnets. However, the synthesis of such compounds is challenging, as is unraveling any contributions from exchange coupling to the overall magnetism. To date, only a few actinide compounds have been shown to exhibit exchange coupling and single-molecule magnetism. Here, we report triangular uranium(III) clusters of the type (CpiPr5)3U3X (1-X; X = Cl, Br, I; CpiPr5 = pentaisopropylcyclopentadienyl), which are synthesized via reaction of the aryloxide-bridged precursor (CpiPr5)2U2(OPhtBu)4 with excess Me3SiX. Spectroscopic analysis suggests the presence of covalency in the uranium-halide interactions arising from 5f orbital participation in bonding. The dc magnetic susceptibility data reveal the presence of antiferromagnetic exchange coupling between the uranium(III) centers in these compounds, with the strength of the exchange decreasing down the halide series. Ac magnetic susceptibility data further reveal all compounds to exhibit slow magnetic relaxation under zero dc field. In 1-I, which exhibits particularly weak exchange, magnetic relaxation occurs via a Raman mechanism associated with the individual uranium(III) centers. In contrast, for 1-Br and 1-Cl, magnetic relaxation occurs via an Orbach mechanism, likely involving relaxation between ground and excited exchange-coupled states. Significantly, in the case of 1-Cl, magnetic relaxation is sufficiently slow such that open magnetic hysteresis is observed up to 2.75 K, and the compound exhibits a 100-s blocking temperature of 2.4 K. This compound provides the first example of magnetic blocking in a compound containing only actinide-based ions, as well as the first example involving the uranium(III) oxidation state

An international multi-institutional validation of T1 sub-staging of intraductal papillary mucinous neoplasm-derived pancreatic cancer

BACKGROUND: Intraductal papillary mucinous neoplasm (IPMN)-derived pancreatic ductal adenocarcinoma (PDAC) is resected at smaller sizes compared with its biologically distinct counterpart, pancreatic intraepithelial neoplasia (PanIN)-derived PDAC. Thus, experts proposed T1 sub-staging for IPMN-derived PDAC. However, this has never been validated. METHODS: Consecutive upfront surgery patients with IPMN-derived PDAC from 5 international high-volume centers were classified by the proposed T1 sub-staging classification (T1a ≤0.5, T1b >0.5 and ≤1.0, and T1c >1.0 and ≤2.0 cm) using the invasive component size. Kaplan-Meier and log-rank tests were used to compare overall survival (OS). A multivariable Cox regression was used to determine hazard ratios (HRs) with confidence intervals (95% CIs). RESULTS: Among 747 patients, 69 (9.2%), 50 (6.7%), 99 (13.0%), and 531 patients (71.1%), comprised the T1a, T1b, T1c, and T2-4 subgroups, respectively. Increasing T-stage was associated with elevated CA19-9, poorer grade, nodal positivity, R1 margin, and tubular subtype. Median OS for T1a, T1b, T1c, and T2-4 were 159.0 (95% CI = 126.0 to NR), 128.8 (98.3 to NR), 77.6 (48.3 to 108.2), and 31.4 (27.5 to 37.7) months, respectively (P < .001). OS decreased with increasing T-stage for all pairwise comparisons (all P < .05). After risk adjustment, older than age 65, elevated CA19-9, T1b [HR = 2.55 (1.22 to 5.32)], T1c [HR = 3.04 (1.60 to 5.76)], and T2-4 [HR = 3.41 (1.89 to 6.17)] compared with T1a, nodal positivity, R1 margin, and no adjuvant chemotherapy were associated with worse OS. Disease recurrence was more common in T2-4 tumors (56.4%) compared with T1a (18.2%), T1b (23.9%), and T1c (36.1%, P < .001). CONCLUSION: T1 sub-staging of IPMN-derived PDAC is valid and has significant prognostic value. Advancing T1 sub-stage is associated with worse histopathology, survival, and recurrence. T1 sub-staging is recommended for future guidelines

Organometallic uranyl complexes for photocatalytic C-H bond activation and functionalization

Chapter one discusses the synthesis and characterization of novel complexes of the uranyl(VI) ion with a substituted phenanthroline ligand ph2phen. The complexes are investigated by electronic and vibrational spectra and their solid-state structures are presented. Luminescence spectra and lifetimes are determined. Density functional theory (DFT) calculations are carried out to investigate the electronic structure of the complexes in the ground and excited states.Chapter two discusses the photocatalytic reactivity of the new uranyl complexes in alkane fluorination, oxidation and C-C coupling reactions. Visible light mediated functionalization of the C-H bond in the substrate is achieved through hydrogen atom abstraction. The identity of the photocatalyst is investigated for the fluorination reactions. DFT calculations are performed to compare reaction energy barriers for different photocatalysts and gauge the interactions between the substrate and ph2phen ligand. Finally, Stern-Volmer analyses are performed to determine the nature of collisional quenching between the substrate and the photocatalyst

Non-Coding RNAs in Glioma

Glioma is the most aggressive brain tumor of the central nervous system. The ability of glioma cells to migrate, rapidly diffuse and invade normal adjacent tissue, their sustained proliferation, and heterogeneity contribute to an overall survival of approximately 15 months for most patients with high grade glioma. Numerous studies indicate that non-coding RNA species have critical functions across biological processes that regulate glioma initiation and progression. Recently, new data emerged, which shows that the cross-regulation between long non-coding RNAs and small non-coding RNAs contribute to phenotypic diversity of glioblastoma subclasses. In this paper, we review data of long non-coding RNA expression, which was evaluated in human glioma tissue samples during a five-year period. Thus, this review summarizes the following: (I) the role of non-coding RNAs in glioblastoma pathogenesis, (II) the potential application of non-coding RNA species in glioma-grading, (III) crosstalk between lncRNAs and miRNAs (IV) future perspectives of non-coding RNAs as biomarkers for glioma

Control of process of building geometry design/Pastatų geometrijos projektavimo proceso valdymas

Methods of the modern building design do not only help designers in their work, but also raise a number of different questions, especially in the cases of using maximum computer possibilities. One of the possible ways is to create a model of the interface of a workstation, which would have the following properties: • The design process (design tools and information) has to be made automatically, depending on the type of the designed object. • There should be a possibility to gain automatically one's experience and to use the existing information. • The way of the automatic control of the digital information has to be evaluated, as well as the means of the maximum use of the automatic information control qualities should be estimated. The controlling of the information becomes rational only by the use of intelligent systems (Fig 1). This investigation covers the problems related with a spatial modelling only (Fig 2). Basic systems could not be rational due to their general purpose (Fig 3), so it is necessary to create a structure of separate groups of problems (Fig 4). The course and the means of solving this problem depend on the way one chooses: the design according to the analogue (Fig 5) or the design of an entirely new object (Fig 6). The rational work could be possible only by making the means of modelling and control (Fig 7–9). General conclusions: • While analysing the methods of computer design used in Lithuanian companies of architectural design, there has been determined: • In the design process computers are being used as simple drawing tools for making different operations like with a pencil, to depict separate lines or even points. Computers are not used as functional objects, which realisation has become possible by using modern means of computer; • integration of computer design is used only in the limits of one project on rudimental level. • The analysis of the mostly used computer aided design (CAD) systems shows: • the most common and specialised CAD systems are used which differ in their possibilities and commercial price; • in spite of the existing technical and programme conditions, the highest achievement is only the development of integration with very low intelligent possibilities. • The interface of the visualisation of building spatial solution has been prepared on the base of analysis and created intellectual models: • the main functions of spatial design interface have been discussed, as well as algorithms of their realisation have been prepared; • a scheme of tool structure has been made. • By using the proposed models and algorithms there have been created the fragments of programme, which are realised by solving an example. This material could be used in the educational and practical design process. The algorithms of main operations and programmed models are made, enabling the use of modern design technologies and projects, created in traditional way. First Published Online: 30 Jul 201

Complementary addressed modification of nucleic acids with the alkylating derivatives of oligothymidylate ethyl phosphotriesters Effect of the phosphotriester fragments' configuration

AbstractThe alkylating derivatives of four individual diastereomers of the oligonucleotide [dTp(Et)]3dTpU and two individual diastereomers of oligonucleotide [dTp(Et)dTp]4 have been synthesized. The reagents with the phosphorus atoms in the enantiomeric p″ configuration are shown to be more efficient in reacting with poly(dA) and with nucleic acids in Krebs-2 ascites carcinoma cells compared to those with the phosphorus atoms in the p′ configuration