O-P05 Gemcitabine and paclitaxel loaded microbubbles for the treatment of pancreatic cancer

Background Ultrasound targeted microbubble destruction (UTMD) has emerged as an effective strategy for the delivery of drug payloads to solid tumours. However, loading a single microbubble (MB) formulation with two drug payloads is challenging and often involves several manipulations post-MB preparation to enable attachment of drug payloads which can be cumbersome and generally results in low / inconsistent drug loading. Here we report a one-step synthesis of a gemcitabine-functionalised phospholipid and its subsequent incorporation into a stable MB formulation co-loaded with paclitaxel (PTX). The efficacy of the MB conjugate was determined in a Panc-1 spheroid model and ectopic BxPC-3 tumour model of pancreatic cancer. Methods Gemcitabine-modified phospholipid (Lipid-Gem MB) was prepared from 1,2-dibehenoyl-sn-glycero-3-phosphocholine (DBPC) though a transphosphatidylation reaction using gemcitabine (Gem) as the acceptor alcohol. Lipid-Gem MB and Lipid-Gem-PTX MB were prepared from Lipid-Gem MB and/or PTX using a standard thin-film hydration technique followed by sonication in the presence of PFB gas. In vitro efficacy of Lipid-Gem MB and Lipid-Gem-PTX MB were determined in Panc-1 spheroids using an MTT assay. The in vivo effectiveness was determined in BxPC-3 tumour bearing mice following IV administration of either Lipid-Gem MB or Lipid-Gem-PTX MB plus ultrasound (US). Free Gem, free Gem + PTX and untreated mice were used for comparative purposes. Results Spheroids treated with Lipid-Gem MB +US or Lipid-Gem-PTX MB +US were significantly reduced relative to spheroids treated with US alone (p = 0.033 and p = 0.0031 respectively) or with the respective MB formulation alone (i.e. no US) (p = 0.0336 and p = 0.0037 respectively). Furthermore, cell viability for spheroids treated with Lipid-Gem-PTX MB +US was significantly reduced compared with spheroids treated with Lipid-Gem MB +US (p = 0.0077) (Figure a). Mice treated with Lipid-Gem MB +US or Lipid-Gem-PTX MB +US showed an average change in tumour volume of + 7 ± 7% and -10 ± 10 % respectively compared with +45 ±10% and +30 ± 10% for free gem and free gem + PTX respectively (Figure b). Conclusions A Gem-modified lipid was succesfully synthesised using a single step reaction and was subsequently incorporated into MBs containging PTX, eliminating the need for cumbersome drug conjgation methods. UTMD mediated treatment of Panc-1 spheroids and BxPC-3 tumours demonstrated the efficacy and tolerability of the formulations. Given that all components of this formulation are already clinicaly apporved, UTMD using Lipid-Gem-PTX MB offers a promising alternative to existing treatments

Statistically bias-corrected and downscaled climate models underestimate the severity of U.S. maize yield shocks

Efforts to understand and quantify how a changing climate can impact agriculture often rely on bias-corrected and downscaled climate information, making it important to quantify potential biases of this approach. Previous studies typically focus their uncertainty analyses on climatic variables and are silent on how these uncertainties propagate into human systems through their subsequent incorporation into econometric models. Here, we use a multi-model ensemble of statistically downscaled and bias-corrected climate models, as well as the corresponding CMIP5 parent models, to analyze uncertainty surrounding annual maize yield variability in the United States. We find that the CMIP5 models considerably overestimate historical yield variability while the bias-corrected and downscaled versions underestimate the largest historically observed yield shocks. We also find large differences in projected yields and other decision-relevant metrics throughout this century, leaving stakeholders with modeling choices that require navigating trade-offs in resolution, historical accuracy, and projection confidence.

Political situation in Subcarpathian Rus as assessed by Czechoslovak officials and scholars

The article analyzes political, social and cultural situation in Subcarpathian Rus in assessments of Czech officials and ethnographers dated by the time when this region joined Czechoslovakia in 1919. The end of the First World War, disintegration of Austria- Hungary and subsequent incorporation of the lands of historical Hungarian Rus into Czechoslovak state presented the Czechoslovak authorities with the vital need to solve numerous problems related to the ethnic and cultural peculiarities and national identity of the local East Slavic population. Czech ethnographers and officials played an important role in the development of the main directions of the specific policy of the Czechoslovak administration in Subcarpathian Rus. In their practical recommendations to the central government Czech officials tried to take into account the social, cultural, and linguistic characteristics of the local population as well as the geopolitical interests of Czechoslovakia in that strategically important region bordering with Poland, Hungary and Romania. The acquaintance of Czech officials and scholars with the situation in Subcarpathian Rus resulted in maneuvering of the Czechoslovak administration between several cultural and national projects in this region. However, during the 1920-ties representatives of the Ukrainian movement enjoyed the preferences of the authorities in the educational and cultural spheres. Subsequently, this led to the reinforced position of the Ukrainian movement in Subcarpathian Rus and to the growing contradictions between Ukrainophiles and Russophiles during 1930-ties.

Algorithmic Agency and Autonomy in Archaeological Practice

A key development in archaeology is the increasing agency of the digital tools brought to bear on archaeological practice. Roles and tasks that were previously thought to be uncomputable are beginning to be digitalized, and the presumption that computerization is best suited to well-defined and restricted tasks is starting to break down. Many of these digital devices seek to reduce routinized and repetitive work in the office environment and in the field. Others incorporate data-driven methods to represent, store, and manipulate information in order to undertake tasks previously thought to be incapable of being automated. Still others substitute the human component in environments which would be otherwise be inaccessible or dangerous. Whichever applies, separately or in combination, such technologies are typically seen as black-boxing practice with often little or no human intervention beyond the allocation of their inputs and subsequent incorporation of their outputs in analyses. This paper addresses the implications of this shift to algorithmic automated practices for archaeology and asks whether there are limits to algorithmic agency within archaeology. In doing so, it highlights several challenges related to the relationship between archaeologists and their digital devices.

Diels-Alder Additions as Mechanistic Probes–Interception of Silyl-Isoindenes: Organometallic Derivatives of Polyphenylated Cycloheptatrienes and Related Seven-Membered Rings

The intermediacy of short-lived isoindenes, generated in the course of metallotropic or silatropic shifts over the indene skeleton, can be shown by Diels-Alder trapping with tetracyanoethylene, leading to the complete elucidation of the dynamic behaviour of a series of polyindenylsilanes. Cyclopentadienones, bearing ferrocenyl and multiple phenyl or naphthyl substituents undergo [4 + 2] cycloadditions with diaryl acetylenes or triphenylcyclopropene to form the corresponding polyarylbenzenes or cycloheptatrienes. The heptaphenyltropylium cation, [C7Ph7+], was shown to adopt a nonplanar shallow boat conformation. In contrast, the attempted Diels-Alder reaction of tetracyclone and phenethynylfluorene yielded electroluminescent tetracenes. Finally, benzyne addition to 9-(2-indenyl)anthracene, and subsequent incorporation of a range of organometallic fragments, led to development of an organometallic molecular brake.

Enhancing the Corrosion Resistance and Mechanical Properties of a High-Alloying Al-Zn-Mg-Cu-Zr Alloy by Ce Addition and Aging Treatment

The corrosion resistance (exfoliation corrosion and inter-granular corrosion) and mechanical properties (strength and hardness) of a high-alloying Al-Zn-Mg-Cu-Zr alloy were improved by the synergistic effect of Ce addition and aging treatment. Ce addition promotes the morphology change of grain boundary precipitates from continuous form to discontinuous form at T6 temper. But the Cu content in grain boundary precipitates became much lower than that in Ce-free alloy, owing to a large amount of Cu being trapped in AlCuCe phase. Hence retrogression and re-aging (RRA) treatment were then adopted. The Cu content in grain boundary precipitates was improved, which can be attributed to the removal of Cu from solid solution during high temperature aging and its subsequent incorporation into grain boundary precipitates. In addition, the size and the distribution discontinuity of the grain boundary precipitates can be further increased and the main intra-grain phases of RRA alloy are still fine η′ phase similar to T6 temper. Therefore, the alloy at RRA temper obtains the optimal corrosion resistance without loss of high strength.

Identification of a novel N-linked glycan on the archaellins and S-layer protein of the thermophilic methanogen, Methanothermococcus thermolithotrophicus

Motility in archaea is facilitated by a unique structure termed the archaellum. N-Glycosylation of the major structural proteins (archaellins) is important for their subsequent incorporation into the archaellum filament. The identity of some of these N-glycans has been determined, but archaea exhibit extensive variation in their glycans, meaning that further investigations can shed light not only on the specific details of archaellin structure and function, but also on archaeal glycobiology in general. Here we describe the structural characterization of the N-linked glycan modifications on the archaellins and S-layer protein of Methanothermococcus thermolithotrophicus, a methanogen that grows optimally at 65 °C. SDS-PAGE and MS analysis revealed that the sheared archaella are composed principally of two of the four predicted archaellins, FlaB1 and FlaB3, which are modified with a branched, heptameric glycan at all N-linked sequons except for the site closest to the N termini of both proteins. NMR analysis of the purified glycan determined the structure to be α-d-glycero-d-manno-Hep3OMe6OMe-(1–3)-[α-GalNAcA3OMe-(1–2)-]-β-Man-(1–4)-[β-GalA3OMe4OAc6CMe-(1–4)-α-GalA-(1–2)-]-α-GalAN-(1–3)-β-GalNAc-Asn. A detailed investigation by hydrophilic interaction liquid ion chromatography–MS discovered the presence of several, less abundant glycan variants, related to but distinct from the main heptameric glycan. In addition, we confirmed that the S-layer protein is modified with the same heptameric glycan, suggesting a common N-glycosylation pathway. The M. thermolithotrophicus archaellin N-linked glycan is larger and more complex than those previously identified on the archaellins of related mesophilic methanogens, Methanococcus voltae and Methanococcus maripaludis. This could indicate that the nature of the glycan modification may have a role to play in maintaining stability at elevated temperatures.

Mass spectrometric method for the unambiguous profiling of cellular dynamic glycosylation

ABSTRACTVarious biological processes at the cellular level are regulated by glycosylation which is a highly micro-heterogeneous post-translational modification (PTM) on proteins and lipids. The dynamic nature of glycosylation can be studied through bio-orthogonal tagging of metabolically engineered non-natural sugars into glycan epitopes. However, this approach possesses a significant drawback due to non-specific background reactions and ambiguity of non-natural sugar metabolism. Here we report a tag-free strategy for their direct detection by glycoproteomics and glycomics using mass spectrometry. The method dramatically simplifies the detection of non-natural functional group bearing monosaccharides installed through promiscuous sialic acid, GalNAc, and GlcNAc biosynthetic pathways. Multistage enrichment of glycoproteins by cellular fractionation, subsequent ZIC-HILIC based glycopeptide enrichment, and a spectral enrichment algorithm for the MS data processing enabled direct detection of non-natural monosaccharides that are incorporated at low abundance on the N/O-glycopeptides along with their natural counterparts. Our approach allowed the detection of both natural and non-natural sugar bearing glycopeptides, N and O-glycopeptides, differentiation of non-natural monosaccharide types on the glycans and also their incorporation efficiency through quantitation. Through this we could deduce some interconversion of monosaccharides during their processing through glycan salvage pathway and subsequent incorporation into glycan chains. The study of glycosylation dynamics through this method can be conducted in high throughput as few sample processing steps are involved, enabling understanding of glycosylation dynamics under various external stimuli and thereby could bolster the use of metabolic glycan engineering in glycosylation functional studies.

Mo or W catalysts promoted with Ni or Co supported on modified bentonite for decane hydroconversion

A clay mineral-type modified bentonite, produced via delamination and subsequent incorporation of AlZr and AlCe species to modulate their acid properties, was used to obtain bifunctional catalysts with the incorporation of NiMo, CoMo, NiW and CoW.