Synthesis of one‐dimensional nanofibers with distinct topological (higher‐order structural) domains in the same main chain is one of the challenging topics in modern supramolecular polymer chemistry. ...Non‐uniform structural transformation of supramolecular polymer chains by external stimuli may enable preparation of such nanofibers. To demonstrate feasibility of this post‐polymerization strategy, we prepared a photoresponsive helically folded supramolecular polymers from a barbiturate monomer containing an azobenzene‐embedded rigid π‐conjugated scaffold. In contrast to previous helically folded supramolecular polymers composed of a more flexible azobenzene monomer, UV‐light induced unfolding of the newly prepared helically folded supramolecular polymers occurred nonuniformly, affording topological block copolymers consisting of folded and unfolded domains. The formation of such blocky copolymers indicates that the photoinduced unfolding of the helically folded structures initiates from relatively flexible parts such as termini or defects. Spontaneous refolding of the unfolded domains was observed after visible‐light irradiation followed by aging to restore fully folded structures.
Helically folded supramolecular polymers with a high internal rigidity undergo non‐uniform unfolding upon UV‐irradiation, affording topological block nanofibers consisting of two distinct domains with helically folded and unfolded structures.
Glioblastoma is the most lethal primary malignant brain tumor in adults. Simplified two-dimensional (2D) cell culture and neurospheres in vitro models fail to recapitulate the complexity of the tumor ...microenvironment, limiting its ability to predict therapeutic response. Three-dimensional (3D) scaffold-based models have emerged as a promising alternative for addressing these concerns. One such 3D system is gelatin methacrylate (GelMA) hydrogels, and we aimed to understand the suitability of using this system to mimic treatment-resistant glioblastoma cells that reside in specific niches. We characterized the phenotype of patient-derived glioma cells cultured in GelMA hydrogels (3D-GMH) for their tumorigenic properties using invasion and chemoresponse assays. In addition, we used integrated single-cell and spatial transcriptome analysis to compare cells cultured in 3D-GMH to neoplastic cells in vivo. Finally, we assessed tumor-immune cell interactions with a macrophage infiltration assay and a cytokine array. We show that the 3D-GMH system enriches treatment-resistant mesenchymal cells that are not represented in neurosphere cultures. Cells cultured in 3D-GMH resemble a mesenchymal-like cellular phenotype found in perivascular and hypoxic regions and recruit macrophages by secreting cytokines, a hallmark of the mesenchymal phenotype. Our 3D-GMH model effectively mimics the phenotype of glioma cells that are found in the perivascular and hypoxic niches of the glioblastoma core in situ, in contrast to the neurosphere cultures that enrich cells of the infiltrative edge of the tumor. This contrast highlights the need for due diligence in selecting an appropriate model when designing a study's objectives.
The aim of this study was to assess the quality of life (QOL) and the severity of depression in people living with HIV/AIDS (PLWHA) and investigate its correlates. This was a cross-sectional study on ...700 PLWHA in India. World Health Organization QOL HIV (WHOQOL HIV-BREF) and Patient Health Questionnaire-9 (PHQ-9) were used to assess QOL and depression in PLWHA, respectively. The study population was divided into five groups on the basis of Cluster of Differentiation 4 (CD4) count as follows: Group A < 50 cells/μL, Group B 50-199 cells/μL, Group C 200-349 cells/μL, Group D 350-499 cells/μL, and Group E >500 cells/μL. The lowest mean scores were noted under Group A < 50 cells/μL in physical and psychological domains and the highest mean scores were noted under Group E > 500 cells/μL in physical and environment domains. PHQ9 scores negatively correlated with QOL domains and the correlation was statistically significant (p < 0.001) with the highest negative correlation was found in relation to the psychological domain (r = -0.739). The PHQ9 score in those who do not have opportunistic illnesses (7.23 ± 6.14) was lower in comparison to those who had opportunistic illnesses (9.81 ± 6.40) and the difference was statistically significant (p < 0.001). We observed that there was almost a chronological increase in the individual QOL domain score and a decrease in the PHQ9 score with an increase in CD4 count. Our result supports the implementation of routine screening for depression in antiretroviral therapy centers and multidisciplinary interventions to improve outcomes among depressed PLWHA.
The dimethylamino functionality has significant importance in industrially relevant molecules and methodologies to install these efficiently are highly desirable. We report herein a highly efficient, ...room-temperature dimethylamination of chloroheteroarenes performed via the in-situ generation of dimethylamine using N,N-dimethylformamide (DMF) as precursor wiith a large substrate scope that includes various heteroarenes, purines as well as commercially relevant drugs such as altretamine, ampyzine and puromycin precursor.
Background model of the CUPID-0 experiment Azzolini, O.; Beeman, J. W.; Bellini, F. ...
The European physical journal. C, Particles and fields,
07/2019, Letnik:
79, Številka:
7
Journal Article
Recenzirano
Odprti dostop
CUPID-0 is the first large mass array of enriched Zn
82
Se scintillating low temperature calorimeters, operated at LNGS since 2017. During its first scientific runs, CUPID-0 collected an exposure of ...9.95 kg year. Thanks to the excellent rejection of
α
particles, we attained the lowest background ever measured with thermal detectors in the energy region where we search for the signature of
82
Se
neutrinoless double beta decay. In this work we develop a model to reconstruct the CUPID-0 background over the whole energy range of experimental data. We identify the background sources exploiting their distinctive signatures and we assess their extremely low contribution down to
∼
10
-
4
counts/(keV kg year) in the region of interest for
82
Se
neutrinoless double beta decay search. This result represents a crucial step towards the comprehension of the background in experiments based on scintillating calorimeters and in next generation projects such as CUPID.
The focus of the present study is to utilize a by‐product obtained during extraction of tocopherols, a valuable vitamin E compound, from sea buckthorn (SBT) oil and in doing so find a reliable ...alternative to petrochemical based polyols. Bio‐based polyurethane (PU) is prepared by using SBT oil based fatty acid methyl ester polyesteramide polyols (SBTPEP) with toluene diisocyanate (TDI). The fatty acid methyl ester is converted to the corresponding fatty amide by reaction with diethanolamine. The formed fatty amide is then esterified with phthalic anhydride to synthesize polyesteramide polyol. Characterization techniques used to evaluate polyesteramide polyol are Fourier‐transform infrared spectroscopy (FTIR) and NMR. The cured PU coating is also put through various mechanical tests to analyze the physical properties. The cured PU coating shows good surface and mechanical properties. It shows a gloss value of 87.4 and passes impact, adhesion, and chemical resistance tests. It is hydrophobic which is evident from its contact angle of 100.2°. It has good thermal stability which is evident by its glass transition temperature of 53.9 °C. Use of phthalic anhydride contributes to the bio‐based characteristics of synthesized PU.
Practical Application: The present study presents a synthesis route which has minimal dependence on hazardous feedstock by utilization of green feedstock. The results obtained from physical and mechanical evaluations favor the use of this PU formulation in the coating sector. The adhesion and impact strength test results show potential application in the industrial sector coatings where the applied coat must be able to withstand high levels of physical stress and strain. The presence of aromatic rings and oil‐based moiety, that is the fatty acid hydrocarbon chain, contributes to the hydrophobic nature of the PU coating. Hydrophobic coatings have tremendous application in various fields such as marine coatings, automotive, electronics, and decorative coatings. These are potential fields of application for the synthesized green PU coating obtained from tocopherol extraction by‐products.
Utilization of oil byproducts helps to develop sustainable synthesis routes. One such byproduct is fatty acid (which is then esterified with methanol) during the tocopherol extraction from sea buckthorn oil. This fatty acid methyl ester is further subjected to chemical modifications of amidation and esterification to yield polyester polyol which is used to form polyurethane resin by crosslinking with an isocyanate.
The Full Dimension-MIMO (FD-MIMO) technology is capable of achieving huge improvements in network throughput with simultaneous connectivity of a large number of mobile wireless devices, unmanned ...aerial vehicles, and the Internet of Things (IoT). In the Long Term Evolution (LTE), with a large number of antennae at the base station and the ability to perform beamforming, the capacity of the physical downlink shared channel (PDSCH) has increased a lot. However, the current 3rd Generation Partnership Project (3GPP) specifications of the LTE do not allow the base station to perform any beamforming techniques for the physical downlink control channel (PDCCH). Hence, PDCCH has neither the capacity nor the coverage of PDSCH. Therefore, PDCCH capacity still limits the performance of a network, as it dictates the number of users that a base station can schedule at a given time instant. In Release 11, 3GPP introduced enhanced PDCCH (EPDCCH) to increase the PDCCH capacity at the cost of sacrificing the PDSCH resources. The problem of enhancing the PDCCH capacity within the available control channel resources has not been addressed yet in the literature. Hence, in this paper, we propose a novel beamformed PDCCH (BF-PDCCH) design which is aligned to the 3GPP specifications and requires simple software changes at the base station. For the evaluation of the proposed BF-PDCCH, we model various link abstractions. We evaluate them through link-level simulations and then use all these abstractions in the system-level simulations. We show that the proposed BF-PDCCH achieves significant improvement in network throughput and outperforms the current state of the art algorithms, PDCCH, and EPDCCH schemes.
We use monodisperse dendrons that allow control over functional group presentation to investigate the influence of the location of a ligand on protein-induced disassembly and release of encapsulated ...small molecules. Based on both experiments and molecular dynamics simulations, we demonstrate that ligand location greatly influences release of guest molecules from the dendron-based supramolecular assembly. We show that a ligand moiety grafted to the dendron periphery is more accessible for the target protein in aqueous solution. On the other hand, the ligand moiety placed at the focal point or at the intermediate layer within the dendritic scaffold is less accessible, since it is surrounded by an environment rich in PEG chains, which hinders binding and even influences nonspecific interactions. We also demonstrate that the specific binding between one ligand and the target protein can destabilize the dendritic assembly. Furthermore, if more ligands are available, multivalent interactions are also possible with extravidin, which speed up disassembly and trigger the release of hydrophobic guests.
The possibility to arrange biological molecules into ordered nanostructures is an important issue in nano- and biotechnology. Nature offers a wide range of molecular “bricks” (e.g., proteins, ...oligonucleotides, etc.) that spontaneously assemble into more complex hierarchical systems with unique functionalities. Such molecular building blocks can be also used for the construction of nanomaterials with peculiar properties (e.g., DNA origami). In some cases, molecular glues able to bind biomolecules and to induce their assembly can be used to control the final structure and properties in a convenient way. Here we provide molecular-level description of how molecular glues designed to stick to the surface of microtubules (MTs) can control and transform the α/β-tubulin assembly upon temperature decreasing. By means of all-atom molecular dynamics (MD) simulations, we compared the adhesion to the MT surface of three molecular glues bearing the same guanidinium ion surface adhesive groups, but having different architecture, i.e., linear or dendritic backbone. Our evidence demonstrates that the adhesive properties of the different molecular glues are dependent on the shape they assume in solution. In particular, adhesion data from our MD simulations explain how globular- or linear-like molecular glues respectively stabilize MTs or transform them into a well-defined array of α/β-tubulin rings at 15 °C, where MTs naturally depolymerize. The comprehension of the MT transformation mechanism provides a useful rationale for designing ad hoc molecular glues to obtain ordered protein nanostructures from different biological materials.
A 10-year-long evolution of ice thickness and volume of the Marmolada glacier is presented. Quantitative measurements have been performed by using two different Ground Penetrating Radar (GPR) ...datasets. A ground-based survey using two different ground-coupled systems equipped with 100 MHz and 35 MHz antennas was performed in 2004. In 2015 the dataset was collected by using a helicopter-borne step frequency GPR equipped with a 100 MHz antenna. Through a critical discussion of the two different methodologies, we show how both approaches are useful to estimate the ice volume within a glacier, as well as its morphological characteristics and changes with time, even if datasets are acquired in different periods of the year.
The observed 2004–2014 ice volume reduction of the Marmolada glacier is equal to about 30%, while the area covered by ice decreased by about 22%. The glacier is now splitted in several separated units. It is very likely that the fragmentation of the Marmolada glacier observed in the period 2004–2014 was accelerated due to irregular karst topography. By applying the observed 2004–2014 ice-melting trend for the future although the Marmolada glacier might behave slightly differently compared to glaciers on non-karstic terrains owing to dominant vertical subglacial drainage, it will likely disappear by the year 2050. Only few isolated very small and thin ice patches will eventually survive due to avalanche feeding and shading at the foot of the north-facing cliffs.
•Helicopter borne and ground based GPR surveys allow estimation of ice volume changes.•GPR demonstrated its high applicability along the whole glaciological year.•10-year-long evolution of Marmolada glacier ice thickness.•Changes in geometry and hypsometry of the glacier result in change of glacier behaviour.•If the glacier keeps shrinking at the same observed rate, it will likely disappear by 2050.
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