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The solution behavior of poly(butylene terephthalate) (PBT) copolyesters with dilinoleic monomer units (dilinoleic diol (LD) / dilinoleic diacid (LA)) is studied to understand the processing behavior from melt. NMR investigations show that the short‐chain branches are characterized by a distribution of different alkyl chain lengths, where n‐butyl (C4) and longer chains have the largest content (>55 mol%). High‐temperature size exclusion chromatography with threefold detection (multi‐angle light‐scattering, refractive index, and viscosity detector) in 1,2,4‐trichlorobenzene is performed to determine molar masses, hydrodynamic radii, viscosity radii, and Kuhn–Mark–Houwink–Sakurada (KMHS) exponents α in dependence of the molar amount of short‐chain branched comonomers. Low concentrations of dilinoleic comonomers in PBT copolyesters improve the solubility of the copolyesters significantly. Higher amounts cause contraction of the polymer coils as illustrated by smaller hydrodynamic radii as well as lower KMHS exponents. The α values decrease with increasing amount of short‐chain branched comonomer except for very low concentrations. The solution behavior of LA and LD copolyesters with a higher aliphatic content shows different trends of the influence of short‐chain branches on the melt behavior, which reflects the influence of intramolecular versus intermolecular entanglements in solution and in melt. [ABSTRACT FROM AUTHOR]

The construction of multiple heptagonal rings in nanographene is the key step for obtaining exotic carbon nanostructures with a negative curvature and intriguing properties. Herein, a novel saddle-shaped nanographene ( 1 ) with four embedded heptagons is synthesized via a highly efficient one-shot Scholl reaction from a predesigned oligophenylene precursor. Notably, a quadruple [6]helicene intermediate was also obtained and isolated by controlling the Scholl reaction conditions. Interestingly, the single crystal structures of 1 display a saddle geometry induced by the four embedded heptagons, resulting in a deep curvature with a width of 16.5 Å and a depth of 8.0 Å. Theoretical calculations at the molecular level suggest a weak antiaromatic character of the heptagons in 1 . Remarkably, compound 1 exhibits dual fluorescence from S 1 and S 2 . The deep-saddle-shaped geometry in 1 defines host-guest interactions with fullerenes, which were explored in titration experiments and by theoretical methods. The resulting 1@C 60 are stable and are subject to an electron transfer from photoexcited 1 to C 60 . Our current study underscores the influence of heptagon rings on the photophysical, self-assembly, and electron-donating properties of NGs.

Background: Post-stroke fatigue (PSF) affects 50% of stroke survivors. Current guidance on management of this condition is limited., Aims: This systematic review and meta-analysis aimed to identify and analyze all randomized clinical trials (RCTs) of non-pharmacological interventions for the treatment of PSF., Summary of Review: Six electronic databases were searched from inception to January 2023 for English-language RCTs investigating the efficacy of non-pharmacological interventions versus passive controls in patients with PSF. The primary outcome was fatigue severity at the end of the intervention. The Cochrane risk-of-bias (ROB)2 tool was used to assess evidence quality. A total of 7990 records were retrieved, 333 studies were scrutinized, and 13 completed RCTs (484 participants) were included. Interventions included psychological therapies, physical therapies, and brain stimulation. Nine studies provided sufficient data for meta-analysis, of which seven also had follow-up data. Fatigue severity was lower in the intervention groups at the end of the intervention compared with control (participants = 310, standardized mean difference (SMD) = -0.57, 95% confidence intervals (CIs) (-0.87 to -0.28)) and at follow-up (participants = 112, SMD = -0.36, 95% CIs (-0.83 to 0.10)). Certainty in the effect estimate was downgraded to low for a serious ROB and imprecision. Subgroup analysis revealed significant benefits with physical therapy and brain stimulation but not psychological therapies, though sample sizes were low., Conclusion: Non-pharmacological interventions improved fatigue but the quality of evidence was low. Further RCTs are needed for PSF management., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Helical nanographenes with high quantum yields and strong chiroptical responses are pivotal for developing circularly polarized luminescence (CPL) materials. Here, we present the successful synthesis of novel π-extended double [7]helicenes (ED7Hs) where two helicene units are fused at the meta- or para-position of the middle benzene ring, respectively, as the structural isomers of the reported ortho-fused ED7H. The structural geometry of these ED7Hs is clearly characterized by single-crystal X-ray analysis. Notably, this class of ED7Hs exhibits bright luminescence with high quantum yields exceeding 40 %. Through geometric regulation of two embedded [7]helicene units from ortho-, meta- to para-position, these ED7Hs display exceptional amplification in chiroptical responses. This enhancement is evident in a remarkable approximate fivefold increase in the absorbance and luminescence dissymmetry factors (g abs and g lum ), respectively, along with a boosted CPL brightness up to 176 M -1  cm -1 , surpassing the performance of most helicene-based chiral NGs. Furthermore, DFT calculations elucidate that the geometric adjustment of two [7]helicene units allows the precise alignment of electric and magnetic transition dipole moments, leading to the observed enhancement of their chiroptical responses. This study offers an effective strategy for magnifying the CPL performance in chiral NGs, promoting their expanded application as CPL emitters., (© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Computed tomography (CT) imaging of the thorax is widely used for the detection and monitoring of pulmonary embolism (PE). However, CT images can contain artifacts due to the acquisition or the processes involved in image reconstruction. Radiologists often have to distinguish between such artifacts and actual PEs. We provide a proof of concept in the form of a scalable hypothesis testing method for CT, to enable quantifying uncertainty of possible PEs. In particular, we introduce a Bayesian Framework to quantify the uncertainty of an observed compact structure that can be identified as a PE. We assess the ability of the method to operate under high-noise environments and with insufficient data., (© The Author(s) 2024. Published by Oxford University Press on behalf of National Academy of Sciences.)

Due to some useful mechanical, dynamic, and dielectric properties along with the ease of processing and forming, liquid rubbers are ideal materials for fabricating dielectric elastomer actuators in various configurations and for many potential applications ranging from automation to automobile and medical industry. In this study, we present a cross-linkable liquid rubber composition where amine-catalyzed esterification reactions lead to the formation of a network structure based on anhydride functional isoprene rubber, carboxyl-terminated nitrile-butadiene rubber, and epoxy end-capped prepolymers. The success of this intricate network formation procedure was verified by HR-MAS NMR spectroscopy. The new isoprene-based elastomeric material exhibits actuation-relevant attributes including a low elastic modulus of 0.45 MPa, soft response to an applied load up to a large deformation of 300%, and a dielectric constant value (2.6) higher than the conventional Elastosil silicone (2.2). A dot actuator comprising of an isoprene dielectric elastomer film in unstretched state and carbon paste electrodes was fabricated that demonstrated an electrode deformation of 0.63%, which is nearly twice as high as for the commercial Elastosil 2030 film (∼0.30%) at 5 kV. Compared to the Elastosil silicone film, the enhanced performance is attributed to the low modulus and high dielectric constant value of the new isoprene elastomer., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Graphene nanoribbons (GNRs) have garnered significant interest due to their highly customizable physicochemical properties and potential utility in nanoelectronics. Besides controlling widths and edge structures, the inclusion of chirality in GNRs brings another dimension for fine-tuning their optoelectronic properties, but related studies remain elusive owing to the absence of feasible synthetic strategies. Here, we demonstrate a novel class of cove-edged chiral GNRs ( CcGNRs ) with a tunable chiral vector ( n , m ). Notably, the bandgap and effective mass of ( n ,2)-CcGNR show a distinct positive correlation with the increasing value of n , as indicated by theory. Within this GNR family, two representative members, namely, (4,2)-CcGNR and (6,2)-CcGNR , are successfully synthesized. Both CcGNRs exhibit prominently curved geometries arising from the incorporated [4]helicene motifs along their peripheries, as also evidenced by the single-crystal structures of the two respective model compounds ( 1 and 2 ). The chemical identities and optoelectronic properties of (4,2)- and (6,2)-CcGNRs are comprehensively investigated via a combination of IR, Raman, solid-state NMR, UV-vis, and THz spectroscopies as well as theoretical calculations. In line with theoretical expectation, the obtained (6,2)-CcGNR possesses a low optical bandgap of 1.37 eV along with charge carrier mobility of ∼8 cm 2 V -1 s -1 , whereas (4,2)-CcGNR exhibits a narrower bandgap of 1.26 eV with increased mobility of ∼14 cm 2 V -1 s -1 . This work opens up a new avenue to precisely engineer the bandgap and carrier mobility of GNRs by manipulating their chiral vector.

Helical nanographenes (NGs) have attracted increasing attention recently because of their intrinsic chirality and exotic chiroptical properties. However, the efficient synthesis of extended helical NGs featuring a multilayer topology is still underdeveloped, and their layer-dependent chiroptical properties remain elusive. In this study, we demonstrate a modular synthetic strategy to construct a series of novel helical NGs ( 1 - 3 ) with a multilayer topology through a consecutive Diels-Alder reaction and regioselective cyclodehydrogenation from the readily accessible phenanthrene-based precursors bearing ethynyl groups. The resultant NGs exhibit bilayer, trilayer, and tetralayer structures with elongated π extension and rigid helical backbones, as unambiguously confirmed by single-crystal X-ray or electron diffraction analysis. We find that the photophysical properties of these helical NGs are notably influenced by the degree of π extension, which varies with the number of layers, leading to obvious redshifted absorption, a fast rising molar extinction coefficient (ε), and markedly boosted fluorescence quantum yield (Φ f ). Moreover, the embedded [7]helicene subunits in these NGs result in stable chirality, enabling both chiral resolution and exploration of their layer-dependent chiroptical properties. Profiting from the good alignment of electric and magnetic dipole moments determined by the multilayer structure, the resultant NGs exhibit excellent circular dichroism and circularly polarized luminescence response with unprecedented high CPL brightness up to 168 M -1 cm -1 , rendering them promising candidates for CPL emitters.

Efficient organic electronic devices are fabricated from both small molecules and disperse polymers, but materials with characteristics in between remain largely unexplored. Here, we present a gram-scale synthesis for a series of discrete n-type oligomers comprising alternating naphthalene diimide (NDI) and bithiophene (T2). Using C-H activation, discrete oligomers of type T2-(NDI-T2) n ( n ≤ 7) and persistence lengths up to ∼10 nm are made. The absence of protection/deprotection reactions and the mechanistic nature of Pd-catalyzed C-H activation allow one to produce symmetrically terminated species almost exclusively, which is key to the fast preparation, high yields, and the general success of the reaction pathway. The reaction scope includes different thiophene-based monomers, end-capping to yield NDI-(T2-NDI) n ( n ≤ 8), and branching at T2 units by nonselective C-H activation under certain conditions. We show how the optical, electronic, thermal, and structural properties depend on oligomer length along with a comparison to the disperse, polymeric analogue PNDIT2. From theory and experiments, we find that the molecular energy levels are not affected by chain length resulting from the strong donor-acceptor system. Absorption maxima saturate for n = 4 in vacuum and for n = 8 in solution. Linear oligomers T2-(NDI-T2) n are highly crystalline with large melting enthalpies up to 33 J/g; NDI-terminated oligomers show reduced crystallinity, stronger supercooling, and more phase transitions. Branched oligomers and those with bulky thiophene comonomers are amorphous. Large oligomers exhibit similar packing characteristics compared to PNDIT2, making these oligomers ideal models to study length-structure-function relationships at constant energy levels.

Introduction Increasing rectal size is associated with increased artefacts on magnetic resonance imaging (MRI) of the prostate and has the potential to degrade image quality. The objective of this study was to analyse the effect of oral laxative medication on rectal distension and image quality in prostate MRI. Methods Eighty patients prospectively received either 15 mg of oral senna (laxative group) or no medication (control group). Patients underwent prostate MRI according to standard local protocol and seven rectal dimensions on axial and sagittal images were measured. A subjective assessment of rectal distension was also made using a five-point Likert scale. Finally, artefacts on diffusion-weighted sequences were assessed using a four-point Likert scale. Results There was a small reduction in rectal diameter on sagittal images in the laxative group compared to the control group, with mean diameters of 27.1 mm and 30.0 mm respectively, p=0.02. There was no significant difference in rectal measurements of anteroposterior diameter, transverse diameter, or rectal circumference on axial imaging. Subjective scoring also demonstrated no significant difference in diffusion-weighted imaging quality between the laxative group and control group, p=0.82. Conclusion Bowel preparation with the oral laxative, senna, provided only a marginal decrease in rectal distension on one measure and no reduction in artefacts on diffusion-weighted sequences. The findings of this study do not support the routine use of this medication in patients undergoing prostate MRI., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Foley et al.)

Objectives: Whole-body single photon emission computed tomography/computed tomography (WB-SPECT/CT) is useful for diagnosing bone metastases. When performed on a dual-headed gamma camera, this may cover from clavicles to proximal femurs due to time constraints. In contrast, the novel 360 o cadmium-zinc-telluride scanner can perform WB-SPECT/CT (from vertex to toes) in approximately 20 min. The aim was to assess the prevalence of additional findings above the clavicles and below the lesser trochanters and the prevalence of incidental findings in the CT component., Methods: Retrospective study of 117 WB-SPECT/CT scans for oncological bone assessment over a 4-month-period. Scan analysis was performed by two independent experienced radionuclide radiologists., Results: The male:female ratio was 71:46 and the mean patient age was 68 years. The primary malignancies were predominantly prostate 65/117 (55.6%) and breast 40/117 (34.2%). There were additional findings of malignancy above the clavicles in 16/116 scans (13.8%) and below the lesser trochanters in 16/117 scans (13.7%). Two cases in the 'above the clavicles' group were suspected solitary metastases, whereas four cases in the 'below lesser trochanters' group were bone metastases at risk of pathological fracture. Incidental findings of clinical significance included suspected new malignancy in 11/117 (9.4%)., Conclusion: A WB-SPECT/CT (from vertex to toes) oncological bone protocol is useful for the detection of additional findings of clinical significance above the clavicles and below the lesser trochanters. Reviewing and reporting the CT findings in SPECT/CT is important., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

The precision synthesis of helical bilayer nanographenes (NGs) with new topology is of substantial interest because of their exotic physicochemical properties. However, helical bilayer NGs bearing non-hexagonal rings remain synthetically challenging. Here we present the efficient synthesis of the first helical bilayer nonbenzenoid nanographene (HBNG1) from a tailor-made azulene-embedded precursor, which contains a novel [10]helicene backbone with two embedded heptagons. Single-crystal X-ray analysis reveals its highly twisted bilayer geometry with a record small interlayer distance of 3.2 Å among the reported helical bilayer NGs. Notably, the close interlayer distance between the two layers offers intramolecular through-space conjugation as revealed by in situ spectroelectrochemistry studies together with DFT simulations. Furthermore, the chiroptical properties of the P/M enantiomers of HBNG1 are also evaluated by circular dichroism and circularly polarized luminescence., (© 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

The impact of phosphorus-containing flame retardants (FR) on rigid polyisocyanurate (PIR) foams is studied by systematic variation of the chemical structure of the FR, including non-NCO-reactive and NCO-reactive dibenzo[d,f][1,3,2]dioxaphosphepine 6-oxide (BPPO)- and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-containing compounds, among them a number of compounds not reported so far. These PIR foams are compared with PIR foams without FR and with standard FRs with respect to foam properties, thermal decomposition, and fire behavior. Although BPPO and DOPO differ by just one oxygen atom, the impact on the FR properties is very significant: when the FR is a filler or a dangling (dead) end in the PIR polymer network, DOPO is more effective than BPPO. When the FR is a subunit of a diol and it is fully incorporated in the PIR network, BPPO delivers superior results.

Aim: To assess improvement in arterial opacification by optimising the contrast medium dosing protocol for computed tomography (CT) prior to trans-catheter aortic valve implantation (TAVI)., Materials and Methods: A wide variation in arterial opacification was observed in the initial CT TAVI protocol (standard protocol). The practice was optimised by considering the time required for the examination and optimising contrast medium flux. This became the optimised protocol with a 30-second contrast medium bolus of iodine flux 15-19 mg iodine/kg body weight/second (mg/kg/s). Attenuation (mean HU) in (a) the ascending aorta (gated systolic acquisition) and (b) the ascending, descending thoracic (at carina), infra-renal abdominal aorta, and right common iliac artery (non-gated acquisition) was measured. Thirty-one sequential optimised examinations were compared to 31 prior standard protocol examinations., Results: There was no difference between the standard and optimised groups regarding age, sex, weight, body mass index (BMI), or voltage. The mean bolus durations were 24.9±4.4 seconds for the standard and 30±0.3 seconds for the optimised protocols (p<0.001). Although there was no difference in the attenuation in the gated ascending aorta (p>0.99), there was improvement at all other anatomical points in the non-gated examinations of the optimised protocol (p<0.002)., Conclusion: Optimising contrast medium flux and matching bolus duration to the CT technology dramatically improves the vascular access component of TAVI planning and provides a reliable method to achieve objectively enhanced arterial opacification. This work highlights how to obtain good arterial contrast medium opacification in haemodynamically fragile patients without excessive contrast medium volumes., (Copyright © 2022 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Aim: To determine the diagnostic accuracy of an automated artificial intelligence derived right ventricle/left ventricle diameter ratio (RV/LV) computed tomography pulmonary angiography (CTPA) analysis tool to detect pulmonary hypertension (PH) in patients with suspected PH referred to a specialist centre., Materials and Methods: The present study was a retrospective analysis of a prospectively maintained database of 202 consecutive patients with suspected PH, who underwent CTPA within 12 months of right heart catheterisation (RHC). Automated ventricular segmentation and RV/LV calculation (Imbio LLC, Minneapolis, MN, USA) was undertaken on the CTPA images. PH diagnosis was made using the RHC reference standard., Results: The automated RV/LV correlated more strongly with RHC metrics than main pulmonary artery (MPA) diameter and MPA to ascending aorta diameter ratio (MPA/AA) measured manually (mean pulmonary arterial pressure [mPAP] r=0.535, R 2  = 0.287 p<0.001; pulmonary vascular resistance [PVR] r=0.607, R 2  = 0.369 p<0.001). In the derivation cohort (n=100), the area under the receiver-operating curve for automated RV/LV discriminating PH was 0.752 (95% confidence interval [CI] 0.677-0.827, p<0.001). Using an optimised Youden's Index of ≥1.12 classified from derivation, automated RV/LV ratio analysis was more sensitive for the detection of PH with higher positive predictive value (PPV) when compared with manual MPA and MPA/AA in the validation cohort (n=102). Automated RV/LV compromise (1.12) and specific (1.335) thresholds were strongly predictive of mortality (log-rank 7.401, p=0.007 and log-rank 16.075, p<0.001 respectively)., Conclusion: In suspected PH, automated RV/LV diameter thresholds have high sensitivity for PH, outperform manual MPA and MPA/AA and can predict survival., (Crown Copyright © 2022. Published by Elsevier Ltd. All rights reserved.)

Curved graphene nanoribbons (GNRs) with hybrid edge structures have recently attracted increasing attention due to their unique band structures and electronic properties as a result of their nonplanar conformation. This work reports the solution synthesis of a long and curved multi-edged GNR (cMGNR) with unprecedented cove-armchair-gulf edge structures. The synthesis involves an efficient A 2 B 2 -type Diels-Alder polymerization between a diethynyl-substituted prefused bichrysene monomer (3b) and a dicyclopenta[e,l]pyrene-5,11-dione derivative (6) followed by FeCl 3 -mediated Scholl oxidative cyclodehydrogenation of the obtained polyarylenes (P1). Model compounds 1a and 1b are first synthesized to examine the suitability and efficiency of the corresponding polymers for the Scholl reaction. The successful formation of cMGNR from polymer P1 bearing prefused bichrysene units is confirmed by FTIR, Raman, and solid-state NMR analyses. The cove-edge structure of the cMGNR imparts the ribbon with a unique nonplanar conformation as revealed by density functional theory (DFT) simulation, which effectively enhances its dispersibility in solution. The cMGNR has a narrow optical bandgap of 1.61 eV, as estimated from the UV-vis absorption spectrum, which is among the family of low-bandgap solution-synthesized GNRs. Moreover, the cMGNR exhibits a carrier mobility of ≈2 cm 2 V -1 s -1 inferred from contact-free terahertz spectroscopy., (© 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Open-shell non-alternant polycyclic hydrocarbons (PHs) are attracting increasing attention due to their promising applications in organic spintronics and quantum computing. Herein we report the synthesis of three cyclohepta[def]fluorene-based diradicaloids (1-3), by fusion of benzo rings on its periphery for the thermodynamic stabilization, as evidenced by multiple characterization techniques. Remarkably, all of them display a very narrow optical energy gap (E g opt =11.7-33.3 h). More importantly, this new type of diradicaloids possess a low-lying triplet state with an extremely small singlet-triplet energy gap, as low as 0.002 kcal mol 1/2 =11.7-33.3 h). More importantly, this new type of diradicaloids possess a low-lying triplet state with an extremely small singlet-triplet energy gap, as low as 0.002 kcal mol -1 , with a clear dependence on the molecular size. This family of compounds thus offers a new route to create non-alternant open-shell PHs with high-spin ground states, and opens up novel possibilities and insights into understanding the structure-property relationships., (© 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Anti-(ds)-DNA antibodies are the serological hallmark of Systemic Lupus Erythematosus (SLE). They assemble in the bloodstream with (ds)-DNA, forming immunocomplexes, which spread all over the body causing, among the other symptoms, lupic glomerulonephritis. Pathological manifestations of the disease may be reduced by destabilizing or inhibiting the formation of the immunocomplexes. In this respect, glycodendrimers showed peculiar interacting abilities towards this kind of biomolecule. Various generations of open-shell maltose-decorated poly(amidoamine) (PAMAM) and poly(propyleneimine) (PPI) dendrimers and two oligopeptides with different polyethylene glycol units were synthesized and characterized, and then tested for their anti-SLE activity. The activity of glycodendrimers and oligopeptides was evaluated in human plasma from patients with SLE, compared to healthy plasma, by means of an enzyme-linked immunosorbent assay (ELISA), and electron paramagnetic resonance (EPR) characterization using spin-label and spin-probe techniques. Different strategies for the immunocomplex formation were tested. The results show that both kinds of glycodendrimers and oligopeptides inhibited the formation of immunocomplexes. Also, a partial breakdown of preformed immunocomplexes was observed. Both ELISA and EPR analyses indicated a better activity of glycodendrimers compared to oligopeptides, the 3 rd generation PPI dendrimer being the most promising against SLE. This study highlights the possibility to develop a new class of dendritic therapeutics for the treatment of Lupus in pre-clinical studies.

Aims: To explore whether the novel 360° gamma camera design of VERITON-CT adversely affects the rate of scan non-completion due to claustrophobia or other patient experience factors, when compared to a standard dual-headed gamma camera. Methods: Single centre prospective study of all nuclear medicine studies on either of two gamma cameras; the VERITON-CT (Spectrum Dynamics Medical) and Discovery NM/CT 670 (GE Healthcare). It was recorded whether the patient had completed the scan as protocoled or, due to claustrophobia, had a shortened scan or no scan. The patients were also offered a patient experience questionnaire, with domains of comfort, scan time, scan noise and claustrophobia assessed using a five-point Likert scale. Results: Over a four-month period, there were 296 patients scanned on the Discovery scanner and 274 patients scanned on the VERITON-CT scanner. There was a scan non-completion rate, due to claustrophobia, of 1.35 % for the Discovery and 1.46 % for the VERITON-CT scanner. 354/570 (62%) of all patients involved returned their questionnaires. There was no statistical difference between the responses for comfort, scan time, scan noise and feelings of claustrophobia. Conclusion: The study provides evidence that the novel 360° gamma camera design of VERITON-CT does not lead to a significantly increased scan failure rate due to claustrophobia and there is no change in the subjective experience for patients., (Copyright © 2021 by the Society of Nuclear Medicine and Molecular Imaging, Inc.)