Plastic ingestion by marine biota has been reported for a variety of different taxa. In this study, we investigated 290 gastrointestinal tracts of demersal (cod, dab and flounder) and pelagic fish ...species (herring and mackerel) from the North and Baltic Sea for the occurrence of plastic ingestion. In 5.5% of all investigated fishes, plastic particles were detected, with 74% of all particles being in the microplastic (<5mm) size range. The polymer types of all found particles were analysed by means of Fourier transform infrared (FT-IR) spectroscopy. Almost 40% of the particles consisted of polyethylene (PE). In 3.4% of the demersal and 10.7% of the pelagic individuals, plastic ingestion was recorded, showing a significantly higher ingestion frequency in the pelagic feeders. The condition factor K was calculated to test differences in the fitness status between individuals with and without ingested plastic, but no direct effect was detected.
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•5.5% of all investigated fishes had ingested plastic.•Significant higher ingestion frequency in pelagic feeders•Identification of the polymer type of all plastic particles•Essential controls to quantify contamination
The implementation of molecular machines in polymer science is of high interest to transfer mechanical motions from nanoscale to macroscale in order to access new kinds of active devices and ...materials. Toward this objective, thermodynamic and topological aspects need to be explored for reaching efficient systems capable of producing a useful work. In this paper we describe the branched polymerization of pH-sensitive bistable c2 daisy chain rotaxanes by using copper(I)-catalyzed Huisgen 1,3-dipolar cycloaddition (“click chemistry”). With this cross-linked topology, the corresponding materials in the form of chemical gels can be contracted and expanded over a large variation of volume (∼50%) by changing the protonation state of the system. HR-MAS 1H NMR and neutron scattering experiments reveal that this macroscopic response of the gels results from the synchronized actuation of the mechanical bonds at the molecular level.
In randomized trials, the term "double-blind" (and its derivatives, single- and triple-blind, fully blind, and partially blind or masked) has no standard or widely accepted definition. Agreement ...about which groups are blinded is poor, and authors using these terms often do not identify which groups were blinded, despite specific reporting guidelines to the contrary. Nevertheless, many readers assume-incorrectly-that they know which groups are blinded. Thus, the term is ambiguous at best, misleading at worst, and, in either case, interferes with the accurate reporting, interpretation, and evaluation of randomized trials. The problems with the terms have been thoroughly documented in the literature, and many authors have recommended that they be abandoned.
We and our co-signers suggest eliminating the use of adjectives that modify "blinding" in randomized trials; a trial would be described as either blinded or unblinded. We also propose that authors report in a standard table which groups or individuals were blinded, what they were blinded to, how blinding was implemented, and whether blinding was maintained. Individuals with dual responsibilities, such as caregiving and data collecting, would also be identified. If blinding was compromised, authors should describe the potential implications of the loss of blinding on interpreting the results.
"Double blind" and its derivatives are terms with little to recommend their continued use. Eliminating the use of adjectives that impart a false specificity to the term would reduce misinterpretations, and recommending that authors report who was blinded to what and how in a standard table would require them to be specific about which groups and individuals were blinded.
We investigate the edge-state magnetism of graphene nanoribbons using projective quantum Monte Carlo simulations and a self-consistent mean-field approximation of the Hubbard model. The static ...magnetic correlations are found to be short ranged. Nevertheless, the correlation length increases with the width of the ribbon such that already for ribbons of moderate widths we observe a strong trend towards mean-field-type ferromagnetic correlations at a zigzag edge. These correlations are accompanied by a dominant low-energy peak in the local spectral function and we propose that this can be used to detect edge-state magnetism by scanning tunneling microscopy. The dynamic spin structure factor at the edge of a ribbon exhibits an approximately linearly dispersing collective magnonlike mode at low energies that decays into Stoner modes beyond the energy scale where it merges into the particle-hole continuum.
In their 4000-year history, abstracts have taken several forms and represented a variety of documents. The scientific journal emerged in the 1600s and gave rise to what would become the modern ...scientific abstract. Here, I describe the contexts in which abstracts evolved, address the subtexts of opinions about their purpose, and review the texts of 12 kinds of abstracts. For most readers, articles do not exist beyond abstracts. However, the quality of abstracts is often poor. Inaccuracies are common, serious, widespread, and long-standing. Abstracts should inform only the choice of what to read and never what to do.
Poor bone quality contributes to bone fragility in diabetes, aging, and osteogenesis imperfecta. However, the mechanisms controlling bone quality are not well understood, contributing to the current ...lack of strategies to diagnose or treat bone quality deficits. Transforming growth factor beta (TGF-β) signaling is a crucial mechanism known to regulate the material quality of bone, but its cellular target in this regulation is unknown. Studies showing that osteocytes directly remodel their perilacunar/canalicular matrix led us to hypothesize that TGF-β controls bone quality through perilacunar/canalicular remodeling (PLR). Using inhibitors and mice with an osteocyte-intrinsic defect in TGF-β signaling (TβRIIocy−/−), we show that TGF-β regulates PLR in a cell-intrinsic manner to control bone quality. Altogether, this study emphasizes that osteocytes are key in executing the biological control of bone quality through PLR, thereby highlighting the fundamental role of osteocyte-mediated PLR in bone homeostasis and fragility.
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•TGF-β is an osteocyte-intrinsic regulator of perilacunar/canalicular remodeling (PLR)•Osteocytes actively maintain bone quality through regulated control of PLR•Osteocytic PLR is the cellular mechanism by which TGF-β controls bone quality•Defects in PLR cause severe bone fragility, even when bone mass is normal
Resistance to fracture requires healthy bone mass and quality. However, the cellular mechanisms regulating bone quality are unclear. Dole et al. show that osteocyte-intrinsic TGF-β signaling maintains bone quality through perilacunar/canalicular remodeling. Thus, osteocytes mediate perilacunar/canalicular remodeling and osteoclast-directed remodeling to cooperatively maintain bone quality and mass and prevent fragility.
We study the quantum phases of fermions with an explicit SU(N)-symmetric, Heisenberg-like nearest-neighbor flavor exchange interaction on the honeycomb lattice at half filling. Employing projective ...(zero temperature) quantum Monte Carlo simulations for even values of N, we explore the evolution from a weak-coupling semimetal into the strong-coupling, insulating regime. Furthermore, we compare our numerical results to a saddle-point approximation in the large-N limit. From the large-N regime down to the SU(6) case, the insulating state is found to be a columnar valence bond crystal, with a direct transition to the semimetal at weak, finite coupling, in agreement with the mean-field result in the large-N limit. At SU(4) however, the insulator exhibits a subtly different valence bond crystal structure, stabilized by resonating valence bond plaquettes. In the SU(2) limit, our results support a direct transition between the semimetal and an antiferromagnetic insulator.
I've been a medical writer and author's editor for 45 years. I have read the instructions for authors in dozens of medical journals. I know what authors (and author's editors) think of these ...instructions, at least among those who know that journals actually have instructions for authors. For almost as long, I've been a member of four professional societies concerned with scientific publishing, and I know a lot of editors-in-chief of medical journals. I appreciate their desire to have authors follow the instructions when preparing manuscripts, at least among those editors who remember that their journals have such instructions and insist, at least occasionally, that they be followed.
Muscle forces are a strong determinant of bone structure, particularly during the process of growth and development. The gender divergence in the bone-muscle relationship becomes strongly evident ...during adolescence. In females, growth is characterized by increased estrogen levels and increased mass and strength of bone relative to that of muscle, whereas in men, increases in testosterone fuel large increases in muscle, resulting in muscle forces that coincide with a large growth in bone dimensions and strength. In adulthood, significant age-related losses are observed for both bone and muscle tissues. Large decrease in estrogen levels in women appears to diminish the skeleton's responsiveness to exercise more than in men. In contrast, the aging of the muscle-bone axis in men is a function of age related declines in both hormones. In addition to the well-known age related changes in the mechanical loading of bone by muscle, newer studies appear to provide evidence of age- and gender-related variations in molecular signaling between bone and muscle that are independent of purely mechanical interactions. In summary, gender differences in the acquisition and age-related loss in bone and muscle tissues may be important for developing gender-specific strategies for using exercise to reduce bone loss with aging.
![Bistable [c2] Daisy Chain R...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0002-7863/small "Bistable [c2] Daisy Chain Rotaxanes as Reversible Muscle-like Actuators in Mechanically Active Gels")
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