Birds that travel long distances between their wintering and breeding grounds may be particularly susceptible to neurotoxic insecticides, but the influence of insecticides on migration ability is ...poorly understood. Following acute exposure to two widely used agricultural insecticides, imidacloprid (neonicotinoid) and chlorpyrifos (organophosphate), we compared effects on body mass, migratory activity and orientation in a seed-eating bird, the white-crowned sparrow (Zonotrichia leucophrys). During spring migration, sparrows were captured, held and dosed by gavage daily for 3 days with either the vehicle control, low (10% LD50) or high (25% LD50) doses of imidacloprid or chlorpyrifos and tested in migratory orientation trials pre-exposure, post-exposure and during recovery. Control birds maintained body mass and a seasonally appropriate northward orientation throughout the experiment. Imidacloprid dosed birds exhibited significant declines in fat stores and body mass (mean loss: -17% low, -25% high dose) and failed to orient correctly. Chlorpyrifos had no overt effects on mass but significantly impaired orientation. These results suggest that wild songbirds consuming the equivalent of just four imidacloprid-treated canola seeds or eight chlorpyrifos granules per day over 3 days could suffer impaired condition, migration delays and improper migratory direction, which could lead to increased risk of mortality or lost breeding opportunity.
The initial Stroke Therapy Academic Industry Roundtable (STAIR) recommendations published in 1999 were intended to improve the quality of preclinical studies of purported acute stroke therapies. ...Although recognized as reasonable, they have not been closely followed nor rigorously validated. Substantial advances have occurred regarding the appropriate quality and breadth of preclinical testing for candidate acute stroke therapies for better clinical translation. The updated STAIR preclinical recommendations reinforce the previous suggestions that reproducibly defining dose response and time windows with both histological and functional outcomes in multiple animal species with appropriate physiological monitoring is appropriate. The updated STAIR recommendations include: the fundamentals of good scientific inquiry should be followed by eliminating randomization and assessment bias, a priori defining inclusion/exclusion criteria, performing appropriate power and sample size calculations, and disclosing potential conflicts of interest. After initial evaluations in young, healthy male animals, further studies should be performed in females, aged animals, and animals with comorbid conditions such as hypertension, diabetes, and hypercholesterolemia. Another consideration is the use of clinically relevant biomarkers in animal studies. Although the recommendations cannot be validated until effective therapies based on them emerge from clinical trials, it is hoped that adherence to them might enhance the chances for success.
Healthcare‐acquired infections as well as increasing antimicrobial resistance have become an urgent global challenge, thus smart alternative solutions are needed to tackle bacterial infections. ...Antibacterial materials in biomedical applications and hospital hygiene have attracted great interest, in particular, the emergence of surface design strategies offer an effective alternative to antibiotics, thereby preventing the possible development of bacterial resistance. In this review, recent progress on advanced surface modifications to prevent bacterial infections are addressed comprehensively, starting with the key factors against bacterial adhesion, followed by varying strategies that can inhibit biofilm formation effectively. Furthermore, “super antibacterial systems” through pre‐treatment defense and targeted bactericidal system, are proposed with increasing evidence of clinical potential. Finally, the advantages and future challenges of surface strategies to resist healthcare‐associated infections are discussed, with promising prospects of developing novel antimicrobial materials.
This review provides a systematic overview of recent progress on advanced surface modifications to prevent bacterial infections, starting with the key factors against bacterial adhesion, followed by varying strategies that can inhibit biofilm formation effectively. Finally, the advantages and future challenges of surface strategies to resist healthcare‐associated infections are discussed, with promising prospects of developing novel antimicrobial materials.
The Route to Functional Graphene Oxide Haubner, Kinga; Murawski, Jan; Olk, Phillip ...
Chemphyschem,
July 12, 2010, Letnik:
11, Številka:
10
Journal Article
Recenzirano
We report on an easy‐to‐use, successful, and reproducible route to synthesize functionalized graphite oxide (GO) and its conversion to graphene‐like materials through chemical or thermal reduction of ...GO. Graphite oxide containing hydroxyl, epoxy, carbonyl, and carboxyl groups loses mainly hydroxyl and epoxy groups during reduction, whereas carboxyl species remain untouched. The interaction of functionalized graphene with fluorescent methylene blue (MB) is investigated and compared to graphite, fully oxidized GO, as well as thermally and chemically reduced GO. Optical absorption and emission spectra of the composites indicate a clear preference for MB interaction with the GO derivatives containing a large number of functional groups (GO and chemically reduced GO), whereas graphite and thermally reduced GO only incorporate a few MB molecules. These findings are consistent with thermogravimetric, X‐ray photoelectron spectroscopic, and Raman data recorded at every stage of preparation. The optical data also indicate concentration‐dependent aggregation of MB on the GO surface leading to stable MB dimers and trimers. The MB dimers are responsible for fluorescence quenching, which can be controlled by varying the pH value.
Dye/graphene oxide composites are obtained by interaction of methylene blue (MB) with functionalized graphene oxide (GO). Formation of MB dimers on the GO surface (see schematic) changes the optical properties of the composite: UV/Vis absorption bands shift to lower wavelength and fluorescence is quenched. By increasing the pH value, the strong electrostatic interaction can be weakened, and the fluorescence intensity increases at high pH.
Abstract This paper presents the results of a descriptive survey on human grasps. Sixty-four videos were selected to represent tasks performed in the main areas of activities of daily living (ADL) ...(personal care, meal preparation, eating, housekeeping, etc.). All the participants were right-handed. Elementary grasps were identified for each hand, and the grasp type (from a 9-type classification), the hands involved, and the duration were registered for each case. The results show that the most commonly used grasps are: pinch, non-prehensile, cylindrical, lateral pinch and lumbrical. The presence of these grasps in the areas of ADL is, however, very different (e.g., pinch is widely used in food preparation and very little in driving). Some grasps were used more frequently with one hand or when both hands were used simultaneously (e.g., special pinch was hardly used by the left hand). Knowing the grasp types most frequently used in ADL is essential to be able to assess grasp rehabilitation processes or hand prostheses development.
Treatment of neuropathic pain, triggered by multiple insults to the nervous system, is a clinical challenge because the underlying mechanisms of neuropathic pain development remain poorly understood. ...Most treatments do not differentiate between different phases of neuropathic pain pathophysiology and simply focus on blocking neurotransmission, producing transient pain relief. Here, we report that early- and late-phase neuropathic pain development in rats and mice after nerve injury require different matrix metalloproteinases (MMPs). After spinal nerve ligation, MMP-9 shows a rapid and transient upregulation in injured dorsal root ganglion (DRG) primary sensory neurons consistent with an early phase of neuropathic pain, whereas MMP-2 shows a delayed response in DRG satellite cells and spinal astrocytes consistent with a late phase of neuropathic pain. Local inhibition of MMP-9 by an intrathecal route inhibits the early phase of neuropathic pain, whereas inhibition of MMP-2 suppresses the late phase of neuropathic pain. Further, intrathecal administration of MMP-9 or MMP-2 is sufficient to produce neuropathic pain symptoms. After nerve injury, MMP-9 induces neuropathic pain through interleukin-1β cleavage and microglial activation at early times, whereas MMP-2 maintains neuropathic pain through interleukin-1β cleavage and astrocyte activation at later times. Inhibition of MMP may provide a novel therapeutic approach for the treatment of neuropathic pain at different phases.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Objective
To compare the effectiveness of short-term ventilation tubes compared to surveillance on conductive hearing loss in children with non-syndromic orofacial clefting involving the muscular ...palate.
Introduction
Chronic otitis media with effusion is a common finding in children with cleft palate. The accepted convention is insertion of short-term ventilation tubes at the time of palate repair, but some centres are choosing conservative management. Each approach has its advantages but there is currently no consensus on the most appropriate management in children with non-syndromic cleft palate.
Inclusion criteria
Children <18 years with cleft lip and palate, or isolated cleft palate, not associated with a genetic syndrome, who have been diagnosed with chronic otitis media with effusion.
Methods
A systematic search of MEDLINE, CINAHL, Embase and Scopus databases was conducted. Grey literature searches were conducted through Central Register of Controlled Trials, Clinicaltrials.gov and ProQuest. Two reviewers screened the studies, conducted critical appraisal, assessed the methodological quality, and extracted the data. Where possible, studies were pooled in statistical meta-analysis with heterogeneity being assessed using the standard Chi-squared and I2 tests.
Results
Four studies met the inclusion criteria but were of low quality with a moderate risk of bias. Only data on hearing thresholds could be pooled for analysis which found no statistically significant difference. Other outcomes were presented in narrative form. Certainty of evidence for all outcomes was deemed low to very low using GRADE criteria.
Conclusions
No definitive conclusions can be drawn regarding most effective management at improving conductive hearing loss. Missing data and inconsistent reporting of outcomes limited capacity for pooled analysis.
Efficient integration of photovoltaic (PV) energy into the power grid calls for a robust regulation of its intermittency. At present, the solar forecasting-assisted proactive power smoothing control ...(PPSC) has shown superiority in handling such PV intermittency due to its battery-less operations. However, the implementation of PPSC is largely dependent on the quality of solar forecasts, i.e, high accuracy over a long horizon, which has seriously limited its extensive application in practice. In this context, this paper proposes a novel PPSC method based on deep reinforcement learning (RL). In addition to the actor-critic structures, a new module, namely, compensator is developed to tackle the problems of sparse reward and state transition stochasticity that are typically associated with the PPSC control task. On top of it, a novel scenario recognized experience replay (SRER) is devised to deal with the data distribution mismatching issue in PPSC. The effectiveness of the proposed method is verified using real-world data from a solar measurement grid. Empirical studies show that compared with the conventional PPSC method, the proposed method can achieve more robust smoothing performance under various forecasting scenarios, rendering it more applicable to practical PV system operations.
A low profile and metal-mountable ultrahigh frequency (UHF) tag antenna, which has a geometrical dimension of 47 mm <inline-formula> <tex-math notation="LaTeX">\times47 </tex-math></inline-formula> ...mm <inline-formula> <tex-math notation="LaTeX">\times0.8128 </tex-math></inline-formula> mm (<inline-formula> <tex-math notation="LaTeX">0.143\lambda \times 0.143\lambda \times 0.0025\lambda </tex-math></inline-formula>), is proposed. It has four identical open stubs attached to the circumference of a circular patch for performing coarse- and fine-tunings on the tag's resonant frequency without affecting the read performances. At the center of the patch, a rectangular slot of <inline-formula> <tex-math notation="LaTeX">0.121\lambda \times 0.009\lambda \times 0.0025\lambda </tex-math></inline-formula> is etched for accommodating a microchip. Good impedance matching between the tag antenna and the microchip can be easily achieved by changing the dimensions of the center slot. It is also found that the introduction of the slot is crucial for bringing down the tag's resonant frequency to the UHF band. In this paper, an equivalent circuit is also derived for studying the impedance characteristics of the proposed tag antenna. Measurements have been carried out with the use of an effective isotropic radiated power of 4 W, and maximum read distances of 3.45 m and ~1.7 m are attainable, respectively, when the tag is placed on metal plate and dielectrics. It is found that the resonant frequency of the proposed tag antenna is stable and not affected much by its backing objects.
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