Aim To test ex vivo the efficiency of laser‐activated irrigation in removing dentine debris from the apical part of the root canal and to visualize in vitro the fluid dynamics during the activation ...of the irrigant by laser, using high‐speed imaging at a relevant timescale.
Methodology Root canals with a standardized groove in one canal wall filled with dentine debris were irrigated with syringe irrigation, ultrasonically or laser‐activated irrigation (LAI) using 2% sodium hypochlorite as irrigant. The quantity of dentine debris after irrigation was determined. Visualization of the fluid dynamics during activation was achieved using a high‐speed camera and a glass model.
Results Laser‐activated irrigation was significantly more effective in removing dentine debris from the apical part of the root canal than passive ultrasonic irrigation or hand irrigation when the irrigant was activated for 20 s.
Conclusions The in vitro recordings suggest that streaming, caused by the collapse of the laser‐induced bubble, is the main cleaning mechanism of LAI.
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•Localised Cr depletion of Fe-based amorphous coating was analysed via SIMS.•The Cr-depleted zones around defects were eliminated by selectively dissolving.•The enhancement of ...corrosion resistance of the coatings was achieved.
Localised Cr depletion caused by defects in Fe-based amorphous coatings, e.g. pores, oxides and crystalline phases, is thought to be the dominating reason for decreasing corrosion resistance in the coatings. An electrochemical polarisation treatment was used to selectively dissolve Cr-depleted zones in the coatings. The corrosion behaviour of the coatings was studied by potentiodynamic and potentiostatic polarisation and electrochemical impedance spectroscopy in 3.5 wt.% NaCl solution. With the elimination of Cr-depleted zones the corrosion resistance of the coatings was enhanced, with an order of magnitude reduction in the passive current density together with the improvement of passive film stability.
The 2019 surface acoustic waves roadmap Delsing, Per; Cleland, Andrew N; Schuetz, Martin J A ...
Journal of physics. D, Applied physics,
08/2019, Letnik:
52, Številka:
35
Journal Article
Recenzirano
Odprti dostop
Today, surface acoustic waves (SAWs) and bulk acoustic waves are already two of the very few phononic technologies of industrial relevance and can been found in a myriad of devices employing these ...nanoscale earthquakes on a chip. Acoustic radio frequency filters, for instance, are integral parts of wireless devices. SAWs in particular find applications in life sciences and microfluidics for sensing and mixing of tiny amounts of liquids. In addition to this continuously growing number of applications, SAWs are ideally suited to probe and control elementary excitations in condensed matter at the limit of single quantum excitations. Even collective excitations, classical or quantum are nowadays coherently interfaced by SAWs. This wide, highly diverse, interdisciplinary and continuously expanding spectrum literally unites advanced sensing and manipulation applications. Remarkably, SAW technology is inherently multiscale and spans from single atomic or nanoscopic units up even to the millimeter scale. The aim of this Roadmap is to present a snapshot of the present state of surface acoustic wave science and technology in 2019 and provide an opinion on the challenges and opportunities that the future holds from a group of renown experts, covering the interdisciplinary key areas, ranging from fundamental quantum effects to practical applications of acoustic devices in life science.
A mixed-species geometric phase gate has been proposed for implementing quantum logic spectroscopy on trapped ions, which combines probe and information transfer from the spectroscopy to the logic ...ion in a single pulse. We experimentally realize this method, show how it can be applied as a technique for identifying transitions in currently intractable atoms or molecules, demonstrate its reduced temperature sensitivity, and observe quantum-enhanced frequency sensitivity when it is applied to multi-ion chains. Potential applications include improved readout of trapped-ion clocks and simplified error syndrome measurements for quantum error correction.
We have used the Linac Coherent Light Source to generate solid-density aluminum plasmas at temperatures of up to 180 eV. By varying the photon energy of the x rays that both create and probe the ...plasma, and observing the K-α fluorescence, we can directly measure the position of the K edge of the highly charged ions within the system. The results are found to disagree with the predictions of the extensively used Stewart-Pyatt model, but are consistent with the earlier model of Ecker and Kröll, which predicts significantly greater depression of the ionization potential.
Staphylococcus pseudintermedius is a coagulase-positive species that colonizes the nares and anal mucosa of healthy dogs and cats. Human infections with S. pseudintermedius range in severity from ...bite wounds and rhinosinusitis to endocarditis; historically, these infections were thought to be uncommon, but new laboratory methods suggest that their true incidence is underreported. Oxacillin and cefoxitin disk and MIC tests were evaluated for the detection of mecA- or mecC-mediated methicillin resistance in 115 human and animal isolates of the Staphylococcus intermedius group (SIG), including 111 Staphylococcus pseudintermediusand 4 Staphylococcus delphini isolates, 37 of which were mecA positive. The disk and MIC breakpoints evaluated included the Clinical and Laboratory Standards Institute (CLSI) M100-S25 Staphylococcus aureus/Staphylococcus lugdunensis oxacillin MIC breakpoints and cefoxitin disk and MIC breakpoints, the CLSI M100-S25 coagulase-negative Staphylococcus (CoNS) oxacillin MIC breakpoint and cefoxitin disk breakpoint, the CLSI VET01-S2 S. pseudintermedius oxacillin MIC and disk breakpoints, and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) S. pseudintermedius cefoxitin disk breakpoint. The oxacillin results interpreted by the VET01-S2 (disk and MIC) and M100-S25 CoNS (MIC) breakpoints agreed with the results of mecA/mecC PCR for all isolates, with the exception of one false-resistant result (1.3% of mecA/mecC PCR-negative isolates). In contrast, cefoxitin tests performed poorly, ranging from 3 to 89% false susceptibility (very major errors) and 0 to 48% false resistance (major errors). BD Phoenix, bioMérieux Vitek 2, and Beckman Coulter MicroScan commercial automated susceptibility test panel oxacillin MIC results were also evaluated and demonstrated >95% categorical agreement with mecA/mecC PCR results if interpreted by using the M100-S25 CoNS breakpoint. The Alere penicillin-binding protein 2a test accurately detected all mecA-positive isolates, although for four isolates, cefoxitin induction was required prior to testing. These data demonstrate that the cefoxitin surrogate test does not reliably detect the presence of mecA in S. pseudintermedius isolates and that laboratories should perform oxacillin disk or MIC tests of these isolates when they are encountered.
Deformation twins were widely observed in polycrystalline Cu with grain sizes varying from micrometers to nanometers during the process of equal channel angular pressing at room temperature and low ...strain rate (∼10
−2
s
−1). The microstructures of deformation twins were characterized by a transmission electron microscope (TEM) and a high-resolution TEM. It was found that deformation twinning in coarse-grained Cu occurred mainly in shear bands and their intersections as a result of the very high local stress resulted from the severe plastic deformation, and followed the well known pole mechanism. With a decrease in the grain size down to submicrometer (<1
μm) and nanometer (<100
nm) dimensions, twinning was observed to take place via partial dislocation emission from grain boundaries and grain boundary junctions, which is different from the pole mechanism operating in coarse-grained Cu. These observations are consistent with the predictions of recent molecular dynamic simulations for nanocrystalline face-centered cubic materials. The deformation conditions required for twinning and the formation mechanism of deformation twins varying with grain size in Cu are discussed.
Glucagon‐like peptide‐1 (GLP‐1) and peptide YY (PYY), secreted by enteroendocrine L‐cells located most densely in the colon and rectum, are of fundamental importance in blood glucose and appetite ...regulation. In animal models, colonic administration of bile acids can stimulate GLP‐1 and PYY by TGR5 receptor activation. We evaluated the effects of taurocholic acid (TCA), administered as an enema, on plasma GLP‐1 and PYY, as well as gastrointestinal sensations in 10 healthy male subjects, and observed that rectal administration of TCA promptly stimulated secretion of both GLP‐1 and PYY, and increased fullness, in a dose‐dependent manner. These observations confirm that topical application of bile acids to the distal gut may have potential for the management of type 2 diabetes and obesity.
Aims
To evaluate the relationship between gestational diabetes (GDM) and incidence of cancer in women within the first decade postpartum.
Methods
This population‐based retrospective cohort study ...compared the risk of cancer in women with GDM with that of a matched control group comprising pregnant women without diabetes. We included women from Ontario, Canada aged 20–50 years with no history of cancer who had given birth between 1995 and 2008 (N = 149 049). Women with GDM (N = 49 684) were matched on age and year of giving birth, in a ratio of 1:2, to pregnant women without diabetes (N = 99 365).
Results
Over a median 8‐year follow‐up, there were a total of 2927 (1.5%) cancers. After adjustment for covariates, we found no significant difference in overall risk of cancer between women with GDM and matched control subjects; however, GDM was associated with a significantly greater risk of thyroid cancer (adjusted hazard ratio 1.24, 95% CI 1.05, 1.46) and a significantly lower risk of premenopausal breast cancer (hazard ratio 0.86, 95% CI 0.75, 0.98) compared with matched control subjects.
Conclusions
This large population‐based study did not find a greater risk of cancers among women with GDM during the first decade postpartum; however, GDM was associated with a higher risk of thyroid cancer and a lower risk of premenopausal breast cancer. Further studies are needed to confirm these findings.
What's new?
This novel study evaluates the relationship between GDM and short‐term incidence of cancer.
There is evidence of a relationship between diabetes and cancer, but few studies have examined whether cancer risk is increased in people with early dysglycaemia, such as women with a history of GDM.
Using population‐based data, we showed a higher risk of thyroid cancer and lower risk of premenopausal breast cancer in women with GDM compared with matched controls.
To our knowledge, this study is the first to document a higher incidence of thyroid cancer in younger women with a history of GDM.
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