The rheological properties of O-carboxymethyl chitosan (O-CMC) – gum Arabic (GA) coacervates varied greatly with the coacervation pH. At pH 3.0, the coacervate displayed the flow induced shear ...thickening property in shear rates below 100s−1 and then behaved as a Newtonian fluid hereafter; at pH 4.5, the coacervate exhibited the characteristic shear thinning property of a pseudoplastic fluid; while at pH 6.0, the coacervate occurred as a Bingham fluid. The highest viscosity and modulus values of the coacervates were recorded not in the pH value with maximum electrostatic interaction. Zeta potential analysis revealed that the high proportion of O-CMC in the coacervates possibly contributed to the unique rheological properties of the coacervates. SEM observation imaged a layer-by-layer structure for the coacervates prepared at pH 3.0, 4.5, and 6.0. It was concluded that the composition of the O-CMC – GA coacervates greatly influenced their rheological properties and the desired property can be obtained by varying the coacervation pH.
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•O-CMC – GA coacervates were viscous or elastic, depending on coacervation pH.•O-CMC – GA coacervates prepared at pH 3.0 was a Newtonian fluid in high shear rate.•O-CMC – GA coacervates behaved as a pseudoplastic fluid at coacervation pH 4.5.•O-CMC – GA coacervates behaved as a Bingham fluid at coacervation pH 6.0.
The diagnosis of labor dystocia generally is determined by the deviation of labor progress, which is assessed by the use of a partogram. Recently, intrapartum transperineal ultrasound for the ...assessment of fetal head descent has been introduced to assess labor progress in the first stage of labor in a more objective and noninvasive way.
The objective of the study was to determine the differences in labor progress by the use of serial transperineal ultrasound assessment of fetal head descent between women having vaginal and cesarean delivery.
This was a prospective longitudinal study performed in 315 women with singleton pregnancy who were undergoing labor induction at term between December 2016 and December 2017. Paired assessment of cervical dilation and fetal head station by vaginal examination and transperineal ultrasonographic assessment of parasagittal angle of progression and head-perineum distance were made serially after the commencement of labor induction. According to the hospital protocol, assessment was performed every 24 hours and 4 hours, respectively, during latent and active phases of labor. The researchers and the clinical team were blinded to each other’s findings. The repeated measures data were analyzed by mixed effect models. To determine the effect of mode of delivery on the association between parasagittal angle of progression and head-perineum distance against fetal head station and cervical dilation, the significance of the interaction term between each mode of delivery and fetal head station or cervical dilation was determined, which accounted for parity and obesity. Area under receiver-operating characteristic curve was used to evaluate the performance of serial intrapartum sonography in predicting women with cesarean delivery because of failure to progress.
The total number of paired vaginal examination and ultrasound assessments was 1198, with a median of 3 per woman. The median assessment-to-assessment interval was 4.6 hours (interquartile range, 4.3–5.1 hours). Women who achieved vaginal delivery (n=261) had steeper slopes of parasagittal angle of progression and head-perineum distance against fetal head station and cervical dilation than those who achieved cesarean delivery (n=54). Objectively, an additional decrease of 5.11 and 1.37 degrees in parasagittal angle of progression was observed for an unit increase in fetal head station and cervical dilation, respectively, in women who required cesarean delivery (P<.01; P=.01), compared with women who achieved vaginal delivery, after taking account of repeated measures from individuals and confounding factors. The respective additional increases in head-perineum distance for a unit increase in fetal head station and cervical dilation were 0.27 cm (P<.01) and 0.12 cm (P<.01). A combination of maternal characteristics with the temporal changes of parasagittal angle of progression for an unit increase in fetal head station achieved an area under receiver-operating characteristic curve of 0.85 (95% confidence interval, 0.76–0.94), with sensitivity of 79% and specificity of 80%, for the prediction of women who required cesarean delivery because of failure to progress.
The differences in labor progress between vaginal and cesarean delivery have been illustrated objectively by serial intrapartum transperineal ultrasonographic assessment of fetal head descent. This tool is potentially predictive of women who will require cesarean delivery because of failure to progress.
Weakly interacting massive particles (WIMPs) are a leading candidate for dark matter and are expected to produce nuclear recoil (NR) events within liquid xenon time-projection chambers. We present a ...measurement of the scintillation timing characteristics of liquid xenon in the LUX dark matter detector and develop a pulse shape discriminant to be used for particle identification. To accurately measure the timing characteristics, we develop a template-fitting method to reconstruct the detection times of photons. Analyzing calibration data collected during the 2013–2016 LUX WIMP search, we provide a new measurement of the singlet-to-triplet scintillation ratio for electron recoils (ER) below 46 keV, and we make, to our knowledge, a first-ever measurement of the NR singlet-to-triplet ratio at recoil energies below 74 keV. We exploit the difference of the photon time spectra for NR and ER events by using a prompt fraction discrimination parameter, which is optimized using calibration data to have the least number of ER events that occur in a 50% NR acceptance region. We then demonstrate how this discriminant can be used in conjunction with the charge-to-light discrimination to possibly improve the signal-to-noise ratio for nuclear recoils.
Glucocorticoids play a critical role in the treatment of lymphoid malignancies. While glucocorticoid efficacy can be largely attributed to lymphocyte-specific apoptosis, its molecular basis remains ...elusive. Here, we studied genome-wide lymphocyte-specific open chromatin domains (LSOs), and integrated LSOs with glucocorticoid-induced RNA transcription and chromatin modulation using an in vivo patient-derived xenograft model of acute lymphoblastic leukemia (ALL). This led to the identification of LSOs critical for glucocorticoid-induced apoptosis. Glucocorticoid receptor cooperated with CTCF at these LSOs to mediate DNA looping, which was inhibited by increased DNA methylation in glucocorticoid-resistant ALL and non-lymphoid cell types. Our study demonstrates that lymphocyte-specific epigenetic modifications pre-determine glucocorticoid resistance in ALL and may account for the lack of glucocorticoid sensitivity in other cell types.
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•Identified open chromatin domains associated with glucocorticoid response in ALL•Glucocorticoid-resistant ALL shows abnormal accessibility at GR-bound enhancers•GR and CTCF bind at a lymphocyte-specific enhancer for BIM to mediate DNA looping•The BIM enhancer is highly methylated in resistant ALL and non-lymphoid cell types
Jing et al. identified lymphocyte-specific open chromatin domains (LSOs) critical for glucocorticoid (GC)-induced acute lymphoblastic leukemia (ALL) apoptosis. GC receptor cooperated with CTCF at these LSOs to mediate DNA looping, which was inhibited by DNA methylation in GC-resistant ALL and non-lymphoid cell types.
Imaging pHe of the tumor microenvironment has paramount importance for characterizing aggressive, invasive tumors, as well as therapeutic responses. Here, a robust approach to image pH changes in the ...tumor microenvironment longitudinally and during sodium bicarbonate treatment was reported. The pH-sensing microbeads were designed and prepared based on materials approved for clinical use, i.e., alginate microbead-containing computed tomography (CT) contrast-agent (iopamidol)-loaded liposomes (Iop-lipobeads). This Iop-lipobead prepared using a customized microfluidic device generated a CEST contrast of 10.6% at 4.2 ppm at pH 7.0, which was stable for 20 days in vitro. The CEST contrast decreased by 11.8% when the pH decreased from 7.0 to 6.5 in vitro. Optimized Iop-lipobeads next to tumors showed a significant increase of 19.7 ± 6.1% (p < 0.01) in CEST contrast at 4.2 ppm during the first 3 days of treatment and decreased to 15.2 ± 4.8% when treatment stopped. Notably, percentage changes in Iop-lipobeads were higher than that of amide CEST (11.7% and 9.1%) in tumors during and after treatment. These findings demonstrated that the Iop-lipobead could provide an independent and sensitive assessment of the pHe changes for a noninvasive and longitudinal monitoring of the treatment effects using multiple CEST contrast.
To enhance the corrosion resistance and mechanical properties of magnetocaloric materials in the application of magnetic refrigeration, Cu was introduced into (Mn,Fe)2(P,Si) system. A series of ...Mn1.05Fe0.9P0.5Si0.5Cux (x = 0, 0.05, 0.10 and 0.15) alloys were prepared by arc-melting and subsequent copper mold suction casting method. The results show that Mn1.05Fe0.9P0.5Si0.5Cux alloys crystallized into a typical Fe2P-type main phase with hexagonal structure. In microstructure, most of Cu segregated at the grain boundaries of main phase, while a small amount of Cu entered the Fe2P structure. The precipitation of pure copper phase at the grain boundaries contribute to the improvement of corrosion and mechanical properties. The Curie temperature of Mn1.05Fe0.9P0.5Si0.5Cux alloys can be continuously tuned from 321 K to 248 K with the increase of copper contents, while the magnetic entropy changes slightly reduced. In comparison with Mn1.05Fe0.9P0.5Si0.5, the corrosion potential of Mn1.05Fe0.9P0.5Si0.5Cu0.15 increases from −0.3932 V to −0.2747 V, while the corrosion current density decreases by 63.2%, which indicates a significantly improved corrosion resistance. The nano-indentation tests also indicate that the incorporation of Cu can effectively improve the mechanical performance of these alloys. All results indicate that Mn1.05Fe0.9P0.5Si0.5Cux alloys are promising candidates for magnetic refrigeration applications.
•The Mn1.05Fe0.9P0.5Si0.5Cux alloys with x = 0, 0.05, 0.10 and 0.15 were prepared by arc-melting and subsequent copper mold suction casting.•The mechanical properties and corrosion resistance of alloys were improved while retaining most of the magnetocaloric properties.•The Curie temperature of Mn1.05Fe0.9P0.5Si0.5Cux alloys can be continuously tuned from 321 K to 248 K.•The ΔSm are 30.5, 25.5, 24.1 and 21.3 J∙kg−1 K−1 under 0–5 T for Mn1.05Fe0.9P0.5Si0.5Cux alloys with x = 0, 0.05, 0.10 and 0.15, respectively.
•M underlayer (M=Ti, Zr, Hf) promotes the ordering of FePt film.•M underlayer refines grain and magnetic domain sizes of FePt film.•M underlayer greatly enhances permanent magnetic properties of FePt ...film.•Significant enhancement in (BH)max over 110% is achieved with M underlayer.
Effect of M underlayer on the structure, microstructure, magnetic properties of FePt films have been studied (M=Ti, Zr, and Hf). The structural results confirm the extensive ordering of FePt in the bilayer films obtained with annealing at temperature 200°C lower than that at which the single layer film has similar ordering. Microstructure data indicate an obvious grain refinement in the bilayer films. Magnetic force microscopy shows a reduced interaction domain size with M underlayer. We suggest that the intermixing between the FePt and underlayers during the post annealing may lower ordering temperature by stimulating the nucleation of the L10 phase, causing refined grain and magnetic domain sizes, leading to remarkable enhancement in permanent magnetic properties at lower Ta. The optimized (BH)max of FePt films is greatly enhanced from 9.5 MGOe for single layer to 18.1, 19.8, 20.2 MGOe for Ti-, Zr-, and Hf-underlayered films, respectively.
BACKGROUND: Although MTBDRplus is validated for the detection of multidrug-resistant tuberculosis (MDR-TB), its role in the assessment of treatment outcome is less clear. We evaluated the association ...of MTBDRplus results with treatment outcome in new and previously treated
patients in an endemic setting in China and determined factors associated with poor treatment outcomes.METHODS: We prospectively enrolled 298 smear-positive pulmonary TB patients who received the World Health Organization recommended initial treatment regimen or retreatment regimen. MTBDRplus
was compared with conventional drug susceptibility testing and DNA sequencing for the detection of MDR-TB. Treatment responses were monitored using sputum smear, culture and chest radiography.RESULTS: MTBDRplus successfully identified all MDR-TB and had good concordance with sequencing.
MDR-TB rates were low among new patients (4/187, 2.1%), but high in previously treated patients (12/28, 42.9%); 65.2% (15/23) of previously treated cases and 17.1% (27/158) of new cases were unsuccessfully treated (P < 0.001). Seven of eight (87.5%) previously treated MDR-TB patients
failed the retreatment regimen. In addition to drug resistance, sputum smear positivity at week 8 and cavitation are associated with treatment failure.CONCLUSION: Not only did MTBDRplus correctly identify all MDR-TB cases, MTBDRplus results are also associated with treatment
outcomes in previously treated patients. The retreatment regimen should no longer be used; treatment should be guided by molecular testing.
We report the transition from bipolar resistive switching (BRS) to unipolar resistive switching (URS) in the Au/Ti/GaO
x
/NiO
x
/ITO device at room temperature. After the proper soft breakdown of the ...p-n junctions (GaO
x
/NiO
x
), the switching operation could be easily transferred from BRS to URS mode. The BRS and URS behaviors are possibly related to the interfacial variation of the Ti/GaO
x
Schottky junction barrier and GaO
x
/NiO
x
p-n junction barrier, respectively. The high/low resistance state can be distinguished clearly and be switched reversibly under a train of voltage pulses in both BRS and URS modes. The endurance characteristics show good reliability of the stored resistance state. These results suggest a potential device for the next generation of nonvolatile memory applications.
The transition of resistive switching behavior from bipolar to unipolar induced by interface was found and investigated in Au/Ti/GaO
x
/NiO
x
/ITO structure.
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