B-cell lymphoma is the most common immune system malignancy. TCL1 transgenic mice (TCL1-tg), in which TCL1 is ectopically expressed in mature lymphocytes, develop multiple B- and T-cell leukemia and ...lymphoma subtypes, supporting an oncogenic role for TCL1 that probably involves AKT and MAPK-ERK signaling pathway augmentation. Additional, largely unknown genetic and epigenetic alterations cooperate with TCL1 during lymphoma progression. We examined DNA methylation patterns in TCL1-tg B-cell tumors to discover tumor-associated epigenetic changes, and identified hypermethylation of sprouty2 (Spry2). Sprouty proteins are context-dependent negative or positive regulators of MAPK-ERK pathway signaling, but their role(s) in B-cell physiology or pathology are unknown. Here we show that repression of Spry2 expression in TCL1-tg mouse and human B-cell lymphomas and cell lines is associated with dense DNA hypermethylation and was reversed by inhibition of DNA methylation. Spry2 expression was induced in normal splenic B cells by CD40/B-cell receptor costimulation and regulated a negative feedback loop that repressed MAPK-ERK signaling and decreased B-cell viability. Conversely, loss of Spry2 function hyperactivated MAPK-ERK signaling and caused increased B-cell proliferation. Combined, these results implicate epigenetic silencing of Spry2 expression in B lymphoma progression and suggest it as a companion lesion to ectopic TCL1 expression in enhancing MAPK-ERK pathway signaling.
A variety of metal oxide films (InGaO x , AlO x , “HafSOx”) prepared from aqueous solutions were found to have non-uniform electron density profiles using X-ray reflectivity. The inhomogeneity in ...HafSOx films (Hf(OH)4–2x−2y (O2) x (SO4) y ·zH2O), which are currently under investigation as inorganic resists, were studied in more detail by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and medium-energy ion scattering (MEIS). The HAADF-STEM images show a greater concentration of heavy atoms near the surface of a single-layer film. MEIS data confirm the aggregation of Hf at the film surface. The denser “crust” layer in HafSOx films may directly impact patterning resolution. More generally, the phenomenon of surface-layer inhomogeneity in solution-deposited films likely influences film properties and may have consequences in other thin-film systems under investigation as resists, dielectrics, and thin-film transistor components.
Miscible displacement column experiments were performed to investigate the mobility of Zn in two different soils, Windsor (mixed, mesic Typic Udipsamment) and Webster (fine‐loamy, mixed, superactive, ...mesic Typic Endoaquoll). In the Webster soil, strong Zn retention was observed due to a higher percentage of clay, organic matter, amorphous Fe and Al, and the presence of carbonates compared with Windsor soil. Observed Zn breakthrough curves (BTCs) were asymmetric and exhibited extensive retardation and slow desorption. The Webster soil exhibited limited Zn mobility, with only 14% recovery of Zn in the effluent solution, whereas considerable mobility was exhibited by Windsor, with 59% recovery. The Zn distribution with depth in the soil column showed that, for Windsor, Zn was retained within the surface layer and decreased with depth, whereas for Webster, a concentration maximum was observed below the soil surface. The presence of P in the Zn pulse solution increased the amount of Zn sorbed for the Windsor soil, whereas the opposite was observed for the Webster soil. Measured BTCs for P indicated higher P sorption for Windsor, with P recovery of 67%, than for Webster, with recovery of 85%. Simulations using a linear model with a first‐order irreversible reaction provided inadequate predictions of Zn BTCs. Therefore, the linear model is not recommended. Improved Zn predictions of the BTC were obtained when a multireaction and transport model (MRTM) was used. Nevertheless, the MRTM model, which accounted for nonlinear kinetic reversible and irreversible retention reactions, provided inadequate Zn BTC predictions for the Webster soil. There is a need for an improved MRTM model that accounts for the various retention mechanisms governing adsorption–desorption reactions during transport in soils.
Conversion of methane (CH4) to ethylene (C2H4) and/or acetylene (C2H2) enables routes to a wide range of products directly from natural gas. However, high reaction temperatures and pressures are ...often required to activate and convert CH4 controllably, and separating C2+ products from unreacted CH4 can be challenging. Here, we report the direct conversion of CH4 to C2H4 and C2H2 driven by non-thermal plasma under ambient (25 °C and 1 atm) and flow conditions over a metal–organic framework material, MFM-300(Fe). The selectivity for the formation of C2H4 and C2H2 reaches 96% with a high time yield of 334 μmol gcat –1 h–1. At a conversion of 10%, the selectivity to C2+ hydrocarbons and time yield exceed 98% and 2056 μmol gcat –1 h–1, respectively, representing a new benchmark for conversion of CH4. In situ neutron powder diffraction, inelastic neutron scattering and solid-state nuclear magnetic resonance, electron paramagnetic resonance (EPR), and diffuse reflectance infrared Fourier transform spectroscopies, coupled with modeling studies, reveal the crucial role of Fe–O(H)–Fe sites in activating CH4 and stabilizing reaction intermediates via the formation of an Fe–O(CH3)–Fe adduct. In addition, a cascade fixed-bed system has been developed to achieve online separation of C2H4 and C2H2 from unreacted CH4 for direct use. Integrating the processes of CH4 activation, conversion, and product separation within one system opens a new avenue for natural gas utility, bridging the gap between fundamental studies and practical applications in this area.
There is a global trend of the shortage of nature resources, such as water and wildlife, which have suffered dramatic losses due to over-use, pollution, habitat loss, and, increasingly, changes ...caused by global warming. To make the planet more sustainable, abundant data has to be collected and analyzed from ecosystems for scientific decision-making, restoring and preserving natural resources. In this paper, an integrated systems approach has been proposed for the data acquisition and analysis in information management of an ecosystem; it is a direct extension of an agriculture ecosystem enterprise information system (AEEIS) developed by Xu et al. (
Genomics Proteomics Bioinformatics 3:5–17, 2008
). The challenges in system development have been discussed, and the significance of the developed system has been illustrated through a thorough discussion and a case study on the genetic coding and expression of antelopes. In the case study, an IoT-based enterprise information system (EIS) has been applied to investigate the effects of the signal transducer and activator of transcription 3 (STAT3) on the adaptation mechanism to high altitude hypoxia. Two remarkable conclusions are (i) the levels of the STAT3 mRNA and protein vary from one tissue to another, and the highest level is in the lung tissue, and (ii) Tibetan antelope’s expression of STAT3 mRNA and protein are higher than that from plain sheep. Based on the fact that a Tibetan antelope has a higher adaptability to hypoxia; it has illustrated that the hypoxic STAT3-specific expression is one of the molecular bases of high altitude hypoxia adaptation in Tibetan antelope.
Ghrelin and peptide tyrosine tyrosine (PYY) are known to affect appetite and body weight, but the acute effects of fat-rich and carbohydrate-rich meals on plasma ghrelin, PYY response, and appetite ...remain unclear. We hypothesized that obese individuals had impaired postprandial ghrelin and PYY response based on macronutrient content of meals, affecting appetite and energy intake. We conducted a randomized crossover trail comparing fasting ghrelin and PYY concentrations, postprandial ghrelin and PYY responses, and subjective appetite in 15 obese and 12 lean Chinese young adults after they consumed isocaloric high-carbohydrate HC; 88% energy carbohydrate, 4% energy fat, 8% energy protein and high-fat (HF; 25% energy carbohydrate, 71% energy fat, 4% energy protein) meals. Ghrelin concentrations over time differed between HC and HF meals (P < 0.01) via repeated measures of ANOVA, with lower postprandial ghrelin suppression after HF meals, especially among obese participants. PYY response differed between meals among lean participants, with a delayed and higher postprandial PYY peak after the HF meal (P < 0.01); however, PYY response did not differ among obese participants. The incremental area under the curve of PYY was higher in lean than in obese participants after the HF meal (P < 0.01). These results suggest that impaired ghrelin response after HF meals may contribute to reduced satiety and overeating, especially among obese individuals. Whether an attenuated response of PYY in obese participants after a HF meal bears any physiological consequences warrants further study.
The hydrous material Al(PO4)0.6O0.6·zH2O (AlPO) is studied in thin-film form to determine whether bulk diffusion or near-surface densification controls thermal dehydration. From X-ray reflectivity ...measurements, a dense surface crust is found to form on heating AlPO films. Capacitance–voltage measurements reveal the presence of mobile protons associated with trapped −OH and H2O in the films. Deposition of a thin solution-processed HfO2 top coat on the AlPO film lowers the dehydration temperature by 250 °C. Characterization of the AlPO/HfO2 interface by medium energy ion scattering and transmission electron microscopy reveals little interdiffusion between the layers. The top coat affects densification of the near-surface region of the AlPO film, thereby amplifying water loss at low temperatures.
In this paper, we present an adaptive two-pass rank order filter to remove impulse noise in highly corrupted images. When the noise ratio is high, rank order filters, such as the median filter for ...example, can produce unsatisfactory results. Better results can be obtained by applying the filter twice, which we call two-pass filtering. To further improve the performance, we develop an adaptive two-pass rank order filter. Between the passes of filtering, an adaptive process is used to detect irregularities in the spatial distribution of the estimated impulse noise. The adaptive process then selectively replaces some pixels changed by the first pass of filtering with their original observed pixel values. These pixels are then kept unchanged during the second filtering. In combination, the adaptive process and the second filter eliminate more impulse noise and restore some pixels that are mistakenly altered by the first filtering. As a final result, the reconstructed image maintains a higher degree of fidelity and has a smaller amount of noise. The idea of adaptive two-pass processing can be applied to many rank order filters, such as a center-weighted median filter (CWMF), adaptive CWMF, lower-upper-middle filter, and soft-decision rank-order-mean filter. Results from computer simulations are used to demonstrate the performance of this type of adaptation using a number of basic rank order filters.
In this paper we have introduced several types of ferroelectric and antiferroelectric thin (thickness <1 μm) and thick (thickness >1 μm) films developed in our group for sensor, actuator and ...transducer applications in microelectromechanical systems (MEMS). Ferroelectric lead zirconate titanate (PZT) films of up to 12 μm in thickness have been prepared on Pt-buffered silicon substrates, which allows for the conventional, through-thickness polarization, and of up to 5 μm in thickness on insulating layer (ZrO
2) passivated silicon substrates, which allows for the novel, in-plane polarization. The in-plane poled films make it possible to develop d
33-mode rather than d
31-mode bending devices, which immediately leads to two-times improvement in device performance because d
33≈2 d
31. It also can greatly increase the voltage sensitivity of bending devices because the film thickness and electrode spacing are separated as independent variables, and thus, smaller film capacitance can be obtained by using wider electrode spacing even for fixed film thickness. In addition to PZT ferroelectric films, we have also developed antiferroelectric films as an alternative for high-strain microactuators. The strain level of the antiferroelectric films can reach more than 0.4%, and both digital and analog actuation can be realized by modifying the compositions of the films. As an example for MEMS applications, micromachined, unimorph-type two-dimensional transducer arrays have been fabricated based on both the through-thickness and in-plane polarized PZT films, which can be used for miniaturized, high-resolution acoustic imaging such as hand-held diver's sonar system, medical ultrasound imaging, and non-destructive testing.
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