Tooth morphogenesis involves dynamic changes in shape and size as it proceeds through the bud, cap, and bell stages. This process requires exact regulation of cell proliferation and differentiation. ...Smad7, a general antagonist against transforming growth factor–β (TGF-β) signaling, is necessary for maintaining homeostasis and proper functionality in many organs. While TGF-β signaling is widely involved in tooth morphogenesis, the precise role of Smad7 in tooth development remains unknown. In this study, we showed that Smad7 is expressed in the developing mouse molars with a high level in the dental epithelium but a moderate to weak level in the dental mesenchyme. Smad7 deficiency led to a profound decrease in tooth size primarily due to a severely compromised cell proliferation capability in the dental epithelium. Consistent with the tooth shrinkage phenotype, RNA sequencing (RNA-seq) analysis revealed that Smad7 ablation downregulated genes referred to epithelial cell proliferation and cell cycle G1/S phase transition, whereas the upregulated genes were involved in responding to TGF-β signaling and cell cycle arrest. Among these genes, the expression of Cdkn1a (encoding p21), a negative cell proliferation regulator, was remarkably elevated in parallel with the diminution of Ccnd1 encoding the crucial cell cycle regulator cyclin D1 in the dental epithelium. Meanwhile, the expression level of p-Smad2/3 was ectopically elevated in the developing tooth germ of Smad7 null mice, indicating the hyperactivation of the canonical TGF-β signaling. These effects were reversed by addition of TGF-β signaling inhibitor in cell cultures of Smad7−/− molar tooth germs, with rescued expression of cyclin D1 and cell proliferation rate. In sum, our studies demonstrate that Smad7 functions primarily as a positive regulator of cell proliferation via inhibition of the canonical TGF-β signaling during dental epithelium development and highlight a crucial role for Smad7 in regulating tooth size.
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CMK, NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, ...propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°<l<125°, |b|<5°) and outer (125°<l<235°, |b|<5°) Galactic plane are detected with 29.1σ and 12.7σ significance, respectively. The outer Galactic plane diffuse emission is detected for the first time in the very- to ultra-high-energy domain (E>10 TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60 TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
Patients with intra-abdominal sepsis suffer from significant mortality and morbidity. The main pillars of treatment for intra-abdominal infections are (1) source control and (2) early delivery of ...antibiotics. Antibiotic therapy should be started as soon as possible. However, the duration of antibiotics remains a matter of debate. Prolonged antibiotic delivery can lead to increased microbial resistance and the development of nosocomial infections. There has been much research on biomarkers and their ability to aid the decision on when to stop antibiotics. Some of these biomarkers include interleukins, C-reactive protein (CRP) and procalcitonin (PCT). PCT’s value as a biomarker has been a focus area of research in recent years. Most studies use either a cut-off value of 0.50 ng/mL or an >80% reduction in PCT levels to determine when to stop antibiotics. This paper performs a literature review and provides a synthesized up-to-date global overview on the value of PCT in managing intra-abdominal infections.
► The supported PtNi bimetallic catalysts exhibited the highest activity. ► A small amount of Pt further improves the activity and selectivity of Ni/Al
2O
3. ► The formation of Pt–Ni compound ...provokes the shift of the reduction peaks.
Pt, Ni, Co, Cu and bimetallic Pt–Ni, Pt–Co, Pt–Cu catalysts supported on γ-Al
2O
3 have been studied for the hydrogenation maleic anhydride (MA) to succinic anhydride (SA). X-ray diffraction (XRD) and H
2 temperature programmed reduction TPR studies were performed to characterize the catalysts. The flow reactor studies demonstrated that Pt–Ni bimetallic catalyst is highly active and selective for the hydrogenation of MA. Hydrogenation of maleic anhydride produced mainly succinic anhydride and γ-butyrolactone, and the selectivity toward γ-butyrolactone increased with pressure. Using Al
2O
3 as support, it was possible to obtain the highest reaction rate ever obtained with 90% selectivity to SA at 100% conversion. The process appears to be controlled by H
2 dissociation on nickel and the catalytic activity can be further improved, without loss of selectivity, by adding a very small amount of Pt(0.3) to increase the rate of H
2 dissociation.
TPR experiments show high-temperature reduction peaks in monometallic Ni catalysts. When Pt is present, the formation of Pt–Ni compound provokes the shift of the reduction peaks and the appearance of new reduction signals.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
A facile method has been developed to prepare a freestanding binder-free nitrogen-doped delaminated-Ti3C2/reduced graphene oxide hybrid films for high-performance supercapacitor electrodes. This film ...exhibits a high specific capacitance of 247 F g−1 (∼445.2 F cm−3) at 1 A g−1 in 6 M KOH, which is still well maintained after 10000 cycles at 10 A g−1, demonstrating excellent long-term electrochemical stability. In addition, a flexible symmetric supercapacitor has been assembled with such films that delivers a maximum energy density of 15.7 W h kg−1 (at 309.3 W kg−1) and a power density of 3738.7 W kg−1 (at 11.1 W h kg−1) in PVA/H2SO4 gel. This impressive electrochemical performance can be attributed to the enhanced conductivity and high pseudocapacitance offered by the heteroatoms of nitrogen and the alleviated self-restacking of MXene layers by the introduction of reduced graphene oxide nanosheets.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We have investigated the impact of the assumed nitrous oxide (N2O) increases on stratospheric chemistry and dynamics using a series of idealized simulations with a coupled chemistry-climate model ...(CCM). In a future cooler stratosphere the net yield of NOy from N2O is shown to decrease in a reference run following the IPCC A1B scenario, but NOy can still be significantly increased by extra increases of N2O over 2001–2050. Over the last decade of simulations, 50% increases in N2O result in a maximal 6% reduction in ozone mixing ratios in the middle stratosphere at around 10 hPa and an average 2% decrease in the total ozone column (TCO) compared with the control run. This enhanced destruction could cause an ozone decline in the first half of this century in the middle stratosphere around 10 hPa, while global TCO still shows an increase at the same time. The results from a multiple linear regression analysis and sensitivity simulations with different forcings show that the chemical effect of N2O increases dominates the N2O-induced ozone depletion in the stratosphere, while the dynamical and radiative effects of N2O increases are overall insignificant. The analysis of the results reveals that the ozone depleting potential of N2O varies with the time period and is influenced by the environmental conditions. For example, carbon dioxide (CO2) increases can strongly offset the ozone depletion effect of N2O.
Aims.
The purpose of this work is to investigate an astrometric method to accurately measure the precise position of the center of mass of the dwarf planet Haumea and its satellites, based on the ...unresolved images taken by ground-based telescopes.
Methods.
A total of 29 nights of CCD observations are reported of the dwarf planet Haumea, taken during the period from February 7 to May 25, 2022 by three telescopes located in Yunnan Province, China. The pixel centroid of the unresolved image of Haumea and its satellites is measured with respect to its reference stars in the
Gaia
EDR3 star catalog. The new theoretical position of Haumea (the center of mass of Haumea and its satellites is assumed) is computed by the Jet Propulsion Laboratory (JPL) Horizon System. The observed minus computed (O–C) positional residuals of Haumea in right ascension and in declination show a significant and periodic variation. Furthermore, when the ephemeris position of Hi’iaka, the larger and brighter satellite of Haumea, with respect to Haumea itself is taken from the Miriade ephemeris service of the Institut de mécanique céleste et de calcul des éphémérides (IMCCE) website, the observed positional measurements of the center of mass of Haumea and Hi’iaka are derived precisely after using a new method.
Results.
The (O–C) positional residuals are confirmed to be caused mainly by the motion of Hi’iaka around its primary. The final mean (O–C) residuals of Haumea and its satellites are found with respect to the most recent version of the JPL ephemeris. As a by-product, a parameter that connects the mass ratio to the light ratio of Haumea and Hi’iaka (by Eq. (2) in the text), is introduced to derive the final mean (O–C) residuals.
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Binder-free Ti3C2 MXene/carbon nanotubes (Ti3C2/CNTs) films were successfully deposited onto graphite paper via electrophoretic deposition (EPD) method for supercapacitor electrodes. The as-prepared ...Ti3C2/CNTs electrode exhibits enhanced specific capacitance, approximately 1.5 times and 2.6 times of that of pristine Ti3C2 and CNTs films, respectively. Impressively, Ti3C2/CNTs electrodes demonstrate excellent cycling stability, without capacitance decay over 10,000 cycles. Incorporation of CNTs into MXene builds a robust structure, preventing MXene from restacking, and thus leading to the enhanced electrochemical performance. These results suggest that robust Ti3C2/CNTs films can be prepared by a simple yet effective EPD method, potentially applicable to other hybrid MXene systems.
•Binder-free Ti3C2/CNTs films were successfully fabricated on graphite substrates by EPD method.•Ti3C2/CNTs films exhibit enhanced specific capacitance compared with pristine Ti3C2 and CNTs film.•Ti3C2/CNTs films show outstanding cycling stability after 10,000 cycles even at 5 A g−1.•CNTs serve as interlayer spacers and offer charge transport pathway, leading to an enhancement in electrochemical performance.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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