Unlike humans, who have a continuous row of teeth, mice have only molars and incisors separated by a toothless region called a diastema. Although tooth buds form in the embryonic diastema, they ...regress and do not develop into teeth. Here, we identify members of the Sprouty (Spry) family, which encode negative feedback regulators of fibroblast growth factor (FGF) and other receptor tyrosine kinase signaling, as genes that repress diastema tooth development. We show that different Sprouty genes are deployed in different tissue compartments—Spry2 in epithelium and Spry4 in mesenchyme—to prevent diastema tooth formation. We provide genetic evidence that they function to ensure that diastema tooth buds are refractory to signaling via FGF ligands that are present in the region and thus prevent these buds from engaging in the FGF-mediated bidirectional signaling between epithelium and mesenchyme that normally sustains tooth development.
The mechanism of synthesis of fine-crystalline corundum from aluminum hydroxide under induced nucleation conditions in a supercritical water fluid at 400°C and initial pressure of 26.4 MPa followed ...by exposure in the synthesis medium was studied. The crystal size distribution was analyzed by electron microscopy. The use of the lognormal function to describe the crystal size distribution of the synthesized corundum particles was substantiated. The possibility of using the lognormal particle size distribution function and the time dependence of its parameters to reveal the routes of product formation was analyzed. The dimensional spectrum of microcrystals has four components, whose appearance is associated with different routes of product formation. The number of distribution components remains unchanged during prolonged exposure, but their average characteristics have different time dependences. The mass redistribution during recrystallization, generally leading to a decrease in the average crystal size, is explained by differences in the crystal structure mobility of different components. It was concluded that the states of corundum in the newly formed crystals and in the overgrown layer on the particles of the inducing additive are different.
A two-dimensional system characterized by the Hertz potential with the parameter α = 7/2 in the region of crystal-phase stability has been studied by the molecular dynamics method. It is shown that ...the anomaly of the density and thermal expansion, found previously for this system in the equation of state along isochores, also manifests itself on isotherms. A study of the translational and orientational order parameters revealed their drop in the density anomaly region, which is most pronounced for the translational order parameter. The obtained results are also in good agreement with the previous data on the attenuation of the transverse phonon mode in this region. This correlation indicates the presence of a strongly diffuse isostructural transformation in the anomalous region of the phase diagram.
Abstract Context Undertreatment of cancer pain among outpatient cancer patients needs to be addressed to enhance care and improve patients' quality of life (QoL). Objectives This prospective, ...cross-sectional, patient-focused study aimed to explore the prevalence of pain and undertreatment of cancer pain in outpatients in Taiwan. Methods A total of 2652 non-selected outpatients with cancer and aged 20 years or older from 16 medical centers across Taiwan were included in this survey. All patients completed a questionnaire based on the Brief Pain Inventory. Pain management index (PMI) was used to evaluate the adequacy of pain management. Possible clinical variables of patients with positive PMI were examined by univariate and multivariate logistic regressions. Results A total of 1659 (62.6%) outpatients had experienced some degree of pain; among these, 32.4% had negative PMI. Patients with a negative PMI score had significantly poor outcomes of QoL and a significantly higher tendency toward dissatisfaction with pain control by the physician and with the prescribed analgesic drugs. Female gender, primary tumor from breast, non–cancer-related cause of pain, and hospital locations from north Taiwan were independent variables that predicated patients with undertreatment of cancer pain. Most importantly, a forward trend of undertreatment of pain among patients who presented with lower prevalent rate of pain was observed. Conclusion One-third of Taiwanese outpatients experienced pain because of undertreatment. Awareness of the prevalence of undertreatment of cancer pain and identification of the vulnerable subjects may assist in enhancing patient care and improving patient's QoL.
Kinetic tensiometric dependences and isotherms of wetting leaves of the Prime potato were obtained for aqueous solutions and submicron dispersions of nonmicelle-forming surfactants (Tween 85, Brij ...L4, and Silwet L-77). A technique has been developed for determining the rate of penetration of the studied liquids into potato leaves. The penetration rate increases with increasing surfactant concentration. The permeability and wetting efficiency increase in the following row: Tween 85 < Brij L4 < Silwet L-77. The data obtained make it possible to evaluate the prospects for using the studied aqueous surfactant dispersions as platforms for the delivery of biologically active components into the leaves of potato plants to inhibit the reproduction of pathogens.
Water confined within carbon nanotubes (CNT) exhibits tremendous enhanced transport properties. Here, we extend this result to ionic liquids (IL) confined in vertically aligned CNT membranes. Under ...confinement, the IL self-diffusion coefficient is increased by a factor 3 compared to its bulk reference. This could lead to high power battery separators.
The paper examines the results of long-term monitoring studies of the physicochemical properties of Holocene silts in Kandalaksha Bay of the White Sea. Based on a comprehensive analysis of the ratios ...of the natural moisture content (
W
n
), moisture content of the liquid (upper plasticity) limit (
W
L
), and organic carbon content (C
org
) for the depth of marine organomineral bottom sediments, it is concluded that the sediments can be separated by physicochemical indicators by introducing the sediment transformation index (
I
st
). Analysis of the distribution of sediment properties in terms of depth carried out in other water areas (e.g., in the Laptev Sea) suggests the universality of this indicator.
Methods of approximation for the distribution law of experimental data find wide application in problems of reliability assessment in tests of both hardware and software of software modules of ...information-measuring and control systems (SM IMCS). Thus, the main task is to solve the problem of increasing the accuracy of the approximation and simplify experimental data processing. In this paper various modification types of Pearson distribution for data taking both positive and negative values, and for data taking only positive values are considered. The described modifications allow one to solve a range of problems related to the existing distributions, as well as to improve the simplicity of the approximation procedure. Pearson logarithmic distributions are proposed for experimental data that take only positive values.
Abstract
We report ulsrasonic measurements of the density and bulk modulus of propylene glycol at room temperature and at the temperature of liquid nitrogen up to a pressure of 1.4 GPa. We perform ...molecular dynamics simulations with two different force fields—COMPASS and Charmm. We show that the COMPASS force field reproduces the experimental data with high accuracy. For this reason we employ this force field to analyze the microstructure and hydrogen bonding in the system. We find that the number of hydrogen bonds does not depend on pressure.
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