Axin2+ PDL Cells Directly Contribute to New Alveolar Bone Formation in Response to Orthodontic Tension Force

Wnt–β-catenin signaling plays a key role in orthodontic tooth movement (OTM), a common clinical practice for malocclusion correction. However, its targeted periodontal ligament (PDL) progenitor cells remain largely unclear. In this study, we first showed a synchronized increase in Wnt–β-catenin levels and Axin2+ PDL progenitor cell numbers during OTM using immunostaining of β-catenin in wild-type mice and X-gal staining in the Axin2-LacZ knock-in line. Next, we demonstrated time-dependent increases in Axin2+ PDL progenitors and their progeny cell numbers within PDL and alveolar bones during OTM using a one-time tamoxifen-induced Axin2 tracing line ( Axin2CreERT2/+; R26RtdTomato/+). Coimmunostaining images displayed both early and late bone markers (such as RUNX2 and DMP1) in the Axin2Lin PDL cells. Conversely, ablation of Axin2+ PDL cells via one-time tamoxifen-induced diphtheria toxin subunit A (DTA) led to a drastic decrease in osteogenic activity (as reflected by alkaline phosphatase) in PDL and alveolar bone. There was also a decrease in new bone mass and a significant reduction in the mineral apposition rate on both the control side (to a moderate degree) and the OTM side (to a severe degree). Thus, we conclude that the Axin2+ PDL cells (the Wnt-targeted key cells) are highly sensitive to orthodontic tension force and play a critical role in OTM-induced PDL expansion and alveolar bone formation. Future drug development targeting the Axin2+ PDL progenitor cells may accelerate alveolar bone formation during orthodontic treatment.

Measurement And Simulation Calculation of Wire Bow Angle During The Diamond Wire Saw Process

The wire bow angle is an important factor that affects the shape precision of an ingot after the diamond wire sawing process. In this research, the wire bow angles of the inside and outside of an ingot were recorded with a high-speed camera. The effects of the processing parameters such as the wire tension force, feed speed, and wire speed on the wire bow angles inside and outside the ingot were analyzed. A numerical simulation model of the wire bow in the wire sawing process is presented in this paper to describe the wire bow angle inside the ingot. It was shown that the wire bow angle inside the ingot was smaller than that of outside the ingot for all of the processing parameters. The wire bow angles improved with the increase of the feed speed and decrease of the wire speed and the wire tension force. The results of the wire bow angle measurement of the inside ingot and the simulation calculation were similar for the process parameters.

OPTIMISING THE DESIGN PARAMETERS OF A FILTER RESPIRATOR

Purpose. The optimum length choice of the headband insert for a dust filter respirator. Design/methodology/approach. The method of experimental planning has been applied to determine the interpolation (regression) and optimisation dependencies of the filter respirator process. The dominant variables for the respirator were selected based on experimental studies. Input controlled variables for mathematical model are length of tape insertion and headband tension force, output parameter is volume of contaminated air suction under face mask. A regression power relationship between the variables has been established. The recall function was approximated by a second-order non-linear mathematical model. The method of least squares was applied in determining the coefficients at the control variables. Regression dependencies and additional constraints on protective and ergonomic requirements have been used in the optimisation calculations. Conclusions. The solution of the set tasks were the following results: the nonlinear mathematical model more adequately characterizes the respirator use process compared to the linear model of the first order. Relative error between experimental and calculated values of air intake does not exceed 0.6 %. The optimization task is formulated with the regression model. The target function and constraints have been defined with safety and ergonomic requirements. The target function does not have an extremum within the defined constraints. The optimum insertion length was determined graphically and was 2–3.2 cm, the headband tension force does not exceed 5 H With this parameter. Research limitations/consequences. The proposed method is universal in determining the optimum parameters for all types of personal protective equipment. Practical implications: the choice of respirator design parameters can be made using experimentation-surface fitting. Originality/value. The proposed method makes it possible to decline heuristic design methods and establish analytical relationships between the requirements and parameters of individual elements of personal protective equipment.

Estimation of the stability of a fishing vessel during purse seining

One of the reasons for the emergency of a fishing vessel, as well as for the failure of fishing equipment, is the sudden tension of the purse rope, which occurs when the fishing equipment is pulled. As a result of the loss of stability the vessel may enter the encircled seine area and even capsize. There are a number of measures to improve stability during the operation of the vessel. However, when designing fishing equipment, it is necessary to know forces acting on the vessel from the seine side. The article presents a method for assessing the static stability of a vessel with a static application of the tension force of the purse rope. As a result of the study, an expression for determining the static heel angle using a three-dimensional representation of the vessel is given. During simulation the geometrical parameters of the purse rope in the process of purse seine were taken into account. The tension force of the purse rope is also presented as a variable.

The experimental study of the influence of the string length and the position of the electromagnetic excitation coil on the metrological characteristics of the strain sensors of the intelligent monitoring system

The article is devoted to the study of the influence of changes in the string length of string converters and the position of the electromagnetic excitation coil relative to the points of attachment of the string on the amplitude of its vibrations. The re-search was carried out on a prototype of a string converter made under the patent for the invention of the Russian Federation No. 2685803 and having a constant string tension force. The results of theoretical and experimental studies showing the influence of the highest harmonics on the amplitude of string vibrations are presented. The factors determining the composition of harmonics are considered. The contribution of the harmonics to the resulting string oscillation amplitude and the measurement error of the controlled parameter of the stress-strain state is considered. The ranges of the measurements with the help of string converters with a constant string tension force and the ways of their expansion are justified.

Conditions for stability of the “vessel-purse seine” system during purse seining

In the process of tightening the rings of the lower seine line, significant forces of hydrodynamic resistance of the netting can capsize the vessel or pull it into the encircled seine area. There is a risk of damage to the propeller-rudder system of the vessel. The list and trim of a fishing vessel can occur. It affects the safety and comfort of the crew, leads to malfunctions of fishing equipment and mechanisms, and can cause accidents. During the vessel’s operation, there are a number of measures to improve stability. However, when designing fishing equipment, it is necessary to know the forces acting from the seine side on the vessel. The article discusses the relationship between the vessel and the seine during purse seining. On the basis of the developed mathematical model of the tension force of the purse rope, taking into account the geometrical parameters of the warp during purse seining, conditions for stability of the “vessel-purse seine” system were obtained.

Self-Localization of Tethered Drones without a Cable Force Sensor in GPS-Denied Environments

This paper considers the self-localization of a tethered drone without using a cable-tension force sensor in GPS-denied environments. The original problem is converted to a state-estimation problem, where the cable-tension force and the three-dimensional position of the drone with respect to a ground platform are estimated using an extended Kalman filter (EKF). The proposed approach uses the data reported by the onboard electric motors (i.e., the pulse width modulation (PWM) signals), accelerometers, gyroscopes, and altimeter, embedded in the commercial-of-the-shelf (COTS) inertial measurement units (IMU). A system-identification experiment was conducted to determine the model that computes the drone thrust force using the PWM signals. The proposed approach was compared with an existing work that assumes known cable-tension force. Simulation results show that the proposed approach produces estimates with less than 0.3-m errors when the actual cable-tension force is greater than 1 N.