Approaches to Evaluating Trunk Muscle Power Balance

The purpose of the study was to evaluate trunk muscle power balance. Subjects is 7 university students(5 male: height 178.5±3.6cm, weight 74.0±8.5kg, 2female : height 157.0±8.4, weight 55.0±0) in this study. Trunk muscle power balance was evaluated using the Sling exercise therapy machine. F1 was weighted the upper part of their body with the scales. F2 was weighted the lower half of the body with the tension scales. The waist torque by change for position of Sling Point(SP) was increased about 1.3 times therefore SP was moved their toe. As to bilateral difference of trunk muscle power balance have a strong tendency to rotate left side motion the effect occurring most often right-handed

Semi-supervised machine learning model for Lagrangian flow state estimation

In recent years, many researchers have demonstrated the strength of supervised machine learning for flow state estimation. Most of the studies assume that the sensors are fixed and the high-resolution ground truth can be prepared. However, the sensors are not always fixed and may be floating in practical situations -- for example, in oceanography and river hydraulics, sensors are generally floating. In addition, floating sensors make it more difficult to collect the high-resolution ground truth. We here propose a machine learning model for state estimation from such floating sensors without requiring high-resolution ground-truth data for training. This model estimates velocity fields only from floating sensor measurements and is trained with a loss function using only sensor locations. We call this loss function as a "semi-supervised" loss function, since the sensor measurements are utilized as the ground truth but high-resolution data of the entire velocity fields are not required. To demonstrate the performance of the proposed model, we consider Stokes' second problem and two-dimensional decaying homogeneous isotropic turbulence. Our results reveal that the proposed semi-supervised model can estimate velocity fields with reasonable accuracy when the appropriate number of sensors are spatially distributed to some extent in the domain. We also discuss the dependence of the estimation accuracy on the number and distribution of sensors.Comment: 10 pages, 10 figure

Hydroamination, Aminoboration, and Carboamination with Electrophilic Amination Reagents: Umpolung-Enabled Regio- and Stereoselective Synthesis of N-Containing Molecules from Alkenes and Alkynes

Nitrogen (N) is ubiquitously found in bioactive molecules, pharmaceutical agents, and organic functional materials. Accordingly, development of new C–N bond-forming catalysis has been one of the long-standing research subjects in synthetic organic chemistry. In this Perspective, recent advances in highly selective amination reactions with electrophilic amination reagents are described: by taking advantage of the concept of nitrogen umpolung, otherwise challenging aminofunctionalizations, such as hydroamination, aminoboration, and carboamination, of readily available feedstock-like alkenes and alkynes are possible, giving densely functionalized complex and often chiral alkylamines with high selectivity. The scope, limitations, and reaction mechanism are briefly summarized.Hirano K., Miura M.. Hydroamination, Aminoboration, and Carboamination with Electrophilic Amination Reagents: Umpolung-Enabled Regio- and Stereoselective Synthesis of N-Containing Molecules from Alkenes and Alkynes. Journal of the American Chemical Society. 144(2), 648-661, (2022), 19 January 2022; © 2022 American Chemical Society. https://doi.org/10.1021/jacs.1c12663

Compatibility of Carnot efficiency with finite power in an underdamped Brownian Carnot cycle in small temperature-difference regime

We study the possibility of achieving the Carnot efficiency in a finite-power underdamped Brownian Carnot cycle. Recently, it was reported that the Carnot efficiency is achievable in a general class of finite-power Carnot cycle in the vanishing limit of the relaxation times. Thus, it may be interesting to clarify how the efficiency and power depend on the relaxation times by using a specific model. By evaluating the heat-leakage effect intrinsic in the underdamped dynamics with the instantaneous adiabatic processes, we demonstrate that the compatibility of the Carnot efficiency and finite power is achieved in the vanishing limit of the relaxation times in the small temperature-difference regime. Furthermore, we show that this result is consistent with a trade-off relation between power and efficiency by explicitly deriving the relation of our cycle in terms of the relaxation times

An umpolung-enabled copper-catalysed regioselective hydroamination approach to α-amino acids

A copper-catalysed regio- and stereoselective hydroamination of acrylates with hydrosilanes and hydroxylamines has been developed to afford the corresponding α-amino acids in good yields. The key to regioselectivity control is the use of hydroxylamine as an umpolung, electrophilic amination reagent. Additionally, a judicious choice of conditions involving the CsOPiv base and DTBM-dppbz ligand of remote steric hindrance enables the otherwise challenging C-N bond formation at the α position to the carbonyl. The point chirality at the β-position is successfully controlled by the Xyl-BINAP or DTBM-SEGPHOS chiral ligand with similarly remote steric bulkiness. The combination with the chiral auxiliary, (−)-8-phenylmenthol, also induces stereoselectivity at the α-position to form the optically active unnatural α-amino acids with two adjacent stereocentres.Nishino S., Miura M., Hirano K.. An umpolung-enabled copper-catalysed regioselective hydroamination approach to α-amino acids. Chemical Science 12, 11525 (2021); https://doi.org/10.1039/d1sc03692k

Copper-Catalyzed Regio- And Enantioselective Hydroallylation of 1-Trifluoromethylalkenes: Effect of Crown Ether

A Cu-catalyzed regio- and enantioselective hydroallylation of 1-trifluoromethylalkenes with hydrosilanes and allylic chlorides has been developed. Anin situgenerated CuH species undergoes the hydrocupration regio- and enantioselectively to form a chiral α-CF3alkylcopper intermediate, which then leads to the optically active hydroallylated product. The key to success is the use of not only an appropriate chiral bisphosphine ligand but also 18-crown-6 to suppress the otherwise predominant β-F elimination from the α-CF3alkylcopper intermediate. The asymmetric Cu catalysis successfully constructs the nonbenzylic and nonallylic CF3-substituted Csp3chiral center, which is difficult to operate by other means.Kojima Y., Miura M., Hirano K.. Copper-Catalyzed Regio- And Enantioselective Hydroallylation of 1-Trifluoromethylalkenes: Effect of Crown Ether. ACS Catalysis. 11(18), 11663-11670, (2021), 17 September 2021; © 2021 American Chemical Society. https://doi.org/10.1021/acscatal.1c02947

Copper-mediated Regioselective CH Cyanation of Phenols with Assistance of Bipyridine-type Bidentate Auxiliary

A Cu-mediated ortho-selective CH cyanation of phenols with ethyl cyanoformate as the cyano source has been developed. The key to success is the introduction of 4,4¤-di-tert-butyl-2,2¤-bipyridine (dtbpy) bidentate auxiliary on the phenol oxygen, which is easily attachable, detachable, and recyclable. The newly developed protocol is tolerant of several carbonyl functional groups, which are incompatible with previous Lewis-acid-promoted cyanation of phenols