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1.
Sci Rep ; 12(1): 16855, 2022 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-36207380

RESUMO

Two capacitive sensing units were designed, fabricated, and embedded into two corresponding fingerstalls through microelectronic and additive manufacturing with flexible materials and ergonomic considerations in this study. The sensing units were routed to an adaptor, which in turn was routed to a transmission port (comprising a signal converter and a Bluetooth module), realizing a wearable and wireless force sensing system for sports science applications as the objective. The collected capacitive signals were converted through a preliminarily established database, indicating local force distributions on finger segments. Practical examinations with badminton actions (forehand cross-net shots) were conducted by players to show the effectiveness of the proposed system as an application example. Statistical and quantified results reflected the visual observations on valid shots (67% and 39% for the professional and amateur players, respectively) and well-controlled racket-holding attitude (19.69% and 35.31% force application difference between the first two segments of the index finger of the professional and amateur player, respectively). These proved that the proposed system outperforms existing similar systems in the market and is able to not only classify players with different skill levels but also distinguish attitude stability and controllability, showing scientific evidence in sports science for the first time.


Assuntos
Esportes com Raquete , Dispositivos Eletrônicos Vestíveis , Fenômenos Mecânicos
2.
Chem Commun (Camb) ; 58(51): 7200-7203, 2022 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-35671164

RESUMO

A photoredox/copper cocatalyzed domino cyclization of oxime esters with TMSCN has been developed. A range of structurally novel tetrasubstituted pyrazines have been obtained. This method features high bond-forming efficiency, high step economy, broad substrate scope, and gram-scale synthesis. Moreover, preliminary bioactivity evaluation of pyrazine products shows their promising antifungal activities.


Assuntos
Cobre , Oximas , Antifúngicos/farmacologia , Catálise , Cobre/farmacologia , Cianetos , Ciclização , Ésteres/farmacologia , Oximas/farmacologia , Pirazinas/farmacologia , Compostos de Trimetilsilil
3.
Materials (Basel) ; 13(12)2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32604752

RESUMO

Even when made by brittle materials, awl-shaped serpentine microsprings (ASSMs) were found to have a nonlinear displacement-force relationship similar to springs made by ductile material. It is found that the nonlinear displacement-force relationship is due to the geometry and dimensions of the ASSMs. The geometric effect of the nonlinear force-displacement relationship of ASSMs for in-plane motion was investigated. A theoretical solution was derived to analyze this nonlinearity. By successfully fabricating and measuring an ASSM, the theoretical results agreed well with the experimental results. The results indicated that ASSMs have a nonlinear force-displacement relationship, which is similar to that of hardening springs. The taper angle has a significant effect on the nonlinear displacement of ASSMs. When the taper angle was small, no obvious effect appeared on the nonlinearity of the microsprings with different numbers of turns. When the beam length increased, the critical force for nonlinear deflection decreased.

4.
Org Biomol Chem ; 17(29): 6989-6993, 2019 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-31298257

RESUMO

An asymmetric (4 + 1) annulation of α-nitro cinnamates with Morita-Baylis-Hillman (MBH) acetates catalyzed by α-isocupreine is reported. It provides chiral isoxazoline N-oxides in moderate to good yields with 88-99% ee, and represents the first catalytic asymmetric (4 + 1) annulation of activated nitroalkenes with in situ generated ammonium ylides. It also affords a practical and efficient access to chiral isoxazoline N-oxides.

5.
Molecules ; 24(24)2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31888142

RESUMO

Tri- or tetrasubstituted furans have been prepared from terminal activated olefins and acyl chlorides or anhydrides by a multicomponental convergent synthesis mode. Instead of stoichiometric nBu3P, only catalytic nBu3P or nBu3P=O is needed to furnish the furans in modest to excellent yields with a good functional group tolerance under the aid of reducing agent silane. This synthetic method features a silane-driven catalytic intramolecular Wittig reaction as a key annulation step and represents the first successful application of catalytic Wittig reaction in multicomponent cascade reaction.


Assuntos
Técnicas de Química Sintética , Furanos/síntese química , Fosfinas/química , Catálise , Furanos/química , Estrutura Molecular
6.
J Agric Food Chem ; 67(19): 5350-5360, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30474370

RESUMO

Tea polysaccharides (TPS) are regarded as some of the main bioactive constituents of tea made from the leaves and buds of the tea plant ( Camellia sinensis L.). An increasing number of studies have demonstrated that TPS can reduce the risk of type 2 diabetes, obesity, and other metabolic diseases. However, the potential mechanisms responsible for antidiabetic and antiobesogenic activities of TPS remain unclear. Therefore, the cellular and physiological mechanisms that underlie the antidiabetic and antiobesogenic effects, including antioxidant and anti-inflammation effects, inhibition of digestive enzymes, prevention of macronutrient absorption, and expression of gene and protein, were summarized in this review. Furthermore, the gastrointestinal functions of TPS and the role of gut microbiota in the prevention and treatment of metabolic diseases were discussed. It is expected that the present review will be helpful for enhancing our knowledge about the health-promoting effects of TPS on metabolic diseases and stimulating further works on TPS.


Assuntos
Camellia sinensis/química , Hipoglicemiantes/administração & dosagem , Doenças Metabólicas/tratamento farmacológico , Extratos Vegetais/administração & dosagem , Polissacarídeos/administração & dosagem , Animais , Humanos , Hipoglicemiantes/química , Doenças Metabólicas/genética , Doenças Metabólicas/metabolismo , Extratos Vegetais/metabolismo , Polissacarídeos/química
7.
Sensors (Basel) ; 15(5): 11685-700, 2015 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-26007725

RESUMO

Recently, saving the cooling power in servers by controlling the fan speed has attracted considerable attention because of the increasing demand for high-density servers. This paper presents an optimal self-tuning proportional-integral-derivative (PID) controller, combining a PID neural network (PIDNN) with fan-power-based optimization in the transient-state temperature response in the time domain, for a server fan cooling system. Because the thermal model of the cooling system is nonlinear and complex, a server mockup system simulating a 1U rack server was constructed and a fan power model was created using a third-order nonlinear curve fit to determine the cooling power consumption by the fan speed control. PIDNN with a time domain criterion is used to tune all online and optimized PID gains. The proposed controller was validated through experiments of step response when the server operated from the low to high power state. The results show that up to 14% of a server's fan cooling power can be saved if the fan control permits a slight temperature response overshoot in the electronic components, which may provide a time-saving strategy for tuning the PID controller to control the server fan speed during low fan power consumption.

8.
Org Biomol Chem ; 13(2): 398-408, 2015 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-25369534

RESUMO

Amine-catalyzed [2 + 2 + 2] annulations of one molecule of Morita-Baylis-Hillman (MBH) acetates 1 with two molecules of 2-(arylmethylidene)indane-1,3-diones 2 or methyleneindolinones 4 have been developed under very mild conditions, which produce multistereogenic dispirocyclohexanes 3 and 5, respectively, in moderate to excellent yields and good diastereoselectivity. This amine-catalyzed annulation constitutes a novel and efficient method for the construction of dispirocyclohexane motifs, and also showcases the divergent catalysis between amines and phosphines with regard to the corresponding phosphine-catalyzed [3 + 2] annulations.

9.
Chem Commun (Camb) ; 49(34): 3543-5, 2013 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-23519093

RESUMO

Amine-catalyzed [2 + 2 + 2] and [2 + 4] annulations of Morita-Baylis-Hillman (MBH) acetates with cyano activated alkenes and 1,3-azadienes have been developed to provide cyclohexanes and tetrahydropyridines. In the annulations, MBH acetates serve as a novel C(2) component with an inactive homoallylic methyl involved in the bond formation.

10.
J Shoulder Elbow Surg ; 22(7): 932-9, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23312816

RESUMO

BACKGROUND: This study aims to clarify the effect of various designs of reverse shoulder prosthesis (RSP) on stress variation of its glenoid component using 2-dimensional (2D) finite element analysis (FEA). This FEA study provides future reference for the optimal design of glenoid component of RSP. MATERIALS AND METHODS: In this study, a 2D finite element (FE) model of human shoulder with implementation of RSP was developed by commercial FE software. The proper material properties were adopted in our model. Various design factors were simulated and all the mechanical profile data were investigated by FEA. RESULTS: Both distal placement and increased lateral offset of glenosphere induce higher stress over glenoid-baseplate junction. Increased thickness of graft, inferiorly tilting of the baseplate, and adoption of BIO-RSA (bony increased-offset reverse shoulder arthroplasty) incur higher stresses over glenoid screws. The inferior screw attains more stress than superior screw. Maximum stress occurs at the base of inferior screw. CONCLUSION: Increased eccentric offset and lateral offset of glenosphere, although being able to reduce notching, may pay the penalty of significant stress concentration over glenoid and its subsequent loosening. Maximum stress occurs at the base of inferior screw elucidate the direct contact failure mode at the middle of inferior screw. This study provides an alternative tool for the optimal design of glenoid component of RSP in the future.


Assuntos
Artroplastia de Substituição/métodos , Análise de Elementos Finitos , Prótese Articular , Articulação do Ombro/cirurgia , Estresse Mecânico , Artroplastia de Substituição/instrumentação , Fenômenos Biomecânicos , Placas Ósseas , Parafusos Ósseos , Humanos , Modelos Anatômicos , Desenho de Prótese , Sensibilidade e Especificidade
11.
Sensors (Basel) ; 12(8): 10881-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23112635

RESUMO

This paper presents a new actuation mechanism to drive comb-drive actuators. An asymmetric configuration of the finger overlap was used to generate capacitive coupling for the actuation mechanism. When the driving voltages were applied on the stators, a voltage would be induced at the rotor due to the capacitive coupling. Then, an electrostatic force would be exerted onto the rotor due to the voltage differences between the stators and the rotor. The actuator's static displacement and resonant frequency were theoretically analyzed. To verify the design, a comb-drive actuator with different initial finger overlaps, i.e., 159.3 µm and 48.9 µm on each side, was fabricated and tested. The results show that the actuator worked well using the proposed actuation mechanism. A static displacement of 41.7 µm and a resonant frequency of 577 Hz were achieved. Using the actuation mechanism, no electrical connection is required between the rotor and the outside power supply. This makes some comb-drive actuators containing heterogeneous structures easy to design and actuate.

12.
Org Lett ; 14(4): 996-9, 2012 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-22304572

RESUMO

An amine-catalyzed [4 + 2] annulation of Morita-Baylis-Hillman allylic acetates 2 with electron-deficient alkenes or diazenes has been developed for efficient syntheses of highly functionalized cyclohexenes, tetrahydropyridazines, and important spirocycles. This reaction unveils a new reactivity pattern of the intensely studied allylic compounds 2 acting as a C(4) synthon in Lewis base catalyzed annulation reactions and also showcases divergent catalysis between tertiary amines and phosphines.

13.
Sensors (Basel) ; 11(7): 7037-54, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22164001

RESUMO

Plasma process tools, which usually cost several millions of US dollars, are often used in the semiconductor fabrication etching process. If the plasma process is halted due to some process fault, the productivity will be reduced and the cost will increase. In order to maximize the product/wafer yield and tool productivity, a timely and effective fault process detection is required in a plasma reactor. The classification of fault events can help the users to quickly identify fault processes, and thus can save downtime of the plasma tool. In this work, optical emission spectroscopy (OES) is employed as the metrology sensor for in-situ process monitoring. Splitting into twelve different match rates by spectrum bands, the matching rate indicator in our previous work (Yang, R.; Chen, R.S. Sensors 2010, 10, 5703-5723) is used to detect the fault process. Based on the match data, a real-time classification of plasma faults is achieved by a novel method, developed in this study. Experiments were conducted to validate the novel fault classification. From the experimental results, we may conclude that the proposed method is feasible inasmuch that the overall accuracy rate of the classification for fault event shifts is 27 out of 28 or about 96.4% in success.

14.
J Org Chem ; 76(18): 7528-38, 2011 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-21823592

RESUMO

A highly stereoselective PBu(3)-mediated vinylogous Wittig olefination between α-methyl allenoates and a variety of aldehydes is presented as the first example of a practical and synthetically useful vinylogous Wittig reaction. Mechanistic experiments including deuterium-labeling, intermediate entrapment, and NMR monitoring have been deliberately conducted. On the basis of mechanistic investigations, a reliable mechanism for the vinylogous Wittig reaction is proposed, which features a water/phosphine-coassisted allylic phosphorus ylide 1,3-rearrangement pathway, rather than previous retro-Diels-Alder ones. It is noteworthy that mechanistic findings in this work also provide supportive evidence for typical mechanisms of important phosphine-mediated reactions of allenoates.

15.
Opt Express ; 19(14): 13257-67, 2011 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-21747480

RESUMO

This work designed and fabricated an optical pickup system based on optical films using the roll-to-roll process. The design combined the advantages of the stacked and planar optical pickup system. Two blazed gratings were used as beam splitters for bending the optical path, while a cylindrical lens was used for astigmatic focus-error detection. The proposed design effectively reduces overall system configuration, component cost, and fabrication complexity.


Assuntos
Dispositivos Ópticos , Fotometria/instrumentação , Refratometria/instrumentação , Desenho Assistido por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Integração de Sistemas
16.
Sensors (Basel) ; 10(6): 5703-23, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-22219683

RESUMO

The plasma process is often used in the fabrication of semiconductor wafers. However, due to the lack of real-time etching control, this may result in some unacceptable process performances and thus leads to significant waste and lower wafer yield. In order to maximize the product wafer yield, a timely and accurately process fault or abnormal detection in a plasma reactor is needed. Optical emission spectroscopy (OES) is one of the most frequently used metrologies in in-situ process monitoring. Even though OES has the advantage of non-invasiveness, it is required to provide a huge amount of information. As a result, the data analysis of OES becomes a big challenge. To accomplish real-time detection, this work employed the sigma matching method technique, which is the time series of OES full spectrum intensity. First, the response model of a healthy plasma spectrum was developed. Then, we defined a matching rate as an indictor for comparing the difference between the tested wafers response and the health sigma model. The experimental results showed that this proposal method can detect process faults in real-time, even in plasma etching tools.


Assuntos
Técnicas Biossensoriais/instrumentação , Análise de Falha de Equipamento/instrumentação , Gases em Plasma/química , Algoritmos , Sistemas Computacionais , Desenho de Equipamento , Análise de Falha de Equipamento/métodos , Lasers Semicondutores , Modelos Biológicos , Modelos Teóricos , Reologia , Processamento de Sinais Assistido por Computador , Análise Espectral
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