Search

Aiming at the problem that the vibration calibration accuracy is seriously affected by the additional dynamic magnetic field interference and eddy current effect of the electromagnetic vibration exciters, a suppression method based on magnetic field tracking compensation is proposed. The influence of the dynamic magnetic field interference of the driving current on the total harmonic distortion of the driving coil output electromagnetic force waveform and the characteristics of the eddy current effect are studied. The compensation current set on the central yoke, its direction opposite to the driving current, to realize the dynamic tracking compensation and suppression of the additional dynamic magnetic field interference and eddy current loss of the driving coil, and effectively improve the vibration waveform accuracy and eliminate the temperature change of the working platform caused by eddy current effect. The simulation results show that the eddy current loss may be reduced by 53 % and the total harmonic distortion of the driving electromagnetic force waveform may be reduced by 0.12 % though the method in this paper.

BackgroundPerioperative rehabilitation management is essential to enhanced recovery after surgery (ERAS). Limited reports, however, have focused on quantitative, detailed early activity plans for patients receiving minimally invasive esophagectomy (MIE). The purpose of this research was to estimate the effectiveness of the Tailored, Early Comprehensive Rehabilitation Program (t-ECRP) based on ERAS in the recovery of bowel and physical functions for patients undergoing MIE.MethodsIn this single-blind, 2-arm, parallel-group, randomized pilot clinical trial, patients admitted to the Affiliated Cancer Hospital of Zhengzhou University from June 2019 to February 2020 were selected and randomly assigned to an intervention group (IG) or a control group (CG). The participants in the IG received medical care based on the t-ECRP strategy during perioperative period, and participants in the CG received routine care. The recovery of bowel and physical functions, readiness for hospital discharge (RHD), and postoperative hospital stay were evaluated on the day of discharge.ResultsTwo hundred and fifteen cases with esophageal cancer (EC) were enrolled and randomized to the IG (n = 107) or CG (n = 108). The mean age was 62.58 years (SD 9.07) and 71.16% were male. For EC, 53.49% were mid-location cancers and 79.07% were classified as pathological stage II and III cancers. There were no significant differences between the two groups in terms of demographic and clinical characteristics and baseline physical functions. Participants in the IG group presented significantly shorter lengths of time to first flatus (P P = 0.024), and for up and go test (P P P ConclusionsThe t-ECRP appears to improve bowel and physical function recovery, ameliorate RHD, and shorten postoperative hospital stay for patients undergoing MIE. Clinicians should consider prescribing quantitative, detailed, and individualized early activity plans for these patients.Trial registrationClinicalTrials.gov (Identifier: NCT01998230)

This paper mainly discusses how to do a good job of daily biosafety protection measures in clinical microbiology laboratories during the epidemic of COVID-19, so as to ensure the safe development of routine clinical microbiology testing items. According to the microbiological and epidemiological characteristics of the novel coronavirus, this paper analyzed the potential risks of the laboratory from the perspective of personal protection before, during, and after testing. Combined with the actual work situation, the improved biosafety protection measures and optimized work flow are introduced to ensure the safety of medical staff and the smooth development of daily work. Danyang People's Hospital of Jiangsu Province, clinical microbiology laboratory of clinical laboratory in strict accordance with the relevant laws and regulations, technical specifications and the expert consensus, combined with their own conditions, the biosafety measures to perfect the working process was optimized, effectively prevent the laboratory exposure, and maintain strict working condition for a long time, continue to improve. We found that the biosafety protection measures of clinical microbiology laboratory have good prevention and control effect on preventing infection of medical staff, which will greatly reduce the risk of infection of medical staff, form good working habits, and provide reference for biosafety protection of microbiology laboratory during the epidemic of COVID-19.

An active negative stiffness regulation and precision micro-vibration isolation technology (ANSVIT) based on composite feedback of acceleration and velocity is proposed to realize the low-frequency isolation of air floating isolators with heavy loads. Adjustable negative stiffness generated by acceleration feedback realizes low-frequency isolation, and absolute velocity feedback is combined to reduce the peak vibration transmissibility and improve isolation performance. The effects of feedback coefficients in the frequency domain are analyzed based on the dynamics model. And the relationship of feedback coefficients that achieves low natural frequency and lower peak vibration transmissibility than passive vibration isolation is derived to guide design. Furthermore, the effects of ANSVIT on vibrations in the low-frequency region, resonance region, and isolation region are investigated numerically in the time domain. Finally, an experimental setup is built, and experiments are conducted. Experimental results show that the introduction of ANSVIT attenuates the natural frequency by 61.54% and achieves lower peak vibration transmissibility and higher vibration level than passive vibration isolation. The promise of the proposed ANSVIT for improving the isolation performance is verified.

Several phosphoinositide 3-kinase (PI3K) inhibitors are currently approved to treat hematolymphatic malignant diseases worldwide, and many drugs that have the same target are in the clinical research stage. In March 2022, duvelisib became the first PI3K inhibitor approved in China indicated for the treatment of hematolymphatic malignant diseases. Meanwhile, linperlisib and copanlisib have almost completed the technical review of the clinical specialty. The Center for Drug Evaluation (CDE) of the China National Medical Products Administration (NMPA) found that class I PI3K inhibitors can cause various degrees of immune-related adverse events, which are associated with action mechanisms, affecting the benefit-risk assessment of the drugs. On April 21, 2021, the United States Food and Drug Administration (FDA) convened the Oncologic Drugs Advisory Committee (ODAC) meeting to discuss the safety of PI3K inhibitors indicated for hematolymphatic malignancies and their related risk of death. The hematological tumor group of CDE of the China NMPA summarized and combined the data on PI3K inhibitors listed or under technical review for marketing authorization applications and found that such products may have unique efficacy and safety characteristics in Chinese patients with malignant lymphoma.

The absence of an appropriate low-frequency vibration velocity detection method to establish feedback control limits the further improvement of the low-frequency vibration performance of electromagnetic vibration exciters. In this article, a low-frequency vibration velocity feedback control method based on the Kalman filter estimation is proposed for the first time to reduce the total harmonic distortion of the vibration waveform. The rationality of establishing velocity feedback control in the velocity characteristic band of the electromagnetic vibration exciter is analyzed. Based on an identification model of the system and measured vibration displacements, the vibration velocity is estimated with high accuracy through the Kalman filter. The velocity feedback control system is established to suppress the impacts of disturbances effectively. Experimental results show that the method proposed in this paper can reduce the harmonic distortion of vibration waveform by 40%, which is 20% higher than the traditional control method, thoroughly verifying its superiority.

The purpose of this paper is to discuss modelling and synchronization of nonlinear supply chain system. Firstly, we present a new supply chain system which is sensitive to various uncertainties along with exogenous disturbances. Synchronization is an important method to reduce the negative impact of uncertainties and disturbances on the supply chain. Since impulsive control can reduce control cost and the amount of transmitted information drastically, we discuss impulsive synchronization behavior of two supply chain systems with the same structure. Finally, simulation experiments are given to show the effectiveness of our analytical results.

Background The incidence of swallowing abnormality was high after minimally invasive esophagectomy (MIE) for esophageal cancer (EC). Few reports, however, focused on interventions for dysphagia after esophagectomy. Aim The purpose of this research was to estimate the effect of Chin‐down‐plus‐larynx‐tightening maneuver on swallowing function for patients receiving esophagectomy. Method This was a 2‐arm, parallel‐group, single‐blind randomized clinical trial, performed in patients suffered from EC from November 2018 to January 2020. Patients were randomly assigned to the intervention group (IG) or the control group (CG). The participants in CG received routine care, and the IG received Chin‐down‐plus‐larynx‐tightening maneuver during feeding. The incidence of choking cough, swallowing function, and dietary outcomes were evaluated before and after intervention for 7 days. Results A total of 237 EC cases were enrolled and randomized to the IG (n = 118) or CG (n = 119). There was no significant difference between the two groups in terms of demographic and clinical characteristics. Postoperative choking cough occurred in 5 of 118 cases (4.24%) in IG and 18 of 119 cases (19.4%) in CG, the differences showed statistically significant (P, The incidence of swallowing abnormality was high after esophagectomy, which affects patients' nutritional intake and quality of life. The Chin‐Down maneuver can achieve good results in improving swallowing performance caused by Stroke, Parkinson and other diseases. In this study, we hypothesized that changing the position of head and body might affect the swallowing parameters and improve swallowing abnormalities in patients after esophagectomy, which we called it as the Chin‐down‐plus‐larynx‐tightening maneuver. The findings suggest that the maneuver can improve swallowing function recovery and oral total food intake and calories in patients undergoing esophagectomy.

To realize high-precision calibration of vibration sensors, the total harmonic distortion (THD) of the output waveform of a standard vibration actuator should be as small as possible, so a harmonic suppression technique based on current feedback control is presented. A low-cost, easy-to-implement feedback control loop of driving current is established in an electromagnetic standard vibration actuator (EVA), and the rationality of driving current in place of acceleration in the acceleration characteristic frequency band to achieve the feedback is analyzed. The influence of different values of the key parameters on the system is studied, and the acceleration characteristic frequency band of low-frequency vibration is effectively extended so that the THD of the output waveform is immensely alleviated. The effectiveness of the proposed method is verified by experiments and compared with traditional control methods, the harmonic distortion of acceleration waveform can be reduced by more than 40% without using any feedback sensors, which proves the superiority of the current feedback control method.

In this paper, we obtain an inequality for unitarily invariant norms which unifies the arithmetic–geometric mean inequality and the Holder inequality for unitarily invariant norms.

This paper establishes a spectral conjugate gradient method for solving unconstrained optimization problems, where the conjugate parameter and the spectral parameter satisfy a restrictive relationship. The search direction is sufficient descent without restarts in per-iteration. Moreover, this feature is independent of any line searches. Under the standard Wolfe line searches, the global convergence of the proposed method is proved when | β k | ≤ β k F R holds. The preliminary numerical results are presented to show effectiveness of the proposed method.

In this short note, we obain some singular value inequalities which are improvement or generalization of ones presented by Zuo et al. [Singular value inequalities related to the Audenaert–Zhan ineq...

Laser-induced ultrasonic measurement is a non-contact non-destructive technology that can be employed for the testing and assessment of surface defects. In order to improve the correct identification of defects, the full matrix capture (FMC) and total focusing method (TFM) are applied on the imaging process. FMC data includes A-scans resulting from the combination of all measurement axes defined by the sequential generation and detection of utilized laser beams in the system. In this paper, an aluminium block with four holes whose diameters range from 1 mm to 2.5 mm is assessed through B-scans, the synthetic aperture focusing technique (SAFT) and FMC/TFM. The results demonstrate that the FMC/TFM technology can significantly improve the imaging quality and signal-to-noise ratio (SNR). In addition, this method has higher lateral resolution and larger imaging range compared with traditional B-scans.

To realize high payload and ultra-low frequency isolation characteristics and effectively restrain the influence of microvibration in the environment on the accuracy of large precision/ultra-precision optical instruments, a high precision analysis method for the performance of air spring isolators is presented. The analysis method that combining theory with simulation studies the structural stiffness and material stiffness characteristics of an air spring isolator respectively, which effectively solves the problem that the traditional theoretical models could not guide the optimization design and precision machining of air spring isolators accurately due to their neglecting of the elastic membrane material stiffness. The analysis results show that the stiffness and stiffness ratio of the elastic membrane increase with the rise of inflatable pressure in the chamber. Structural designs of large chamber volume and small bearing area, the working pattern of high inflatable pressure, as well as material parameters of large cord angle and a small distance from cord to the neutral surface of the elastic membrane, are beneficial to reduce the stiffness of the air spring isolator. The research is beneficial to realize the low stiffness and ultra-low frequency isolation of air spring isolators.

Background: Perioperative rehabilitation management is essential to enhanced recovery after surgery. Few reports, however, focused on quantitative, detailed early activity plans for patients after esophagectomy. Aim: The purpose of this research was to estimate the effect of the Early Rehabilitation Program (ERP) on the recovery of bowel function and physical function for patients undergoing esophagectomy. Method: In this single-blind, 2-arm, parallel-group, randomized pilot clinical trial, patients were selected from June 2019 to February 2020 and assigned to the intervention group (IG) or the control group(CG) randomly. The participants in IG received an ERP strategy during the perioperative period, and the CG received routine care. The recovery of bowel and physical function, readiness for hospital discharge (RHD) and postoperative hospital stay were evaluated on the day of discharge. Results: 215 cases were enrolled and randomized to the CG (n=108) or IG (n=107). There was no significant difference between the two groups in terms of demographic and clinical characteristics and baseline physical function. After the ERP intervention, the IG group presented a significantly shorter time to first flatus (PP=0.024), and a better physical function recovery (P＜0.001), compared with the CG group. The analysis also showed that participants in the IG have higher scores of RHD and shorter length of postoperative stay than the CG (P＜0.05). Conclusion: The findings suggest that the ERP can improve bowel and physical function recovery, ameliorate patients' RHD, and shorten postoperative hospital stay for patients undergoing MIE.Trial registration：ClinicalTrials.gov Identifier: NCT01998230

A magnetic ring array (MRA) with high-amplitude negative stiffness is proposed to counteract the positive stiffness of vibration isolators and improve the low-frequency performance of heavy-load precision micro-vibration isolation. The MRA uses magnetic rings mounted coaxially and magnetized perpendicularly to form an array structure that produces high-amplitude negative stiffness. An analytical model of its magnetic force and stiffness is established, and the influence of geometric parameters on stiffness is analyzed for optimization. Furthermore, the effectiveness of the MRA is validated through comparisons with existing schemes. A set of experiments are carried out to prove the validity of the analytical model and the performance of the MRA. Experimental results show that the natural frequency of the vibration isolation experimental setup decreases from 4.75 Hz to 1.13 Hz after the introduction of the MRA, and the peak of the one-third octave band velocity spectra decreases from 5.03 μm/s @ 5 Hz to 2.60 μm/s @ 1.25 Hz. The effectiveness of the proposed MRA in improving the performance of micro-vibration isolation is verified.

A novel low-nonlinearity Michelson microprobe fiber interferometer against light intensity disturbance for high-precision embedded displacement measurements is introduced. To analyze the influence of light intensity disturbance on the microprobe and measurement accuracy of the integrated fiber interferometer, an equivalent model of micro-probe sensing with the tilted target is established. The proposed PGC demodulation and nonlinearity correction method with simple principle helps avoid DC component varying with light intensity. The experiments show that residual displacement errors of the micro-probe fiber interferometer are reduced from 4.36 nm to 0.46 nm, thus allowing embedded displacement detection with sub-nanometer accuracy under low frequency light intensity disturbance.

To improve the low-frequency isolation performance of optical platforms, an electromagnetic active-negative-stiffness generator (EANSG) was proposed, using nano-resolution laser interferometry sensors to monitor the micro-vibration of an optical platform, and precision electromagnetic actuators integrated with a relative displacement feedback strategy to counteract the positive stiffness of pneumatic springs within a micro-vibration stroke, thereby producing high-static-low-dynamic stiffness characteristics. The effectiveness of the method was verified by both theoretical and experimental analyses. The experimental results show that the vertical natural frequency of the optical platform was reduced from 2.00 to 1.37 Hz, the root mean square of displacement was reduced from 1.28 to 0.69 &mu, m, and the root mean square of velocity was reduced from 14.60 to 9.33 &mu, m/s, proving that the proposed method can effectively enhance the low frequency isolation performance of optical platforms.

High-performance magnetic circuit offering uniform magnetic flux density (MFD) along ultra-long stroke is the key to develop a vibration exciter for ultra-low-frequency (ULF) vibration calibration. In this paper, a rectangular closed double magnetic circuit (RCDMC) offering ultra-long stroke up to 1.2 m is modeled and optimized. In order to overcome the modeling difficulty arising from the long stroke, a high-accuracy theoretical model is established taking advantage of the structural symmetry of the RCDMC through lumped parameter magnetic equivalent circuit method. Matrix equations are derived based on Kirchhoff&rsquo, s law and solved by iteration calculation to deal with the strong nonlinear characteristics of the yoke material. The deviations between the model and finite element method (FEM) analysis results are less than 1% for non-saturated yokes and ~10% for saturated yokes. Theoretically, an MFD up to 122 mT and an acceleration waveform harmonic distortion (AWHD) as low as 0.45% are achieved through model-based optimization. Experiments are carried out using an RCDMC prototype assembled in a horizontal vibration exciter. The experimental results show that an MFD of 102 mT and an AWHD of 0.27% along 1.2 m stroke are achieved, making the proposed RCDMC a solution for ULF vibration exciter.

Previous studies confirmed the safety and feasibility of oral feeding on the first postoperative day (POD) for patients with minimally invasive esophagectomy (MIE). Nonetheless, some clinical concern can lead to delays in early oral feeding on POD 1. To our knowledge, few reports have focused on resolving these clinical concerns. The aims of this study were to evaluate the effects of an early, quantified, modified oral feeding protocol for patients after MIE and to explore its effect on nutritional status and quality of life (QoL).In this prospective controlled trail, 200 patients were selected as the intervention group (IG) from March 2020 to June 2021; 115 patients hospitalized from June 2019 to February 2020 were assigned to the control group (CG). For 2 wk during the postoperative period, IG participants received an early, quantified, modified oral feeding protocol. The recovery of dietary outcomes, nutritional status, and QoL were evaluated after the intervention.There was no significant difference between the two groups in terms of demographic and clinical characteristics and baseline physical function. After the intervention, patients in the IG showed a more rapid growth in daily total oral caloric intake and the ratio of oral calorie intake to total calorie required by the body (K/R value) from POD 1 to POD 14, and less weight loss (1.5 ± 1 versus 2.1 ± 1.7 kg; P0.05), better serum prealbumin (193.0 ± 26.9 versus 139.3 ± 27.2 mg/L; P0.05) than the CG with statistical significance. By the second week of the intervention, IG patients reported higher global QoL and function scores and lower symptom scores than patients in the CG. The IG participants presented a shorter time to first flatus and bowel movement (P0.001), a shorter postoperative hospital length of stay, and higher activities of daily living scores (P0.05) the those in the CG.The findings demonstrated that the early, quantified, modified oral feeding protocol can alleviate postoperative body weight loss, improve the patient's nutritional status, and have a positive effect on QoL and early recovery for patients undergoing MIE.

This paper focuses on the synchronization control methodology for a class of delayed reaction–diffusion memristor-based neural networks. Adaptive controllers are designed such that the considered model can realize asymptotical and exponential synchronization goal under the framework of inequality techniques and Lyapunov method. The results obtained in this paper consider the effect of time delays as well as the reaction–diffusion terms, which generalize and improve some existing results. The derived synchronization criteria are presented in the form of algebraic, which can be easily verified. Finally, numerical example and its simulations are given to show the correctness of the obtained results.

In this short note, we give a new equivalent form of the arithmetic–geometric mean inequality for singular values. As applications of our result, we give a new proof of an inequality due to Bhatia and Davis (1993) [4] and we obtain a singular value inequality for matrix means, which is similar to one proved by Drury (2012) [9] . Finally, we present a log-majorization inequality for singular values.

In this paper, a non-mechanical axial zoom scanning method based on a phase only liquid crystal spatial light modulator is proposed. This novel method is to overcome the measurement error caused by moving mechanical parts in the axial mechanical scanning methods in the confocal microscopy system. The modulation on the incident wave front is completed by a spatial light modulator, which provides this scanning method some outstanding advantages including the flexibility of control and the absence of moving mechanical parts, especially suitable for the fixed sample imaging occasions. By simulating the multiple Fresnel lens with LCSLM to generate controllable multi-focal points and thus realizing this method of axial multi-focus scanning to enhance the axial scanning efficiency and the range. Simulations and experiments on the axial scanning features of the axial multi-focus zoom scanning method are carried out. Results of simulations and experiments indicate that non-mechanical axial zoom scanning can be realized with the use of a spatial light modulator in the confocal microscopy system.