Publications by authors named "Guo-Zheng Yan"

Oxidative stress and inflammation responses are closely related to the occurrence and development of many diseases. Therefore, anti-oxidation and anti-inflammation have become hot spots in the treatment of diseases. A series of novel resveratrol derivatives which hybrid with benzoylhydrazines were designed, synthesized and assessed for their in vitro antioxidant and anti-inflammatory activity.

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Objective: The evaluation of GI-pill gastrointestinal electronic capsule for colonic transit test in patients with slow transit constipation (STC) was studied.

Materials And Methods: STC patients (n = 162) were randomly divided into experimental group (n = 84, orally taken GI-pill gastrointestinal electronic capsule and X-ray granule capsule) and control group (n = 78, orally taken X-ray granule capsule). Comparison of the time in colonic transit test between the two groups was conducted.

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This paper presents some of the latest progress in the development of a novel artificial anal sphincter system (AASS) to treat severe fecal incontinence. We have redesigned and integrated an intelligent, remote-controlled artificial anal sphincter based on biological signal feedback mechanisms. The device consists of an external telemetry unit, an internal artificial anal sphincter (IAAS), and a transcutaneous energy transfer system (TETS).

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This paper reports on the electromagnetic effects on the biological tissue surrounding a transcutaneous transformer for an artificial anal sphincter. The coupling coils and human tissues, including the skin, fat, muscle, liver, and blood, were considered. Specific absorption rate (SAR) and current density were analyzed by a finite-length solenoid model.

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A series of 1-acyl-3-isopropenylbenzimidazolone derivatives were synthesized, and their structures were characterized by (1)H and (13)C NMR and elemental analysis. Their fungicidal activities against Botrytis cinerea were also evaluated by spore germination assay. The acrylic acid, methacrylic acid, 4-chlorophenyl acetic acid, and 2-chlorobenzoic acid derivatives exhibited strong fungicidal activity.

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A novel artificial anal sphincter system has been developed to simulate the normal physiology of the human anorectum. With the goal of engineering a safe and reliable device, the model of human colonic blood flow has been built and the relationship between the colonic blood flow rate and the operating occlusion pressure of the anorectum is achieved. The tissue ischemia is analyzed based on constitutive relations for human anorectum.

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A wireless energy transmission system for the MEMS system inside alimentary tracts is reported here in the paper. It consists of an automatic frequency tracking circuit of phase lock loop and phase shift PWM control circuit. Experimental results show that the energy transmission system is capable of automatic frequency-tracking and transmission power-adjusting and has stable received energy.

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Aim: To study the prolonged colonic motility under normal conditions with a novel capsule-style micro-system and to assess its clinical significance.

Methods: A single use telemetry capsule (10 mm in diameter, 20 mm in length) embedded with a pressure sensor was ingested by the subjects. The sensor is capable of transmitting colonic pressure wirelessly for more than 130 h.

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A newly-developed gastrointestinal (GI) monitoring system based on a smart capsule is presented in the paper. The unprecedented 130-200 hours battery life and smaller size (10 mm x 20 mm) allows the physician to get total pan-colonic measurements of high-amplitude propagating contractions (HAPCs). To test the in vivo performance of the monitoring system, 15 healthy volunteers and 10 patients with slow transportation constipation (STC) participate in this study.

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A method based on wavelet packet best basis decomposition (WPBBD) is investigated for the purpose of extracting features of electroencephalogram signals produced during motor imagery tasks in brain-computer interfaces. The method includes the following three steps. (1) Original signals are decomposed by wavelet packet transform (WPT) and a wavelet packet library can be formed.

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In this paper we discuss a subject-based feature extraction method using wavelet packet best basis decomposition (WPBBD) in brain-computer interfaces (BCIs). The idea is to employ the wavelet packet best basis algorithm to adapt to each subject separately. Firstly, original electroencephalogram (EEG) signals are decomposed to a given level by wavelet packet transform.

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This paper introduces the general constitutions and principle of BCI systems. In addition, some characteristics and limitations of different research methods are discussed and compared. Finally, this paper points out the existing problems and future trends of BCIs.

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This paper makes a comparison between the traditional endoscope system and the active robotic endoscope system, discusses the human intestine-working conditions of the robotic endoscope system in detail and its design requirements. An active robotic endoscope system based on earthworn-locomotion principles is proposed here and besides, its structure and locomotion mechanism are analyzed. A new method of human intestinal intervention is brought out and it can prevent the robotic endoscope guided by a cone-shaped guide pipe from being jammed or damaged.

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This paper presents the properties of Pneumatic artificial muscles and its application in medical robots. The linear model construction and minimum predictive error control algorithm for artificial muscles are discussed here too. This paper provides the experimental results of linear adaptive control, which show the control algorithm has certain applicable value.

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Swallowable biotelemetry systems are one kind of implantable biotelemetry systems. The research about swallowable biotelemetry systems is rapidly growing recently because they can be used to measure physiological and pathological parameters of human gastrointestinal tracts in vivo and they significantly improve patient comfort. This paper presents the current research of swallowable biotelemetry systems domestically and abroad.

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Aim: To propose a new, non-invasive method for monitoring 24-h pressure, temperature and pH value in gastrointestinal tract.

Methods: The authors developed a miniature, multi-functional gastrointestinal monitoring system, which comprises a set of indigestible biotelemetry capsules and a data recorder. The capsule, after ingested by patients, could measure pressure, temperature and pH value in the gastrointestinal tract and transmit the data to the data recorder outside the body through a 434 MHz radio frequency data link.

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