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Fuqiang Zhang

Publications and source records attributed to Fuqiang Zhang.

16 recordsLinked to original sources
PubMed2006

Triconstituent co-assembly to ordered mesostructured polymer-silica and carbon-silica nanocomposites and large-pore mesoporous carbons with high surface areas.

Highly ordered mesoporous polymer-silica and carbon-silica nanocomposites with interpenetrating networks have been successfully synthesized by the evaporation-induced triconstituent co-assembly method, wherein soluble resol polymer is used as an organic precursor, prehydrolyzed TEOS is used as an inorganic precursor, and triblock copolymer F127 is used as a template. It is proposed for the first time that ordered mesoporous nanocomposites have "reinforced concrete"-structured frameworks. By adjusting the initial mass ratios of TEOS to resol, we determined the obtained nanocomposites possess continuous composition with the ratios ranging from zero to infinity for the two constituents that are "homogeneously" dispersed inside the pore walls. The presence of silicates in nanocomposites dramatically inhibits framework shrinkage during the calcination, resulting in highly ordered large-pore mesoporous carbon-silica nanocomposites. Combustion in air or etching in HF solution can remove carbon or silica from the carbon-silica nanocomposites and yield ordered mesoporous pure silica or carbon frameworks. The process generates plenty of small pores in carbon or/and silica pore walls. Ordered mesoporous carbons can then be obtained with large pore sizes of approximately 6.7 nm, pore volumes of approximately 2.0 cm(3)/g, and high surface areas of approximately 2470 m(2)/g. The pore structures and textures can be controlled by varying the sizes and polymerization degrees of two constituent precursors. Accordingly, by simply tuning the aging time of TEOS, ordered mesoporous carbons with evident bimodal pores at 2.6 and 5.8 nm can be synthesized.

Journal Article↗
PubMed2006

SuperState: a computer program for the control of operant behavioral experimentation.

Operant behavioral researches require precise control of experimental devices for delivering stimuli and monitoring behavioral responses. The author developed a software solution named SuperState for controlling hardware devices and running reinforcement schedules. The Microsoft Windows compatible software was written by use of an object-oriented programming language Borland Delphi 5.0, which has simplified the programming of the application. SuperState is a stand-alone easy-to-use green software, without the need for the experimenter to master any scripting languages. It features: (1) control of multiple operant cages running independent reinforcement schedules; (2) enough cage devices (16 digital inputs and 16 digital outputs for each cage) suitable for the need of most operant behavioral equipments; (3) control of most standard ISA-type digital interface cards including Med-Associates Super-port cards and a PCI-type card AC6412, and highly expandable to support other PCI-type interface cards; (4) high-resolution device control (1ms); (5) a built-in real-time cumulative recorder; (6) extensive data analyzing including event recorder, cumulative recorder, block analyzing; the summarized results can be transferred easily to Microsoft Excel spreadsheets through the Clipboard.

Animals↗
PubMed2005

The dissociation of heroin-seeking patterns induced by contextual, discriminative, or discrete conditioned cues in a model of relapse to heroin in rats.

RATIONALE: The role of heroin-related stimuli in motivating the resumption of heroin use is not fully understood. OBJECTIVES: The objective was to characterize the relative importance of drug-related contextual stimuli, discriminative stimuli (DS), or discrete conditioned stimuli (CSs) on drug seeking when rats were reintroduced into the operant context after withdrawal. METHODS: Nose-poke responding by male rats was reinforced with intravenous heroin (0.05 mg/kg per infusion, 4-h session daily) under a progressive ratio schedule of reinforcement for 14 days. Each session began with the illumination of a green light in the active hole that served as DS. Each earned heroin injection was paired with a 5-s compound cue light and the sound of the infusion pump that served as the discrete CSs. RESULTS: Response rates of heroin seeking induced by the contextual stimuli were comparable to the average rates of responding during self-administration training, but rates induced by either DS or CSs were greater than those induced by the contextual stimuli alone (P<0.05). The responding induced by contingent presentations of CSs was higher than that of DS after extinction of instrumental behavior. The drug seeking induced by CSs can be maintained after 3 days extinction with DS in the original context, although the responding elicited by DS cannot be recovered after 3 days of extinction with CSs. CONCLUSIONS: The relapse to drug seeking can be elicited separately by environmental cues, heroin-predictive DS, or discrete CSs in the same rat after withdrawal.

Analgesics, Opioid↗
PubMed2005

Increased c-Fos expression in the medial part of the lateral habenula during cue-evoked heroin-seeking in rats.

Conditioned environmental stimuli are known to be important determinants of drug seeking behavior. c-Fos, the protein product of the protooncogene c-Fos, is expressed in neurons when there are drug-associated cue-induced drug-seeking behaviour. Therefore, its expression could serve as a marker of regional neuronal activation. Using an extinction/reinstatement paradigm of relapse animal model, we trained Sprague-Dawley rats to nose-poke for i.v. heroin (0.05 mg/kg/infusion) either daily for 4h or 25 infusions for 14 consecutive days. We then tested these animals for cue-evoked heroin-seeking behavior after abstinence from self-administration of heroin for 14 days. Expression of c-Fos was examined in the lateral habenula (LHb), a region important for conveying information between the limbic forebrain and midbrain. Findings showed that heroin-associated conditioned stimuli could induce robust heroin-seeking behavior that was associated with increased c-Fos immunoreactivity in the medial part of the LHb. This observation suggests the involvement of the LHb in mediating drug cue-induced heroin-seeking behavior after abstinence from self-administration of heroin.

Animals↗
PubMed2005

Understanding effect of wall structure on the hydrothermal stability of mesostructured silica SBA-15.

Mesostructured silica SBA-15 materials with different structural parameters, such as pore size, pore volume, and wall thickness, etc., were prepared by varying the postsynthesis hydrothermal treatment temperature and adding inorganic salts. The hydrothermal stabilities of these materials in steam (100% water vapor) were systematically investigated using a variety of techniques including powder X-ray diffraction, transmission electron microscopy, nitrogen sorption, and (29)Si solid-state NMR. The effect of the pore size, microporosity or mesoporosity, and wall thickness on the stability was discussed. The results show that all of the SBA-15 materials have a good hydrothermal stability under steam of 600 degrees C for at least 24 h. N(2) sorption measurements show that the Brumauer-Emmett-Teller surface area of SBA-15 materials is decreased by about 62% after treatment under steam at 600 degrees C for 24 h. The materials with thicker walls and more micropores show relatively better hydrothermal stability in steam of 600 degrees C. Interestingly, we found that the microporosity of the mesostructured silica SBA-15 is a very important factor for the hydrothermal stability. To the materials with more micropores, the recombination of Si-O-Si bonds during the high-temperature steam treatment may not cause direct destruction to the wall structure. As a result, SBA-15 materials with more micropores show better stability in pure steam of 600 degrees C. Nevertheless, these materials are easily destroyed in steam of 800 degrees C for 6 h. Two methods to effectively improve the hydrothermal stability are introduced here: one is a high-temperature treatment, and another is a carbon-propping thermal treatment. Thermal treatment at 900 degrees C can enhance the polymerization degree of Si-O-Si bonds and effectively improve the hydrothermal stability of these SBA-15 materials in 800 degrees C steam for 12 h. But, this approach will cause very serious shrinkage of the mesopores, resulting in smaller pore diameter and low surface area. A carbon-propping thermal treating method was employed to enhance the polymerization of Si-O-Si bonds and minimize the serious shrinkage of mesopores at the same time. It was demonstrated to be an effective method that can greatly improve the hydrothermal stability of SBA-15 materials in 800 degrees C steam for 12 h. Furthermore, the SBA-15 materials obtained by using the carbon-propping method possess larger pores and higher surface area after the steam treatment at 800 degrees C compared to the materials from the direct thermal treatment method after the steam treatment.

Journal Article↗
PubMed2005

[Fabricating facial prostheses using CAD/CAM and rapid prototyping technique].

At present, the treatments of hemifacial microsomia such as the missing of ear and eye still rely on the skill of technician to make the wax model of contralateral apparatus of patient in China. In this paper, CAD/CAM and rapid prototyping (RP) techniques are integrated to successfully create a silastic prosthesis by using the patient's data of CT or laser scanning. The clinical results suggest that a high accuracy has been achieved in shape, size, and protrusion of the facial prostheses, which indicates that the application of RP techniques in conjunction with CAD/CAM is a suitable approach for fabricating facial prosthesis.

Biocompatible Materials↗
PubMed2004

Low dose of heroin inhibits drug-seeking elicited by cues after prolonged withdrawal from heroin self-administration in rats.

Environmental stimuli and conditioned cues associated with heroin can induce drug-seeking behavior, but how heroin lapse interacts with cues is unclear. Rats were trained to nose-poke for i.v. heroin for 14 days and then tested for heroin seeking after withdrawal from heroin self-administration. Heroin seeking induced by cues persisted over several weeks after withdrawal, and the responding was not easily extinguished after 4 weeks withdrawal. A single injection of heroin (250 micro g/kg) enhanced the responding at early stage of withdrawal, but a low dose of heroin (50, 250 micro g/kg) suppressed the responding induced by contextual or conditioned cues at 4 weeks of withdrawal. The results suggest that prolonged withdrawal may increase the risk of relapse to heroin seeking.

Animals↗
PubMed2004

Facile synthesis and characterization of novel mesoporous and mesorelief oxides with gyroidal structures.

In this paper, we bring forward an effective strategy, solvothermal postsynthesis, to prepare ordered mesoporous silica materials with highly branched channels. Structural characterizations indicate that the titled mesoporous materials basically have the cubic double gyroidal (space group Ia-3d) structure with small fraction of distortions. The mesopore sizes and surface areas can be up to 8.8 nm and 540 m2/g, respectively, when microwave digestion is employed to remove the organic templates. A phase transition model is proposed, and possible explanations for the successful phase transition are elucidated. The results show that the flexible inorganic framework, high content of organic matrix, and nonpenetration of poly(ethylene oxide) segments may facilitate the structural evolution. This new synthetic strategy can also be extended to the preparation of other double gyroidal silica-based mesoporous materials, such as metal and nonmetal ions doped silica and organo-functionalized silica materials. The prepared 3D mesoporous silica can be further utilized to fabricate various ordered crystalline gyroidal metal oxide "negatives". The mesorelief "negatives" (Co3O4 and In2O3 are detailed here) prepared by impregnation and thermolysis procedures exhibit undisplaced, displaced, and uncoupled enantiomeric gyroidal subframeworks. It has been found that the amount of metal oxide precursors (hydrated metal nitrates) greatly influence the (sub)framework structure and single crystallinity of the mesorelief metal oxide particles. The single crystalline gyroidal metal oxides are ordered both at mesoscale and atomic scale. However, these orders are not commensurate with each other.

Journal Article↗
PubMed2004

Motivation of heroin-seeking elicited by drug-associated cues is related to total amount of heroin exposure during self-administration in rats.

Conditioned stimuli (CSs) previously associated with heroin are critically involved in activating long-lasting relapse and compulsive drug seeking. This study examined the magnitude of heroin seeking induced by drug-related cues in relation to the total amount of drug exposure during training. Five groups of male Sprague-Dawley rats (n=6/group) were trained by the nose-poking response to self-administer different doses of heroin (0, 0.01, 0.025, 0.05, and 0.1 mg/kg per infusion respectively, one 4-h session daily, limited to 25 infusions per session) under an identical progressive ratio schedule with gradual incremental response requirements. All the rats established stable heroin self-administration within 14 days of self-administration training, and the time needed to obtain all the 25 heroin infusions decreased across sessions. After 14 days of abstinence, heroin seeking elicited by contextual cues (self-administration chamber) or discrete contingent CSs previously associated with heroin infusions was measured in two consecutive 1-h test phases. During both test phases, the rats trained with heroin even at the lowest dose (0.01 mg/kg) showed higher active responses than saline controls, and the active responses were also higher in rats trained with doses of 0.025, 0.05, and 0.10 mg/kg in comparison with those trained with a dose of 0.01 mg/kg. There was no observable dose-dependence increase of responses at doses above 0.025 mg/kg. The results suggested that an increased motivation to seek heroin induced by drug-related cues is associated with the total amount of heroin intake.

Animals↗
PubMed2003

[The effects of pH in artificial saliva on the corrosion resistance of magnetic retainers].

OBJECTIVE: The aim of this article was to discover the corrosion resistance of magnetic attachments, which were encapsulated in stainless steel, when pH value of artificial saliva was lower than normal. METHODS: Three kinds of magnetic retainers were exposed for 6 months to artificial saliva with pH ranging from 5.6 to 7.0, thermostated at 36.5 degrees C. This study included electrochemical test as polarization curves, chemical test as immersion test and SEM to analyze the corrosion behavior of the materials. RESULTS: Fe3+ ions in stainless steel released more than ten times in an environment pH 5.6 than pH 7.0. The higher concentration of H+, the more elemental release. That pH value of artificial saliva reduced may affect the corrosion speed. The magnetic retainers were not resistant to acidic environments during exposure. CONCLUSION: Transient exposure of stainless steel to an acidic oral environment can increase elemental release significantly. So acid resistance of magnetic retainers was relatively weak, and it would affect the life span of magnets.

Corrosion↗
PubMedDate not supplied

Design and fabrication of auricular prostheses by CAD/CAM system.

PURPOSE: The purpose of this report is to describe a new technique for fabricating auricular prostheses by a computer-aided design/manufacturing (CAD/CAM) system. MATERIALS AND METHODS: A spiral CT was performed on a patient who had a right ear defect resulting from an accident. A 3-D image was reconstructed with the CT data. Through image ware, the image of the normal ear was extracted, mirrored, and Boolean operated with the image of the deformed side of the face. It was well modified and smoothed in the FreeForm model system so that it could precisely adapt to the deficient side of the face. A paper model ear was manufactured by rapid prototyping from the digitized data. Finally, silicone was poured into a silicone mold from the paper ear to create a silicone auricular prosthesis. RESULTS: The dimension, shape, and anatomic contour of the auricular prosthesis were quite similar to those of the normal ear and precisely matched the deformed area. CONCLUSION: The CAD/CAM system for creating auricular prostheses appears to be a practical technique.

Adult↗