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Biomedical subjects

Bing Zhou

Publications and source records attributed to Bing Zhou.

At least 37 records · Page 2Linked to original sources
PubMed2005

Visible luminescence of carbon nanotubes and dependence on functionalization.

Strong luminescence emissions over a broad wavelength region were detected from well-dispersed carbon nanotubes in most functionalized samples, even with excitation wavelengths into the near-IR. Apparently, the better dispersion and functionalization of the nanotubes resulted in more intense luminescence emissions. These emissions may logically be attributed to the trapping of excitation energy by defect sites in the nanotube structure, which are passivated upon the appropriate functionalization of the nanotubes. Better functionalization improves not only the nanotube dispersion (thus diminishing the quenching due to intertube interactions) but also the surface passivation to make the energy trapping sites more emissive, leading to stronger luminescence emissions. Because of such high sensitivity, the visible luminescence emissions may prove valuable in the evaluation of dispersion in functionalized carbon nanotube samples and related nanocomposite materials.

Letter↗
PubMed2005

Size-controllable synthesis of monodispersed SnO2 nanoparticles and application in electrocatalysts.

Size-controllable tin oxide nanoparticles are prepared by heating ethylene glycol solutions containing SnCl(2) at atmospheric pressure. The particles were characterized by means of transmission electron microscopic (TEM), X-ray diffraction (XRD) studies. TEM micrographs show that the obtained material are spherical nanoparticles, the size and size distribution of which depends on the initial experimental conditions of pH value, reaction time, water concentration, and tin precursor concentration. The XRD pattern result shows that the obtained powder is SnO(2) with tetragonal crystalline structure. On the basis of UV/vis and FTIR characterization, the formation mechanism of SnO(2) nanoparticles is deduced. Moreover, the SnO(2) nanoparticles were employed to synthesize carbon-supported PtSnO(2) catalyst, and it exhibits surprisingly high promoting catalytic activity for ethanol electrooxidation.

Journal Article↗
PubMed2005

Dementia subtypes in China: prevalence in Beijing, Xian, Shanghai, and Chengdu.

BACKGROUND: Prevalences of Alzheimer disease (AD) and vascular dementia (VaD) in China reportedly differ from those in Western countries. OBJECTIVE: To estimate prevalence of AD and VaD in 4 regions of China. DESIGN: Cross-sectional, population-based prevalence survey with a stratified, multistage cluster sampling design. SETTING: Rural (n = 99) and urbanized (n = 71) communities of Beijing, Xian, Shanghai, and Chengdu. PARTICIPANTS: A sample of 34 807 community residents (94% of those eligible) 55 years or older. MAIN OUTCOME MEASURES: Participants were screened with the Chinese Mini-Mental State Examination. Those who screened positive (n = 3950) underwent a standardized diagnostic workup. Screening sensitivity was assessed in a 3.3% random sample (n = 1008 of the 30 857 who passed the screening). Diagnoses of AD and VaD were made according to National Institute of Neurological and Communicative Diseases and Stroke-Alzheimer Disease and Related Disorders Association and National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences criteria, respectively. Final diagnoses were made after a 6-month confirmation interval. RESULTS: We identified 732 AD cases and 295 VaD cases. Prevalence in persons 65 years or older was 3.5% (95% confidence interval, 3.0%-3.9%) for AD and 1.1% (95% confidence interval, 0.9%-1.1%) for VaD. After post hoc correction for negative screening errors, prevalence increased to 4.8% for AD and remained at 1.1% for VaD. CONCLUSION: Prevalence of dementia subtypes in China is comparable with that in Western countries.

Aged↗
PubMed2005

Association between DNA variant sites in the apolipoprotein A5 gene and coronary heart disease in Chinese.

The recently discovered apolipoprotein A5 ( APOA5 ) gene has been shown to be important in determining plasma triglyceride levels, a major cardiovascular disease risk factor. We searched for possible associations of the APOA5 gene polymorphisms S19W and -1131T>C with coronary heart disease (CHD) in a Chinese population. A total of 483 Chinese CHD patients and 502 control non-CHD subjects were genotyped by polymerase chain reaction-restriction fragment length polymorphism for these 2 single nucleotide polymorphisms. We found that the minor allele 19W was observed only in CHD patients and not in controls, with allelic frequencies of 0.047 and 0.000, respectively ( P < .000001), and the minor allele -1131C was significantly higher in CHD patients than in controls (0.391 vs 0.299, P < .0001). These results suggest that both the S19W and -1131T>C variations in the APOA5 gene are associated with the CHD and appear to be 2 genetic risk factors for CHD susceptibility in Chinese. Moreover, we found that triglyceride levels were significantly higher in -1131C carriers than in -1131T subjects of the control group and that high-density-lipoprotein cholesterol was decreased in -1131C carriers among CHD patients.

Apolipoprotein A-V↗
PubMed2005

Poly(ethylene-co-vinyl alcohol) functionalized single-walled carbon nanotubes and related nanocomposites.

Single-walled carbon nanotubes (SWNTs) were functionalized by poly(ethylene-co-vinyl alcohol) (EVOH) copolymer under carbodiimide-activated esterification reaction conditions. Similar to the parent EVOH copolymer, the EVOH-functionalized carbon nanotubes are soluble in highly polar solvent systems such as DMSO and hot ethanol-water mixtures. The soluble EVOH-SWNT sample was characterized by various techniques, including optical absorption, Raman, NMR, electron microscopy, and thermogravimetric analysis. The common solubility of EVOH and EVOH-SWNT allowed their intimate mixing in solution, and thus the fabrication of nanocomposites in which the SWNTs are homogeneously dispersed in the polymer matrix.

Ethanol↗
PubMed2005

Single microspore reverse transcription-polymerase chain reaction: dynamic change of gene expression during microsporogenesis.

A sensitive and reliable single microspore reverse transcription-polymerase chain reaction (RT-PCR) assay was developed that requires little sample material and only a short sampling time and ensures template preservation. We propose that the assay provides a useful tool to study not only cell-cycle related events in developing pollen but also the molecular mechanisms underlying male sterility and mutants impaired in pollen development.

Cell Division↗
PubMed2005

Yeast model uncovers dual roles of mitochondria in action of artemisinin.

Artemisinins, derived from the wormwood herb Artemisia annua, are the most potent antimalarial drugs currently available. Despite extensive research, the exact mode of action of artemisinins has not been established. Here we use yeast, Saccharamyces cerevisiae, to probe the core working mechanism of this class of antimalarial agents. We demonstrate that artemisinin's inhibitory effect is mediated by disrupting the normal function of mitochondria through depolarizing their membrane potential. Moreover, in a genetic study, we identify the electron transport chain as an important player in artemisinin's action: Deletion of NDE1 or NDI1, which encode mitochondrial NADH dehydrogenases, confers resistance to artemisinin, whereas overexpression of NDE1 or NDI1 dramatically increases sensitivity to artemisinin. Mutations or environmental conditions that affect electron transport also alter host's sensitivity to artemisinin. Sensitivity is partially restored when the Plasmodium falciparum NDI1 ortholog is expressed in yeast ndi1 strain. Finally, we showed that artemisinin's inhibitory effect is mediated by reactive oxygen species. Our results demonstrate that artemisinin's effect is primarily mediated through disruption of membrane potential by its interaction with the electron transport chain, resulting in dysfunctional mitochondria. We propose a dual role of mitochondria played during the action of artemisinin: the electron transport chain stimulates artemisinin's effect, most likely by activating it, and the mitochondria are subsequently damaged by the locally generated free radicals.

Animals↗
PubMed2005

[Surgery of osteomas of the sinuses].

OBJECTIVE: To explore the different surgical choices for treating osteomas of the sinuses. To summarize the management and characteristics of each surgical operation. METHOD: A retrospective evaluation of thirty-one patients with osteomas of the sinuses from June 1993 to December 2001 was presented. Fourteen patients were operated through a lateral rhinotomy with radical operation in 13 cases. Eight patients were operated by nasal endoscopic management, osteomas were completely removed. Eight osteomas were removed with a coronal incision. One case underwent Caldwell-Luc surgery. The clinical symptoms, location of osteomas, and surgical procedures were analyzed. RESULT: The complications of brain spinal fistula occurred in 2 cases, but they were treated in the same time of operations. One patient had a single blindness after the operation. Twenty-eight cases were followed-up for 1 to 9 years with an average of three point seven years. Twenty-six patients had no recurrence, two cases lived with the remains of osteomas. CONCLUSION: The choice of surgical operations on osteomas of the sinuses was mainly decided by the location and size of osteomas, and the anatomic characteristics of sinuses, in the meanwhile, the organ function, the cosmetology, and the doctors experience were taken into account.

Adolescent↗
PubMed2005

[Relationship between allergic factors and chronic sinusitis with or without nasal polyps].

OBJECTIVE: To explore the effects of allergic factors in chronic sinusitis and nasal polyps. METHOD: Eosinophil in nasal secretions and allergen skin test of 1882 patients with chronic sinusitis and nasal polyps were examined before endoscopic sinus surgery. The occurrence ratios of allergic symptoms and syndromes were analyzed and compared with clinical stages of chronic sinusitis and nasal polyps. RESULTS: (1) Allergic symptoms (or syndromes) were presented in 60.4% (1137 cases) of patients in different degrees, 25.3% (477 cases) patients suffered from allergic rhinitis, 2.1% (39 cases) patients had asthma; (2) The morbidities of allergic rhinitis and asthma, the positive rates of eosinophil and allergen skin test, the occurrence rates of allergic symptoms were rising with the clinical stages in type I and type II, especially in type II stage 3; (3) There were 42.2% (795 cases) positive patients in allergen skin test, among them, 94% were sensitive to perennial allergens; (4) Allergic symptoms appeared in 26.3% (495 cases) patients, among them, 99.8% attacked perennially; (5) Of all patients, there were 38.9% (732 cases) had been operated cases before, among them 38.3% (280 cases) with allergy rhinitis. In chronic sinusitis with allergy rhinitis patients, 58.7% (477 cases) were suffered from operation. CONCLUSIONS: Allergic factors,especially perennial allergic rhinitis, are relative to clinical stages of chronic sinusitis and nasal polyps. Allergic rhinitis is an important factors in recurrence.

Adolescent↗
PubMed2005

[Effect of intranasal interleukin-12 gene therapy for allergic rhinitis in murine model].

OBJECTIVE: To investigate whether the local application of IL-12 gene with EBV-plasmid vector to nasal mucosa could prevent allergic inflammation in murine allergic rhinitis model. METHODS: Thirty-six BALB/C mice were randomly divided into allergic rhinitis group gene therapy group and control group. In mice with OVA-induced allergic rhinitis, the EBV/lipoplex (a novel cationic lipid combined with EBV-plasmid vector, pGEG. mIL-12) was locally administered into nasal mucosa before OVA challenge. The expression of IL-12 mRNA and protein, the change of eosinophilia and mast cell, and Th2 cytokine production in the nasal mucosa were measured. RESULTS: The amounts of IL-12 mRNA positive cells and IL-12 positive cells in nasal mucosa of gene therapy group were significantly higher than that of allergic rhinitis group (P < 0.01 and P < 0.05). The amount of eosinophils, mast cells, and the level of IL-5 expression in nasal mucosa in allergic rhinitis group were significantly higher than those in gene therapy group and control group (P < 0.01). The level of total IgE of peripheral blood in allergic rhinitis group was significantly higher than that in gene therapy group and control group (F = 1216.21, P < 0.01). CONCLUSIONS: These findings indicated that IL-12 mRNA and protein were expressed effectively after the local administration of pGEG. mIL-12 in the nasal mucosa. The local application of pGEG. mIL-12 is effective in modulating nasal allergic response and may be a convenient method for future approach to allergic rhinitis.

Animals↗
PubMed2005

[Modified intranasal endoscopic Lothrop procedure].

OBJECTIVE: To report the experience of modified endoscopic Lothrop procedure (MELP) in 6 cases and to discuss the operative technique and indications. METHODS: Six patients (four males and 2 females) aged from 6 to 63 years old with frontal sinus diseases were enrolled in this study, including 3 cases of frontal mucocele, 1 case of recurrent hemangioma, 1 case of recurrent inverted papilloma and 1 case of osteoma. All patients were underwent intranasal modified Lothrop procedure with the guidance of nasal endoscope. The image-guided navigational system was used for the location of frontal sinus in 2 cases. RESULTS: The operation was successful in all 6 patients without any operative and postoperative complications. The average operation time was 3.2 h. The endoscopic examination demonstrated the wide communicational frontal sinus openings and well epithelization after 6-40 months follow-up. The patients were asymptomatic up to now and no recurrence was found. CONCLUSIONS: The modified intranasal endoscopic Lothrop procedure is an ideal surgical approach for recalcitrant frontal sinus disorders on the basis of proper selection of surgical equipments and patients by the experienced surgeon.

Adolescent↗
PubMed2005

[Endoscopic frontal sinus surgery through agger nasi cell approach].

OBJECTIVE: To evaluate the access to the frontal recess by identifying the agger nasi cell and uncinate process. METHODS: Forty-seven patients (85 sides) who underwent endoscopic frontal sinus surgery in our department constituted the study population. Computed tomographic (CT) scans of the sinuses were obtained in coronal and axial views. The frontal ostium was identified by using agger nasi cell approach or identifying the uncinate process. RESULTS: The frontal sinus ostium was identified in 100% of patients (85 sides). After an average follow-up of 9 months, 41 sides of 49 sides (84%) had endoscopically healed sinuses by using agger nasi cell approach. And 21 sides of 36 sides (81%) had endoscopically healed sinuses by identifying the uncinate process. CONCLUSIONS: The agger nasi cell approach to the frontal recess gives an access and allows identification of the frontal ostium. In addition, it provides direct visualization with a 0 degree endoscope into the frontal recess.

Adult↗
PubMed2005

[Endoscopic surgery for nasal septal perforation].

OBJECTIVE: To describe the relevant factors of endoscopic surgery in patients with nasal septal perforation. METHODS: Twenty-three patients with nasal septal perforation were treated under nasal endoscope. Four kinds of reconstruction materials were used to accomplish the closure of perforation: residual osseous septum or temporalis fascia, inverting septal mucoperichondrial flap, autologous connective tissue insert overlaid with mucous flaps and turbinate flap. The reconstructed septum was packed by moist dressing with silicone or plastic splints. RESULTS: Seven patients underwent direct closure. Inverting flap repair for five cases, shifting flap closure for ten cases, and repair with turbinate flap in one case. During the follow-up ranging from four weeks to seven months, the successful reconstruction was achieved in 19 cases (82.6%). The problems in the remaining four cases were: mucosal flap displacement, fascia flap shrank and so caused reperforation, two perforations present with only the larger one repaired, the mucosal flap was smaller in size than the perforation. CONCLUSIONS: Intranasal endoscopic reconstruction surgery is a reasonable management for nasal septal perforation.

Endoscopy↗
PubMed2005

[Therapeutic effects of the combination of traditional Chinese medicine and western medicine on patients with peptic ulcers].

OBJECTIVE: To explore the therapeutic effects and mechanisms of the combination of traditional Chinese medicine and western medicine on patients with peptic ulcers. METHODS: One hundred and twenty patients were randomly divided into 6 groups. Another 10 patients as the control group were confirmed with no peptic ulcers by endoscope, but had digestive tract symptoms. The clinical effects were compared among each group after the one month treatment. RESULTS: The clinical effects of the combination of Jianweiyuyang granules and ranitidine capsules were better than those of western medicine, with improvement in symptoms and syndrome (P < 0.01 to 0.05), but there was not significant difference with the rate of ulcer healing and the Hp clearance among the combination of Jianweiyuyang granules and ranitidine capsules, Jianweiyuyang granules, and ranitidine capsules (P > 0.05). The combination of Jianweiyuyang granules and ranitidine capsules could significantly upregulate the expression of MUCSAC mRNA (P < 0.01), while downregulate the expression of ETAR mRNA (P < 0.01). CONCLUSION: There is obvious advantage in treating peptic ulcers by the combination of Jianweiyuyang granules and ranitidine capsules, and its mechanisms may be to protect the gastric mucosal barrier by up-regulating the expression of MUCSAC mRNA and to improve the gastric mucosal blood flow by down-regulating the expression of ETAR mRNA.

Adult↗
PubMed2005

[Anatomical and computed tomographic analysis of the interaction between uncinate process and agger nasi cells].

OBJECTIVE: To investigate the anatomical interaction between uncinate process and agger nasi cell to better understand the anatomy of the frontal sinus drainage pathway by endoscopy, spiral computed tomography (CT) and sectioning. METHODS: Twenty-one skeletal skulls (forty-two sides) and one cadaver head (two sides) were studied by spiral CT together with endoscopy and collodion embedded thin sectioning at coronal plane. The sections with the thickness of 100 microm were stained with hemotoxylin and eosin. RESULTS: Under endoscopy, a leaflet of bone to the middle turbinate, which is given off by uncinate process, forms the anterior insertion of the middle turbinate onto the lateral nasal wall. The middle portion of the uncinate process attached to the frontal process of the maxilla in all of the skeletal nasal cavities, as well as the lacrimal bone in 78.6% of the skeletal nasal cavities. On CT scans, the agger nasi cell is present in 90.5% of the skeletal nasal cavities. While the lateral wall of the agger nasi cell is formed by lacrimal bone, the medial wall of the agger nasi cell is formed by uncinate process. And the anterior wall is formed by the frontal process of the maxilla. The superior portion of the uncinate process forms the medial, posterior and top wall of the agger nasi cells. The superior portion of the uncinate extends into the frontal recess and may insert into lamina papyracea (33.3%), skull base (9.5%), middle turbinate, combination of these (57.2%). CONCLUSIONS: The agger nasi cell is the key that unlocks the frontal recess.

Adult↗
PubMed2004

Diminished band-gap transitions of single-walled carbon nanotubes in complexation with aromatic molecules.

The near-IR absorption spectrum of semiconducting single-walled carbon nanotubes is characterized by the transitions associated with the first (S11) and second (S22) pairs of van Hove singularities in the electronic density of states. We report that a significant effect on the transitions can be caused by non-covalent complexation of the nanotube with planar aromatic molecules such as pyrenes in solution, resulting in the absence of S11 and S22 bands in the near-IR absorption spectrum. Since the complexation is reversible, the characteristic absorption bands can be turned on and off with the complexation in a reversible fashion.

Journal Article↗
PubMed2004

Influence of octadecyl dihydrogen phosphate on the formation of active super-fine calcium carbonate.

A carbonation process for the synthesis of active super-fine calcium carbonate particles from Ca(OH)(2) slurry at room temperature using a CO(2)-N(2) gas mixture was investigated. Industrial octadecyl dihydrogen phosphate (A) was added as a size-controlling additive and modifier in different reaction periods according to the pH of the medium. Analysis of the reaction products led to the conclusion that the addition of A in the digestion period could inhibit the crystal growth of calcium carbonate, while the addition of A at pH 7 of the medium could modify the surface character of the calcium carbonate particle, which was found to exhibit hydrophobic properties. From transmission electron microscopy (TEM), the hydrophobic property was attributed to the deposition of calcium alkyl phosphates, produced in the reaction mixture, onto the surface of calcium carbonate particle. IR spectra and TGA analysis of the obtained products indicated that A was bound onto the crystalline CaCO(3).

Journal Article↗