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Qiang Li

Publications and source records attributed to Qiang Li.

At least 73 records · Page 4Linked to original sources
PubMed2006

Linear energy transfer dependence of the effects of carbon ion beams on adventitious shoot regeneration from in vitro leaf explants of Saintpaulia ionahta.

PURPOSE: To determine the effects of carbon ion beams with five different linear energy transfer (LET) values on adventitious shoots from in vitro leaf explants of Saintpaulia ionahta Mauve cultivar with regard to tissue increase, shoots differentiation and morphology changes in the shoots. MATERIALS AND METHODS: In vitro leaf explant samples were irradiated with carbon ion beams with LET values in the range of 31 approximately 151 keV/microm or 8 MeV of X-rays (LET = 0.2 keV/microm) at different doses. Fresh weight increase, surviving fraction and percentage of the explants with regenerated malformed shoots in all the irradiated leaf explants were statistically analysed. RESULTS: The fresh weight increase (FWI) and surviving fraction (SF) decreased dramatically with increasing LET at the same doses. In addition, malformed shoots, including curliness, carnification, nicks and chlorophyll deficiency, occurred in both carbon ion beam and X-ray irradiations. The induction frequency with the former, however, was far more than that with the X-rays. CONCLUSIONS: This work demonstrated the LET dependence of the relative biological effectiveness (RBE) of tissue culture of Saintpaulia ionahta according to 50% FWI and 50% SF. After irradiating leaf explants with 5 Gy of a 221 MeV carbon ion beam having a LET value of 96 keV/microm throughout the sample, a chlorophyll-deficient (CD) mutant, which could transmit the character of chlorophyll deficiency to its progeny through three continuous tissue culture cycles, and plantlets with other malformations were obtained.

Carbon Radioisotopes↗
PubMed2006

Plasma pharmacokinetics of alfaxalone in dogs after an intravenous bolus of Alfaxan-CD RTU.

OBJECTIVE: To determine the pharmacokinetic parameters of alfaxalone in dogs after the intravenous (IV) administration of clinical and supra-clinical doses of a 2-hydroxypropyl-beta-cyclodextrin (HPCD) alfaxalone formulation (Alfaxan-CD RTU). EXPERIMENTAL DESIGN: Prospective two-period crossover design. Animals Eight (four male and four female) young adult healthy Beagle dogs. Methods The steroid anaesthetic alfaxalone was administered IV at two doses in a crossover design (2 and 10 mg kg(-1)) with a washout period of 21 days. Blood samples were collected before and up to 8 hours after dosing. Plasma concentrations of alfaxalone were assayed using a liquid chromatograph/mass selective detector technique and analyzed to estimate the main pharmacokinetic parameters by noncompartmental analysis. Results were expressed as mean +/- SD. RESULTS: The mean duration of anaesthesia from endotracheal intubation to extubation was 6.4 +/- 2.9 and 26.2 +/- 7.5 minutes, for the 2 and 10 mg kg(-1) doses, respectively. The plasma clearance of alfaxalone for the 2 and 10 mg kg(-1) doses differed statistically at 59.4 +/- 12.9 and 52.9 +/- 12.8 mL kg(-1) minute(-1), respectively (p = 0.008) but this difference was deemed clinically unimportant; the harmonic mean plasma terminal half-lives (t(1/2)) were 24.0 +/- 1.9 and 37.4 +/- 1.6 minutes respectively. The volume of distribution was between 2 and 3 L kg(-1) and did not differ between the two doses. No sex effect was observed. CONCLUSIONS AND CLINICAL RELEVANCE: Alfaxalone, as an HPCD formulation (Alfaxan-CD RTU) administered in the dog provides rapid and smooth induction of anaesthesia, satisfactory conditions for endotracheal intubation and a short duration of anaesthesia. There was no clinically significant modification of the pharmacokinetic parameters between sexes and between the clinical (2 mg kg(-1)) and supra-clinical (10 mg kg(-1)) doses.

Anesthesia, General↗
PubMed2006

Sedative and GABAergic effects of ethanol on male and female rats.

BACKGROUND: Women consume less alcohol than men, and yet they are more susceptible than men to the negative medical consequences of alcohol use, such as cirrhosis of the liver, cardiac disease, and cognitive impairments. This sex difference is also reflected in animal studies, in which male and female rats differ on both behavioral and electrophysiological measures. Given that one significant difference between males and females is the cycling fluctuations of the sex hormones, this study aimed to compare the relative sensitivity of adolescent and adult rats of both sexes and varying estrous stages to the behavioral and electrophysiological effects of ethanol. METHODS: Adult female rats were lavaged daily for estrous cycle assessment. Following administration of 5 g/kg ethanol, adolescent and adult male and female animals were observed for loss of the righting reflex. Then, using whole-cell recording, we tested the response of spontaneous, gamma-aminobutyric acid (GABA(A)) receptor-mediated inhibitory postsynaptic currents (sIPSCs) in hippocampal slices from drug-naïve adult male and female rats. RESULTS: Consistent with previous findings, adolescent animals were less sensitive than adults to the effect of ethanol on the righting reflex. In addition, adult proestrous and diestrous female rats were less sensitive than male rats to the sedative effects of ethanol. Finally, ethanol increased the frequency of sIPSCs in hippocampal pyramidal neurons and did so more potently in cells from male rats than in those from female rats. CONCLUSIONS: Female animals are less sensitive to the behavioral sedative effects of ethanol than adult male rats, and the effect is pronounced in the proestrous and diestrous states. This sex difference may be related to differential sensitivity of GABA receptor-mediated central nervous system function to ethanol in females.

Age Factors↗
PubMed2006

Developmental differences in the sensitivity of spontaneous and miniature IPSCs to ethanol.

BACKGROUND: Ethanol (EtOH) consumption by juveniles and adolescents is an important public health problem. Recent studies have indicated that adolescent animals are less sedated by EtOH than adult animals and experience less motor impairment. Thus, human adolescents may be able to consume more EtOH prior to sedation, putting them at greater risk for EtOH addiction and other negative consequences of EtOH use. However, the mechanisms underlying this developmental difference are unknown. One contributing factor may be gamma-aminobutyric acid-A (GABA(A)) receptor-mediated inhibition, which is known to produce sedation. We have shown that evoked, GABA(A) receptor-mediated inhibitory postsynaptic currents (IPSCs) are less powerfully enhanced by EtOH in neurons from juvenile or adolescent animals than in those from adult animals; however, the mechanisms of this developmental difference in sensitivity are unknown. METHODS: Using whole-cell recording, we tested the response of spontaneous and miniature GABA(A) receptor-mediated IPSCs (sIPSCs and mIPSCs) to EtOH in rat hippocampal slices from animals representing two distinct developmental stages: adolescent and adult. RESULTS: We found significantly greater EtOH-induced enhancement of the frequency of sIPSCs in cells from adult animals compared to those from adolescent animals. Although EtOH also increased the frequency of mIPSCs, this effect was not age dependent. EtOH did not significantly affect the kinetics of mIPSCs. CONCLUSIONS: We conclude that the sensitivity of GABA(A) receptor-mediated inhibitory processes to EtOH increases with development from the adolescent period to adulthood, and that this is likely mediated by developmental changes in the effect of EtOH on interneuron excitation.

Age Factors↗
PubMed2006

Advanced glycation end products induce actin rearrangement and subsequent hyperpermeability of endothelial cells.

This study aimed to determine the effects of advanced glycation end products (AGEs) on endothelial cytoskeleton morphology and permeability, and to detect the underlying signaling mechanisms involved in these responses. Cultured endothelial cells (ECs) were exposed to AGE-modified human serum albumin (AGE-HSA), and EC cytoskeletal changes were evaluated by observing fluorescence of F-actin following ligation with labeled antibodies. Endothelial permeability was detected by measuring the flux of TRITC-albumin across the EC monolayers. To explore the signaling pathways behind AGE-induced EC alteration, ECs were treated with either soluble anti-AGE receptor (RAGE) IgG, or the MAPK inhibitors PD98059 and SB203580 before AGE-HSA administration. To further elucidate possible involvement of the ERK and p38 pathways in AGE-induced EC changes, adenovirus-carried recombinant constitutive dominant-negative forms of upstream ERK and p38 kinases, namely MEK1(A) and MKK6b(A), were pre-infected into ECs 24 h prior to AGE-HSA exposure. AGE-HSA induced actin cytoskeleton rearrangement, as well as EC hyperpermeability, in a dose and time-dependent manner. The effects were attenuated in cells pretreated with anti-RAGE IgG, PD98059 or SB203580, respectively. EC pre-infection with MEK1(A) and MKK6b(A) also alleviated the effect of AGEs. Furthermore, adenovirus-mediated administration of activated forms of either MEK1 or MKK6b alone induced rearrangement of F-actin and hyperpermeability. The results indicate that ERK and p38 MAPK play important roles in the mediation of AGE-induced EC barrier dysfunction associated with morphological changes of the F-actin.

Actins↗
PubMed2006

Analysis and minimization of overtraining effect in rule-based classifiers for computer-aided diagnosis.

Computer-aided diagnostic (CAD) schemes have been developed to assist radiologists detect various lesions in medical images. In CAD schemes, classifiers play a key role in achieving a high lesion detection rate and a low false-positive rate. Although many popular classifiers such as linear discriminant analysis and artificial neural networks have been employed in CAD schemes for reduction of false positives, a rule-based classifier has probably been the simplest and most frequently used one since the early days of development of various CAD schemes. However, with existing rule-based classifiers, there are major disadvantages that significantly reduce their practicality and credibility. The disadvantages include manual design, poor reproducibility, poor evaluation methods such as resubstitution, and a large overtraining effect. An automated rule-based classifier with a minimized overtraining effect can overcome or significantly reduce the extent of the above-mentioned disadvantages. In this study, we developed an "optimal" method for the selection of cutoff thresholds and a fully automated rule-based classifier. Experimental results performed with Monte Carlo simulation and a real lung nodule CT data set demonstrated that the automated threshold selection method can completely eliminate overtraining effect in the procedure of cutoff threshold selection, and thus can minimize overall overtraining effect in the constructed rule-based classifier. We believe that this threshold selection method is very useful in the construction of automated rule-based classifiers with minimized overtraining effect.

Diagnosis, Computer-Assisted↗
PubMed2006

Computerized detection of intracranial aneurysms for three-dimensional MR angiography: feature extraction of small protrusions based on a shape-based difference image technique.

We have improved a computerized scheme for the detection of intracranial aneurysms for three-dimensional (3-D) magnetic resonance angiography (MRA) by the use of image features of small protrusions extracted based on a shape-based difference image (SBDI) technique. Initial candidates were identified by use of a multiple gray-level thresholding technique in dot enhanced images, and by finding short branches in skeleton images. Image features related to aneurysms were determined based on candidate regions segmented by use of a region growing technique. For extracting additional features on small protrusions or small aneurysms, we have developed an SBDI technique, which was based on the shape-based difference between an original segmented vessel and a vessel with suppressed local change in thickness. The SBDI technique was useful for obtaining local changes in vessel thickness, i.e., SBD regions, which could be small aneurysms in the case of true positives, but thin or very small regions in the case of false positives. Many false positives were removed by means of rule-based schemes and linear discriminant analysis on various 3-D localized image features, including SBDI features. We tested the computerized scheme on 53 cases with 61 aneurysms and 62 nonaneurysm cases based on a leave-one-out-by-patient test method. As a result, false positives per patient decreased from 5.8 to 3.8, while a high sensitivity of 97% was maintained by use of the SBDI technique, in which SBDI features were effective for removing some false positives. The computer-aided diagnostic (CAD) scheme may be robust and useful in assisting radiologists in the detection of intracranial aneurysms for MRA.

False Positive Reactions↗
PubMed2006

Reduction of bias and variance for evaluation of computer-aided diagnostic schemes.

Computer-aided diagnostic (CAD) schemes have been developed to assist radiologists in detecting various lesions in medical images. In addition to the development, an equally important problem is the reliable evaluation of the performance levels of various CAD schemes. It is good to see that more and more investigators are employing more reliable evaluation methods such as leave-one-out and cross validation, instead of less reliable methods such as resubstitution, for assessing their CAD schemes. However, the common applications of leave-one-out and cross-validation evaluation methods do not necessarily imply that the estimated performance levels are accurate and precise. Pitfalls often occur in the use of leave-one-out and cross-validation evaluation methods, and they lead to unreliable estimation of performance levels. In this study, we first identified a number of typical pitfalls for the evaluation of CAD schemes, and conducted a Monte Carlo simulation experiment for each of the pitfalls to demonstrate quantitatively the extent of bias and/or variance caused by the pitfall. Our experimental results indicate that considerable bias and variance may exist in the estimated performance levels of CAD schemes if one employs various flawed leave-one-out and cross-validation evaluation methods. In addition, for promoting and utilizing a high standard for reliable evaluation of CAD schemes, we attempt to make recommendations, whenever possible, for overcoming these pitfalls. We believe that, with the recommended evaluation methods, we can considerably reduce the bias and variance in the estimated performance levels of CAD schemes.

Algorithms↗
PubMed2006

Computer-aided diagnostic scheme for the detection of lung nodules on chest radiographs: localized search method based on anatomical classification.

We developed an advanced computer-aided diagnostic (CAD) scheme for the detection of various types of lung nodules on chest radiographs intended for implementation in clinical situations. We used 924 digitized chest images (992 noncalcified nodules) which had a 500 x 500 matrix size with a 1024 gray scale. The images were divided randomly into two sets which were used for training and testing of the computerized scheme. In this scheme, the lung field was first segmented by use of a ribcage detection technique, and then a large search area (448 x 448 matrix size) within the chest image was automatically determined by taking into account the locations of a midline and a top edge of the segmented ribcage. In order to detect lung nodule candidates based on a localized search method, we divided the entire search area into 7 x 7 regions of interest (ROIs: 64 x 64 matrix size). In the next step, each ROI was classified anatomically into apical, peripheral, hilar, and diaphragm/heart regions by use of its image features. Identification of lung nodule candidates and extraction of image features were applied for each localized region (128 x 128 matrix size), each having its central part (64 x 64 matrix size) located at a position corresponding to a ROI that was classified anatomically in the previous step. Initial candidates were identified by use of the nodule-enhanced image obtained with the average radial-gradient filtering technique, in which the filter size was varied adaptively depending on the location and the anatomical classification of the ROI. We extracted 57 image features from the original and nodule-enhanced images based on geometric, gray-level, background structure, and edge-gradient features. In addition, 14 image features were obtained from the corresponding locations in the contralateral subtraction image. A total of 71 image features were employed for three sequential artificial neural networks (ANNs) in order to reduce the number of false-positive candidates. All parameters for ANNs, i.e., the number of iterations, slope of sigmoid functions, learning rate, and threshold values for removing the false positives, were determined automatically by use of a bootstrap technique with training cases. We employed four different combinations of training and test image data sets which was selected randomly from the 924 cases. By use of our localized search method based on anatomical classification, the average sensitivity was increased to 92.5% with 59.3 false positives per image at the level of initial detection for four different sets of test cases, whereas our previous technique achieved an 82.8% of sensitivity with 56.8 false positives per image. The computer performance in the final step obtained from four different data sets indicated that the average sensitivity in detecting lung nodules was 70.1% with 5.0 false positives per image for testing cases and 70.4% sensitivity with 4.2 false positives per image for training cases. The advanced CAD scheme involving the localized search method with anatomical classification provided improved detection of pulmonary nodules on chest radiographs for 924 lung nodule cases.

Databases, Factual↗
PubMed2006

Experimental determination of subjective similarity for pairs of clustered microcalcifications on mammograms: observer study results.

Presentation of images of lesions similar to that of an unknown lesion might be useful to radiologists in distinguishing between benign and malignant clustered microcalcifications on mammograms. Investigators have been developing computerized schemes to select similar images from large databases. However, whether selected images are really similar in appearance is not examined for most of the schemes. In order to retrieve images that are useful to radiologists, the selected images must be similar from radiologists' diagnostic points of view. Therefore, in this study, the data of radiologists' subjective similarity for pairs of clustered microcalcification images were obtained from a number of observers, and the intra- and inter-observer variations and the intergroup correlations were determined to investigate whether reliable similarity ratings by human observers can be determined. Nineteen images of clustered microcalcifications, each of which was paired with six other images, were selected for the observer study. Thus, subjective similarity ratings for 114 pairs of clustered microcalcifications were determined by each observer. Thirteen breast, ten general, and ten nonradiologists participated in the observer study; some of them completed the study multiple times. Although the intraobserver variations for the individual readings and the interobserver variations for pairs of observers were not small, the interobserver agreements were improved by taking the average of readings by the same observers. When the similarity ratings by a number of observers were averaged among the groups of breast, general, and nonradiologists, the mean differences of the ratings between the groups decreased, and good concordance correlations (0.846, 0.817, and 0.785) between the groups were obtained. The result indicates that reliable similarity ratings can be determined by use of this method, and the average similarity ratings by breast radiologists can be considered meaningful and useful for the development and evaluation of a computerized scheme for selection of similar images.

Breast Diseases↗
PubMed2006

Nox2 and Rac1 regulate H2O2-dependent recruitment of TRAF6 to endosomal interleukin-1 receptor complexes.

Reactive oxygen species (ROS) generated by NADPH oxidases (Nox) have been implicated in the regulation of signal transduction. However, the cellular mechanisms that link Nox activation with plasma membrane receptor signaling remain poorly defined. We have found that Nox2-derived ROS influence the formation of an active interleukin-1 (IL-1) receptor complex in the endosomal compartment by directing the H2O2-dependent binding of TRAF6 to the IL-1R1/MyD88 complex. Clearance of both superoxide and H2O2 from within the endosomal compartment significantly abrogated IL-1beta-dependent IKK and NF-kappaB activation. MyD88-dependent endocytosis of IL-1R1 following IL-1beta binding was required for the redox-dependent formation of an active endosomal receptor complex competent for IKK and NF-kappaB activation. Small interfering RNAs to either MyD88 or Rac1 inhibited IL-1beta induction of endosomal superoxide and NF-kappaB activation. However, MyD88 and Rac1 appear to be recruited independently to IL-1R1 following ligand stimulation. In this context, MyD88 binding was required for inducing endocytosis of IL-1R1 following ligand binding, while Rac1 facilitated the recruitment of Nox2 into the endosomal compartment and subsequent redox-dependent recruitment of TRAF6 to the MyD88/IL-1R1 complex. The identification of Nox-active endosomes helps explain how subcellular compartmentalization of redox signals can be used to direct receptor activation from the plasma membrane.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Genetic diversity of nine populations of the black goat (Capra hircus) in Sichuan, PR China.

Sixteen polymorphic primers screened from 100 random primers were selected to analyze the randomly amplified polymorphic DNA (RAPD) of 540 domesticated black goats (Capra hircas) from 9 different geographical populations in Sichuan Province of China. After the test, 170 entirely repeatable RAPD markers representing goat polymorphisms were obtained from the 16 polymorphic primers, the lengths of the markers ranging from 0.1 to 2.5 kb. The genetic distance among the black goat populations ranges from 0.1051 to 0.2978. The similarity coefficient (0.9002) between Jintang and Lezhi black goats was the highest in the 9 populations, followed by the coefficient (0.8953) between Jialing and Yinshan goats, while that between Jiangan and Huili goats was found to be the lowest (0.7424). The coefficient of differentiation among population genes (Gst) was 0.2766, indicating a comparatively low degree of differentiation among the black goat populations. A UPGMA dendrogram constructed from similarity coefficients showed that the two populations from Huili and Baiyu, which are found mostly on the Western Sichuan plateau and in mountainous areas, clustered together, and the other seven populations formed another group. It can also be clearly seen that the Huili and Baiyu populations are very special, and must have been closely related in the past, even though their link with the other populations is quite weak as a result of genetic communication. The results of the experiment offer some crucial scientific data useful for the breeding of black goats.

Animals↗
PubMed2006

[The study on biocompatibility of diamond-like carbon coated nickel-titanium shape memory alloy with osteoblasts cultured in vitro].

OBJECTIVE: To investigate the biocompatibility of diamond-like carbon (DLC) coated Nickel-Titanium shape memory alloy with osteoblasts cultured in vitro. METHODS: Rabbit's osteoblasts were incubated with DLC-coated Nickel-Titanium shape memory alloy disks and uncoated ones of equal size for 5 days. The control group (without shape memory alloy in culture media) was performed simultaneously. The cultured cells were counted and graphed. The samples from culture media were collected and the concentrations of alkaline phosphatase (ALP) and nickel (Ni2+) were measured from the 1st to 5th day respectively. RESULTS: The proliferation of osteoblasts and the concentration of ALP in both DLC-coated group and control group was higher than uncoated group. The proliferation of osteoblasts on the 3rd, 4th, and 5th day in both DLC-coated group and control group was significantly higher than that in the uncoated group (P < 0.05). The concentration of ALP in DLC-coated group on the 2nd, 3rd, and 5th day and in the control group on the 3rd, 4th, and 5th day was significantly higher than that in the uncoated group (P < 0.05). The concentration of Ni2+ on the 3rd, 4th, and 5th day was significantly lower than that in the uncoated group (P < 0.05). CONCLUSION: DLC- coated Nickel-Titanium shape memory alloys appears to have better biocompatibility with osteoblast cultured in vitro compared to uncoated ones.

Alloys↗
PubMed2006

[Immunotherapeutic efficacy of both helper T lymphocytes and cytotoxic T lymphocytes epitopes augmented dendritic cells tumor vaccine on gastric cancer].

OBJECTIVE: To investigate the immunotherapy efficacy of both helper T lymphocytes (Th) and cytotoxic T lymphocytes (CTL) epitopes augmented dendritic cells (DCs) tumor vaccine on gastric cancer. METHODS: Naïve spleen T cells were stimulated by mixed peptides (a mixture of Th epitope MAGE-3 (22-36)) primed DCs per week in vitro. After 4 cycles of restimulation, peptide specific T cells were harvested and subgroups of which were determined with flow cytometry. Cytokines secreting profiles by CD4+ T cells and cytotoxicities of CD8+ T cells on tumor cells were assessed. The protective immunity by referred DCs tumor vaccines was also monitored. RESULTS: Both Th and CTL epitopes primed DCs could elicit both CD4+ T cells and CD8+ T cells in vitro,of which CD4+ T cells released high amount of Th1 type cytokines (IFN-gamma, IL-2) on recognizing specific antigen, as well as CD8+ T cells exhibited efficient tumor-killing capacity. The effects induced by DCs pulsed with single epitope (Th or CTL epitope) in vivo were less effective than those induced by DCs pulsed with mixture epitopes. CONCLUSIONS: Both Th and CTL epitopes augmented DCs tumor vaccine can induce CD4+ Th1 and CD8+ CTL mediated immune responses to eradicate gastric cancer cells.

Animals↗
PubMed2006

[Biocompatibility of acellular urinary bladder submucosa].

OBJECTIVE: To investigate the biocompatibility of acellular urinary bladder submucosa (AUBS). METHODS: The acellular collagen matrix of human urinary bladder submucosa was developed using freeze-thawed enzymatic treatment and freeze-drying technique. Human oral keratinocytes were cultured and seeded on AUBS at a density of 2 x 10(6)/ml in vitro. The proliferation of the cells were observed. Pockets were created in the abdominal muscle wall of 18 SD rats. AUBS in size 1 cm x 1 cm was implanted into the pocket. The grafts were observed by light microscope 3, 6, 10, 14, 21 and 28 days after operation. RESULTS: AUBS mainly consisted of collagen fibers with a three-dimensional network structure. After the oral keratinocytes were seeded, continuous oral epithelium layer was formed on the surface of AUBS after 10 days in vitro. Histological observation of the grafted AUBS showed progressive cell infiltration at 6 days. New capillaries formed at 14 days. The collagen fibers arranged regularly at 28 days after implantation. CONCLUSION: Freeze-dried AUBS may be used as a suitable scaffold for tissue regeneration, which can induce cell proliferation both in vivo and in vitro and has good biocompatibility.

Animals↗
PubMed2006

[One stage repair of hypospadias using meatal-based flap overlapping with buccal mucosal graft].

OBJECTIVE: To explore the feasibility of one-stage repair of hypospadias using the meatal-based flap overlapping with buccal mucosal graft. METHODS: From March 2002 to May 2004, 21 patients with hypospadias were treated with the meatal-based flap overlapping with buccal mucosal graft. Their ages ranged from 14 months to 8 years. The procedure were as follows: urethral plate at proximal corona was cut to correct glandular tilt and chordee; the buccal mucosa taking from inner cheek was then fixed on tunica albuginea of ventral shaft with suture; and the meatal-based flap was rotated distally and overlaid with buccal mucosal graft to repair urethra. RESULTS: All patients were followed up 3-18 months (7 months on average). A cosmetic glans and a vertically oriented, normal appearing slit meatus were achieved. Two patients had fistulas on lateral corona. Fistula spontaneously healed in 1 case and the other one was repaired after 6 months. CONCLUSION: The technique of meatal-based flap overlapping with buccal mucosal graft can completely correct glandular tilt and chordee, prove good cosmetic and functional glans and meatus.

Child↗
PubMed2006

[Adsorption mechanism of chromium cation by floc-type biosorbent ZL 5-2].

Biosorption of Cr(VI) by the novel biosorbent ZL5-2 produced by Agrobacterium sp. was studied and infrared spectra of native, absorbing and desorbing ZL 5-2 were compared. The initial pH was important for biosorption. The optimum effect on Cr(VI) biosorption was acquired within initial pH 0.5 to approximately 1.5, then with the pH increasing, the effect on Cr6+ biosorption was reduced. The biosorption for Cr(VI) was a quick process,only within 10 min 65.4% Cr(VI) is biosorbed, and the biosorption rate was over 90% after 60 min, then all the Cr(VI) was biosorbed after 80 min. The biosorption were fitted with Langmuir and Freundlich isotherm adsorption equations. The absorbed Cr(VI) could be recovered by desorption and the desorption rate reached 13.696% to approximately 67.9%. Progress of biosorption was reversible adsorption and irreversible adsorption simultaneously through infrared spectra analysis, however the reversible adsorption was more important in the biosorption and the adsorption belongs to physics adsorption.

Adsorption↗