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1.
Chem Commun (Camb) ; 51(73): 13910-3, 2015 Sep 21.
Article in English | MEDLINE | ID: mdl-26239759

ABSTRACT

We present a novel approach to remove the structure-directing agent (SDA) from as-synthesized zeolites using an atmospheric pressure plasma jet (APPJ). This reduces the time required to less than 60 seconds as compared to the existing thermal calcination, whose durations range from hours to days. The highly reactive plasma also results in a pronounced Q(3)-to-Q(4) transformation in the pure-silica zeolite MFI.

2.
J Pediatr Urol ; 10(6): 1227-31, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25214038

ABSTRACT

INTRODUCTION: Patients with lower urinary tract anomalies or neurogenic disorders often suffer from voiding difficulties. Clean intermittent catheterization (CIC) is effective for bladder drainage; however, this is often painful. Transurethral catheterization is also impossible in patients with urethral stricture. A Mitrofanoff conduit may solve some of these problems, but a few disadvantages have been reported, including: difficult surgical techniques and frequent operative complications. A vesicostomy is easy to perform but persistent urine leak over the abdomen and diaper rash can be annoying. A better way to achieve continent urinary diversion is indicated. METHOD: Between December 01 1998 and December 31 2013, six patients underwent a vesico-cutaneous fistula for CIC. The etiologies included urethral stricture (n=2) and neurogenic bladder (n=4). The fistula was created at the bladder dome with only the muscle layer of the bladder sutured to the skin. A Foley catheter was left in place for at least two weeks to prevent stoma stricture. After removing the Foley catheter, regular CIC from the fistula was performed every 2 h during the daytime with a Fr. 10-12 feeding tube, depending on the patient's age. Further stenting during the night in the first six months was necessary to prevent early closure of the fistula. Patients were followed with periodic renal ultrasonography, blood tests and urinalysis in the outpatient department. RESULTS: Follow-up ranged from 6 months to 16 years. All patients showed improvements in hydronephrosis. Decreased UTI frequency was seen in five patients. Renal function was normal in five patients, whilst the other suffered from chronic renal failure preoperatively. Only one patient had occasional mild urine leakage from the stoma at night, which was once in two weeks. No patient experienced painful or difficult catheterization and CIC becomes easy, even by young children. CONCLUSIONS: The vesico-cutaneous fistula is a simple, effective and tolerable method for CIC. It may be a substitute for or a transition to a Mitrofanoff conduit in some patients.


Subject(s)
Urethral Stricture/surgery , Urinary Bladder, Neurogenic/surgery , Urinary Catheterization/methods , Urinary Diversion/methods , Urologic Surgical Procedures/methods , Adolescent , Child , Child, Preschool , Cystostomy , Female , Humans , Infant , Infant, Newborn , Male , Treatment Outcome , Young Adult
3.
Med J Malaysia ; 69(2): 95-7, 2014 Apr.
Article in English | MEDLINE | ID: mdl-25241821

ABSTRACT

Langerhans Cell Histiocytosis (LCH) is an uncommon neoplastic disorder characterized by accumulation of histiocytes in various tissues. The clinical manifestation is highly variable, ranging from an isolated skin rash or a single bony lesion, to fatal multi-organ failure. Due to its rarity and systemic involvement, the epidemiology of LCH is still not fully understood and most studies focus on the paediatric population. The extent of clinical involvement has important prognostic implications. Treatment options may be local or systemic depending on disease extent. Here we describe a rare case of adult onset LCH who presented with recurrent pneumothoraces, diabetes insipidus and papules and plaques over the scalp and forehead.

4.
J Appl Phys ; 113(3): 33706, 2013 Jan 21.
Article in English | MEDLINE | ID: mdl-23405036

ABSTRACT

The intrinsic oxygen-vacancies and the extrinsic dopants are two major fundamental free-carrier sources for the extrinsic conducting oxides, such as Sn-doped In(2)O(3). Yet, the individual contributions of the above two free-carrier sources to the total carrier concentrations have never been unraveled. A carrier-concentration separation model is derived in this work, which can define the individual contributions to the total carrier concentration from the intrinsic oxygen-vacancies and the extrinsic dopants, separately. The individual contributions obtained from the present carrier-concentration separation model are verified by the two-state trapping model, photoluminescence, and positron annihilation lifetime (PAL) spectroscopy. In addition, the oxygen-vacancy formation energy of the Sn:In(2)O(3) thin film is determined to be 0.25 eV by PAL spectroscopy.

5.
Aliment Pharmacol Ther ; 34(4): 424-31, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21692822

ABSTRACT

BACKGROUND: Previous studies suggested that a finite course of peginterferon alfa-2a may offer an alternative rescue therapy for patients with lamivudine resistance. However, because of the limitation of study design and small sample size, it is difficult to make definitive conclusion. AIM: To explore the role of peginterferon alfa-2a, in the rescue treatment of HBeAg-positive chronic hepatitis B patients with lamivudine resistance. METHODS: In this randomised study, chronic hepatitis B patients with lamivudine resistance were treated with peginterferon alfa-2a for 48 weeks (n=155) or adefovir for 72 weeks (n=80). All enrolled patients were treated with lamivudine for the first 12weeks. RESULTS: At 6 months posttreatment, 14.6% (18/123) of peginterferon alfa-2a-treated patients achieved HBeAg seroconversion, in contrast to 3.8% (3/80) of adefovir-treated patients after 72 weeks continuous therapy (P=0.01). For peginterferon alfa-2a-treated patients, the rate of HBeAg seroconversion at week 72 was significantly higher in patients who had HBsAg decline >0.5 Log(10) IU/mL from baseline at week 24, compared with patients with HBsAg decline ≤0.5 Log(10) IU/mL from baseline at week 24 (25.5% vs. 7.7%, P=0.01). After 72 weeks continuous adefovir treatment, 22.5% of patients achieved HBV DNA <80 IU/mL, compared with 10.6% in peginterferon alfa-2a-treated patients at 6months off-treatment (P=0.02). CONCLUSIONS: Overall, the response to peginterferon alfa-2a among patients with lamivudine resistance was suboptimal. HBeAg seroconversion rate at week 72 by 48 weeks peginterferon alfa-2a treatment was higher than continuous adefovir therapy. Monitoring HBsAg levels can help to predict response to peginterferon alfa-2a.


Subject(s)
Adenine/analogs & derivatives , Antiviral Agents/therapeutic use , Drug Resistance, Viral/drug effects , Hepatitis B, Chronic/drug therapy , Interferon-alpha/therapeutic use , Lamivudine/therapeutic use , Organophosphonates/therapeutic use , Polyethylene Glycols/therapeutic use , Adenine/therapeutic use , Adolescent , Adult , Aged , China , Drug Therapy, Combination , Female , Humans , Interferon alpha-2 , Male , Middle Aged , Recombinant Proteins , Time Factors , Treatment Outcome , Young Adult
6.
Hong Kong Med J ; 16(6): 463-9, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21135423

ABSTRACT

OBJECTIVE: To test our hypothesis that there is inadequate knowledge and awareness of hepatitis B infection among the general population in Hong Kong. DESIGN: A random telephone survey using a structured multiple-choice questionnaire. SETTING: Hong Kong community. PARTICIPANTS: Hong Kong residents aged 18 years or above. RESULTS: A total of 506 respondents were successfully interviewed in February 2010. Approximately half of respondents (55%) were aware that hepatitis B virus is the most common cause of chronic viral hepatitis in Hong Kong. Regarding knowledge about the mode of transmission, mother-to-infant transmission and blood contact were recognised as risk factors by 67% and 65% of respondents, respectively. Transmission by sexual contact, sharing a razor or toothbrush, and tattooing or body piercing were appreciated by 44%, 41%, and 37% of respondents, respectively. A majority (73%) had the mistaken belief that the virus is transmitted by eating contaminated seafood. Over half of respondents (53%) knew nothing about the clinical presentation of acute hepatitis B. Only 35% of respondents realised that periodic abdominal ultrasonographic examinations are indicated for asymptomatic hepatitis B carriers. While 51% of respondents reported being tested for hepatitis B virus infection, only 36% acknowledged being vaccinated against the infection. Education level, occupation, and marital status were factors associated with both hepatitis B virus screening and vaccination. CONCLUSION: These findings support our hypothesis that there is inadequate knowledge and awareness about hepatitis B infection in the general population in Hong Kong.


Subject(s)
Health Knowledge, Attitudes, Practice , Hepatitis B/prevention & control , Adolescent , Adult , Aged , Aged, 80 and over , Female , Hepatitis B/transmission , Humans , Male , Middle Aged , Surveys and Questionnaires , Telephone , Vaccination
7.
Appl Microbiol Biotechnol ; 85(3): 753-62, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19789865

ABSTRACT

The aerobic sludge granules cultivated at high organic loading rates could effectively convert 100-700 mg l(-1) nitrite to nitrogen gas with 400 or 1,200 mg l(-1) dosed acetate. The denitrifying microbial community structure of the so-cultivated granules was investigated by 16S rRNA gene sequences and localized using fluorescence in situ hybridization (FISH). The 16S rRNA gene phylotypes in the clone library and FISH probes used exhibited high diversity among the bacteria and denitrifying communities, with the members of Betaproteobacteria predominant that were closely related to families Comamonadaceae, Nitrosomonadaceae, Alcaligenaceae, and Rhodocyclaceae. The confocal laser scanning microscope and staining test revealed that active microbial community principally distributed at 200-250 microm beneath the outer surface, embedded in extracellular polymeric substances.


Subject(s)
Bacteria, Aerobic/classification , Bacteria, Aerobic/genetics , Biodiversity , Nitrites/metabolism , Nitrogen/metabolism , Sewage/microbiology , Bacteria, Aerobic/metabolism , Cluster Analysis , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , In Situ Hybridization, Fluorescence , Microscopy, Confocal , Microscopy, Electron, Scanning , Molecular Sequence Data , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Staining and Labeling
8.
Appl Microbiol Biotechnol ; 85(3): 773-8, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19809812

ABSTRACT

Nitrite accumulates during biological denitrification processes when carbon sources are insufficient. Acetate, methanol, and ethanol were investigated as supplementary carbon sources in the nitrite denitrification process using biogranules. Without supplementary external electron donors (control), the biogranules degraded 200 mg l(-1) nitrite at a rate of 0.27 mg NO(2)-N g(-1) VSS h(-1). Notably, 1,500 mg l(-1) acetate and 700 mg l(-1) methanol or ethanol enhanced denitrification rates for 200 mg l(-1) nitrite at 2.07, 1.20, and 1.60 mg NO(2)-N g(-1) VSS h(-1), respectively; these rates were significantly higher than that of the control. The sodium dodecyl sulfate polyacrylamide gel electrophoresis of the nitrite reductase (NiR) enzyme identified three prominent bands with molecular weights of 37-41 kDa. A linear correlation existed between incremental denitrification rates and incremental activity of the NiR enzyme. The NiR enzyme activity was enhanced by the supplementary carbon sources, thereby increasing the nitrite denitrification rate. The capacity of supplementary carbon source on enhancing NiR enzyme activity follows: methanol > acetate > ethanol on molar basis or acetate > ethanol > methanol on an added weight basis.


Subject(s)
Acetates/metabolism , Ethanol/metabolism , Methanol/metabolism , Nitrites/metabolism , Nitrogen/metabolism , Water Microbiology , Electrophoresis, Polyacrylamide Gel , Molecular Weight , Nitrate Reductase/chemistry , Nitrate Reductase/isolation & purification
9.
Eur J Pediatr Surg ; 20(2): 82-4, 2010 Mar.
Article in English | MEDLINE | ID: mdl-19899040

ABSTRACT

INTRODUCTION: Various scales and measurement methods including X-rays and computed tomography (CT) have been used to quantify the degree of deformity in pectus excavatum. This study describes a non-invasive method for recording the deviation of the anterior chest wall (ACW) in pectus excavatum (PE) patients. Data obtained using this non-invasive method were compared with CT data. MATERIALS AND METHODS: Twenty-one patients treated at our institutions between June 2008 and February 2009 were enrolled in this study. All patients underwent CT and thermal plastic strip measurement. A thermal plastic strip was positioned and taped to the supine patient's ACW at the skin level from the posterior axillary line, over the depressed sternum, to the contralateral posterior axillary line and used to create a casting of the ACW. RESULTS: The funnel index (FI) was defined as the width of the ACW divided by its height; the concave index (CI) was defined as the breadth of the depressed area of the funnel chest divided by its depth. Pearson's correlation coefficient was used to compare the FI and CI obtained with the thermal plastic strip method and with CT; measurements obtained with both methods were found to correlate well (FI: r (2)=0.965; CI: r (2)=0.947). CONCLUSIONS: The thermal plastic strip measurement method provides a two-dimensional record of the shape of the anterior chest wall. The measurement can be repeated, does not involve the patient being exposed to radiation, and offers a good longitudinal assessment of chest wall growth in PE patients.


Subject(s)
Body Weights and Measures/methods , Funnel Chest/diagnosis , Funnel Chest/surgery , Thoracic Wall/anatomy & histology , Adolescent , Child , Child, Preschool , Female , Humans , Male , Treatment Outcome
10.
Bioresour Technol ; 100(5): 1734-9, 2009 Mar.
Article in English | MEDLINE | ID: mdl-18990565

ABSTRACT

The concept of carbon credit arose out of increasing awareness of the need to reduce emissions of greenhouse gases to combat global warming which was formalized in the Kyoto protocol. In addition to contribution to sustainable development with energy recovery in the form of methane, carbon credits can be claimed by application of advanced anaerobic processes in wastewater treatment for reducing emissions of greenhouse gases. As anaerobic granular systems are capable of handling high organic loadings concomitant with high strength wastewater and short hydraulic retention time, they could render much more carbon credits than other conventional anaerobic systems. This study investigated the potential carbon credit derived from laboratory-scale upflow anaerobic sludge blanket (UASB) reactors based on a carbon balance analysis. Methane emission reduction could be calculated by calculating the difference of UASB reactors and open lagoon treatment systems. Based on the 2.5l bench-scale reactor, the total CH(4) emissions reduction was calculated as 29 kg CO(2)/year. On scaling up to a typical full-scale anaerobic digester, the total CH(4) emissions reduction could achieve 46,420 tons CO(2) reduction/year. The estimated carbon credits would amount to 278,500 US$ per year by assuming a carbon price of 6 US$ per metric ton CO(2) reduction. The analysis postulated that it is financially viable to invest in advanced anaerobic granular treatment system from the revenue generated from carbon credits.


Subject(s)
Bacteria, Anaerobic/metabolism , Bioreactors , Carbon/metabolism , Conservation of Natural Resources/methods , Greenhouse Effect , Waste Disposal, Fluid/methods , Water Purification/methods , Methane/metabolism
11.
Appl Microbiol Biotechnol ; 77(1): 175-82, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17710392

ABSTRACT

Effect of air aeration intensities on granule formation and extracellular polymeric substances content in three identical sequential batch reactors were investigated. The excitation-emission-matrix spectra and multiple staining and confocal laser scanning microscope revealed proteins, polysaccharides, lipids, and humic substances in the sludge and granule samples. Seed sludge flocs were compacted at low aeration rate, with produced extracellular polymeric substances of 50.2-76.7 mg g(-1) of proteins, 50.2-77.3 mg g(-1) carbohydrates and 74 mg g(-1) humic substances. High aeration rate accelerated formation of 1.0-1.5 mm granules with smooth outer surface. The corresponding quantities of extracellular polymeric substances were 309-537 mg g(-1) of proteins, 61-109 mg g(-1) carbohydrates, 49-92 mg g(-1) humic substances, and 49-68 mg g(-1) lipids. Intermediate aeration rate produced 3.0-3.5 mm granules with surface filaments. Reactor failure occurred with overgrowth of filaments, probably owing to the deficiency of nutrient in liquid phase. No correlation was noted between extracellular polymeric substances composition and the proliferation of filamentous microorganisms on granule surface.


Subject(s)
Phenol/metabolism , Polymers/analysis , Sewage/microbiology , Aerobiosis , Bioreactors/microbiology , Humic Substances/analysis , Microscopy, Confocal , Polysaccharides/analysis , Proteins/analysis , Spectrometry, Fluorescence
12.
Langmuir ; 23(15): 8042-7, 2007 Jul 17.
Article in English | MEDLINE | ID: mdl-17590025

ABSTRACT

The spreading dynamics of power-law fluids, both shear-thinning and shear-thickening fluids, that completely or partially wet solid substrate was investigated theoretically and experimentally. An evolution equation for liquid-film thickness was derived using a lubrication approximation, from which the dynamic contact angle versus the contact line moving velocity relationship was evaluated. In the capillary spreading regime, film thickness h is proportional to xi3/(n+2) (xi is the distance from the contact line), whereas in the gravitational regime, h is proportional to xi1/(n+2), relating to the rheological power exponent n. The derived model fit the experimental data well for a shear-thinning fluid (0.2% w/w xanthan solution) or a shear-thickening fluid (7.5% w/w 10 nm silica in polypropylene glycol) on a completely wetted substrate. The derived model was extended using Hoffmann's proposal for partially wetting fluids. Good agreement was also attained between model predictions and the shear-thinning fluid (1% w/w cmc solution) and shear-thickening fluid (10% w/w 15 nm silica) on partially wetted surfaces.

13.
Aliment Pharmacol Ther ; 25(11): 1283-92, 2007 Jun 01.
Article in English | MEDLINE | ID: mdl-17509096

ABSTRACT

BACKGROUND: Although chronic hepatitis C virus-infected patients with persistently normal alanine aminotransaminase levels usually have mild liver disease, disease progression can still occur. However, it is uncertain which group of patients is at risk of disease progression. AIM: To examine the severity of liver disease on liver biopsy in Chinese patients with persistently normal alanine aminotransaminase levels, and their disease progression over time. METHODS: Eighty-two patients with persistently normal alanine aminotransaminase levels were followed up longitudinally. The median time of follow-up was 8.1 years. Forty-seven of the 82 patients (57.3%) had a second liver biopsy. RESULTS: At the time of analysis, six of the 82 patients (7.3%) developed decompensated liver cirrhosis. Patients with an initial fibrosis stage F2 or F3 [6/23 (26.1%) vs. 0/59 (0%), P < 0.0001] or inflammatory grade A2 or A3 [5/40 (12.5%) vs. 1/42 (2.4%), P = 0.04] were more likely to develop decompensated liver cirrhosis. On multivariate analysis, initial fibrosis stage F2 or F3 was independently associated with progression to decompensated liver cirrhosis (relative risk 2.3, 95% confidence interval 0.03-2.5, P = 0.02). CONCLUSION: Chinese chronic hepatitis C virus patients with persistently normal alanine aminotransaminase levels with moderate to severe fibrosis at initial evaluation are more likely to develop decompensated liver cirrhosis.


Subject(s)
Alanine Transaminase/metabolism , Hepatitis C, Chronic/enzymology , Liver/pathology , Adult , Biopsy , China/ethnology , Disease Progression , Female , Follow-Up Studies , Hepatitis C, Chronic/ethnology , Hepatitis C, Chronic/pathology , Humans , Liver Cirrhosis/pathology , Liver Cirrhosis/virology , Longitudinal Studies , Male , Middle Aged , Prevalence , Prognosis , Risk Factors
14.
Appl Microbiol Biotechnol ; 75(3): 685-91, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17294183

ABSTRACT

The interior structure of aerobic granules is highly heterogeneous, hence, affecting the transport and reaction processes in the granules. The granule structure and the dissolved oxygen profiles were probed at the same granule in the current work for possible estimation of transport and kinetic parameters in the granule. With the tested granules fed by phenol or acetate as carbon source, most inflow oxygen was consumed by an active layer thickness of less than 125 microm on the granule surface. The confocal laser scanning microscopy scans also revealed a surface layer thickness of approximately 100 microm consisting of cells. The diffusivities of oxygen transport and the kinetic constant of oxygen consumption in the active layers only were evaluated. The theoretical models adopted in literature that ignored the contributions of the layered structure of aerobic granule could have overlooked the possible limitations on oxygen transport.


Subject(s)
Oxygen Consumption , Oxygen/metabolism , Sewage/microbiology , Acetates/metabolism , Aerobiosis , Bioreactors , Diffusion , Microscopy, Confocal , Oxidation-Reduction , Oxygen/chemistry , Phenol/metabolism
15.
J Environ Manage ; 85(4): 1009-14, 2007 Dec.
Article in English | MEDLINE | ID: mdl-17202026

ABSTRACT

The Hsinchu Science-based Industrial Park (HSIP) is the hi-tech manufacturing hub of Taiwan. Wastewater from the HSIP contains numerous nano-sized silicate particles whose size distributions peak at 2 and 90 nm. A 3-5 mg l(-1) as Al dose of polyaluminum chloride (PACl) was used in the field to coagulate these particles, but the removal efficiency was low. Laboratory scale tests indicated that although PACl coagulation removed 52% of the turbidity and 48% of the chemical oxygen demand (COD) from water, its effect on nano-particle removal was minimal. About 58% of the soluble COD was associated with colloidal Si particles. A light scattering test and transmission electron microscopy (TEM) demonstrated that the nano-particles agglomerated in approximately linear aggregates of sizes 100-300 nm. Prolonged contact between residual PACl and the nano-particles generated large aggregates with sizes of up to 10 microm and a fractal dimension of 2.24-2.63. The results presented herein should be of interest in the processing of "high-tech" wastewater that contains nanosized silica particles.


Subject(s)
Aluminum Hydroxide/chemistry , Industrial Waste/analysis , Nanoparticles/chemistry , Waste Disposal, Fluid/methods , Microscopy, Electron, Transmission , Nanoparticles/ultrastructure , Taiwan
16.
Water Res ; 41(4): 884-92, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17224172

ABSTRACT

High biomass density and large size limit the transfer of dissolved oxygen (DO) in aerobic granules. In the literature, the oxygen diffusivity is often employed as an input parameter for modeling transport processes in aerobic granules. The interior of an aerobic granule was observed to be highly heterogeneous. In this work, the distributions of extracellular polymeric substances (EPS) and cells in the interior of phenol-fed and acetate-fed granules were built up using a five-fold staining scheme, combined with the use of a confocal laser scanning microscope (CLSM). The steady-state and transient DO with step changes in surrounding DO levels at various depths were measured in the granules using microelectrodes. Cells were probed in a surface layer of thickness 125-375 microm. A marked fall in DO was also noted over this surface layer. No aerobic oxidation could occur beneath the active layer, indicating the oxygen transfer limit. Fitting the steady-state and transient DO data over the active surface layer yielded apparent diffusivities of oxygen were (9.5+/-3.5)x10(-10)m(2)s(-1) for the phenol-fed granule and (3.5+/-1.0)x10(-10)m(2)s(-1) for the phenol-fed granule. These values were lower than those adopted in models in the literature.


Subject(s)
Biomass , Oxygen/metabolism , Waste Disposal, Fluid , Acetates/metabolism , Aerobiosis , Bioreactors , Diffusion , Kinetics , Microscopy, Confocal , Oxidation-Reduction , Oxygen/chemistry , Phenol/metabolism , Time Factors
17.
Appl Microbiol Biotechnol ; 74(3): 699-707, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17115206

ABSTRACT

This study extracted the soluble microbial products and loosely bound and tightly bound extracellular polymeric substances (EPS) from suspended sludge from a membrane bioreactor, original and aerobically/anaerobically digested, and compared their fouling potentials on a microfiltration membrane. The resistance of cake layer accounts for 95-98% of the total filtration resistances when filtering the whole sludges, with anaerobically digested sludge presenting the highest resistance among the three tested sludges. The tightly bound EPS has the highest potential to foul the membrane; however, the loosely bound EPS contribute most of the filtration resistances of the whole sludges. The foulants corresponding to the irreversible fouling have chemical fingerprints similar to those from loosely bound EPS, which have a greater predilection to proteins and humic substances than to polysaccharides.


Subject(s)
Biopolymers/metabolism , Bioreactors , Equipment Failure Analysis , Filtration/instrumentation , Sewage/chemistry , Aerobiosis , Anaerobiosis , Micropore Filters
18.
Environ Sci Technol ; 40(21): 6642-6, 2006 Nov 01.
Article in English | MEDLINE | ID: mdl-17144290

ABSTRACT

Membrane biofouling by microbial products adversely impacts the feasibility of adopting membrane bioreactors (MBRs) for treating wastewater. The fouling layer structure determines the pressure drop across the fouling layer. Three-dimensional distributions of nucleic acids, proteins, alpha-D-GLUCOPYRANOSE POLYSACCHARIDES, AND B-D-glucopyranose polysaccharides in the fouling layer formed on a mixed cellulose ester membrane were generated utilizing a quadruple staining protocol combined with confocal laser scanning microscopy (CLSM). For the first time, this study constructed a three-dimensional volumetric grids model representing the fouling layer structure on the basis of a series of CLSM images. Quantitative structural information about the fouling layer was extracted from the CLSM images.


Subject(s)
Environmental Monitoring/methods , Membranes, Artificial , Polymers/analysis , Waste Disposal, Fluid/methods , Water Purification/instrumentation , Bacteria/metabolism , Biofilms/growth & development , Biopolymers/analysis , Bioreactors , Environmental Monitoring/instrumentation , Fluorescent Dyes/pharmacology , Lasers , Microscopy, Confocal , Polymers/chemistry , Sewage , Water Pollutants, Chemical , Water Purification/methods
19.
Pediatr Surg Int ; 22(8): 665-9, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16821019

ABSTRACT

Colon perforation is an abdominal surgical emergency in the pediatric population, but is seldom reported when occurring from non-traumatic causes in children beyond the neonate. The goal of this study was to identify the clinical characteristics, management, and outcomes of non-traumatic colon perforation in children. Medical records for the 10-year period from September 1994 to September 2004 were reviewed for children beyond the neonate with non-traumatic colon perforation. Data gathered included age, gender, symptoms, duration of symptoms, physical findings, and length of postoperative hospital stay. Diagnostic information included laboratory data, radiographic imaging, and operative findings. Forty-four patients with non-traumatic colon perforation were recruited into this study. The mean age was 2.22 +/- 1.87 years; 91.4% of cases were younger than 5 years old. The most common presenting symptom was fever (97.7%); the most common sign was abdominal distention (93.1%). The mean duration of symptoms prior to admission was 6.19 days. Pneumoperitoneum was presented in 86.3% of patients by plain abdominal radiograph. Ascending and transverse colon were the most common perforation sites. Non-typhoid salmonella was the leading pathogen isolated, causing 20.4% of episodes. One case died due to Clostridium speticum infection. Non-traumatic colon perforation most commonly affects children younger than 5 years of age. It may be secondary to infection, especially non-typhoid salmonella. Plain abdominal radiograph can be an adjuvant tool for the high index of suspicion for colon perforation in children with abdominal distention and history of fever or diarrhea for more than 5 days.


Subject(s)
Colonic Diseases/diagnosis , Colonic Diseases/surgery , Intestinal Perforation/diagnosis , Intestinal Perforation/surgery , Abdomen, Acute , Child , Child, Preschool , Colonic Diseases/microbiology , Diagnosis, Differential , Diarrhea , Female , Fever , Humans , Infant , Infant, Newborn , Intestinal Perforation/microbiology , Male , Pneumoperitoneum/etiology , Retrospective Studies
20.
J Clin Virol ; 35(4): 435-41, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16420985

ABSTRACT

BACKGROUND: Plantaris verrucae are a common diagnosis in childhood, consume a significant amount of health-care resources, have many painful treatment options and many recurrences. OBJECTIVES: The objective of this study was to design and test a single site-anchored, multiplexed and expandable PCR assay for common types of cutaneous HPVs. STUDY DESIGN: Common forward and unique reverse primers were selected from the E2 open reading frames of five cutaneous HPV genotypes. These were analyzed for sensitivity and selectivity using pHPV plasmids and several control DNAs in an optimized multiplexed assay. This standardized assay was used to analyze human verruca plantaris tissue for genome type and to evaluate the effect of a commonly used treatment protocol. RESULTS: A sensitive, multiplexed PCR assay for human cutaneous HPV genotypes 1a, 2a and 4 was developed. Specific-unique primers and a consensus anchor primer were selected within the HPV E2 region to produce amplicons varying by greater than 100bp. In analytical sensitivity studies, fewer than 100 genome copies of HPV1a and 2a were detected, and fewer than 1000 copies of HPV4 were detected. The multiplexed assay did not amplify regions of human placenta, calf thymus, CaSki or SiHa DNA and E. coli, pBR322 or non-HPV virus DNAs. In combination with a forensic DNA extraction procedure, the multiplexed HPV assay detected and identified HPV types in 23 of 51 (45%) deep plantaris verrucae. Two patients were found with two different genotypes in single deep plantaris verruca. Detection of the HPV genome was followed as a function of tissue ablation and Mediplast treatment in one patient. In healing tissue, the genome content was reduced but had not totally disappeared. CONCLUSIONS: The multiplexed HPV assay can be used to determine genotype prevalence that may correlate with treatment efficacy.


Subject(s)
Papillomaviridae/classification , Papillomaviridae/genetics , Papillomavirus Infections/virology , Polymerase Chain Reaction/methods , Skin Diseases, Viral/virology , Warts/virology , Genotype , Humans , Papillomaviridae/isolation & purification , Sensitivity and Specificity
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