bluuebunny/crossref_metadata_2025 huggingface dataset:
Membrane biofilm reactors for nitrogen removal: state-of-the-art and research needs
Authors: Hwang Jong Hyuk , Cicek Nazim , Oleszkiewicz Jan A.
Published: November 2009

Historical developments up-to-date and operational challenges of membrane biofilm reactor (MBfR) were reviewed. A database of international, peer-reviewed journal articles regarding MBfR research from 1984 to 2008 was established and analyzed with a total of 107 papers. MBfR studies began to evolve in the early 1980s, since then the number of published papers increased steadily. After 2000, geographic locations where the research was conducted widened beyond North America and Europe to Asia. Research studies were divided into 4 categories and reviewed according to their main research focuses. In spite of the short history of MBfRs, studies have shown promising potential, possibly extending their application beyond nitrogen removal and organics removal. The MBfR research branched out to new fields including autotrophic denitrification. There are some important aspects of MBfRs that pose significant challenges to the application of this technology on a commercial scale in the near-future. The main challenge revolves around biofilm thickness and activity control. Further laboratory and demonstration scale studies on some of the proposed strategies for biofilm control are needed. Ultimately, more field studies with real wastewater should be performed to evaluate the resilience of the process in the face of flow and strength fluctuations, establishing optimum operational strategies.
A single chamber packed bed microbial fuel cell biosensor for measuring organic content of wastewater
Authors: Di Lorenzo Mirella , Curtis Tom P. , Head Ian M. , Velasquez-Orta Sharon B. , Scott Keith
Published: November 2009

This study reports an investigation of the effect of the anode surface area on the performance of a single chamber microbial fuel cell (SCMFC) based biosensor for measuring the organic content of wastewater. A packed bed of graphite granules was used as the anode. The surface area of the anode was changed by altering the granule bed thickness (0.3 cm and 1 cm). The anode surface area was found to play a role in the dynamic response of the system. For a granule bed thickness of 1 cm and with an external resistance of 500 Ω, the response time (defined as the time required to achieve 95% of the steady-state current) was reduced by approximately 65% in comparison to a SCMFC biosensor with a carbon cloth anode.
Physicochemical water quality of the Mfoundi River watershed at Yaoundé, Cameroon, and its relevance to the distribution of bacterial indicators of faecal contamination
Authors: Djuikom E. , Jugnia L. B. , Nola M. , Foto S. , Sikati V.
Published: November 2009

Water quality of the Mfoundi River and four of its tributaries was studied by assessing some physicochemical variables (temperature, pH, conductivity, chlorides, phosphates and nitrogen ammonia, dissolved oxygen and carbon dioxide, organic matter content and Biological Oxygen Demand) and their influence on the distribution of bacterial indicators of faecal contamination (total coliform, faecal coliform and faecal streptococci). For this, standard methods for the examination of physicochemical parameters in water were followed, and statistical analysis (Pearson correlations) used to establish any relationships between physicochemical and biological variables. Our results revealed that almost all of the examined physicochemical variables exceeded World Health Organization (WHO) guidelines for recreational water. This was in agreement with a previous microbiological study indicating that these waters were not safe for human use or primary contact according to water quality standards established by the WHO. Results of our correlation analysis suggested that physicochemical and biological variables interact in complicated ways reflecting the complex processes occurring in the natural environment. It was also concluded that pollution in the Mfoundi River watershed poses an increased risk of infection for users and there exists an urgent need to control dumping of wastewater into this watershed.
Enhanced bio-recalcitrant organics removal by combined adsorption and ozonation
Authors: Merle T. , Pic J. S. , Manero M. H. , Debellefontaine H.
Published: November 2009

Removal of bio-recalcitrant and toxic compounds from wastewaters has been a major objective of industrial manufacturers for a few years. Due to the potential risk toward public health, regulations are becoming increasingly strict and classical treatments like biological treatments are not efficient. Other techniques such as incineration, oxidation or adsorption provide higher levels of removal but with a high energy and capital cost. A coupled process involving adsorption and oxidation is studied. Four adsorbents are tested and compared according to two objectives, their adsorption capacity and their capability to decompose ozone into powerful hydroxyl radicals. Two model compounds were chosen: 2,4-dichlorophenol and nitrobenzene. Experimental results allow comparing coupled process with results obtained during ozonation alone. Zeolite (Faujasite Y) gave disappointing results in term of both adsorption kinetics and ozone decomposition. On the contrary, activated carbons showed fast adsorptions and important capabilites to decompose ozone into radicals, almost in nitrobenzene experiments. S-23 activated carbon proved to be the most interesting adsorbent for better mechanical and chemical stabilities over time. Sequential adsorption/ozonation experiments were conducted, showing a strong loss of adsorption efficiency after the first operation, but the positive point is that the adsorption capacity remains almost constant during further cycles.
Real-time fault detection and isolation in biological wastewater treatment plants
Authors: Baggiani F. , Marsili-Libelli S.
Published: November 2009

Automatic fault detection is becoming increasingly important in wastewater treatment plant operation, given the stringent treatment standards and the need to protect the investment costs from the potential damage of an unchecked fault propagating through the plant. This paper describes the development of a real-time Fault Detection and Isolation (FDI) system based on an adaptive Principal Component Analysis (PCA) algorithm, used to compare the current plant operation with a correct performance model based on a reference data set and the output of three ion-specific sensors (Hach-Lange gmbh, Düsseldorf, Germany): two Nitratax® NOx UV sensors, in the denitrification tank and downstream of the oxidation tanks, where an Amtax® ammonium-N sensor was also installed. The algorithm was initially developed in the Matlab environment and then ported into the LabView 8.20 (National Instruments, Austin, TX, USA) platform for real-time operation using a compact Field Point®, a Programmable Automation Controller by National Instruments. The FDI was tested with a large set of operational data with 1 min sampling time from August 2007 through May 2008 from a full-scale plant. After describing the real-time version of the PCA algorithm, this was tested with nine months of operational data which were sequentially processes by the algorithm in order to simulate an on-line operation. The FDI performance was assessed by organizing the sequential data in two differing moving windows: a short-horizon window to test the response to single malfunctions and a longer time-horizon to simulate multiple unrepaired failures. In both cases the algorithm performance was very satisfactory, with a 100% failure detection in the short window case, which decreased to 84% in the long window setting. The short-window performance was very effective in isolating sensor failures and short duration disturbances such as spikes, whereas the long term horizon provided accurate detection of long-term drifts and proved robust enough to allow for some delay in failure recovery. The system robustness is based on the use of multiple statistics which proved instrumental in discriminating among the various causes of malfunctioning.
Coupled UASB-activated sludge process for COD and nitrogen removals in municipal sewage treatment in warm climate
Authors: Cao Ye Shi , Ang Chee Meng
Published: November 2009

A laboratory-scale system consisting of an upflow anaerobic sludge blanket (UASB) reactor followed by a modified Ludzack-Ettinger (MLE) activated sludge process was adopted to investigate COD and nitrogen removals in municipal sewage treatment in warm climate. The COD, SCOD, acetic acid (HAc), NH4+-N and PO43−-P conversions in the UASB reactor were investigated. A 35% reduction in volatile suspended solid (VSS) was achieved in the UASB process. The net methane (CH4) production was 0.06 l (g CODremoved)−1. Acids accumulation was not observed. In the MLE activated sludge process, nitrification was almost complete while denitrification was modest. Little excess sludge was produced as the bulk of the COD was removed in the UASB reactor, which reduced the COD mass load to the activated sludge process. The average COD and SCOD of the final effluent of the activated sludge process were 51 and 25 mg l−1, respectively and the average NH4+-N concentration of the final effluent was 3.1 mg N l−1. The results illustrated that the coupled process is feasible for COD and nitrogen removals in municipal sewage treatment in warm climate. However, the low pH of the final effluent (<6 on average) remains an issue to be solved.
Development of a portable analyzer with polymer lab-on-a-chip (LOC) for continuous sampling and monitoring of Pb(II)
Authors: Jang A. , Zou Z. , MacKnight E. , Wu P. M. , Kim I. S. , Ahn C. H. , Bishop P. L.
Published: November 2009

A new portable analyzer with polymer lab-on-a-chip (LOC) has been designed, fabricated and fully characterized for continuous sampling and monitoring of lead (Pb(II)) in this work. As the working electrodes of the sensor, bismuth (Bi (III)) which allowed the advantage of being more environmentally friendly than traditional mercury drop electrodes was used, while maintaining similar sensitivity and other desirable characteristics. The size of a portable analyzer was 30 cm × 23 cm × 7 cm, and the weight was around 3 kg. The small size gives the advantage of being portable for field use while not sacrificing portability for accuracy of measurement. Furthermore, the autonomous system developed in coordination with the development of new polymer LOC integrated with electrochemical sensors can provide an innovative way to monitor surface waters in an efficient, cost-effective and sustainable manner.
Radiotherapeutical chromosomal aberrations in laryngeal cancer patients
Authors: Stosic-Divjak Svetlana , Novakovic Ivana , Kastratovic Dragana , Pavlovic Milan , Divjak Isidora , Markovic Srdjan , Jovic Rajko
Published: November 2009

Introduction. The authors present the results of cytogenetic analysis of 21 patients with laryngeal carcinomas diagnosed and treated in the period 1995-2000 at the Institute of Otorhinolaryngology and Maxillofacial Surgery, Clinical Center of Serbia and Clinical Center of Novi Sad. Material and methods. The patients were specially monitored and the material was analyzed at the Institute of Human Genetics of the School of Medicine in Belgrade as well as in the Laboratory for Radiological Protection of the Institute of Occupational and Radiological Health 'Dr Dragomir Karajovic' in Belgrade. Results. The incidence of chromosomal aberrations and incidence of exchange of material between sister chromatids were observed in the preparation of the metaphasic lymphocyte chromosomes of the peripheral blood obtained in the culture. Structural aberrations were found on the chromosomes in the form of breakups, rings, translocations and dicentrics as early as after a single exposure of patients to tumor radiation dose of 2 Gy in the field sized 5x7. Out of the total number of 35 cultivated blood samples obtained from 13 patients, 21 were successfully cultivated and they were proved to contain chromosomal aberrations. Some of the peripheral blood samples failed to show cell growth in vitro due to the lethal cell damages in vivo. Discussion.. We have consluded that the number of structural aberrations cannot be used as a biological measure of the absorbed ionizing radiation dose. The presence of aberrations per se is indicative of the mutagenic effect of the ionizing radiation, which was also confirmed in our series on the original model by cultivation of the peripheral blood lymphocytes in the culture of the cells of the volunteer donors upon in vitro radiation. Using the method of bromdeoxyuridylreductase, the increased incidence of SCE as a mutagenic effect was registered. Conclusion. It has been concluded that the increase of absorbed radiation dose in vitro leads to prolonged duration of cell cycle in the same conditions, which proves cytostatic effect of radiation. Further fundamental studies are required for clinical implementation of the findings.
Blood glucose self-monitoring among patients with diabetes mellitus type 2 in family medicine practice
Authors: Herenda Samira , Tahirovic Husref
Published: November 2009

Introduction. Good knowledge of diabetic patients about their disease is often not related with good glycemic control. The aim of this study was to determine the level of application of acquired knowledge about diabetes in recognizing and resolving hypoglycemic and hyperglycemic conditions in patients who did or did not do blood glucose self-monitoring as well as the impact of self-monitoring on HbA1c during education of patients with diabetes type 2. Material and methods. There were 91 patients with the type 2 diabetes who completed six months education about their disease in four family medicine practices in Tuzla Canton during the period from March to September 2005. The patients who did or did not do self-monitoring with glucometer were interviewed on knowledge about recognizing and resolving hypoglycemia and hyperglycemia by family physician and HbA1c was assessed at the beginning of the education, 3 months after reading the brochure (passive education) and additional 3 months of group (intensive) education. Results. Out of 91 interviewed patients, there were 29 who did self-monitoring by glucometer at the beginning of the education, 30 patients during the passive education and 34 after the intensive education. At the beginning of education, regardless of doing self-monitoring, the patients were less able to recognize and resolve hypoglycemia and even less hyperglycemia. At the end of education, their knowledge was better at both recognizing and resolving hypoglycemia (P=0.01) as well as at recognizing (P=0.01) and resolving hyperglycemia (P=0.001). In the patients who did self-monitoring the average value of the HbA1c did not improve significantly (P=0.44) compared to those who did not practice self-monitoring (P=0.10) during education. Conclusion. Only one third of patients with type 2 diabetes had done self-monitoring with glucometer and although their knowledge about hypoglycemia and hyperglycemia was improved during education, these patients did not have improved significant values of the HbA1c compared to patients who had not done self-monitoring.
Relations of aqueduct with some structures of mesencephalon
Authors: Stankovic Gordana , Nikolic Valentina , Puskas Nela , Filipovic Branislav , Puskas Laslo , Krivokuca Dragan
Published: November 2009

Introduction. Aqueductus mesencephali is the biggest part of the ventricular system and that is why it is the most common place of intraventricular obstruction of cerebrospinal fluid. This study was done in order to study topographic characteristics of aqueduct more thoroughly. Materials and methods. Transversal sections of mesencephalon were made in three levels. The first section was made caudally immediately from the posterior commissure. The second section was made in the middle part of the superior colliculi, and the third section was made in the rostral parts of the caudal sections of the superior colliculi. Distances of the aqueduct from structures of mesencephalon, obtained on the second section, are: 1. The distance of the aqueduct from the superior colliculi - 6.96 mm; 2. The distance of the aqueduct from the red nucleus - 6.02 mm; 3. The distance of the aqueduct from the substantia nigra - 12.29 mm; 4. The distance of the aqueduct from the interpeduncular fossa - 10.22 mm. Conclusion. Knowledge of the anatomy of the aqueductus mesencephali is very important because of interpretation of patogenesis of hidrocefalus as well as of other syndromes that occure in some pathological processes in the system of ventricles.
Surgical treatment of big splenic artery aneurysm: Case report
Authors: Kacanski Milos , Markovic Vladimir , Pasternak Janko , Popovic Vladan , Pfau Jovan , Nikolic Dragan
Published: November 2009

An aneurysm has been defined as a permanent local dilatation of the diameter of an artery by at least 50% of its normal value. A splenic artery aneurysm is most frequently a visceral artery aneurysm and clinically it is usually asymptomatic but potentially life-threatening at the same time, with the incidence of its rupturing being 2-10% and then the mortality rate ranges from 20 to 36%. A 51-year-old female patient was admitted to the Department of Vascular and Transplantation Surgery in Novi Sad having been found to have a big splenic artery aneurysm during the ultrasound examination of her abdomen after cholecystectomy. The additional diagnostic procedure - computerized tomography of the abdomen with i.v contrast subtraction angiography-confirmed the splenic artery aneurysm to have the diameter of 5 cm and therefore the elective surgical treatment was indicated after the preoperative preparation and risk assessment. The aneurysm was exposed through Chevron incision, and the detailed surgical exploration was done after the omental bursa had been opened. The aneurysmectomy and the reconstruction of the splenic artery by the termino-terminal anastomosis were performed after the weakening of the wall had been verified. The biopsies of the liver and the aneurysmal sac were done during the surgery. The pathohistological finding confirmed the atherosclerotic etiology of the aneurysm. Since the postoperative course was normal, the patient was discharged on the eighth postoperative day.
Modeling the effect of spray/wall impingement on combustion process and emission of DI diesel engine
Authors: Jafarmadar Samad , Khalilarya Shram , Shafee Sina , Barzegar Ramin
Published: November 2009

This work is presented to study the effect of spray impinging on the combustion process and emissions in a direct injection diesel engine at various engine speeds. Computations are carried out using a three-dimensional modeling for sprays, spray-wall interactions, flow field, emission, and combustion process. Results indicate an increase in engine speed leads to increased spray impinging (wall film formation), turbulence intensity and average wall temperature in cylinder. The enhanced air/fuel mixing and intensified evaporation of wall film decreases soot emission by reducing the extent of the fuel rich regions specially in impinging zones. Also at higher engine speeds, combustion is delayed and fuel is consumed in a shorter time period by the enhanced air and fuel mixing. The shorter combustion duration provides less available time for soot and NOx formations. However, only a few attempts have been made to address the effect of impingement of spray with piston walls on the emissions and combustion process. The results of model in addition to approving the corresponding data in the literature are also compared with the experimental data and shown good agreement.
Mathematical modeling and simulation of a reed valve reciprocating air compressor
Authors: Govindan Nagarajan , Jayaraman Venkatesan , Venkatasamy Retteripatti , Ramasamy Murugan
Published: November 2009

Mathematical modeling is the process of designing a model of a real system and conducting experiments with it for the purpose of understanding the behavior of the system. Mathematical simulation is widely used for investigating and designing the compressors. Investigations of the processes of reciprocating compressors using mathematical models is an effective tool by high development of computing technique, which enables complicated problems to be solved with a minimal number of simplifying assumptions. A considerable number of previous works has been done on the mathematical modeling and simulation. The aim of the present work is to construct a model which is easy to understand, easy to detect errors in the process of building a model, and easy to compute a solution. This paper presents a simplified and effective mathematical model for the estimation of reciprocating compressor performance using personal computers that can be easily handled. The effect of operating parameters, speed and discharge pressure on thermodynamic behavior of compressor in working condition has been analyzed. The model has been developed for obtaining cylinder pressure, cylinder volume, cylinder temperature, valve lift and resultant torque at different crank angles and free air delivered and indicated power of the compressor. The model has been validated using experimental results.
Experimental investigation and performance evaluation of DI diesel engine fueled by waste oil-diesel mixture in emulsion with water
Authors: Nanthagopal Kasianantham , Subbarao Rayapati
Published: November 2009

Exploitation of the natural reserves of petroleum products has put a tremendous onus on the automotive industry. Increasing pollution levels and the depletion of the petroleum reserves have lead to the search for alternate fuel sources for internal combustion engines. Usage of vegetable oils poses some challenges like poor spray penetration, valve sticking and clogging of injector nozzles. Most of these problems may be solved by partial substitution of diesel with vegetable oil. In this work, the performance and emission characteristics of a direct injection diesel engine fueled by waste cooking oil-diesel emulsion with different water contents are evaluated. The use of waste cooking oil-diesel emulsion lowers the peak temperature, which reduces the formation of NOx. Moreover the phenomenon of micro explosion that results during the combustion of an emulsified fuel finely atomizes the fuel droplets and thus enhances combustion. Experiments show that CO concentration is reduced as the water content is increased and it is seen that 20% water content gives optimum results. Also, there is a significant reduction in NOx emissions.
H2-O2 supercritical combustion modeling using a CFD code
Authors: Benarous Abdallah , Liazid Abdelkrim
Published: November 2009

The characteristics of propellant injection, mixing, and combustion have a profound effect on liquid rocket engine performance. The necessity of raising rocket engines performance requires a combustion chamber operation often in a supercritical regime. A supercritical combustion model based on a one-phase multi-components approach is developed and tested on a non-premixed H2-O2 flame configuration. A two equations turbulence model is used for describing the jet dynamics where a limited Pope correction is added to account for the oxidant spreading rate. Transport properties of the mixture are calculated using extended high pressure forms of the mixing rules. An equilibrium chemistry scheme is adopted in this combustion case, with both algebraic and stochastic expressions for the chemistry/turbulence coupling. The model was incorporated into a computational fluid dynamics commercial code (Fluent 6.2.16). The validity of the present model was investigated by comparing predictions of temperature, species mass fractions, recirculation zones and visible flame length to the experimental data measured on the Mascotte test rig. The results were confronted also with advanced code simulations. It appears that the agreement between the results was fairly good in the chamber regions situated downstream the near injection zone.
Smart ceramic materials for homogeneous combustion in internal combustion engines: A review
Authors: Chidambaram Kannan , Packirisamy Tamilporai
Published: November 2009

The advantages of using ceramics in advanced heat engines include increased fuel efficiency due to higher engine operating temperatures, more compact designs with lower capacity cooling system. Future internal combustion engines will be characterized by near zero emission level along with low specific fuel consumption. Homogenous combustion which realized inside the engine cylinder has the potential of providing near zero emission level with better fuel economy. However, the accomplishment of homogeneous combustion depends on the air flow structure inside the combustion chamber, fuel injection conditions and turbulence as well as ignition conditions. Various methods and procedures are being adopted to establish the homogeneous combustion inside the engine cylinder. In recent days, porous ceramic materials are being introduced inside the combustion chamber to achieve the homogeneous combustion. This paper investigates the desirable structures, types, and properties of such porous ceramic materials and their positive influence on the combustion process.
Accounting for Debt Instruments Held as Assets
Authors: Trott Edward W.
Published: November 2009

SYNOPSIS: I propose that all debt instruments held as assets be accounted for using a combination of reported amounts that reflect a measurement at the initial recognition date and fair value. The proposal eliminates the “incurred loss” and “other-than-temporary-impairment (hereafter, OTTI)” models and replaces them with a valuation account that adjusts the amortized reported amounts to fair value each reporting date. Disclosures, on a disaggregated basis, about the debt instruments, charge-offs, and fair value measurements will provide significantly more information than currently provided. The advantages of this proposal are to (1) reduce accounting complexity through use of a single objective for reporting all debt instruments held as assets; (2) use the most relevant, representationally faithful, and verifiable measurement attribute for the assets; and (3) increase transparency and information about the assets.
A Point Mutation in Sec61α1 Leads to Diabetes and Hepatosteatosis in Mice
Authors: Lloyd David J. , Wheeler Matthew C. , Gekakis Nicholas
Published: November 2009

OBJECTIVE

Type 2 diabetes is caused by both environmental and genetic factors. To better understand the genetic factors we used forward genetics to discover genes that have not previously been implicated in the development of hyperglycemia or diabetes.

RESEARCH DESIGN AND METHODS

Offspring of ethylnitrosurea-mutagenized C57BL/6 mice were bred to homozygosity, maintained on high-fat diet, and screened for hyperglycemia. The phenotype in one diabetic family of mice was mapped among hybrid F2s with single nucleotide polymorphic markers, followed by candidate gene sequencing to identify the gene harboring the causative mutation. Subsequent analysis was done on wild-type, heterozygous, and homozygous mutant mice on a pure C57BL/6 background.

RESULTS

Diabetes mapped to a point mutation in the Sec61a1 gene that encodes a His to Tyr substitution at amino acid 344 (Y344H). Metabolic profiling, histological examination, and electron microscopy revealed that hyperglycemia was a result of insulin insufficiency due to β-cell apoptosis brought on by endoplasmic reticulum (ER) stress. Transgenic β-cell–specific expression of Sec61a1 in mutant mice rescued diabetes, β-cell apoptosis, and ER stress. In vitro experiments showed that Sec61α1 plays a critical role in the β-cell response to glucose.

CONCLUSIONS

Here we phenotypically characterize diabetes in mice with a novel point mutation in a basic component of the cell's ER protein translocation machinery, Sec61α1. Translocation by the mutant protein does not appear to be affected. Rather, ER homeostasis is perturbed leading to β-cell death and diabetes.
AMP-Activated Protein Kinase–Deficient Mice Are Resistant to the Metabolic Effects of Resveratrol
Authors: Um Jee-Hyun , Park Sung-Jun , Kang Hyeog , Yang Shutong , Foretz Marc , McBurney Michael W. , Kim Myung K. , Viollet Benoit , Chung Jay H.
Published: November 2009

OBJECTIVE

Resveratrol, a natural polyphenolic compound that is found in grapes and red wine, increases metabolic rate, insulin sensitivity, mitochondrial biogenesis, and physical endurance and reduces fat accumulation in mice. Although it is thought that resveratrol targets Sirt1, this is controversial because resveratrol also activates 5′ AMP-activated protein kinase (AMPK), which also regulates insulin sensitivity and mitochondrial biogenesis. Here, we use mice deficient in AMPKα1 or -α2 to determine whether the metabolic effects of resveratrol are mediated by AMPK.

RESEARCH DESIGN AND METHODS

Mice deficient in the catalytic subunit of AMPK (α1 or α2) and wild-type mice were fed a high-fat diet or high-fat diet supplemented with resveratrol for 13 weeks. Body weight was recorded biweekly and metabolic parameters were measured. We also used mouse embryonic fibroblasts deficient in AMPK to study the role of AMPK in resveratrol-mediated effects in vitro.

RESULTS

Resveratrol increased the metabolic rate and reduced fat mass in wild-type mice but not in AMPKα1−/− mice. In the absence of either AMPKα1 or -α2, resveratrol failed to increase insulin sensitivity, glucose tolerance, mitochondrial biogenesis, and physical endurance. Consistent with this, the expression of genes important for mitochondrial biogenesis was not induced by resveratrol in AMPK-deficient mice. In addition, resveratrol increased the NAD-to-NADH ratio in an AMPK-dependent manner, which may explain how resveratrol may activate Sirt1 indirectly.

CONCLUSIONS

We conclude that AMPK, which was thought to be an off-target hit of resveratrol, is the central target for the metabolic effects of resveratrol.
Differential Effect of Saturated and Unsaturated Free Fatty Acids on the Generation of Monocyte Adhesion and Chemotactic Factors by Adipocytes
Authors: Han Chang Yeop , Kargi Atil Y. , Omer Mohamed , Chan Christina K. , Wabitsch Martin , O'Brien Kevin D. , Wight Thomas N. , Chait Alan
Published: November 2009

OBJECTIVE

Obesity is associated with monocyte-macrophage accumulation in adipose tissue. Previously, we showed that glucose-stimulated production by adipocytes of serum amyloid A (SAA), monocyte chemoattractant protein (MCP)-1, and hyaluronan (HA) facilitated monocyte accumulation. The current objective was to determine how the other major nutrient, free fatty acids (FFAs), affects these molecules and monocyte recruitment by adipocytes.

RESEARCH DESIGN AND METHODS

Differentiated 3T3-L1, Simpson-Golabi-Behmel syndrome adipocytes, and mouse embryonic fibroblasts were exposed to various FFAs (250 μmol/l) in either 5 or 25 mmol/l (high) glucose for evaluation of SAA, MCP-1, and HA regulation in vitro.

RESULTS

Saturated fatty acids (SFAs) such as laurate, myristate, and palmitate increased cellular triglyceride accumulation, SAA, and MCP-1 expression; generated reactive oxygen species (ROS); and increased nuclear factor (NF) κB translocation in both 5 and 25 mmol/l glucose. Conversely, polyunsaturated fatty acids (PUFAs) such as arachidonate, eicosapentaenate, and docosahexaenate (DHA) decreased these events. Gene expression could be dissociated from triglyceride accumulation. Although excess glucose increased HA content, SFAs, oleate, and linoleate did not. Antioxidant treatment repressed glucose- and palmitate-stimulated ROS generation and NFκB translocation and decreased SAA and MCP-1 expression and monocyte chemotaxis. Silencing toll-like receptor-4 (TLR4) markedly reduced SAA and MCP-1 expression in response to palmitate but not glucose. DHA suppressed NFκB translocation stimulated by both excess glucose and palmitate via a peroxisome prolifterator–activated receptor (PPAR) γ–dependent pathway.

CONCLUSIONS

Excess glucose and SFAs regulate chemotactic factor expression by a mechanism that involves ROS generation, NFκB, and PPARγ, and which is repressed by PUFAs. Certain SFAs, but not excess glucose, trigger chemotactic factor expression via a TLR4-dependent pathway.
Role of Quantitative Bone Scanning in the Assessment of Bone Turnover in Patients With Charcot Foot
Authors: Bem Robert , Jirkovská Alexandra , Dubský Michal , Fejfarová Vladimira , Buncová Marie , Skibová Jelena , Jude Edward B.
Published: November 2009

OBJECTIVE

To assess the new quantitative bone scan parameters as markers of Charcot neuroosteoarthropathy (CNO) activity.

RESEARCH DESIGN AND METHODS

Forty-two patients with acute (n = 21) and nonacute (n = 21) CNO underwent quantitative bone scanning. Patients with acute CNO were followed for 3–12 months and bone scans were repeated after treatment. New quantitative parameters were assessed and compared with markers of bone turnover and with skin temperature difference (STD).

RESULTS

Significant correlations between quantitative bone scan parameters and bone turnover markers were observed (all P < 0.05). These parameters decreased after treatment of CNO, and its reduction to the baseline value correlated with differences of bone turnover markers and STD (all P < 0.05).

CONCLUSIONS

Our study suggests that bone scanning can be used not only for diagnosis of CNO but also for monitoring disease activity by quantitative bone scan parameters.
Delayed Treatment with Plasminogen Activator Inhibitor-1 Decoys Reduces Tubulointerstitial Fibrosis
Authors: Gonzalez Julien , Klein Julie , Chauhan Sharmila D. , Neau Eric , Calise Denis , Nevoit Caroline , Chaaya Rana , Miravete Mathieu , Delage Christine , Bascands Jean-Loup , Schanstra Joost P. , Buffin-Meyer Bénédicte
Published: November 2009

We examined the capacity of delayed inhibition of plasminogen activator inhibitor-1 (PAI-1) to reduce tubulointerstitial fibrosis induced by unilateral ureteral obstruction (UUO) in mice. Small peptides mimicking parts of urokinase (uPA) and tissular plasminogen activator (tPA) and serving as decoy molecules for PAI-1 were administered daily during the late stages (3 to 8 days) of UUO. Treatment with PAI-1 decoys reduced interstitial deposition of fibronectin, collagen III and collagen IV without changes in macrophage and myofibroblast infiltration. Interestingly, while PAI-1 activity was reduced and the combined uPA and tPA activity was increased, the antifibrotic effect was obtained without modification of plasmin activity but with increased of hepatocyte growth factor (HGF) expression. We show for the first time that treatment with small PAI-1 decoy peptides reduces established tubulointerstitial fibrosis. This protective effect probably resulted from increased degradation of the extracellular matrix by an HGF dependent mechanism.
Characterization of TWIK-2, a Two-Pore Domain K+ Channel, Cloned from the Rat Middle Cerebral Artery
Authors: Lloyd Eric E. , Marrelli Sean P. , Namiranian Khodadad , Bryan Robert M.
Published: November 2009

TWIK-2, a member of the Two-Pore Domain K channel family, is expressed in a number of mammalian tissues including the vascular system. The function of TWIK-2 is not known. The purpose of this study was to clone the TWIK-2 channel from the rat middle cerebral artery, express it in CHO cells, and characterize the channel’s electrical properties. In light of the fact that there are no specific TWIK-2 inhibitors or activators, a better characterization of the channel should enhance our understanding of its role in the vascular system. TWIK-2 was cloned from the rat middle cerebral artery and expressed with an N-terminal green fluorescence protein (GFP) in CHO cells. We report that rTWIK-2-GFP currents were relatively linear at physiological K+ concentrations but become slightly inwardly rectifying in symmetrical K+. rTWIK-2-GFP was insensitive to 10 mM TEA, 3 mM 4-aminopyridine, and 10 μM glibenclamide. However, rTWIK-2-GFP was inhibited by Ba2+ with 50% of the current being blocked at 80 μM. rTWIK-2-GFP activity was enhanced 60% by 100 μM arachidonic acid. The electrophysiological characteristics of TWIK-2 indicate that it could serve an important role in ion homeostasis and regulation of the membrane potential in arteries and arterioles.
Brucella melitensis, B. neotomaeandB. ovisElicit Common and Distinctive Macrophage Defense Transcriptional Responses
Authors: Covert Jill , Mathison Angela J. , Eskra Linda , Banai Menachem , Splitter Gary
Published: November 2009

Brucella spp. establish an intracellular replicative niche in macrophages, while macrophages attempt to eliminate the bacteria by innate defense mechanisms. Brucella spp. possess similar genomes yet exhibit different macrophage infections. Few B. melitensis and B. neotomae enter macrophages with intracellular adaptation occurring over 4–8 hr. Conversely, B. ovis are readily ingested by macrophages and exhibit a persistent plateau of infection. Evaluating early macrophage interaction with Brucella spp. allows discovery of host entry and intracellular translocation mechanisms. Microarray analysis of macrophage transcriptional response following a 4 hr infection by different Brucella spp. revealed common macrophage genes altered in expression compared to uninfected macrophages. Macrophage infection with three different Brucella spp. provokes a common innate immune theme with increased transcript levels of chemokines and defense response genes and decreased transcript levels of GTPase signaling and cytoskeletal function that may affect trafficking of Brucella containing vesicles. For example, transcript levels of genes associated with chemotaxis ( IL-1β , MIP-1α), cytokine regulation ( Socs3) and defense ( Fas, Tnf) were increased, while transcript levels of genes associated with vesicular trafficking ( Rab3d) and lysosomal associated enzymes ( prosaposin) were decreased. Genes with altered macrophage transcript levels among Brucella spp. infections may correlate with species specific host defenses and intracellular survival strategies. Depending on the infecting Brucella species, gene ontology categorization identified genes differentially involved in cell growth and maintenance, endopeptidase inhibitor activity and G-protein mediated signaling. Examples of decreased gene expression in B. melitensis infection but not other Brucella spp. were growth arrest ( Gas2), immunoglobulin receptor ( Fcγ rI) and chemokine receptor ( Cxcr4) genes, suggesting opposing effects on intracellular functions.
Angiogenesis Induced by hVEGF165 Gene Controlled by Hypoxic Response Elements in Rabbit Ischemia Myocardium
Authors: Dong Hongyan , Wang Qiang , Zhang Yiqian , Jiang Bo , Xu Xiahong , Zhang Zhongming
Published: November 2009

Hypoxic response element (HRE) offers satisfactory control over expression of hVEGF165 in cell levels. However, the characteristics of regenerated blood vessels induced by long-term expression of transferred hVEGF165 under control of HRE in vivo remain unknown. This study aims to investigate the effect of HRE on control of long-term expression of rAAV-delivered hVEGF165 gene to ischemic myocardium and evaluate characteristics of angiogenesis induced by hVEGF165 in vivo. Rabbit ischemic heart models were established surgically, rAAV-9HRE- hVEGF165 was transfected to ischemia hearts subjected to 12 week ischemia. Molecular biological and immunohistochemistry were employed to determine expressions of HIF-1α and hVEGF165. Microvessel densities of CD31+ and α-SMA+ regenerated vessels were also evaluated. Expressions of both hVEGF165 mRNA and protein were upregulated following over-expression of endogenous HIF-1α early after ischemia, peaked at 4–6 weeks post-MI, declined, and approached pre-ischemia level at the end of 12 weeks of ischemia ( P < 0.01). The significantly upregulated CD31 in hVEGF165-treated hearts presented from 8 to 12 weeks of ischemia compared with the control ( P < 0.01). However, α-SMA expression was rapidly downregulated after ischemia and remained lower than the control level by the end of 12 weeks post-MI ( P < 0.01). Overexpression of hVEGF165 controlled by HIF-1α-HRE system shows a stably regional angiogenic efficacy in vivo. But, VEGF, as an early angiogenic cytokine, is inadequate for mediating histologically mature vessels in ischemia myocardium.
Editorial: Our First Issue
Authors: Begum Noorzahan
Published: November 2009

Bangabandhu Sheikh Mujib Medical University Journal Vol.1(1) 2008
Non-surgical Management of Endodontic Periradicular Pathosis - A Clinical Research
Authors: Ahmed Tahmeena Ishrat , Howlader Mujibur Rahman
Published: November 2009

Background: In most cases the aetiological factors of periradicular diseases are oral contaminants through the root canal or degenerating pulpal tissues. Therefore, the mere surgical removal of the periapical lesions without proper root canal disinfection and obturation will not result in the healing of the periradicular tissues. On the other hand, traditional surgical technique rather fearful and troublesome job due to various reasons. So successful apical and periapical repair depends on conventional root canal treatment - a non surgical procedure. Crucial to this management and ultimate success is the complete debridement of the root canal system, followed by three-dimensional obturation to seal both the apical foramen and coronal orifice. Objective: Thus, the purpose of this study was to clinically verify the possibility of management of periradicular pathosis by non-surgical conventional root canal therapy. Methods: The present study was a prospective observational study carried out in the department of Conservative Dentistry and Endodontics, Faculty of Dentistry, Bangabandhu Sheikh Mujib Medical University (BSMMU), Shahbag, Dhaka. Here, 75 cases of eondodontically involved symptomatic non-vital teeth having periradicular pathosis were managed by conventional root canal therapy. Result: After 18 months follow up with post operative clinical and radiological evaluations, in this study the final outcome was favourable-88%, doubtful-08 %, and failure-04%. Key words: Endodontics; Periarticular pathosisDOI: 10.3329/bsmmuj.v1i1.3694 BSMMU J 2008; 1(1): 22-28
3-O-Methylfunicone, a Selective Inhibitor of Mammalian Y-Family DNA Polymerases from an Australian Sea Salt Fungal Strain
Authors: Mizushina Yoshiyuki , Motoshima Hirohisa , Yamaguchi Yasuhiro , Takeuchi Toshifumi , Hirano Ken , Sugawara Fumio , Yoshida Hiromi
Published: November 2009

We isolated a pol inhibitor from the cultured mycelia extract of a fungal strain isolated from natural salt from a sea salt pan in Australia, which was identified as 3-O-methylfunicone by spectroscopic analyses. This compound selectively inhibited the activities of mammalian Y-family DNA polymerases (pols) (i.e., pols η, ι and κ). Among these pols, human pol κ activity was most strongly inhibited, with an IC50 value of 12.5 μM. On the other hand, the compound barely influenced the activities of the other families of mammalian pols, such as A-family (i.e., pol γ), B-family (i.e., pols α, δ and ε) or X-family (i.e., pols β, λ and terminal deoxynucleotidyl transferase), and showed no effect on the activities of fish pol δ, plant pols, prokaryotic pols and other DNA metabolic enzymes, such as calf primase of pol α, human immunodeficiency virus type-1 (HIV-1) reverse transcriptase, human telomerase, T7 RNA polymerase, mouse IMP dehydrogenase (type II), human topoisomerases I and II, T4 polynucleotide kinase or bovine deoxyribonuclease I. This compound also suppressed the growth of two cultured human cancer cell lines, HCT116 (colon carcinoma cells) and HeLa (cervix carcinoma cells), and UV-treated HeLa cells exhibited lower clonogenic survival in the presence of inhibitor.
Synthetic Approaches and Biological Activities of 4-Hydroxycoumarin Derivatives
Authors: Jung Jae-Chul , Park Oee-Sook
Published: November 2009

The main purpose of this review is to summarize recent chemical syntheses and structural modifications of 4-hydroxycoumarin and its derivatives, of interest due to their characteristic conjugated molecular architecture and biological activities.
A Non-invasive Methodology for Fetal Monitoring during Pregnancy
Authors: Karvounis E. C. , Tsipouras M. G. , Papaloukas C. , Tsalikakis D. G. , Naka K. K. , Fotiadis D. I.
Published: November 2009

Objectives: This paper describes a methodology for the monitoring of the fetal cardiac health status during pregnancy, through the effective and non-invasive monitoring of the abdominal ECG signals (abdECG) of the mother.

Methods: For this purpose, a three-stage methodology has been developed. In the first stage, the fetal heart rate (fHR) is extracted from the abdECG signals, using nonlinear analysis. Also, the eliminated ECG (eECG) is calculated, which is the abdECG after the maternal QRSs elimination. In the second stage, a blind source separation technique is applied to the eECG signals and the fetal ECG (fECG) is obtained. Finally, monitoring of the fetus is implemented using features extracted from the fHR and f ECG, such as the T/QRS ratio and the characterization of the fetal ST waveforms.

Results: The methodology is evaluated using a dataset of simulated multichannel abdECG signals: 94.79% accuracy for fHR extraction, 92.49% accuracy in T/QRS ratio calculation and 79.87% in ST waveform classification.

Conclusions: The novel non-invasive proposed methodology is advantageous since it offers automated identification of fHR and fECG and automated ST waveform analysis, exhibiting a high diagnostic accuracy.
PREDESIGN COST ESTIMATION OF URBAN RAILWAY PROJECTS WITH PARAMETRIC MODELING
Authors: Sonmez Rifat , Ontepeli Bahadir
Published: November 2009

This paper presents a parametric modeling method for predesign cost estimation of urban railway systems. Data of 13 light rail and metro projects located in Turkey were compiled for quantification of the impacts of parameters on the project costs. Parametric models have been developed using regression analysis and neural networks techniques. Ten linear regression models were used for determination of the parameters significantly impacting cost of urban railway projects. Two neural networks were considered as an alternative to regression models, particularly for the identification of the non‐linear relations. Predictive behaviour and performance of the models were compared to determine a model that presents adequate relations and has a reasonable accuracy. The proposed method provides a powerful approach for determination of a satisfactory parametric cost model during early project stages by incorporating a coordinated use of regression analysis and neural network techniques. Santrauka Pateiktas miesto geležinkelių sistemų priešprojektinių išlaidų skaičiavimo metodas, pagrįstas parametriniu modeliavimu. Parametrų įtaka projekto išlaidoms nustatyta išnagrinėjus 13 nedidelių geležinkelių ir metro projektų Turkijoje. Parametriniai modeliai sudaryti taikant regresinę analizę bei dirbtinio intelekto tinklus. Parametrų įtakos miestų geležinkelių projektavimo išlaidoms reikšmingumui nustatyti sudaryta 10 tiesinės regresijos modelių. Kaip alternatyva regresijos modeliams sudaryti 2 neuroniniai tinklai, ypač nagrinėjant netiesines priklausomybes. Pasiūlytais modeliais gauti rezultatai palyginti tarpusavyje, siekiant nustatyti adekvačias priklausomybes ir užtikrinti reikiamą tikslumą. Pasiūlytas metodas leidžia sukurti parametrinį projekto išlaidų modelį ankstyvojoje priešprojektinėje stadijoje. Tai pasiekta suderintai panaudojus regresinę analizę ir dirbtinio intelekto tinklus.