The effect of the static compaction on the mechanical and physical properties of asphalt concrete hot-mixes

The objective of this investigation was to study the effect of the static compaction effort upon the physical and mechanical properties of asphalt concrete hot mixes. To study the effect of the static compaction upon the physical properties of the asphalt mixes, six mixes were prepared using hard, well graded crushed limestone as an aggregate, blended with an 85-100 penetration grade asphalt cement. The control mix was prepared and tested in accordance with the Marshall method for mix design. The other five mixes were prepared and tested using the same procedures of Marshall except for compaction, where five different static pressures were applied. The effect of the static compaction upon the mechanical properties of the mixes was also studied. Test specimens 2.1 inches in diameter and 4.00 inches in height were compacted using different static compaction efforts. These specimens were tested in unconfined compression. Both of these studies indicated that a relationship exists between the static compaction effort and the physical and mechanical properties of the asphalt concrete mixes --Abstract, page ii

A New Monte Carlo Based Algorithm for the Gaussian Process Classification Problem

Gaussian process is a very promising novel technology that has been applied to both the regression problem and the classification problem. While for the regression problem it yields simple exact solutions, this is not the case for the classification problem, because we encounter intractable integrals. In this paper we develop a new derivation that transforms the problem into that of evaluating the ratio of multivariate Gaussian orthant integrals. Moreover, we develop a new Monte Carlo procedure that evaluates these integrals. It is based on some aspects of bootstrap sampling and acceptancerejection. The proposed approach has beneficial properties compared to the existing Markov Chain Monte Carlo approach, such as simplicity, reliability, and speed

Selective simultaneous ultra-performance liquid chromatographic quantification of some benzodiazepines drug residues in pharmaceutical industrial wastewater

Purpose: To investigate the sensitivity and selectivity of ultra-performance liquid chromatographic (UPLC) quantification of bromazepam (BRZ) and diazepam (DZP) in pharmaceutical industrial wastewater. Methods: Wastewater samples were collected from the effluents of a pharmaceutical industrial plant producing BRZ and DZP in tablet dosage forms. The quantification of BRZ and DZP was done after their solid-phase extraction. The resolution process was performed on WatersTM column as the stationary phase. The mobile phase was acetonitrile: methanol: 0.05 M phosphate buffer (pH 6.5), at a volume ratio of 5:2:3, with a flow rate of 0.7 mL/min. Detection was carried out at 240 nm in a concentration range of 10 – 250 ng/mL. The method was fully validated in line with ICH-Q2B regulations. Results: The UPLC method was validated for the quantification of BRZ and DZP. The relative percentage recoveries were 99.55 ± 0.48 (n = 5) and 101.34 ± 0.86 (n = 5), for BRZ and DZP, respectively, in spiked distilled water, and 99.16 ± 0.77 (n = 5) and 99.32 ± 0.56 (n = 5), in tap water, respectively. The UPLC revealed effluent content ranging from 20.68 – 44.77 mg/mL for BRZ and 22.77 – 41.83 ng/mL for DZP. These values were not significantly different from their reference standards (p > 0.05). Conclusion: A sensitive and selective UPLC-method has been developed for the reproducible determination of BRZ and DZP in industrial wastewater samples. The effective monitoring of the pharmaceutical industrial pollutant will help to conserve the environment and minimize the hazardous effects of these pollutants

Solid-phase extraction and validated spectrofluorimetric quantification of pamidronate in human plasma

Purpose: To design a simple and sensitive quantification procedure for pamidronate disodium (PAM) after its solid phase extraction from plasma.Methods: The procedure was based on derivatization of PAM using a suitable fluorogen, 4-chloro-7-nitro-2,1,3-benzoxazole. The  product was determined spectrofluorometrically at excitation and emission wavelengths of 390 and 535 nm, respectively. The method was optimized for all factors that affect the reaction between PAM and the fluorogen. These factors include diluting solvent, pH of the reaction medium, volume of fluorogen solution, buffer pH, buffer volume, temperature and heating time. The method was fully validated according to US-FDA guidelines with respect to linearity, accuracy, precision, recovery, robustness and stability.Results: PAM was successfully extracted from human plasma with solid-phase extraction technique. A linear response was obtained in the concentration range of 10 – 100 ng/mL, with correlation coefficient of 0.998. Mean maximum plasma concentration of PAM was 9.73.2 ± 3.2 µmol/L, which was within the linear range of the proposed method, thereby confirming its sensitivity for the determination of plasma PAM.Conclusion: The proposed procedure is suitable for the quantification of PAM in human plasma after its solid phase extraction. The method is sensitive enough for use in PAM determination in pharmacokinetic studies. Moreover, it is likely a more cost-effective and simpler alternative method than high performance liquid chromatograph (HPLC) methods. Keywords: Pamidronate disodium, Derivatization, Spectrofluorimetry, Fluorogen, Quantificatio

Spectrodensitometric and ultra-performance liquid chromatographic quantification of dapagliflozin and saxagliptin in their dosage form and human plasma

Purpose: To simultaneously quantify dapagliflozin (DAPA) and saxagliptin (SAX) in a pharmaceutical product and human plasma. Methods: Separation and quantification of DAPA and SAX were performed on pre-coated TLC plates in TLC-densitometric method using a solvent system of chloroform, ethyl acetate and methanol at a volume ratio of 8:1:1 as the mobile phase. The developed spots were scanned at 225 and 210 nm in absorbance mode. Moreover, the studied drugs were concurrently determined in human plasma using ultra-performance liquid chromatography (UPLC). The separation process was carried out in WatersTM Acquity C18 BEH column using a solvent system of 0.02 M KH2PO4 buffer, pH 4; MeOH and acetonitrile (2:1:1, v:v:v) isocratically at a flow speed of 0.5 mL/min. The absorbance of each eluent was read at 220 nm. Results: Concurrent evaluation of DAPA and SAX was carried without separation using TLC-densitometric method, and it was successful in determination of DAPA and SAX in concentration ranges of 10 – 70 μg/band and 5 – 60 μg/band, respectively. In addition, retardation factor (Rf) values for SAX and DAPA were 0.17 and 0.31, respectively. Furthermore, the studied drugs were concurrently determined in human plasma using UPLC, which was sensitive enough to quantify DAPA and SAX in concentration ranges of 100 – 1000 and 20 – 200 ng/mL, respectively. Conclusion: These methods can be utilized for sensitive monitoring of DAPA and SAX in pharmacokinetic and bioequivalence studies

Ultra-performance liquid chromatography–tandem mass spectrometric determination of ramipril in human plasma

Purpose: To develop a sensitive and accurate ultra-performance liquid chromatography–tandem mass spectrometric (UPLC-MS) method for quantification of ramipril in human plasma.Methods: Ramipril was extracted from biological fluid using equal volumes of n-hexane and propanol (1:1, v/v), and then chromatographed in a suitable C18 column with methanol: 0.1 % HCOOH (4: 1, v/v) as mobile phase. Atorvastatin was used as an internal standard for the  chromatographic separation and quantification. The method was validated according to the United States Food and Drug Administration guidelines for standard indices.Results: Ramipril was determined in the concentration range 0.05 and 1000 ng/mL the validation procedure exhibited a correlation coefficient of 0.9979 + 0.002 (p = 0.05). The studied drug was quantified with lower ceiling of 0.05 ng/mL, and showed an accuracy of 105.00 %.Conclusion: A sensitive UPLC-MS analytical method has been successfully developed for the quantification of ramipril in human plasma. This method can be applied efficiently for the quantification of ramipril in bioavailability and pharmacokinetic studies. Keywords: Liquid chromatography–tandem mass, Ramipril, Stability, Biological fluids, Plasm

Solid phase extraction and LC-MS/MS quantification of ibandronate in human plasma

Purpose: To develop and validate a simple, highly sensitive and accurate method for the quantification of ibandronate (IBN) in human plasma.Methods: Electrospray ionization liquid chromatography tandem mass spectrometry (LC-MS/MS) in positive ion mode was applied to obtain optimum signals. The parent ion was acquired under collisionactivated dissociation conditions, and the abundant fragments used to design multiple reaction monitoring experiments for monitoring two ibandronate transitions (m/z 376 to m/z 114, and m/z 376 to m/z 250). The IBN was isolated from plasma with weak anion exchange solid phase extraction columns with ‘on-cartridge’ derivatization using tri-methylsilyl-diazomethane (TMSDZ) reagent to convert IBN to tetra-methyl derivative.Results: The studied drug was successfully extracted from plasma samples without any interference at a retention time of 3.2 min. The matrix effect averaged 110 %, indicating that endogenous materials had little effect on ionization. The relationship between plasma analyte concentration and IBN signal area was satisfactorily linear, with correlation coefficient (r2) ranging from 0.9817 to 0.9942 in the concentration range of 0.5 – 200 ng/ml. The lower and upper limits of quantification (LLOQ and ULOQ) for IBN were 0.5 and 200 ng/ml, respectively. Relative recovery of IBN from plasma after extraction and derivatization at 3 distinct concentrations was 83.93 to 85.06 %, relative to standard solutions. The ranges of intra- and inter-day accuracies of quantification of quality controls were 89.39 - 106.40 %, and 90.50 - 107.96 %, respectively. Processed plasma IBN extracts were stable in autosampler at 4 0C (91.12 to 103.49%). Long-term stability in plasma after 30 days at -24 0C ranged from 89.52 to 113.18 %.Conclusion: This validated LC-MS/MS method can be successfully applied for determination of IBN in pharmacokinetic studies. It is a sensitive and specific assay for plasma IBN in bioequivalence studies. Keywords: Ibandronate, LC-MS/MS, Validation, Derivatization, Solid-phase extractio

Irrigation and drainage in the new millennium

Presented at the 2000 USCID international conference, Challenges facing irrigation and drainage in the new millennium on June 20-24 in Fort Collins, Colorado.Includes bibliographical references.A field study was conducted at Mashtul Pilot Area MPA (260 feddans' 1 feddan = 4200 m2) situated at north Zagazig to evaluate the performance of the long term constructed subsurface drainage system. The evaluation of grades, alignment and clogging of drain lines can give an indication of the system performance and efficiency. Three drainage units served by the same collector were selected. Four 30 m interval PVC lateral pipes were installed at different depths. The results revealed that, the collector drain slopes were either steep or flat while the overall slope of the collector drain was considered steep for about 45.50% of the sections and flat for the rest. On the other hand, some sections showed an inverse slope which can cause a decrease in the discharge rate. The regularity was classified as good for about 82% of the sections and moderate for the rest. The slope of the lateral drains was correct for 41.7% of those under study (12 lateral drains), steep for 16.60%, and flat for the rest, and the regularity was classified as poor except lateral number 71 which had moderate regularity in the first approach while, in the second approach 41.67% had moderate regularity and poor for the rest. Also the deviation of the drain pipes from the straight line was generally larger than pipe diameter. Consequently, air entrapment and sedimentation resulted. The results also indicated that, the average height of sedimentation inside lateral drains was 12.70 mm (618.30 gm/m drain length) while for collector drains, sediment was in 22.88% of pipe diameter. The average reduction in discharge capacity due to sedimentation for laterals and collectors upstream and downstream parts were 17.17%, 32.80% and 17.60% respectively. Also using Manning, Visser and Wesseling equations leads to different safety factors

Study of Treg FOXP3 in childhood bronchial asthma in relation to corticosteroid therapy

Background: T cells are considered the main cells responsible for production of suppressive cytokines, and play a key role in balancing the immune responses to maintain the peripheral tolerance against allergens. Objective: The present study investigates T regulatory (Treg) forkheadwinged helix protein 3 FOXP3 expression in childhood asthma and its relation to corticosteroid therapy. Methods: In this case control study, Treg FOXP3 was measured in blood of 60 children using real time polymerase chain reaction (RT-PCR) technique. Two asthmatic groups were included, one on corticosteroid therapy (20 patients) and the other not on corticosteroid treatment (20 patients). They were compared to 20 healthy children as controls. Results: FOXP3 concentration was significantly elevated in asthmatic patients (90 ± 77.4) compared to healthy children (12.844 ± 10.6) (p= 0.000). FOXP3 was significantly more elevated in asthmatics on corticosteroids (161.158 ± 63.9) than steroid naive asthmatics (36.038 ± 23.4) (p=0.000). Levels of Treg FOXP3 in asthmatics with inhaled corticosteroids (mean 151.16 ± 53.79) were almost similar to FOXP3 in asthmatics with systemic corticosteroids (161.49±72.5) (p>0.05). FOXP3 levels did not differ with smoking, asthma severity or disease control and did not correlate with age, FEV1, blood lymphocytes percentage or eosinophils percentage. Conclusion: Asthmatics have increased expression of FOXP3, and corticosteroid therapy –whether oral or inhaled - enhances FOXP3 expression.Keywords: FOXP3, Treg, Corticosteroids, Bronchial asthma, Transcription factors, CytokinesEgypt J Pediatr Allergy Immunol 2012;10(1):39-43

Modulation of L-arginine-induced acute pancreatitis by meloxicam and/or L-carnitine in rats

Background: Acute pancreatitis (AP) is an inflammatory disease, where oxidative stress, subsequently inflammatory mediators activation play a pivotal role. Currently, no definite treatment exists and therapy is mainly supportive that directed to inhibit local pancreatic injury and systemic inflammatory complications. This study is presented to explore whether anti-inflammatory and/or antioxidant drug could ameliorate L-arginine-induced AP.Methods: Rats were sub-grouped randomly into five groups. Control group, AP was provoked by a single intraperitoneal injection of L-arginine (250 mg/100g), rat treated with meloxicam (4 mg/kg, IP), animals treated with L-carnitine (500 mg/kg, IP), and rats were treated with both meloxicam and L-carnitine. All treatments were once daily for 7 consecutive days and started 1 hr later after L-arginine administration. Serum and tissues samples were prepared for biochemical analysis. Histopathological examination for the other pancreatic tissues was done.Results: L-arginine significantly elevated serum activity of amylase and lipase enzymes, while notably reduced serum calcium level. Moreover, L-arginine markedly increased the pancreatic tissues content of tumor necrosis factor-α, malondialdehyde, and nitric oxide. In addition, L-arginine significantly increased pancreatic activity of myeloperoxidase, while markedly depleted glutathione level. Treatment with either meloxicam or L-carnitine significantly attenuated L-arginine-induced biochemical changes. On the other hand, co-administration of both meloxicam and carnitine has an ameliorative effect greater than each drug alone.Conclusion: Treatment with both meloxicam and L-carnitine is a more effective than each of them alone which is attributed to augmentation their antioxidant, anti‑inflammatory effects