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We investigate the effect of the restriction and induction functors on the indecomposable modules of finite cyclicp-group algebra over a field of characteristic. Such functors are significant in studying modules in blocks with cyclic defect groups.

The dried Iraqi marshlands were re-flooded after the year 2003. Because of the water shortage feeds the marshes during the last years, the re-flooded marshes began to dry again. The Al-Sanaf marsh is part of the Al Hammar marsh located in the Thi Qar province. It is not separated hydraulically from the Al Hammar marsh. The study suggested separating the two marshes by replacing the culverts under security dyke with uncontrolled weir to keep the area of Al-Sanaf marsh submerged. If there is any added water, it will cross from the suggested structure to the Al Hammar marsh. A hydrodynamic and water quality routing models (RMA2 and RMA4) were prepared based on mass conservation low, mass balance model, and four scenarios were applied for the Al-Sanaf marsh based on the incoming discharges. The suggested model was calibrated with field data measured in the marsh. The four suggested scenarios are to keep the requirement of the Al-Sanaf marsh restoration. The maximum submerged area of the marsh is 100 km2 under any operation conditions while this area was reduced to 72 km2 under low flow conditions (minimum inflow from the feeders). The three scenarios operated considering values of inflow from Euphrates River with the required inflow from Al Khamissiya canal to keep the minimum level of salinity in the submerged area. While the fourth scenario operated with the minimum value of discharge from all feeders.

Marshlands in arid and semi-arid areas are considered constantly changing environments due to unsecured water supplies as a result of high evapotranspiration and limited and highly variable rainfall. Classification of marshlands in these regions and mapping of their land cover is not an easy task and maps need to be upgraded frequently. Satellites provide enormous amounts of information and data for the continuous monitoring of changes. The aim of this paper is to introduce an approach using multispectral satellite imagery that was adopted to classify and monitor the Al Hammar Marsh (Iraq) over several years and to suggest a relationship between the Normalized Difference Vegetation Index (NDVI), the Normalized Difference Moisture Index (NDMI), and the Normalized Difference Water Index (NDWI), using Landsat 8 data with a resolution of 30 m × 30 m, validated with Sentinel-2 datasets at 10 m × 10 m. Six land cover classes were used: (1) open water, (2) dry area, (3) dense vegetation, (4) medium-density vegetation, (5) sparse vegetation, and (6) wet soil. Three indices, NDWI, NDMI, and NDVI, were chosen for the automatic classification of each pixel and the creation of a time series of land cover maps. The proposed method can efficiently classify and monitor marshlands and can be used to study different marshlands by adjusting the thresholds for NDVI, NDMI, and NDWI. Overall, the correlation for all classes (R) between Landsat 8 and Sentinel-2 is about 0.78. Thus, this approach will help to preserve marshes through improved water management.

This research discusses the performance of closed loop control system to control the first order process with dead time which represents most of the chemical processes. Proportional, proportional integral and proportional integral derivative controls were used to characterize the performance of the closed loop. Fuzzy logic control as advanced strategy was used to improve the characteristic of the response. Different tuning methods (Cohen-Coon, Ziegler Nichols and internal model) were used for tuning the controllers. The results showed that the fuzzy control greatly improves the performance of the closed loop system because the rise in the controlled variable is arrested more quickly, and it returns rapidly to the original value with little or no oscillation. Hence, the system is more stable with Fuzzy control.

The most common method used to strengthening, rehabilitation or repairing of reinforced concrete (RC) members is to use external carbon fiber reinforced polymer (CFRP) sheets. CFRP can greatly improve the flexural and shear capacity of deteriorated members and therefore extends their useful life. The main problem of external CFRP is the debonding of the sheets from the concrete surface at some point of loading, which negatively affects the efficiency of strengthening and may consequently lead to an unanticipated failure of the strengthened members. The major reason for this early debonding is likely due to the low accuracy of the preparation and the high stress concentration at the flat contact area exists between CFRP sheets and the concrete. The problem has been extensively discussed in the literature and some CFRP application techniques such as “Externally Bonded Reinforcement on Grooves (EBROG)” and “Externally Bonded Reinforcement in Grooves (EBRIG)” have been proposed as alternatives to the conventional application methods. Although some research has been carried out, there have been few experimental investigations that provided quantitative discussion of the efficiency of the new developed techniques. This research was aimed to experimentally assess the efficiency of grooving techniques and to provide a quantitative data regarding the behaviour of bonding between CFRP and concrete. The effects of shape and direction of the grooves and CFRP layers on the load carrying capacity, mid-span deflection and failure mode of thirteen RC beams have been investigated and discussed. In general, CFRP has significantly improved the flexural capacity of strengthened beams especially when grooving technique has been employed.

The brackish water of the Main Outfall Drain (MOD) is supplied to the west part of Al Hammar Marsh to overcome the shortage of water supply and prevent dryness of the marsh. However, salts started to accumulate in high concentrations in the marsh as the MOD water contains high salt concentrations. This study aims to find an optimal outlet location in the west part of Al Hammar Marsh to drain out the water of the marsh back to the (MOD). Hydrodynamic and water quality distribution mathematical models for the marsh were developed to specify the depths of water, flow velocity profiles, and the distribution of salt concentrations in the marsh. The obtained hydrodynamic properties and the quality of the water within the marsh area were used as indicators for selecting the optimal outlet location among five suggested locations at six operation conditions. Results showed that the water depth, velocity profiles, and concentration of the total dissolved solids (TDS) are affected by the location, discharge, the concentration of the TDS of the feeders, location of the outlet, the topographic characteristics at the upstream of outlet, and evapotranspiration. It is found that the third location of the outlet, located at E=699003 and N=3404760, gives the minimum deterioration in the concentration of the TDS, depending on the overall distribution of TDS concentrations.

Dissipating the high kinetic energy of an open channel flow under sluice gates can have a significant impact on eliminating scoring of the riverbed at the downstream. This paper discusses the outcome of an experimental study consisting of 28 runs, with the aim of achieving minimum hydrodynamic forces and maximum energy dissipation downstream of hydraulic structures through stilling basins with directional diverting blocks, DDBs and straight wall baffle, and SWB. Stilling basins with a distinct configuration were made for this purpose. The hydraulic parameters that were involved were evaluated and experimentally analyzed using a rectangular flume in the hydraulic laboratory of the University of Thi-Qar, Thi-Qar, Iraq. Two different kinds of DDB models were made of wood with a triangular form, and the striate line impact wall had indistinct dimensions. The study showed that the configuration characterized by two rows of DDB with SWB between them is the most effective in dispersing energy. Out of all the suggested constructions, the DDB are more effective with two or more rows, rather than the SWB, but they are subjected to forces in the flow direction.

In this work, we study a generalization of the concept of modules by considering more general setting which is called OG-diagrams. We use Higman criteria and relative projectivity as the main tools to get our results.

Individuals with spinal cord injury or neurological disorders have problems in urinary bladder storage and in voiding function. In these people, the detrusor of bladder contracts at low volume and this causes incontinence. The goal of bladder control is to increase the bladder capacity by electrical stimulation of relative nerves such as pelvic nerves, sacral nerve roots or pudendal nerves. For this purpose, the bladder pressure has to be monitored continuously. In this paper, we propose a method for real-time estimating the bladder pressure using artificial neural network. The method is based upon measurements of electroneurogram (ENG) signal of pudendal nerve. This approach yields synthetic bladder pressure estimates during bladder contraction. The experiments were conducted on three rats. The results show that neural predictor can provide accurate estimation and prediction of bladder pressure with good generalization ability. The average error of 1-second and 5-second ahead prediction of bladder pressure are 9.62% and 10.54%, respectively.

The Wilms tumor protein WT1 is involved in the development of several organs, including the gonads. WT1 mutations in humans lead to syndromes associated with impaired sexual development and Wt1 knockout mice show regression of gonad anlagen. As a transcription factor, WT1 fulfills its function by regulating a set of target genes. With respect to gonad development only few in vivo WT1 targets, e.g. steroidogenic factor 1 (SF1) have been identified so far. To get a comprehensive view of WT1 targets in the gonad, we compared gene expression in urogenital ridges of wild-type and Wt1–/– embryos. We found almost 150 genes differentially expressed higher than factor three, using microarray analysis. To confirm these results we performed quantitative real-time RT-PCR for many genes and observed a high degree of concordance between microarray and real-time RT-PCR results. Employing in situ hybridization we found ‘WT1 activated genes’ to be expressed in gonads, mesonephroi and coelomic epithelium – those parts of the urogenital ridge with Wt1 expression. Interestingly, many of the differentially expressed genes are known to show sex-specific expression at later time-points. These results provide a basis for investigation of developmental pathways in the urogenital ridge downstream of WT1 and for identification of new candidate genes involved in early urogenital ridge development. For example we provide a first potential target of WT1 in the coelomic epithelium – Muc16, and a gene regulated by the WT1 target SF1 – Gata4.

Background A unilateral breast reduction procedure to mimic the contralateral breast poses a challenge to the plastic surgeon. All aspects of breast aesthetics are essential surgical considerations. The authors have used a vertical scar technique with glandular transposition of the nipple-areola complex. Methods In this series of patients, the larger of the asymmetrical breasts was reduced using a modified vertical scar breast reduction technique to simulate the shape and size of the smaller breast. Thirty-four patients are presented. Preoperative marking of the patient was modified to simulate the smaller breast, including measurements from the sternal notch to the nipple, to the midline of the submammary fold, the base of the breast, and the diameter of the nipple-areola complex. The mean resection weight was 282 g (range, 76 to 860 g) and the mean follow-up period was 15 months. A glanduloplasty was performed to simulate the shape of the contralateral breast. Results Thirty-one of the 34 patients reported that, overall, they were satisfied (91 percent) with the final shape of the breasts, symmetry, and the nature of the scars. Three patients were not entirely satisfied. Two of these requested further resection and one requested a minor scar revision because of persistent wrinkles in the submammary fold. Conclusions Adequate long-term breast symmetry was achieved as confirmed by a high patient satisfaction rate. Unilateral vertical scar breast reduction with glandular transposition of the nipple-areola has been a valuable method in selected cases of breast asymmetry.

Trimethylpsoralen (TMP) is often used to treat skin diseases (i.e., psoriasis, vitiligo, etc.). This drug permeates moderately the skin barrier. In the present study, we investigated the effect of formulation on the improvement of TMP skin bioavailability. Three formulations were performed. Each form (liposomes, nanospheres, and EtOH solution) contained 0.05% of TMP. For each preparation, the quantity deposited on the skin surface was 250 µg (Q0). The TMP percutaneous penetration through ex-vivo human skin was processed by Franz® cells (n=4) using a human albumin solution (1.4% w/v) as receiver medium. The percentages of the extracted TMP that permeated through the skin and that were retained in the skin over 24 h, were calculated with respect to Q0. The values obtained were reported, respectively, as follows: EtOH solution (1.33 vs. 0.08%), liposomes (0.93 vs. 0.93%), and PLG-nanospheres (0.79 vs. 3.01%). So, considering the correlation between the cumulated amounts of TMP permeated through the skin and the TMP stocked in the skin, the nanosphere form showed the higher quantity of TMP accumulated in the skin structures. On the other hand, the maximum value of the flux (ng/cm2/h) in the steady state of TMP incorporated in each formulation was at 6 h for all formulations: 173.5±1.06 (EtOH solution) > 120.4±1.06 (liposomes) > 93.82±0.88 (PLG-nanospheres). These results indicate that the controlled release of TMP by incorporation in PLG-nanospheres may increase drug content in the skin, while maintaining a minimal percutaneous absorption. Finally, this work shows that the PLG-nanospheres could constitute a promising approach for controlling TMP release in order to maintain its topical activity. Drug Dev. Res. 61:86–94, 2004. © 2004 Wiley-Liss, Inc.

Background: Reactive oxygen species generated by ultraviolet light result in photocarcinogenic and photoaging changes in the skin. Antioxidants protect the skin from these insults. Objective: The aim of this study was to determine the ex vivo ascorbic acid penetration and its degradation in the skin after its topical application from an 8% new formulation. Method: Ascorbic acid was applied to human skin fragments. Ascorbic acid and its metabolites were collected by microdialysis and assessed by gas chromatography mass spectrometry. Results: After topical application of the new formulation, the ascorbic acid level achieved was 8.5% higher than the normal tissue value. This high ascorbic acid dermal concentration remained constant if a topical application was made every 8 h. No degradation of ascorbic acid was detected. Conclusion: Ascorbic acid penetrates rapidly after its topical application. The persistent reservoir of ascorbic acid provides an important and attractive photoprotection strategy.

The purpose of the present study was to compare Franz cells (FC) and microdialysis (MD) for monitoring the skin absorption of salicylic acid (SA). The influence of pH on SA flux was also assessed by these two techniques. Excised abdominal human skin was used in the experiments. SA was dissolved in phosphate buffer solutions of pH 2, 5 and 7 (2 mg/ml). SA concentrations in the receptor FC solutions and in MD samples were assessed by high performance liquid chromatography (HPLC). The results demonstrate that the flux of SA decreased with increased pH. The profiles permeation determined by Franz cells and microdialysis were similar. However, whatever the pH, the SA flux was higher with microdialysis than with Franz cells. The results showed that SA percutaneous permeation conformed to the pH partition hypothesis. The flux of SA was different when it was determined by the two techniques. The collect of SA, by these two techniques is different. The results of the two techniques are compared and discussed.

TCP typically offers reasonable end-to-end performance to users regardless of the bandwidth and error characteristics of particular network technology. The robustness of TCP has contributed to its success in the Internet environment. The role of communications is already well established in the office environment. With the advent of cheap, affordable broadband communications and the increasing complexity of consumer goods, it seems natural to extend the network into homes. In-home networking means a high-speed communication among the digital appliances within a home. Introduction of application over high-speed home network using TCP/IP protocol is increasing. The integrated environment of Internet and home network is demanding as well. We have validated TCP model over high-speed home network environment, investigated the throughput behavior of TCP over IEEE 1394 home networks, and evaluated a potential solution for high performance of TCP over IEEE 1394 home networks. The simulation model has produced several interesting results in the performance of TCP over IEEE 1394 home network.

The retention of psoralen derivatives, i.e., 8‐methoxypsoralen (8‐MOP), 5‐methoxypsoralen (5‐MOP), and trimethylpsoralen (TMP) in high performance liquid chromatography (HPLC) was investigated using a C18 bond silica column, hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) as mobile phase additive (0–19 mM) and a wide range of column temperature (−5°C–55°C). Such a study was carried out to demonstrate the potential drug complexing role of this cyclodextrin for a future application in pharmaceutical formulation. Assuming a 1:1 stoichiometry, the association constants (K) were calculated from the chromatographic data. At a column temperature of −5°C, and in a 42% water–58% methanol (v/v) mixture, K was equal to 30, 75, and 40 M−1 for the 8‐MOP/, 5MOP/, and TMP/, HP‐β‐CD associations, respectively. The thermodynamic parameters of the complexes were determined from linear van't Hoff plots for the three complexes. From the enthalpy and entropy changes, it appeared that the recognition mechanism of HP‐β‐CD for 8...

Nowadays, the determination of human skin microtopography is usually carried out by methods based on mechanical techniques (profilometry and surfometry), or founded on optical conception (shadowing method and profilometry). Negative skin replicas made of a silicone rubber material (Silflo((R))) or positive casts performed from an epoxy resin (Araldite((R))), are used to assess the skin microstructure. Skin surface microtopography is quantified by measuring furrows depths and spaces between them. An original application using confocal scanning laser microscope (CLSM) is described in this paper. The CLSM gives simultaneously images of the skin surface associated with quantitative measurements of the microtopography. With this apparatus, it is easy to achieve perfect skin replica images with assessment of its microstructure, before and after applications of topical medicines or cosmetic products to evaluate the skin surface restoration. It is worth to mention that it is indispensable to analyse the same skin surface (same plateaux and same furrows). For this reason, it is necessary to localize exactly and to replicate the same skin surface area (4 mm(2)) before and after the cosmetic use, whatever the extended period of the topical application.

Methicillin-resistant Staphylococcus aureus (MRSA), a pathogen which has increased over the past three decades, is responsible for nosocomial infections and adverse patient outcomes. It is a pathogen of global importance. Rates of patient colonization or infection vary greatly internationally. Lower rates have been observed in Canada and Saudi Arabia compared to the United States and United Kingdom. Although these lower rates may appear reassuring, the trend in MRSA observed in two capital cities, Winnipeg, Canada and Riyadh, Saudi Arabia are consistent with a widespread global increase in MRSA.

The recent trend towards a more market-oriented global economy has reduced public support to commodity programs and led to a decline in buffer stocks of food grains in several cereal-exporting countries. Countries have to look for alternative means to stabilize prices and consumption particularly when carrying buffer stocks is expensive and self-sufficiency is economically inefficient. In today's market place, any country has the option of consuming food that is produced domestically or imported. This paper shows that trade and buffer stocks are two principal means to reconcile the conflicting realities of unstable harvests and stable consumption needs.

A graded-reflectivity-mirror (GRM) unstable resonator with low output coupling is described, where a custom-made optical phase element is used inside the resonator to provide maximally flat output. The phase element removes the dip in the output beam by pre-compensating the internal Gaussian mode. An experiment is performed with a flashlamp-pumped Nd:YAG laser. The resonator's magnification (M) and the GRM's central reflectivity (R/sub 0/) are 2.3 and 0.7, respectively. The large dip in the center of the output is removed using the custom-made phase element. This resonator has the advantage over a conventional GRM unstable resonator of being suitable for lower-gain laser media. The gain required to overcome fundamental mode cavity losses for maximally flat output is decreased from 22.3 (for a conventional GRM resonator) to 4.3 (for the resonator containing the phase element). This reduction in required gain comes with essentially no loss to the resonator modal discrimination.

Creating the right incentives towards increasing farmers' participation in crop insurance has been one of the major goals of the U.S. farm policy in recent years. Although insured acres increased in the 1990s, only one-third of farm producers participated in the crop insurance program. In addition, there exists high variation in the growth of insured acres and availability of crop insurance products across crops and geographical areas. In this article, we examine factors that influence farmers'

Ascorbic acid (AA) plays a significant role in preventing photobiological damage in human skin which could lead to cutaneous disorders such as premature aging or skin cancer. The aim of this work was to assess AA concentrations in human dermis by a microdialysis technique associated with gas chromatography-mass spectrometry (GC-MS). Due to the non-volatility of AA, it was necessary to derivatize this acid. Three methods, one methylation and two silylations, were validated and compared to determine the most sensitive. To validate the methods, calibration curves were plotted from AA concentrations ranging from 34 to 500 nmol mL−1. The calibration curves were linear with a good correlation coefficient ( r ≥ 0.99). Repeatability and reproducibility were significant with a coefficient of variation of less than 10%. The accuracy of the techniques was meaningful as the bias was low (ranging from −5.6 to 5.0%). According to our results, silylation was the most sensitive method to assess AA. Thus, this method was performed to determine AA concentrations in microdialysates. In order to study AA in human dermis, a microdialysis method was used to sample AA and the GC-MS technique used to assess this acid in the microdialysates. Microdialysis can only partially collect AA from human dermis. An ex vivo recovery of AA was 30 ± 2% ( n = 7). The average concentration of AA in microdialysates was 250 ± 66 nmol mL−1 (Mean ± SD, n = 5). In view of the AA recovery, AA concentrations in human skin ranged from 759 to 891 nmol mL−1.

A solid-state laser cavity is studied where the laser crystal aberrations are corrected by a diffractive optic element. The type of aberration and the location of the correction plate are found to significantly influence the modal performance of the cavity. The largest modal discrimination is obtained for axicon-like crystal aberrations and when the correction is performed close to the end mirror. An experiment is performed with a laser diode-pumped Nd:YVO/sub 4/ laser. With no correction, a thermal aberration of approximately two waves is measured across the crystal. By using a diffractive corrector plate, the single-mode slope efficiency is increased by a factor of 4, and the total single-mode output power is increased by a factor of 3.

We present an efficient distributed algorithm for constructing an Eulerian tour in a distributed environment. This algorithm requires (1+r)(|E|+|V|) messages and time units for constructing an Eulerian circuit, where |E| is the number of the communication links, |V| the number of the nodes in the underlying network graph, and [email protected]?r

This study examines the returns to U.S. agricultural research investments for the years 1930 through 1990 using a cointegration model. Time series data on agricultural productivity, public and private research investments, farmers’ education, terms of trade, and commodity programs were found to be nonstationary and cointegrated. The estimated internal rates of return are 27 percent for public research and 6 percent for private research. These estimates from the most comprehensive and timely data assembled to date indicate that returns to public agricultural research compare favorably to real returns on alternative long-run investments, but do not call for large increases in investments suggested by previous studies or for the drop in public research expenditures appropriated by the U.S. Congress in recent years.

The long-term impact of research, education, and various government support programs on U.S. agricultural productivity was analyzed using an error correction model. Results indicate that the proposed reduction in commodity program expenditures (e.g. 1996 Farm Bill) is unlikely to reduce agricultural productivity. Results suggest that shifting public funds from commodity programs to education and research would raise U.S. agricultural productivity. Our estimates of long-term rates of return to public research are lower than those from most previous, perhaps due to our improved model specification, but are high enough to justify continued public investments to raise productivity.

Few publications in the past have addressed specifically the effects of reduction mammaplasty in reducing symptoms associated with macromastia, and even fewer have surveyed patient satisfaction after reduction mammaplasty. This study investigates long-term results, morbidity, and patient satisfaction after reduction mammaplasty. A comprehensive questionnaire was sent to 296 patients who underwent reduction mammaplasty at Hamad Medical Corporation during the study period between January 1987 and December 1996. The response rate to the questionnaire was 55.4% on a single mailing. The charts of responding patients (164 patients) were reviewed retrospectively. The mean patient age at the time of surgery was 29.7 years, and the mean preoperative weight was 75.9 kg. Seventy-eight percent of respondents listed the relief of physical symptoms of large breasts as their primary motivation for surgery. An average of 1,037 g of tissue was resected per breast. Ninety-one percent of subjects realized improvement of symptoms and 65% were asymptomatic. The overall satisfaction rate was 67.6%, whereas 18.4% were dissatisfied and 14% were unsure. Minor complications that did not require further surgery were reported by 29% of subjects. Twenty-seven percent of respondents would have preferred to have more preoperative discussions with the surgeon, and 78% of subjects would recommend breast reduction to others.

The microdialysis method is extensively developed in neuropharmacological experiments. It is a non-invasive technique with promising applications in biological research. The aim of this work was to establish and to optimize a process to microdialyse chemicals. Three lipophilic molecules used in dermatology were tested: 5-methoxypsoralen (5-MOP), 8-methoxypsoralen (8-MOP) and trimethylpsoralen (TMP). These psoralens have the same basic chemical structure (furocoumarin). The different radical substitutions are responsible for their different lipophilicities. In this work, different microdialysis parameters were studied: the relative recovery and the equilibrium time in relation to the perfusion rate and to the drug lipophilicity. The equipment was composed of a CMA/100® microinjection pump, CMA/20® microdialysis probes (membrane length of 10 mm, cut off 20 and 100 kDa) and a CMA/140® microcollector. The perfusate was a phosphate buffer 0.06 M (pH 7.4). The psoralen dialysates were assessed by high performance liquid chromatography. The relative recovery of psoralens increased with the decreasing perfusion rates and with the drug lipophilicity. The equilibrium time decreased with the increasing perfusion rates. TMP was not detected under these experimental conditions. This work defines the optimal parameters for in vivo studies and shows the limit of this technique for the investigation of lipophilic drugs.

The purpose of this work was to assess the surface free energy (SFE) of bare and bile-salt-precontacted pellet surfaces of psoralens (lipophilic molecules). This study was carried out according to the approach of van Oss et al. to the solid-liquid interfacial free energy using the Lifshitz-van der Waals component, electron acceptor and electron donor parameters of the SFE. With the help of a hydraulic press, powders of 8-methoxypsoralen (8-MOP), 5-methoxypsoralen (5-MOP) and 4,5',8-trimethylpsoralen (TMP) were compacted sufficiently to obtain smooth and glossy disc surfaces. One set of pressed discs was used directly after preparation and another set was treated with a bile salt (sodium cholate/sodium deoxycholate mixture) aqueous solution of 0.1 mol l −1 for 2 h at 37°C before droplet deposition. The surface free energies of bare and bile-salt-treated discs were determined by advancing contact angles using polar (water and formamide) and apolar (diiodomethane) standard liquids. The measurements were carried out at 21.5 ± 1.5°C using a surgical microscope fitted with a slanted mirror and equipped with a video camera linked to a computer. In addition, the surface and interfacial tensions of a biphasic system of octanol and water in which psoralens were solubilized were measured using the De Nouy ring method. The results were correlated with the lipophilicity and solubility of these drugs. The data of contact angle values of psoralen bare surfaces indicated the hydrophobicity order 8-MOP γ s LW ) components corroborated this. 8-MOP showed the same acidic and basic values ( γ s AB = 6.5 mJm −2 , while γ s AB was equal to 1.8 and 0.4 mJm −2 for 5-MOP and TMP respectively. However, when the psoralens were treated with sodium cholate sodium deoxycholate ( NaC NaDC ) mixture, the presence of micelles on the surface modified the previous data by decreasing the contact angles with polar solvents and γ s LW . In contrast, the total surface free energy of all the psoralens increased, especially the electron onor component ( γ − ) and γ s AB . When comparing the three psoralens, 5-MOP behaved peculiarly as it had the lowest γ s − (29.5 mJm −2 ) and γ s AB (21.4 mJm −2 ). Theoretical explanations concerning the reactivity of the psoralens vis a vis standard liquids were assumed. The results of this work enabled us to understand qualitatively and quantitatively the types of interaction between the molecules of each studied psoralen and to predict their behaviour when they permeate through a given biological membrane (e.g. human skin). From this work the adsorption of bile salts on to the hydrophobic surface was confirmed for the psoralen case. This result could constitute the beginning of a physicochemical explanation of the digestion step for orally taken psoralens.

8-methoxypsoralen (8-MOP), 5-methoxypsoralen (5-MOP) and 4,5',8-trimethylpsoralen (TMP) are commonly used in PUVA therapy [psoralen (P) + ultraviolet light A (UVA) irradiation] to treat skin diseases such as psoriasis and vitiligo. In order to predict the choice of the suitable drug(s) for topical applications, with appropriate dosage, percutaneous permeation of the psoralens, in connection with their solubilities and partition coefficients in an octanol/water system, were investigated. The percutaneous penetration experiments were accomplished by the deposit of ethanolic psoralen solution onto human skin and epidermis fragments mounted on Franz cells. Six cells were employed for each psoralen solution and for the whole skin layer as well as for the epidermis. The diffused psoralens in the receptor solution (1.4%, of human serum albumin) were quantified by using high performance liquid chromatography. The solubilities and the partition coefficients (PC) were carried out in an octanol/water system, in triplicate by using spectrofluorimetry. The results demonstrated that cumulated permeated quantities (ng/cm2) over 24 h, across the whole skin and the epidermis were in the following order for the three psoralens: 8-MOP > 5-MOP > TMP. The lipophilicity, expressed via the log PC, was as follows: 1.93 +/- 0.01 (8-MOP), 2.00 +/- 0.01 (5-MOP) and 3.14 +/- 0.01 (TMP). It was inversely correlated with cumulated penetrated amounts over 24 h in both whole skin and epidermis. From these results, TMP could be predicted as the most convenient psoralen for topical applications, because of its weak penetrability. Considering the relationship between psoralens lipophilicity and permeation, only 5-MOP and 8-MOP could be used, topically or orally, especially in the case of generalised skin disorders.

Occlusion is recognised as an enhancer of percutaneous absorption. Some authors suggested that this effect is related to the molecular polarities of applied drugs. To verify this hypothesis, an in vitro study was performed to assess a topical absorption, under occlusion, in relation to the molecular polarity of three furanocoumarins: 5-methoxypsoralen (5-MOP), 8-methoxypsoralen (8-MOP) and trimethylpsoralen (TMP). These compounds present the same basic chemical structure but have different degrees of lipophilicity. They are commonly used, orally or topically, in conjunction with UVA irradiations to treat skin diseases such as psoriasis and vitiligo. Ethanolic solutions of the psoralens were deposited onto human abdominal skin fragments (6.3 μg/cm 2 ), mounted on Franz® diffusion cells ( n = 12), which were maintained at 37°C. Occlusion was retained by placing rubber corks on the top of Franz® cells ( n = 6). The receptor fluid was constituted with 1.4% of human serum albumin solution. At each sample point (2, 4, 6, 8, 12 and 24 h), the entire content of the receptor chamber was removed and replaced by fresh albumin solution. Psoralens quantities in the removed solutions were determined by HPLC. The lipophilicity of the psoralens was established via the partition coefficient in an octanol/water system: TMP > 5-MOP > 8-MOP. The outcome of the results illustrates that occlusion does not always have an enhancing effect in percutaneous absorption. Occlusion impact is influenced by the polarity of the drug. It increases the absorption of moderately lipophilic molecules (i.e. 8-MOP, 5-MOP) but is almost ineffective on the absorption rate of molecules highly lipophilic (i.e. TMP).

Domestic and international linkages in speculative stockholdings and trade of wheat are analyzed using a dynamic rational expectations model of the world wheat market dominated by the U.S. and the EU. The results demonstrate the importance of endogenizing both storage and trade in studying commodity markets and suggest that past government stockholdings have not followed efficient market outcomes. Results indicate that elimination of the Export Enhancement Program by the U.S. and of export restitution payments by the EU are unlikely to have a major impact on wheat exports from the two regions but will save millions of tax dollars in both regions. Copyright 1996, Oxford University Press.

The sulfaguanidine—water (SG-H2O) system is a binary system with non-negligible vapour pressure which presents a monohydrate. The phase diagram of this system is drawn from DTA experimental results, using the temperature-specific volume-molar fraction (T-v-x) model which was described in part I of this work.

This study views multilateral trade negotiations as a strategic game among nations or regions, including taxpayer, consumer, and producer components. Payoffs are calculated from an intermediate-run international trade model initialized with 1989 data. For the public at large, the Nash equilibrium and socially optimal outcome is liberalization of trade - unilateral or multilateral. Maintenance of the status quo of market distortions costing the world billions of dollars each year is rational only if producer payoffs are sovereign so that strategies optimal for producers are considered optimal for nations. Remedial policies are discussed, including opportunities for economic education, political system reform, and less incentives for producers to scuttle multilateral trade negotiations.

The binding of 5-methoxypsoralen (5-MOP) to human serum and blood fractions was studied by equilibrium dialysis associated to high-performance liquid chromatography. 5-MOP serum binding was 95% and kept constant in the range of therapeutic concentrations. Albumin was the main binding protein with one class of binding sites (n = 2.05) and with a moderate affinity constant (Ka = 10,270 M-1). Free fatty acids (FFA) enhanced 5-MOP binding to albumin. Binding to other proteins, α1-acid glycoprotein, gamma-globulins and lipoproteins (LDL, HDL, VLDL) also occurred, but was negligible. 5-MOP bound to red blood cells (RBCs) with a binding index (ratio of intra- to extra-globular 5-MOP concentrations) of 3.84 and 1.48 in buffer and plasma, respectively. 5-MOP distribution in blood was simulated. The free fraction of 5-MOP in blood could be increased in hypoalbuminemia, unchanged in acute inflammation, and decreased by FFA.

Citropten (5,7-dimethoxycoumarin) and bergapten (5-methoxypsoralen) are present in bergamot oil which is used as a tanning cosmetic product. The aim of this study was to quantify, using high-performance liquid chromatography, the amount of citropten and bergapten in the skin after suntan products application (an emulsion and an oil formulation). A suction blister technique performed of the anterior aspect of the forearm permitted the collection of these two accumulated molecules. Fluorometric and ultraviolet detections were used for citropten and bergapten determinations, respectively.

Citropten (5,7-dimethoxycoumarin) and bergapten (5-methoxypsoralen) are present in bergamot oil which is used as a cosmetic tanning product. The aim of this study was to quantify, using HPLC, the amount of citropten and bergapten in the skin after the application of suntan products (emulsion and oil formulations). A suction blister technique, performed on the volar aspect of the forearm, permitted the collection of these two molecules. The blister fluid concentrations were 37 and 51 ng/ml (emulsion) and 26 and 23 ng/ml (oil), respectively, for citropten and bergapten. Our results show that the suction blister technique could be used for comparing transepidermal penetration of several compounds in vivo in man.

We report on the pulse shape of an actively Q-switched fiber laser. This master oscillator power amplifier architecture generates pulses with multiple peaks due to its intrinsic dynamics. Modeling and experimental results provide us a detailed understanding of the relative importance of the different time constants on the dynamics of the laser, which allows us to define optimized design parameters that lead to smooth and controlled pulse shapes. This solution is simple and robust; operation over a broad range of repetition rate and output power is achieved without any adjustment of the laser settings, and the corresponding variation of the optical performances is minimal.

International audience; Concern is continuously raised about the safety of parabens which are present in most of the cosmetic preparations. In this investigation, methyl-, ethyl-, propyl- and butyl paraben (MP, EP, PP, BP), in a commercial cosmetic lotion, were deposited on human skin fragments, collected after surgical operations. Permeated parabens were determined after their passage through human epidermis-dermis layers, fixed on Franz diffusion cells. Bovine serum albumin (3%) was employed as receptor fluid. Then, parabens were assessed by liquid chromatography. The objective of this research was to determine the permeation of these molecules through human epidermis-dermis layers, and their possible passage to body tissues and/or accumulation in skin layers. Two groups of experiments were performed. In the first experimental group (G1), unique doses of the cosmetic were deposited on skin fragments fixed on Franz cells (n = 6), at time 0 h, followed with different withdrawn times of the receptor fluid at 12, 24 and 36 h. G1 results demonstrated that parabens penetration was influenced by their lipophilicity: more lipophilic the parabens were (BP > PP > EP > MP), less they crossed the skin layers (BP < PP < EP < MP). The second experimental group (G2) was constituted of three equal deposits on each Franz cell (n = 6) at different hour times 0, 12 and 24 h followed with three withdrawn times of the receptor fluid at 12, 24 and 36 h. The G2 results indicated that investigated parabens had significant increasing permeations in skin layers. This situation provokes the accumulation of these molecules which were considered by some authors as the cause of skin toxicities and carcinogenicity.