Single-Pixel Near-Infrared 3D Image Reconstruction in Outdoor Conditions.

In the last decade, the vision systems have improved their capabilities to capture 3D images in bad weather scenarios. Currently, there exist several techniques for image acquisition in foggy or rainy scenarios that use infrared (IR) sensors. Due to the reduced light scattering at the IR spectra it is possible to discriminate the objects in a scene compared with the images obtained in the visible spectrum. Therefore, in this work, we proposed 3D image generation in foggy conditions using the single-pixel imaging (SPI) active illumination approach in combination with the Time-of-Flight technique (ToF) at 1550 nm wavelength. For the generation of 3D images, we make use of space-filling projection with compressed sensing (CS-SRCNN) and depth information based on ToF. To evaluate the performance, the vision system included a designed test chamber to simulate different fog and background illumination environments and calculate the parameters related to image quality.

Quantitative phase imaging with increased spatial coherence based on Fourier filtering.

This Letter reports a method for tuning the degree of spatial coherence in an optical microscope. The method employs an amplitude spatial light modulator (aSLM) placed in the Fourier plane of the microscope. The aSLM displays a set of binary filters that blocks specific frequencies of the Fourier spectrum of the complex object field. It is shown that numerical processing of these filtered fields provides a final intensity with increased spatial coherence. Coherence tuning is used in a new hybrid phase reconstruction algorithm that employs the transport of intensity equation and an iterative phase retrieval technique. It is validated experimentally that this hybrid approach is able to retrieve the phase information with high resolution, and effective artifact noise suppression when employing at minimum two symmetrical defocused intensities and large sources.

[Experience in treating mucoceles in Primary Care]. / Experiencia en el tratamiento de los mucoceles en atención primaria.

Several cases of mucocele have been treated in our Primary Health Care centre. These are benign lesions, relatively frequent (2.5/1000), which is caused by a retention of mucous from the minor salivary glands into the oral cavity, mainly at the level of the lower lip. The experience in their treatment in this centre is presented, along with a review of the literature to see if our treatment was correct.

Multi-filter transport of intensity equation solver with equalized noise sensitivity.

Phase retrieval based on the Transport of Intensity Equation (TIE) has shown to be a powerful tool to obtain the phase of complex fields. Recently, it has been proven that the performance of TIE techniques can be improved when using unequally spaced measurement planes. In this paper, an algorithm is presented that recovers accurately the phase of a complex objects from a set of intensity measurements obtained at unequal plane separations. This technique employs multiple band-pass filters in the frequency domain of the axial derivative and uses these specific frequency bands for the calculation of the final phase. This provides highest accuracy for TIE based phase recovery giving minimal phase error for a given set of measurement planes. Moreover, because each of these band-pass filters has a distinct sensitivity to noise, a new plane selection strategy is derived that equalizes the error contribution of all frequency bands. It is shown that this new separation strategy allows controlling the final error of the retrieved phase without using a priori information of the object. This is an advantage compared to previous optimum phase retrieval techniques. In order to show the stability and robustness of this new technique, we present the numerical simulations.

Wear Fast, Die Young: More Worn Teeth and Shorter Lives in Iberian Compared to Scottish Red Deer.

Teeth in Cervidae are permanent structures that are not replaceable or repairable; consequently their rate of wear, due to the grinding effect of food and dental attrition, affects their duration and can determine an animal's lifespan. Tooth wear is also a useful indicator of accumulative life energy investment in intake and mastication and their interactions with diet. Little is known regarding how natural and sexual selection operate on dental structures within a species in contrasting environments and how these relate to life history traits to explain differences in population rates of tooth wear and longevity. We hypothesised that populations under harsh environmental conditions should be selected for more hypsodont teeth while sexual selection may maintain similar sex differences within different populations. We investigated the patterns of tooth wear in males and females of Iberian red deer (Cervus elaphus hispanicus) in Southern Spain and Scottish red deer (C. e. scoticus) across Scotland, that occur in very different environments, using 10343 samples from legal hunting activities. We found higher rates of both incisor and molar wear in the Spanish compared to Scottish populations. However, Scottish red deer had larger incisors at emergence than Iberian red deer, whilst molars emerged at a similar size in both populations and sexes. Iberian and Scottish males had earlier tooth depletion than females, in support of a similar sexual selection process in both populations. However, whilst average lifespan for Iberian males was 4 years shorter than that for Iberian females and Scottish males, Scottish males only showed a reduction of 1 year in average lifespan with respect to Scottish females. More worn molars were associated with larger mandibles in both populations, suggesting that higher intake and/or greater investment in food comminution may have favoured increased body growth, before later loss of tooth efficiency due to severe wear. These results illustrate how independent selection in both subspecies, that diverged 11,700 years BP, has resulted in the evolution of different longevity, although sexual selection has maintained a similar pattern of relative sex differences in tooth depletion. This study opens interesting questions on optimal allocation in life history trade-offs and the independent evolution of allopatric populations.

Non-tuberculous mycobacteria in wild boar (Sus scrofa) from Southern Spain: epidemiological, clinical and diagnostic concerns.

Non-tuberculous mycobacteria (NTM) are widely distributed in the environment, particularly in wet soil, marshland, rivers or streams, but also are causative agents of a wide variety of infections in animals and humans. Little information is available regarding the NTM prevalence in wildlife and their effects or significance in the bovine tuberculosis (bTB) epidemiology and diagnosis. This research shows the most frequently NTM isolated in lymph nodes of wild boar (Sus scrofa) from southern Spain, relating the NTM presence with the individual characteristics, the management of animals and the possible misdiagnosis of Mycobacterium bovis in concurrent infections. A total of 219 NTM isolates were obtained from 1249 wild boar mandibular lymph nodes sampled between 2007 and 2011. All but 75 isolates were identified by the PCR-restriction analysis-hsp65, and a partial sequencing of the 16S rDNA was carried out to identify the rest of the isolates. Results showed that Mycobacterium chelonae was the most frequently isolated NTM specie (133 isolates, 60.7%), followed by Mycobacterium avium (24 isolates, 11%). No relation was found regarding sex, body condition and management, but M. chelonae was more frequently detected in adults, whereas M. avium was more prevalent in subadults. The high NTM prevalence observed in the studied wild boar populations could make difficult the bTB diagnostic.

Optimum plane selection for transport-of-intensity-equation-based solvers.

Deterministic single beam phase retrieval techniques based on the transport of intensity equation (TIE) use the axial intensity derivative obtained from a series of intensities recorded along the propagation axis as an input to the TIE-based solver. The common belief is that, when reducing the error present in the axial intensity derivative, there will be minimal error in the retrieved phase. Thus, reported optimization schemes of measurement condition focuses on the minimization of error in the axial intensity derivative. As it is shown in this contribution, this assumption is not correct and leads to underestimating the value of plane separation, which increases the phase retrieval errors and sensitivity to noise of the TIE-based measurement system. Therefore, in this paper, a detailed analysis that shows the existence of an optimal separation that minimizes the error in the retrieved phase for a given TIE-based solver is carried out. The developed model is used to derive analytical expressions that provide an optimal plane separation for a given number of planes and level of noise for the case of equidistant plane separation. The obtained results are derived for the widely used Fourier-transform-based TIE solver, but it is shown that they can also be applied to multigrid-based techniques.

Optimum measurement criteria for the axial derivative intensity used in transport of intensity-equation-based solvers.

For several years, scientific, industrial, and biological fields have benefited from knowledge of phase information, which allows for the revealing of hidden features of various objects. An alternative to interferometry is single-beam phase retrieval techniques that are based on the transport of intensity equation, which describes the relation between the axial derivative of the intensity and the phase distribution for a given plane in the Fresnel region. The estimation of the axial intensity derivative is obtained from a series of intensity measurements, where the accuracy is subject to an optimum separation between the measurement planes depending on the number of planes, the level of noise, and the actual object phase distribution. In this Letter, a quantitative analysis of the error in estimated axial derivative is carried out and a model is reported that describes the interdependence between these parameters. The results of this work allow for estimation of the optimum separation between measurement planes with minimal error in the axial derivative.

Influence of porcine circovirus type 2 infections on bovine tuberculosis in wild boar populations.

The wild boar is an important reservoir of bovine tuberculosis (bTB) in south-western Spain. Some risk factors such as wild boar density or age have been associated with the presence of high prevalences of bTB in wild boar. However, the influence of other risk factors such as co-infections with other pathogens has not yet been studied. This work aims to assess the influence of porcine circovirus type 2 (PCV-2) infection on bTB prevalence and bTB lesional patterns observed in wild boar. The presence of bTB-like lesions was evaluated in 551 hunted wild boar from 11 different game estates in south-western Spain, with a known history of bTB. Tuberculosis prevalences in each estate were calculated based on the percentage of animals found with bTB-like lesions. The percentage of animals with generalized bTB lesional patterns (bTB lesions in more than one organ) was also assessed. The prevalence of PCV-2 was studied in each estate using a specific PCR assay. The relationship between PCV-2 and bTB prevalences and between PCV-2 infections and the presence of generalized lesional patterns in wild boar were analysed. A statistical relationship between the prevalences of bTB and PCV-2 was found, with bTB prevalences being higher in estates where prevalences of PCV-2 were high. On the other hand, animals infected with PCV-2 were more likely to develop a generalized lesional pattern. Porcine circovirus type 2 prevalences seem to be associated with prevalences of bTB in wild boar. PCV-2 infection may aggravate the development and severity of bTB, favouring the presence of generalized lesional patterns and raising the risk of contagion in these estates. The implementation of sanitary measures that focus on the control of PCV-2 infection may be necessary as a preliminary measure in bTB control programmes for wild boar.

Acanthamoeba castellanii: in vitro UAH-T17c3 trophozoite growth study in different culture media.

Acanthamoeba is one of the most common free-living amoebae. It is widespread in the environment and can infect humans, causing diseases such as keratitis and encephalitis. In this study, we used a strain of Acanthamoeba castellanii (UAH-T17c3) isolated from cooling towers, and we evaluated the efficiency of three different culture media in its growth, with the aim of selecting one which allowed better growth, was easier to prepare, and was able to keep the trophozoites by long periods of time. We compared the growth of A. castellanii in peptone-yeast extract-glucose (PYG, the most commonly used medium to grow this strain) to the growth in PYG-Bactocasitone (PYG with 2% Bactocasitone) and brain-heart infusion broth (BHI is a standard microbiological medium rarely used in the culture of amoebae). Flow cytometry and cell count results showed all three media allowed the growth of trophozoites. PYG-Bactocasitone was shown to be the best for long-term culture. The BHI and PYG-Bactocasitone media have not been used for Acanthamoeba spp. trophozoite growth. In view of the results, we can affirm that these media are adequate to grow the above-mentioned strain for in vitro screening assays.

Management practices and their association with Mycobacterium tuberculosis complex prevalence in red deer populations in Southwestern Spain.

Intensification of game management may increase the prevalence of tuberculosis (TB) in wildlife despite eradication programs implemented in cattle herds in the same areas. In this cross-sectional study, we investigated the association between wild game management practices and the presence of tuberculosis in red deer populations in Southwestern Spain. Five hundred and fifty-one animals were examined by necropsy to detect tuberculosis-like lesions in the main lymph nodes. Prevalence, as determined by TB-like lesions, was estimated to be 5.1% of animals, with 77% of TB-like lesions confirmed by PCR. Our results suggest that population density, in addition to factors which promote the local aggregation of animals, is factors associated with increased prevalence of TB in red deer populations. We suggest that management practices including supplementary feeding, fencing, water ponds and interaction with domestic livestock should be revised in order to prevent TB in wild deer both.

Female-biased dispersal under conditions of low male mating competition in a polygynous mammal.

Sex-biased dispersal is a common phenomenon in birds and mammals. Competition for mates has been argued to be an important selective pressure favouring dispersal. Sexual differences in the level of intrasexual competition may produce asymmetries in the costs-benefits balance of dispersal and philopatry for males and females, which may favour male-biased dispersal in polygynous species such as most mammals. This being the case, condition-dependent dispersal predicts that male-bias should decrease if mating competition relaxes. We test this expectation for red deer, where male-biased dispersal is the norm. In southwestern Spain, red deer populations located in nonfenced hunting estates presented altered structures with sex ratio strongly biased to females and high proportion of young males. As a consequence, mate competition in these populations was lower than in other, most typical red deer populations. We found that, under such conditions of altered population structure, dispersal was female-biased rather than male-biased. Additionally, mate competition positively related to male dispersal but negatively to female dispersal. Other factors such as resource competition, age of individuals and sex ratio were not related to male or female dispersal. Males may not disperse if intrasexual competition is low and then females may disperse as a response to male philopatry. We propose hypotheses related to female mate choice to explain female dispersal under male philopatry. The shift of the sex-biased dispersal pattern along the gradient of mate competition highlights its condition-dependence as well as the interaction between male and female dispersal in the evolution of sex-biased dispersal.

Parents' genetic dissimilarity and offspring sex in a polygynous mammal.

Offspring quality may benefit from genetic dissimilarity between parents. However, genetic dissimilarity may trade-off with additive genetic benefits. We hypothesized that when sexual selection produces sex-specific selective scenarios, the relative benefits of additive genetic vs. dissimilarity may differ for sons and daughters. Here we study a sample of 666 red deer (Cervus elaphus) microsatellite genotypes, including males, females and their foetuses, from 20 wild populations in Spain (the main analyses are based on 241 different foetuses and 190 mother-foetus pairs). We found that parental lineages were more dissimilar in daughters than in sons. On average, every mother was less related to her mate than to the sample of fathers in the population when producing daughters not sons. Male foetuses conceived early in the rutting season were much more inbred than any other foetuses. These differences maintained through gestation length, ruling out intrauterine mortality as a cause for the results, and indicating that the potential mechanism producing the association between parents' dissimilarity and offspring sex should operate close to mating or conception time. Our findings highlight the relevance of considering the sex of offspring when studying genetic similarity between parents.

Polygyny can increase rather than decrease genetic diversity contributed by males relative to females: evidence from red deer.

Polygyny is expected to erode genetic variability by reducing the diversity of genetic contribution of males to the next generation, although empirical evidence shows that genetic variability in polygynous populations is not lost as rapidly as expected. We used microsatellite markers to study the genetic variability transmitted by mothers and fathers to offspring during a reproductive season in wild populations of a polygynous mammal, the red deer. Contrary to expectations, we found that males contributed more genetic diversity than females. Also, we compared study populations with different degrees of polygyny to find that polygyny was not related to a decrease in genetic diversity contributed by males. On the contrary, when population genetic diversity was relatively low, polygyny associated with higher genetic diversity of paternal lineage. Our results show that sexual selection, by favouring heterozygote individuals, may compensate the potential reduction of effective population size caused by polygyny, thus contributing to explain why genetic diversity is not depleted in polygynous systems.

[Suitability of the use of low-molecular-weight heparins in the prevention of venous thromboembolism]. / Adecuación de la utilización de heparinas de bajo peso molecular en la prevención de la enfermedad tromboembólica venosa.

OBJECTIVE: To investigate the prevalence of low-molecular-weight heparin (LMWH) prescription in venous thromboembolism prophylaxis in a general hospital and the suitability of the recommendations from the clinical practice guidelines. METHOD: A descriptive, observational and cross-sectional study of the indication-prescription type, carried out on patients admitted to medical departments and for surgery. RESULTS: 345 patients were included. The prevalence of HBPM use was 44.6% (95% CI, 39.3-50.1). Depending on the risk of thromboembolism, the decision to treat prophylactically (or not) was appropriate in 261 cases (75.7%; 95% CI, 70.7-80.1), and the action guidelines were not suitable for the remainder of patients. 55 patients (15.9%; 95% CI, 12.2-20.2) presented a high risk and were not prescribed prophylactically (underuse); and 29 patients (8.4%; 95% CI, 5.7-11.8) at low risk were treated prophylactically (overuse). There was a relationship between the appropriateness of the prescription and the type of patient (p<0.01). In the group of medical patients the prevalence of prescription was 22.6% (95% CI, 16.9-29.1) and only 33.3% of patients with a high to moderate risk of thromboembolism received prophylaxis. The prevalence of prescription in general surgery was 84.2% and 91.3% in traumatology. CONCLUSIONS: The degree of prophylaxis is adequate in surgical patients, but there was a significant percentage of medical patients with a high to moderate risk who did not receive suitable prophylaxis (underuse), despite recommendations with scientific and professional backing.

Seroprevalencia de anticuerpos contra el virus de hepatitis C (VHC) en trabajadoras sexuales que acuden a un Centro de Referencia de Infecciones de Transmisión Sexual (CERITSS) de la ciudad de Iquitos, Perú / Seroprevalence of antibodies against hepatitis C virus in Female sex workers patients from the sexually transmitted Infections Reference Center in Iquitos, Peru

Introducción: los principales factores de riesgo descritos para contraer la infección por el virus de la hepatitis C (VHC) son antecedentes de transfusión sanguínea y uso de droga endovenosa; el riesgo por transmisión sexual es controversial. Existen pocos estudios de VHC en trabajadoras sexuales (TS) en el Perú, encontrando bajas prevalencias de VHC (0-1%). El presente estudio se ha realizado en Iquitos, una ciudad en la selva peruana, en donde existe gran comercio sexual y la prevalencia de HIV/SIDA y otras Infecciones de Transmisión Sexual (ITS) es alta. Objetivo: determinar la seroprevalencia de anticuerpos contra el VHC en TS de la ciudad de Iquitos atendidas en un Centro Especializado de Referencia de Infecciones de transmisión sexual (CERITSS) e identificar los factores de riesgo asociados a esta. Material y métodos: es un estudio de corte transversal en TS quienes acudieron a su control periódico al CERITSS San Juan entre mayo 2003 a enero 2004. Una encuesta clínica-epidemiológica fue utilizada para determinar la frecuencia de factores de riesgo para adquirir la infección por VHC. Para determinar la presencia de anticuerpos contra el VHC, se utilizó la prueba de enzima inmunoensayo (EIA); todos los resultados positivos fueron confirmados con la prueba inmunoblot recombinante (RIBA). Resultados: cuatro de las 200 TS enroladas en el estudio fueron positivos para la prueba EIA, todas ellas tuvieron resultados positivos de RIBA (prevalencia de 2%, IC95% 0,06-3,94%). Estas 4 TS reportaron ser naturales de Iquitos, tener mas de 5 años de trabajo sexual, reportaron un bajo uso de condón (<50%). Tres de ellas reportaron haber tenido mas de 9 parejas/ día, realizar trabajo sexual bajo efecto del alcohol y tener sexo anal frecuentemente. Ninguna refirió transfusiones sanguíneas, antecedente de tatuajes o uso de drogas endovenosas. Solo una de las 4 VHC positivas tuvo serología positiva para sífilis co-existentemente y ninguna para VIH. Una de las 200 TS enroladas tuvo infección por VIH. Conclusiones: la seroprevalencia de anticuerpos contra el VHC en TS es mayor que la reportada en poblaciones similares en otras ciudades del Perú. Esta población se caracterizó por tener una conducta sexual de alto riesgo y no tener antecedentes de transfusión sanguínea ni consumo de droga endovenosa.

Introducction: the principal described risk factors to contract the hepatitis C virus (HCV) are blood transfusion antecedents and intravenous drug use; sexual transmission risk is controversial. In Peru there exist few studies whose female sex worker (FSW) HCV prevalence oscillates between 0-1%. The present study is based in Iquitos, a Peruvian jungle city with high sexual commerce and HIV/AIDS prevalence. Objetive: determine the HCV serological prevalence in Iquitos FSWs attending the STI/ HIV specialist center (CERITSS) and identify associated risk factors. Material and methods: cross-sectional study in FSWs who attended periodic San Juan CERITSS examinations from May 2003 to January 2004. Epidemical questionnaires where used to evaluate the risk factors. To determine HCV antibodies presence, the immunoassay enzyme (EIA) positive results were confirmed by the recombinant immunoblot assay (RIBA) test. Results: 4/200 FSWs enrolled in the study were EIA test positive; all had confirmed positive RIBA results, representing 2%(95%IC 0,06%-3,94%) prevalence. the 4 FSWs referred to be were born in Iquitos, to having been a sex worker for five years and stated condom use was <50%. Three to having had 9 sexual clients daily; to heavy alcohol consumption and to frequent anal sex . None declared intravenous drug use; having had tattoos and blood transfusions. Only one of 4 HCV positives had syphilis serology and none had HIV infections. 1/200 was diagnosed with HIV. Conclusion: the antibody against HCV seroprevalence in Iquitos FSWs is greater than reported in similar populations or the general population of other Peruvian cities. This population was characterized by having high risk sexual behavior and no blood transfusion antecedent nor intravenous drug user.

Molecular characterisation of Trypanosoma rangeli strains isolated from Rhodnius ecuadoriensis in Peru, R. colombiensis in Colombia and R. pallescens in Panama, supports a co-evolutionary association between parasites and vectors.

We present data on the molecular characterisation of strains of Trypanosoma rangeli isolated from naturally infected Rhodnius ecuadoriensis in Peru, from Rhodnius colombiensis, Rhodnius pallescens and Rhodnius prolixus in Colombia, and from Rhodnius pallescens in Panama. Strain characterisation involved a duplex PCR with S35/S36/KP1L primers. Mini-exon gene analysis was also carried out using TrINT-1/TrINT-2 oligonucleotides. kDNA and mini-exon amplification indicated dimorphism within both DNA sequences: (i) KP1, KP2 and KP3 or (ii) KP2 and KP3 products for kDNA, and 380 bp or 340 bp products for the mini-exon. All T. rangeli strains isolated from R. prolixus presented KP1, KP2 and KP3 products with the 340 bp mini-exon product. By contrast, all T. rangeli strains isolated from R. ecuadoriensis, R. pallescens and R. colombiensis, presented profiles with KP2 and KP3 kDNA products and the 380 bp mini-exon product. Combined with other studies, these results provide evidence of co-evolution of T. rangeli strains associated with different Rhodnius species groups east and west of the Andean mountains.

Phylogeography of roe deer (Capreolus capreolus) populations: the effects of historical genetic subdivisions and recent nonequilibrium dynamics.

We sequenced 704 mitochondrial DNA (mtDNA) control-region nucleotides and genotyped 11 autosomal microsatellites (STR) in 617 European roe deer (Capreolus capreolus) samples, aiming to infer the species' phylogeographical structure. The mtDNA sequences were split in three distinct haplogroups, respectively, named: Clade West, sampled mainly in Iberia; Clade East, sampled mainly in Greece and in the Balkans; and Clade Central, which was widespread throughout Europe, including the eastern countries and Iberia, but not Greece. These clades might have originated in distinct Iberian and Balkanic refuges during the penultimate or the last glaciations. Clades East and West contributed little to the current postglacial mtDNA diversity in central Europe, which apparently was recolonized mainly by haplotypes belonging to Clade Central. A unique subclade within Clade Central grouped all the haplotypes sampled from populations of the Italian subspecies C. c. italicus. In contrast, haplotypes sampled in central and southern Spain joined both Clade Central and Clade West, suggesting that subspecies C. c. garganta has admixed origin. STR data support a genetic distinction of peripheral populations in north Iberia and southern Italy, and show the effects of anthropogenic disturbance in fragmented populations, which were recently reintroduced or restocked and not may be in mutation-drift equilibrium. Roe deer in central Europe are mainly admixed, while peripheral populations in north Portugal, the southern Italian Apennines and Greece represent the remains of refugial populations and should be managed accordingly.

[The efficiency and cost-utility ratio of interferon beta in the treatment of multiple sclerosis in Andalusia]. / Eficiencia y relación coste-utilidad del interferón beta en la esclerosis múltiple en Andalucía.

INTRODUCTION: The availability of the interferon beta in its three forms at the moment available in our country and of glatiramer acetate has marked a point of flexion in the natural history of multiple sclerosis (MS), but the high cost of these treatments cause that its use is questioned. In this work we have studied the effectiveness and efficiency of the processing with interferon beta, and the cost-utility of these treatments in MS in Spain has been also analyzed. PATIENTS AND METHODS: For this work we studied 102 patients affected of RR MS, treated with the three interferons beta which we have available in our country. We used as control 330 patients who had participated in the pivotal clinical interferon trials with both interferon beta 1a. In these patients in addition to effectiveness data, we have studied the disability measured as area below curve and the quality of life (AVACs). We also calculated the economical costs, considering the relation cost-utility in our country. RESULTS: Besides to confirm the data of effectiveness of three interferons, in this study a saving of 23 days/year is demonstrated what corresponds to 0.063 AVACs. The additional cost of interferons is greater than the avoided cost until the fifth year of treatment in which the tendency is reversed in favor of the group of treated patients, if we assume that the same effectiveness that we found in the first years is maintained in the long term. CONCLUSION: The use of the treatment with interferon beta is justified by its effectiveness, efficacy and efficiency. The additional cost of the treatment will be compensated in the long term if the effectiveness of the interferon beta is maintained.

Adsorptive stripping voltammetric determination of cefepime at the mercury electrode in human urine and cerebrospinal fluid, and differential pulse polarographic determination in serum.

The cephalosporin cefepime has been studied by adsorptive stripping voltammetric on the hanging mercury drop electrode, followed by linear sweep voltammetry (staircase). The adsorptive stripping response was evaluated with respect to preconcentration dependence and other variables. The drug is strongly adsorbed in acid media, with maximum adsorption at pH 5.8. The detection limit found was 4.8 x 10(-10) M, with 120-s preconcentration. The relative standard deviation at the 10(-7) M level was 0.93%. This method was applied to the determination of cefepime in human urine and cerebrospinal fluid. Differential pulse polarography has been applied to determination in human serum.