RESUMO
The present study employed data collected during the Mycosands survey to investigate the environmental factors influencing yeasts and molds distribution along European shores applying a species distribution modelling approach. Occurrence data were compared to climatic datasets (temperature, precipitation, and solar radiation), soil datasets (chemical and physical properties), and water datasets (temperature, salinity, and chlorophyll-a concentration) downloaded from web databases. Analyses were performed by MaxEnt software. Results suggested a different probability of distribution of yeasts and molds along European shores. Yeasts seem to tolerate low temperatures better during winter than molds and this reflects a higher suitability for the Northern European coasts. This difference is more evident considering suitability in waters. Both distributions of molds and yeasts are influenced by basic soil pH, probably because acidic soils are more favorable to bacterial growth. Soils with high nitrogen concentrations are not suitable for fungal growth, which, in contrast, are optimal for plant growth, favored by this environment. Finally, molds show affinity with soil rich in nickel and yeasts with soils rich in cadmium resulting in a distribution mainly at the mouths of European rivers or lagoons, where these metals accumulate in river sediments.
Assuntos
Rios , Poluentes do Solo , Rios/química , Solo/química , Cádmio/análise , Poluentes do Solo/análise , Metais/análise , Leveduras , Monitoramento AmbientalRESUMO
BACKGROUND: Lipid homeostasis is an evolutionarily conserved process that is crucial for energy production, storage and consumption. Drosophila larvae feed continuously to achieve the roughly 200-fold increase in size and accumulate sufficient reserves to provide all energy and nutrients necessary for the development of the adult fly. The mechanisms controlling this metabolic program are poorly understood. RESULTS: Herein we identified a highly conserved gene, orsai (osi), as a key player in lipid metabolism in Drosophila. Lack of osi function in the larval fat body, the regulatory hub of lipid homeostasis, reduces lipid reserves and energy output, evidenced by decreased ATP production and increased ROS levels. Metabolic defects due to reduced Orsai (Osi) in time trigger defective food-seeking behavior and lethality. Further, we demonstrate that downregulation of Lipase 3, a fat body-specific lipase involved in lipid catabolism in response to starvation, rescues the reduced lipid droplet size associated with defective orsai. Finally, we show that osi-related phenotypes are rescued through the expression of its human ortholog ETFRF1/LYRm5, known to modulate the entry of ß-oxidation products into the electron transport chain; moreover, knocking down electron transport flavoproteins EtfQ0 and walrus/ETFA rescues osi-related phenotypes, further supporting this mode of action. CONCLUSIONS: These findings suggest that Osi may act in concert with the ETF complex to coordinate lipid homeostasis in the fat body in response to stage-specific demands, supporting cellular functions that in turn result in an adaptive behavioral response.
Assuntos
Proteínas de Drosophila , Drosophila melanogaster , Metabolismo dos Lipídeos , Animais , Humanos , Trifosfato de Adenosina/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Corpo Adiposo/metabolismo , Flavoproteínas/metabolismo , Larva , Lipase/genética , Lipase/metabolismo , Metabolismo dos Lipídeos/genética , Lipídeos , Espécies Reativas de Oxigênio/metabolismoRESUMO
Transmission measurements through three-port microwave graphs are performed, in analogy to three-terminal voltage drop devices with orthogonal, unitary, and symplectic symmetry. The terminal used as a probe is symmetrically located between two chaotic subgraphs, and each graph is connected to one port, the input and the output, respectively. The analysis of the experimental data clearly exhibits the weak localization and antilocalization phenomena. We find a good agreement with theoretical predictions, provided that the effects of dissipation and imperfect coupling to the ports are taken into account.
RESUMO
Tinea capitis is seen world-wide among children up to 12 years. The most severe type is Kerion Celsi with painful abscesses and lymphadenopathy. We report on an 11-year-old boy with Kerion Celsi, who was initially treated using antibiotics under the common misdiagnosis of a bacterial infection. Mycological investigations could identify Microsporum canis. The patient was treated orally with griseofulvin, which resulted in complete mycological remission after 8 weeks. Cicatrical alopecia, however, could not be prevented. Purulent infections of the scalp should lead to early mycological diagnostics in children.
Assuntos
Microsporum , Tinha do Couro Cabeludo , Alopecia , Antifúngicos/uso terapêutico , Criança , Humanos , Masculino , Couro Cabeludo , Tinha do Couro Cabeludo/diagnóstico , Tinha do Couro Cabeludo/tratamento farmacológicoRESUMO
The goal of most studies published on sand contaminants is to gather and discuss knowledge to avoid faecal contamination of water by run-offs and tide-retractions. Other life forms in the sand, however, are seldom studied but always pointed out as relevant. The Mycosands initiative was created to generate data on fungi in beach sands and waters, of both coastal and freshwater inland bathing sites. A team of medical mycologists and water quality specialists explored the sand culturable mycobiota of 91 bathing sites, and water of 67 of these, spanning from the Atlantic to the Eastern Mediterranean coasts, including the Italian lakes and the Adriatic, Baltic, and Black Seas. Sydney (Australia) was also included in the study. Thirteen countries took part in the initiative. The present study considered several fungal parameters (all fungi, several species of the genus Aspergillus and Candida and the genera themselves, plus other yeasts, allergenic fungi, dematiaceous fungi and dermatophytes). The study considered four variables that the team expected would influence the results of the analytical parameters, such as coast or inland location, urban and non-urban sites, period of the year, geographical proximity and type of sediment. The genera most frequently found were Aspergillus spp., Candida spp., Fusarium spp. and Cryptococcus spp. both in sand and in water. A site-blind median was found to be 89 Colony-Forming Units (CFU) of fungi per gram of sand in coastal and inland freshwaters, with variability between 0 and 6400 CFU/g. For freshwater sites, that number was 201.7 CFU/g (0, 6400 CFU/g (p = 0.01)) and for coastal sites was 76.7 CFU/g (0, 3497.5 CFU/g). For coastal waters and all waters, the median was 0 CFU/ml (0, 1592 CFU/ml) and for freshwaters 6.7 (0, 310.0) CFU/ml (p < 0.001). The results advocate that beaches should be monitored for fungi for safer use and better management.
Assuntos
Praias , Areia , Austrália , Mar Negro , Fungos , Humanos , Itália , Microbiologia da ÁguaRESUMO
Malaria is a worldwide serious-threatening infectious disease caused by Plasmodium and the parasite resistance to antimalarial drugs has confirmed a significant obstacle to novel therapeutic antimalarial drugs. In this article, we assessed the antioxidant and anti-inflammatory activity of nanoparticles prepared from Indigofera oblongifolia extract (AgNPs) against the infection with Plasmodium chabaudi caused in mice spleen. AgNPs could significantly suppress the parasitaemia caused by the parasite to approximately 98% on day 7 postinfection with P. chabaudi and could improve the histopathological induced spleen damage. Also, AgNPs were able to increase the capsule thickness of the infected mice spleen. In addition, the AgNPs functioned as an antioxidant agent that affects the change in glutathione, nitric oxide and catalase levels in the spleen. Moreover spleen IL1ß, IL-6 and TNF-α-mRNA expression was regulated by AgNPs administration to the infected mice. These results indicated the anti-oxidant and the anti-inflammatory protective role of AgNPs against P. chabaudi-induced spleen injury.
Assuntos
Antioxidantes/farmacologia , Indigofera/metabolismo , Malária/tratamento farmacológico , Extratos Vegetais/farmacologia , Plasmodium chabaudi/efeitos dos fármacos , Prata/farmacologia , Animais , Catalase/metabolismo , Glutationa/metabolismo , Interleucina-1beta/análise , Interleucina-6/análise , Malária/parasitologia , Malária/patologia , Masculino , Nanopartículas Metálicas , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico/metabolismo , Parasitemia/tratamento farmacológico , Parasitemia/patologia , Baço/parasitologia , Fator de Necrose Tumoral alfa/análiseRESUMO
BACKGROUND: EUCAST has revised the definition of the susceptibility category I from 'Intermediate' to 'Susceptible, Increased exposure'. This implies that I can be used where the drug concentration at the site of infection is high, either because of dose escalation or through other means to ensure efficacy. Consequently, I is no longer used as a buffer zone to prevent technical factors from causing misclassifications and discrepancies in interpretations. Instead, an Area of Technical Uncertainty (ATU) has been introduced for MICs that cannot be categorized without additional information as a warning to the laboratory that decision on how to act has to be made. To implement these changes, the EUCAST-AFST (Subcommittee on Antifungal Susceptibility Testing) reviewed all, and revised some, clinical antifungal breakpoints. OBJECTIVES: The aim was to present an overview of the current antifungal breakpoints and supporting evidence behind the changes. SOURCES: This document is based on the ten recently updated EUCAST rationale documents, clinical breakpoint and breakpoint ECOFF documents. CONTENT: The following breakpoints (in mg/L) have been revised or established for Candida species: micafungin against C. albicans (ATU = 0.03); amphotericin B (S ≤/> R = 1/1), fluconazole (S ≤/> R = 2/4), itraconazole (S ≤/> R = 0.06/0.06), posaconazole (S ≤/> R = 0.06/0.06) and voriconazole (S ≤/> R = 0.06/0.25) against C. dubliniensis; fluconazole against C. glabrata (S ≤/> R = 0.001/16); and anidulafungin (S ≤/> R = 4/4) and micafungin (S ≤/> R = 2/2) against C. parapsilosis. For Aspergillus, new or revised breakpoints include itraconazole (ATU = 2) and isavuconazole against A. flavus (S ≤/> R = 1/2, ATU = 2); amphotericin B (S ≤/> R = 1/1), isavuconazole (S ≤ /> R = 1/2, ATU = 2), itraconazole (S ≤/> R = 1/1, ATU = 2), posaconazole (ATU = 0.25) and voriconazole (S ≤/> R = 1/1, ATU = 2) against A. fumigatus; itraconazole (S ≤/> R = 1/1, ATU = 2) and voriconazole (S ≤/> R = 1/1, ATU = 2) against A. nidulans; amphotericin B against A. niger (S ≤/> R = 1/1); and itraconazole (S ≤/> R = 1/1, ATU = 2) and posaconazole (ATU = 0.25) against A. terreus. IMPLICATIONS: EUCAST-AFST has released ten new documents summarizing existing and new breakpoints and MIC ranges for control strains. A failure to adopt the breakpoint changes may lead to misclassifications and suboptimal or inappropriate therapy of patients with fungal infections.
Assuntos
Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Candida/efeitos dos fármacos , Anfotericina B/farmacologia , Fluconazol/farmacologia , Itraconazol/farmacologia , Testes de Sensibilidade Microbiana , Guias de Prática Clínica como Assunto , Triazóis/farmacologia , Voriconazol/farmacologiaRESUMO
We study the voltage drop along three-terminal disordered wires in all transport regimes, from the ballistic to the localized regime. This is performed by measuring the voltage drop on one side of a one-dimensional disordered wire in a three-terminal setup as a function of disorder. Two models of disorder in the wire are considered: (i) the one-dimensional Anderson model with diagonal disorder and (ii) finite-width bulk-disordered waveguides. Based on the known ß dependence of the voltage drop distribution of the three-terminal chaotic case, ß being the Dyson symmetry index (ß=1, 2, and 4 for orthogonal, unitary, and symplectic symmetries, respectively), the analysis is extended to a continuous parameter ß>0 and uses the corresponding expression as a phenomenological one to reach the disordered phase. We show that our proposal encompasses all the transport regimes with ß depending linearly on the disorder strength.
RESUMO
Coherent transport phenomena are difficult to observe due to several sources of decoherence. For instance, in the electronic transport through quantum devices the thermal smearing and dephasing, the latter induced by inelastic scattering by phonons or impurities, destroy phase coherence. In other wave systems, the temperature and dephasing may not destroy the coherence and can then be used to observe the underlying wave behaviour of the coherent phenomena. Here, we observe coherent transmission of mechanical waves through a two-dimensional elastic Sinai billiard with two waveguides. The flexural-wave transmission, performed by non-contact means, shows the quantization when a new mode becomes open. These measurements agree with the theoretical predictions of the simplest model highlighting the universal character of the transmission fluctuations.
RESUMO
Lupeol exhibits anti-inflammatory effects; unfortunately it shows low water solubility. An alternative to overcome this is the development of nanomaterials. Several methods for nanomaterial production are available. One of them is emulsification/solvent-evaporation. The objective of the present work was to evaluate physical properties, transport and in vitro modulator effects on NF-κB of poly (lactide-co-glycolide) (PLGA) nanoparticles loaded with lupeol. Nanonutraceuticals were prepared with 16% (w/v) of lupeol. Size distribution and morphology were measured by particle size analyzer and TEM. In vitro release of lupeol was studied by three different models: Higuchi, Siepmann & Peppas, and Power law. Transport of nanonutraceutical was studied in a Caco-2 cell model and by GC-MS. Modulator effect on NK-κB was studied by western blot analysis. Nanonutraceuticals were 10% larger than the nanoparticles without lupeol (372 vs 337 nm) and presented a broader size distribution (0.28 vs 0.22). TEM results displayed spherical structures with a broader size distribution. Entrapment efficiency of lupeol was 64.54% and it in vitro release data fitted well to the Power law and Higuchi equation (R > 0.84-0.84). Strong regulation of NF-κB of nanonutraceutical was observed. It was not observed any transport across the Caco-2 cell model at the different experimental conditions.
Assuntos
Anti-Inflamatórios não Esteroides/metabolismo , Enterócitos/metabolismo , Absorção Intestinal , NF-kappa B/metabolismo , Nanopartículas/efeitos adversos , Triterpenos Pentacíclicos/metabolismo , Poliglactina 910/efeitos adversos , Transporte Ativo do Núcleo Celular , Algoritmos , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/análise , Anti-Inflamatórios não Esteroides/química , Células CACO-2 , Permeabilidade da Membrana Celular , Sobrevivência Celular , Fenômenos Químicos , Suplementos Nutricionais/análise , Emulsões , Humanos , Microscopia Eletrônica de Transmissão , NF-kappa B/agonistas , NF-kappa B/antagonistas & inibidores , Nanopartículas/química , Nanopartículas/ultraestrutura , Tamanho da Partícula , Triterpenos Pentacíclicos/administração & dosagem , Triterpenos Pentacíclicos/análise , Triterpenos Pentacíclicos/química , Poliglactina 910/química , Polivinil/química , Solubilidade , Tensoativos/químicaRESUMO
This is the first multi-centre study regarding yeast infections in Romania. The aim was to determine the aetiological spectrum and susceptibility pattern to fluconazole, voriconazole and the novel compound MXP-4509. The 551 isolates were identified using routine laboratory methods, matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) and DNA sequence analysis. Susceptibility testing was performed using the European Committee for Antimicrobial Susceptibility Testing (EUCAST) method and breakpoints. The yeasts originated from superficial infections (SUP, 51.5 %), bloodstream infections (BSI, 31.6 %) and deep-seated infections (DEEP, 16.9 %), from patients of all ages. Nine genera and 30 species were identified. The 20 Candida species accounted for 94.6 % of all isolates. C. albicans was the overall leading pathogen (50.5 %). Lodderomyces elongisporus is reported for the first time as a fungaemia cause in Europe. C. glabrata and Saccharomyces cerevisiae, as well as the non-Candida spp. and non-albicans Candida spp. groups, showed decreased fluconazole susceptibility (<75 %). The overall fluconazole resistance was 10.2 %. C. krusei accounted for 27 of the 56 fluconazole-resistant isolates. The overall voriconazole resistance was 2.5 % and was due mainly to C. glabrata and C. tropicalis isolates. Fluconazole resistance rates for the three categories of infection were similar to the overall value; voriconazole resistance rates differed: 4 % for BSI, 3.2 % for DEEP and 1.4 % for SUP. The antifungal activity of MXP-4509 was superior to voriconazole against C. glabrata and many fluconazole-resistant isolates. There was a large percentage of non-albicans Candida isolates. A large part of the high fluconazole resistance was not acquired but intrinsic, resulting from the high percentage of C. krusei.
Assuntos
Antifúngicos/farmacologia , Micoses/epidemiologia , Triazóis/farmacologia , Leveduras/efeitos dos fármacos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Candida/efeitos dos fármacos , Candida/isolamento & purificação , Criança , Pré-Escolar , Farmacorresistência Fúngica , Feminino , Fluconazol/farmacologia , Fungemia , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Micoses/microbiologia , Romênia/epidemiologia , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/isolamento & purificação , Voriconazol/farmacologia , Leveduras/isolamento & purificação , Adulto JovemRESUMO
UNLABELLED: Infections caused by bacterial species are common in immunocompromised patients and carry significant treatment costs and mortality. The emerging resistance of microorganisms to some synthetic antimicrobial agents makes it necessary to continue the research for new antimicrobial drugs. AIM: To design new sulphonamide compounds with potential antibacterial and antioxidant activity. MATERIAL AND METHODS: New N-hydrazino acetyl-sulphonamides were prepared by condensation of some sulphonamides with chloroacetyl chloride and amination of intermediate compounds with hydrazine hydrate. RESULTS: The synthesized compounds were screened for their antibacterial activity against Gram positive (Klebsiellapneumoniae. Proteus vulgaris, Citrobacter freundii, Enterobacter cloacae, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis) and Gram negative bacterial strains (Pseudomonas aeruginosa, Escherichia coli). Some of them were found to have good antibacterial activity. The antioxidant activity of these compounds was also tested using different methods: total antioxidant capacity, reducing power, and DPPH radical scavenging activity. CONCLUSIONS: Chemical modulations performed on sulphonamide structure have a good influence on the biological activity of the synthesized compounds, especially on their antioxidant effects.
Assuntos
Acetatos/química , Anti-Infecciosos/síntese química , Antioxidantes/síntese química , Hidrazinas/síntese química , Solventes/química , Sulfonamidas/síntese química , Aminação , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Hidrazinas/química , Hidrazinas/farmacologia , Testes de Sensibilidade Microbiana , Sulfonamidas/química , Sulfonamidas/farmacologiaRESUMO
We study the scattering of waves in systems with losses or gains simulated by imaginary potentials. This is done for a complex delta potential that corresponds to a spatially localized absorption or amplification. In the Argand plane the scattering matrix moves on a circle C centered on the real axis, but not at the origin, that is tangent to the unit circle. From the numerical simulations it is concluded that the distribution of the scattering matrix, when measured from the center of the circle C, agrees with the nonunitary Poisson kernel. This result is also obtained analytically by extending the analyticity condition, of unitary scattering matrices, to the no-unitary ones. We use this nonunitary Poisson kernel to obtain the distribution of nonunitary scattering matrices when measured from the origin of the Argand plane. The obtained marginal distributions have excellent agreement with the numerical results.
Assuntos
Algoritmos , Transferência de Energia , Modelos Teóricos , Reologia/métodos , Simulação por ComputadorRESUMO
We show that the key transport states, insulating and conducting, of large regular networks of scatterers can be described generically by negative and zero Lyapunov exponents, respectively, of Möbius maps that relate the scattering matrix of systems with successive sizes. The conductive phase is represented by weakly chaotic attractors that have been linked with anomalous transport and ergodicity breaking. Our conclusions, verified for serial as well as parallel stub and ring structures, reveal that mesoscopic behavior results from a drastic reduction of degrees of freedom.
RESUMO
By nature, defensive behavior is risky. In social insects, such behavior is more likely to occur in individuals whose potential for other tasks is diminished. We show that workers of the termite Neocapritermes taracua develop an exceptional two-component suicidal apparatus consisting of copper-containing protein crystals, stored in external pouches, and internal salivary glands. During aggressive encounters, their bodies rupture, and the crystals react with the salivary gland secretion to produce a toxic droplet. Both the amount of defensive substances and the readiness to explode increase with workers' age, as their food-collecting ability declines.
Assuntos
Comportamento Animal , Proteínas de Insetos/química , Isópteros/fisiologia , Agressão , Envelhecimento , Animais , Cobre/análise , Cristalização , Glândulas Exócrinas/anatomia & histologia , Glândulas Exócrinas/química , Glândulas Exócrinas/fisiologia , Isópteros/anatomia & histologia , Isópteros/química , Glândulas Salivares/metabolismoRESUMO
We exhibit a remarkable equivalence between the dynamics of an intermittent nonlinear map and the electronic transport properties (obtained via the scattering matrix) of a crystal defined on a double Cayley tree. This strict analogy reveals in detail the nature of the mobility edge normally studied near (not at) the metal-insulator transition in electronic systems. We provide an analytical expression for the conductance as a function of the system size that at the transition obeys a q-exponential form. This manifests as power-law decay or few and far between large spike oscillations according to different kinds of boundary conditions.
Assuntos
Algoritmos , Manufaturas , Modelos Químicos , Dinâmica não Linear , Simulação por Computador , Transporte de ElétronsRESUMO
SCOPE: Genital infections represent one of the most important causes of infertility, affecting: fallopian tubes, endometrial mucosa, sperm parameters. The aim of this study is to evaluate the involvement of four sexually transmitted infections (STD) in the achievement of infertility and to establish the prevalence of each infectious agent in our patients. METHODS: We analyzed the presence of Chlamydia trachomatis (CT) antigen, Ureaplasma urealyticum (UU), Mycoplasma hominis (MH) and Neisseria gonorrhoeae (NG) in the endocervical secretions and Chlamydia trachomatis antibodies IgA, IgG, IgM in the serum of 125 infertile women as well as in 30 pregnant women in the 3rd trimester of pregnancy, as a control group. RESULTS. In infertile women, the prevalence rate of the four bacterial markers was: CT antigen 1/125 (0.80%), CT IgG antibodies 19/125 (15.20%), MH 6/125 (4.80%), UU 51/125 (40.80%) and NG 1/125 (0.8%). From the control group, none was positive for CT antigen, but 1/30 (3.33% of patients) was positive for CT IgA while the prevalence rate for MH and UU were 16.66% and 43.33% respectively. CONCLUSIONS: We couldn't prove any association between genital MH/UU and infertility as the prevalence was higher in the control group than in the cases, but the correlation of the CT infection with the infertility was clearly shown. However, it is necessary to perform routine tests to screen for CT, NG, UU and MH among infertile patients. The positivity for CT IgG is a marker better correlated with fallopian tube obstruction than the CT antigen.
Assuntos
Infecções Bacterianas/epidemiologia , Infertilidade Feminina/epidemiologia , Infertilidade Feminina/microbiologia , Adulto , Infecções Bacterianas/microbiologia , Feminino , Humanos , Romênia/epidemiologia , Estudos SoroepidemiológicosRESUMO
We derive an exact formula to calculate the absorption strength in absorbing chaotic systems such as microwave cavities or acoustic resonators. The formula allows us to estimate the absorption strength as a function of the averaged reflection coefficient and the real coupling parameter. We also define the weak and strong absorption regimes in terms of the coupling parameter and the absorption strength.
RESUMO
Worldwide, vaginal candidosis represents a significant health problem in women of childbearing age. The aim of this paper is to evaluate under in vitro conditions resembling the vaginal microenvironment, the antifungal activity of a new propiconazole derivative against 64 strains of yeast species isolated from vulvovaginitis. The tests exhibited low MICs for all strains and this finding may be useful in using of this new azole compound for treatment of mycotic vaginitis.
Assuntos
Antifúngicos/farmacologia , Candida/classificação , Candida/efeitos dos fármacos , Candidíase Vulvovaginal/tratamento farmacológico , Triazóis/farmacologia , Algoritmos , Antifúngicos/uso terapêutico , Candida/isolamento & purificação , Feminino , Humanos , Técnicas In Vitro , Testes de Sensibilidade Microbiana , Resultado do Tratamento , Triazóis/uso terapêutico , Leveduras/classificação , Leveduras/efeitos dos fármacosRESUMO
We propose a model to describe the statistical properties of wave scattering through a classically chaotic cavity in the presence of surface absorption. Experimentally, surface absorption could be realized by attaching an "absorbing patch" to the inner wall of the cavity. In our model, the cavity is connected to the outside by a waveguide with N open modes (or channels), while an experimental patch is simulated by an "absorbing mirror" attached to the inside wall of the cavity; the mirror, consisting of a waveguide that supports N(a) channels, with absorption inside and a perfectly reflecting wall at its end, is described by a subunitary scattering matrix S(a). The number of channels N(a) , as a measure of the geometric cross section of the mirror, and the lack of unitarity P(a) = [symbol: see text]N(a) - S(a)(+)S(a) , as a measure of absorption, are under our control: these parameters have an important physical significance for real experiments. The absorption strength in the cavity is quantified by gamma(a) = tr P(a). The statistical distribution of the resulting S matrix for N = 1 open channel and only one absorbing channel, N(a) = 1, is solved analytically for the orthogonal and unitary universality classes, beta = 1 and beta = 2, respectively, and the results are compared with those arising from numerical simulations. The relation with other models existing in the literature, in some of which absorption has a volumetric character, is also studied.