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1.
Phys Rev Lett ; 130(10): 101001, 2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36962014

RESUMO

Dark matter elastic scattering off nuclei can result in the excitation and ionization of the recoiling atom through the so-called Migdal effect. The energy deposition from the ionization electron adds to the energy deposited by the recoiling nuclear system and allows for the detection of interactions of sub-GeV/c^{2} mass dark matter. We present new constraints for sub-GeV/c^{2} dark matter using the dual-phase liquid argon time projection chamber of the DarkSide-50 experiment with an exposure of (12 306±184) kg d. The analysis is based on the ionization signal alone and significantly enhances the sensitivity of DarkSide-50, enabling sensitivity to dark matter with masses down to 40 MeV/c^{2}. Furthermore, it sets the most stringent upper limit on the spin independent dark matter nucleon cross section for masses below 3.6 GeV/c^{2}.

2.
Phys Rev Lett ; 130(10): 101002, 2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36962032

RESUMO

We present a search for dark matter particles with sub-GeV/c^{2} masses whose interactions have final state electrons using the DarkSide-50 experiment's (12 306±184) kg d low-radioactivity liquid argon exposure. By analyzing the ionization signals, we exclude new parameter space for the dark matter-electron cross section σ[over ¯]_{e}, the axioelectric coupling constant g_{Ae}, and the dark photon kinetic mixing parameter κ. We also set the first dark matter direct-detection constraints on the mixing angle |U_{e4}|^{2} for keV/c^{2} sterile neutrinos.

3.
J Drugs Dermatol ; 18(1): 86-91, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30681803

RESUMO

Background: Calcium hydroxylapatite (CaHA, Radiesse®) with integral 0.3% lidocaine (CaHA(+)) has recently been approved for use in aesthetic medicine. This study assessed the performance of CaHA(+) in subjects undergoing treatment for facial volume loss and evaluated subject and physician satisfaction. Methods: In a prospective, open-label, post-marketing study, 25 women seeking treatment for age-related facial volume loss received CaHA(+) injections in 1­3 facial areas including the cheeks, marionette lines, prejowl sulcus, and jawline. Subjects returned for follow-up at 14 and 120 days, with the option of touch-up injections at day 14 if required to achieve optimal correction. Filler performance was assessed using the Merz Aesthetics Scales (MAS) and subject satisfaction using the Global Impression of Change Scale (GICS). Physician satisfaction was assessed in terms of CaHA(+)-related properties (eg, ease of injection, distribution, positioning) and aesthetic outcomes. Adverse events were recorded. Results: Mean MAS scores at baseline were ~2 corresponding to moderate facial volume loss/sagging in the treated area. At day 14, the mean score had improved to ≤1.4 for all treated areas, indicating mild volume loss. At day 120, mean scores had further improved to ≤1.1. At both follow-up visits, mean GICS scores were ≥2 indicating facial appearance was 'much improved' compared with baseline. All subjects reported willingness to repeat treatment and recommend it to family/friends. Physician ratings were high for ease of CaHA(+) injection, distribution, positioning, sculpturing outcome, and effect on skin tension. Compared to CaHA without lidocaine, the physician rated CaHA(+) as better or similar in performance. Adverse events were mostly mild and expected with CaHA and filler injections in general. Conclusion: The well-established efficacy and safety profile of CaHA appears unchanged by the addition of integral lidocaine. CaHA(+) was effective for volume enhancement in a number of facial areas and associated with high subject and physician satisfaction. J Drugs Dermatol. 2019;18(1):86-91.


Assuntos
Anestésicos Locais/uso terapêutico , Preenchedores Dérmicos/uso terapêutico , Durapatita/uso terapêutico , Dermatoses Faciais/tratamento farmacológico , Lidocaína/uso terapêutico , Satisfação do Paciente , Envelhecimento da Pele , Adulto , Idoso , Anestésicos Locais/administração & dosagem , Anestésicos Locais/efeitos adversos , Anestésicos Locais/química , Preenchedores Dérmicos/administração & dosagem , Preenchedores Dérmicos/efeitos adversos , Preenchedores Dérmicos/química , Combinação de Medicamentos , Durapatita/administração & dosagem , Durapatita/efeitos adversos , Durapatita/química , Dermatoses Faciais/patologia , Feminino , Humanos , Injeções Subcutâneas , Lidocaína/administração & dosagem , Lidocaína/efeitos adversos , Lidocaína/química , Pessoa de Meia-Idade , Estudos Prospectivos , Inquéritos e Questionários , Resultado do Tratamento
4.
Phys Rev Lett ; 115(23): 231802, 2015 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-26684111

RESUMO

Borexino is a liquid scintillation detector located deep underground at the Laboratori Nazionali del Gran Sasso (LNGS, Italy). Thanks to the unmatched radio purity of the scintillator, and to the well understood detector response at low energy, a new limit on the stability of the electron for decay into a neutrino and a single monoenergetic photon was obtained. This new bound, τ≥6.6×10^{28} yr at 90% C.L., is 2 orders of magnitude better than the previous limit.

5.
J Drugs Dermatol ; 14(9): 948-54, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26355612

RESUMO

To assess the use and safety of calcium hydroxylapatite for volume restoration of the face and hands in clinical practice, subjects from four Italian aesthetic clinics who had received calcium hydroxylapatite augmentation treatment between January 2012 and December 2013 were recruited. Records were retrospectively reviewed for demographic characteristics, number of treatments, area treated, injection depth and volume, method of administration, and adverse events. A total of 1,783 treatments were administered to 800 subjects (female: 93.5%; mean age: 49.6 years). Overall, 620 (77.5%) subjects were treated over two sessions for a particular indication, and 243 (30.3%) treated over three sessions. The most frequently treated areas were the zygomatic area (men: 30.2%; women: 30.6% of all treatments), malar area (24.5% and 24.3%), and marionette lines (18.9% and 11.6%). A cannula was used for most treatments (86.7%). Injection volume ranged from 0.4 mL to 1.5 mL. Injection-site swelling and bruising occurred with 18.2% and 11.3% of treatments, respectively. Most cases resolved within one week and two weeks, respectively. No serious/unexpected adverse events occurred. In clinical practice, calcium hydroxylapatite is a versatile, well-tolerated treatment for filling folds and volume restoration of the face and hands.


Assuntos
Técnicas Cosméticas , Preenchedores Dérmicos/administração & dosagem , Durapatita/administração & dosagem , Envelhecimento da Pele , Adulto , Idoso , Idoso de 80 Anos ou mais , Catéteres , Contusões/etiologia , Preenchedores Dérmicos/efeitos adversos , Durapatita/efeitos adversos , Face , Feminino , Mãos , Humanos , Injeções/instrumentação , Injeções/métodos , Itália , Masculino , Pessoa de Meia-Idade , Agulhas , Estudos Retrospectivos , Adulto Jovem
6.
Phys Rev Lett ; 106(23): 236601, 2011 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-21770530

RESUMO

Evidence is presented for the finite wave vector crossing of the two lowest one-dimensional spin-split subbands in quantum point contacts fabricated from two-dimensional hole gases with strong spin-orbit interaction. This phenomenon offers an elegant explanation for the anomalous sign of the spin polarization filtered by a point contact, as observed in magnetic focusing experiments. Anticrossing is introduced by a magnetic field parallel to the channel or an asymmetric potential transverse to it. Controlling the magnitude of the spin splitting affords a novel mechanism for inverting the sign of the spin polarization.

7.
J Cosmet Dermatol ; 20 Suppl 2: 7-11, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34318989

RESUMO

BACKGROUND: In the evaluation of the facial aging, the midface certainly represents the part that undergoes the most modifications and in which the aging process is most evident. The filling and redefinition of this part are fundamental to modify the perception of the age of the face and create a global rejuvenation effect. In general, high G' fillers with a deep implant are used to treat the midface, taking advantage of the high lifting capacity and persistence of the implant in place. METHODS: We report our experience in the treatment of 20 patients with a hyaluronic acid (HA) filler based on an innovative crosslinking technology (XTR™-eXcellent Tridimensional Reticulation) for midface treatment. GAIS (Global Aesthetic Improvement Scale) at 1 month and 3 months after treatment was evaluated as primary endpoint. Patient satisfaction with the overall appearance, repeatability of treatment, and also an instrumental evaluation of the improvement were performed. RESULTS: Global Aesthetic Improvement Scale and patient satisfaction were very good 1 month and 3 months after treatment. The majority of patients said they would undergo treatment again. Clinical results were confirmed by instrumental evaluation. CONCLUSION: The treatment of midface with this innovative HA high G' filler is really effective in restoration of the volumes and in reshaping the curves of zygomatic area.


Assuntos
Técnicas Cosméticas , Preenchedores Dérmicos , Envelhecimento da Pele , Face , Humanos , Ácido Hialurônico , Satisfação do Paciente , Rejuvenescimento
9.
Anesthesiology ; 116(5): 1151, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21970885
10.
Lab Anim ; 41(4): 492-5, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17988443

RESUMO

The purpose of our study was to describe an efficient, reliable and inexpensive surgical method for cerebral venous blood gas sampling in acutely instrumented pigs in a research setting. Parameters from the blood samples are used to monitor brain perfusion and oxygenation in different animal models. To the authors' knowledge, this is the first detailed description of an accurate surgical technique for catheterization of the sagittal sinus in pigs.


Assuntos
Cateterismo/veterinária , Cavidades Cranianas/cirurgia , Sus scrofa/cirurgia , Animais , Gasometria , Cateterismo/métodos , Feminino , Sus scrofa/anatomia & histologia
11.
J Clin Aesthet Dermatol ; 10(9): 27-29, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29344324

RESUMO

BACKGROUND: IncobotulinumtoxinA is a botulinum neurotoxin type A that is free from complexing proteins and is used in various therapeutic indications and aesthetic medicine. It is approved for the treatment of glabellar frown lines in the United States. In Europe, it is also approved for the treatment of lateral periorbital lines (crow's feet) and for the combined treatment of upper facial lines, including glabellar frown lines, crow's feet, and horizontal forehead lines. METHODS: In the present study, incobotulinumtoxinA was injected at two different dilutions to treat female subjects aged 40 to 50 years who had moderate-to-severe lateral periorbital lines at maximum contraction according to a score of 2 or 3 points on the 5-point Merz Aesthetics Scales (MAS). For Group 1 (n=20), 50U of incobotulinumtoxinA were reconstituted with 1.60mL of 0.9% NaCI, and for Group 2 (n=20), a reconstitution volume of 0.55mL was used. RESULTS: Merz Aesthetics Scales scores were markedly improved by at least one point in both groups at one month and three months. The mean Merz Aesthetics Scales scores at one month were 0.4 and 0.6 points for Group 1 and Group 2, respectively, corresponding to a mean improvement of 2.0 and 1.8 points compared with baseline, respectively. CONCLUSION: No significant differences in efficacy and tolerability of incobotulinumtoxinA were seen between the two dilutions at any time point.

12.
Aquat Toxicol ; 73(2): 190-209, 2005 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-15917094

RESUMO

Microcosm studies unveil relevant information in ecotoxicology. However, statistical evaluation of data gained from the different parts of the ecosystem often remain on unsatisfying, discretely level, e.g. separately for different species communities. A combination of different multivariate statistical methods enables an ecological interpretation of the found changes in zoo- and phytoplankton abundances in connection with the physico-chemical variables. To investigate the effects of nonylphenol (NP) on plankton communities, NP was continuously applicated in microcosms by controlled release. Plankton taxa were identified and quantified, various physico-chemical variables were measured. Maximum NP concentration ranged between 29 and 129 microg/L. The most important abiotic variable explaining both zoo- and phytoplankton abundances was NP concentration. NP primarily inhibited Crustaceae, especially juveniles. Cladocera and Copepoda abundances decreased. Rotatoria tend to increase, probably due to a decline of competition and predator pressure. Shifts in phytoplankton structure occurred with a time lag. Aggregating phytoplankton on class level did not show NP effects, whereas aggregating them according to feeding protection strategies did. Thus NP influences phytoplankton at least prevailingly indirectly via zooplankton. Zooplankton shifts led to species composition with different feeding preferences and strategies. Thereby the feeding pressure on phytoplankton changed. NP reorganized the plankton interrelation. Whereas without NP phytoplankton composition was dominated by Rotatoria, in the NP treated microcosms the Crustaceae unveiled highest explanatory power. The found effects were reversible in all but the highest treated microcosm. There are indications that the found effects were caused by endocrine activity of the chemical. Iteratively combining multivariate statistical methods with ecological and toxicological knowledge proved to provide a deeper insight into the mode of ecosystem disturbance by toxic substances.


Assuntos
Ecossistema , Eucariotos/efeitos dos fármacos , Cadeia Alimentar , Invertebrados/efeitos dos fármacos , Fenóis/toxicidade , Plâncton/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Eucariotos/crescimento & desenvolvimento , Invertebrados/crescimento & desenvolvimento , Modelos Estatísticos , Análise Multivariada , Especificidade da Espécie
13.
Int J Parasitol ; 27(7): 855-9, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9279590

RESUMO

Levels of the cytokines IFN-gamma, IL-2, IL-3, IL-4 and IL-5 were monitored in cells from the mesenteric lymph nodes (MLN) of BALB/c mice infected with Hymenolepis diminuta after stimulation in vitro with Con-A. Infection was associated with an increased production of IL-3, IL-4 and IL-5 and a low production of IFN-gamma, indicating the preferential activation of a Th2 response. It is suggested that this reflects the purely lumenal development of this worm. The results are discussed in relation to effector mechanisms known to be involved in immunity to intestinal helminths.


Assuntos
Himenolepíase/imunologia , Interferon gama/biossíntese , Interleucinas/biossíntese , Animais , Feminino , Himenolepíase/parasitologia , Hymenolepis/isolamento & purificação , Interleucina-2/biossíntese , Interleucina-3/biossíntese , Interleucina-4/biossíntese , Interleucina-5/biossíntese , Linfonodos/imunologia , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Organismos Livres de Patógenos Específicos , Células Th2/imunologia
14.
Int J Parasitol ; 27(3): 321-7, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9138035

RESUMO

Analysis of cytokine production (IFN-gamma, IL-2, IL-3, IL-4, IL-5) by in vitro Con A-stimulated mesenteric lymph node cells measured daily after egg or cyst infection of mice with Hymenolepis nana showed that cytokine production varies during parasite development and between different host strains (BALB/c and C3H/He mice). Egg infection stimulates a rapid increase in IFN-gamma, independent of mouse strain. In addition, in BALB/c mice a Th2-like response (IL-4, IL-5 secretion) was stimulated 4-5 days p.i., when the parasites are thought to begin their lumenal phase. After infection with cysts significant increases in IFN-gamma, IL-2, IL-4 and IL-5 were observed at the time when autoinfection with eggs is thought to occur. The level of IFN-gamma paralleled that seen after a primary egg infection. This suggests that there is a predominantly Th1-type response during the tissue phase of H. nana development and that, in BALB/c mice, a Th2 polarization occurs during the first few days of the lumenal phase. The cytokine patterns observed are discussed in relation to host responses during chronic helminth infection.


Assuntos
Citocinas/biossíntese , Himenolepíase/imunologia , Hymenolepis/imunologia , Animais , Feminino , Hymenolepis/crescimento & desenvolvimento , Interferon gama/biossíntese , Interleucina-2/biossíntese , Interleucina-3/biossíntese , Interleucina-4/biossíntese , Interleucina-5/biossíntese , Larva/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Óvulo/imunologia , Células Th1/imunologia , Fatores de Tempo
15.
J Neurotrauma ; 21(6): 667-77, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15253795

RESUMO

The role of lipid peroxidation after brain injury is still not completely understood, and results of different studies have been equivocal. In this study, three proposed peroxidation markers were determined in patients early after isolated head injury and results compared to healthy controls. Malondialdehyde (MDA) and thiobarbituric acid-reactive substances (TBARS) were measured in plasma, and n-pentane was determined in patients' exhaled air. For MDA and TBARS no significant differences could be shown (0.267 vs. 0.358 ng/mL, and 0.896 vs. 0.814 ng/mL in patients vs. healthy volunteers, respectively). n-Pentane, however, was significantly increased in the expired air of patients (0.471 vs. 0.118 nmol/L in healthy volunteers). Similar results for n-pentane were obtained when only male patients and volunteers were considered (0.510 vs. 0.113 nmol/L). Stratification according to clinical outcome showed significantly higher values for n-pentane in male patients with poor outcome (0.656 nmol/L) in comparison with healthy male volunteers (0.113 nmol/L). No difference was found when patients were stratified according to the presence or absence of subarachnoid hemorrhage. It is concluded that, only in a sub-population of patients with brain injury, lipid-peroxidation is a crucial mechanism. n-Pentane seems to be a valuable marker to detect lipid peroxidation early after brain trauma. Malondialdehyde may be of value only later in the course of the disease. TBARS are not a specific marker and should therefore not be used.


Assuntos
Lesões Encefálicas/sangue , Peroxidação de Lipídeos/fisiologia , Malondialdeído/sangue , Pentanos/sangue , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Reação de Fase Aguda/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Estudos de Casos e Controles , Feminino , Humanos , Ventilação com Pressão Positiva Intermitente , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
16.
Expert Rev Mol Diagn ; 4(5): 619-29, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15347256

RESUMO

Breath tests are attractive since they are noninvasive and can be repeated frequently in the dynamically changing state of critically ill patients. Volatile organic compounds can be produced anywhere in the body and are transported via the bloodstream and exhaled through the lung. They can reflect physiologic or pathologic biochemical processes such as lipid peroxidation, liver disease, renal failure, allograft rejection, and dextrose or cholesterol metabolism. This review describes the diagnostic potential of endogenous organic volatile substances in the breath of critically ill patients. Since many of these patients require ventilatory support, aspects of breath analysis under mechanical ventilation will be addressed. Analytical procedures, problems concerning the physiologic meaning of breath markers and future developments will be discussed.


Assuntos
Biomarcadores/análise , Testes Respiratórios , Estado Terminal , Colesterol/metabolismo , Desenho de Equipamento , Rejeição de Enxerto , Humanos , Hidrocarbonetos/análise , Hidrocarbonetos/metabolismo , Peroxidação de Lipídeos , Hepatopatias/metabolismo , Modelos Teóricos , Insuficiência Renal/metabolismo , Respiração Artificial/instrumentação , Volatilização
17.
Clin Chim Acta ; 347(1-2): 25-39, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15313139

RESUMO

Breath analysis has attracted a considerable amount of scientific and clinical interest during the last decade. In contrast to NO, which is predominantly generated in the bronchial system, volatile organic compounds (VOCs) are mainly blood borne and therefore enable monitoring of different processes in the body. Exhaled ethane and pentane concentrations were elevated in inflammatory diseases. Acetone was linked to dextrose metabolism and lipolysis. Exhaled isoprene concentrations showed correlations with cholesterol biosynthesis. Exhaled levels of sulphur-containing compounds were elevated in liver failure and allograft rejection. Looking at a set of volatile markers may enable recognition and diagnosis of complex diseases such as lung or breast cancer. Due to technical problems of sampling and analysis and a lack of normalization and standardization, huge variations exist between results of different studies. This is among the main reasons why breath analysis could not yet been introduced into clinical practice. This review addresses the basic principles of breath analysis and the diagnostic potential of different volatile breath markers. Analytical procedures, issues concerning biochemistry and exhalation mechanisms of volatile substances, and future developments will be discussed.


Assuntos
Testes Respiratórios , Compostos Orgânicos/análise , Ar/análise , Biomarcadores/análise , Testes Respiratórios/métodos , Humanos
18.
Maturitas ; 27(2): 125-32, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9255747

RESUMO

OBJECTIVE: To assess urodynamic alterations in patients with varying degrees of cystocele but without prolapse of the uterus, rectocele and/or enterocele. PATIENTS AND METHODS: Between September 1993 and June 1995 we examined 83 patients with varying degrees of isolated cystocele. All subjects were questioned about their medical history and underwent urogynaecological examination and urodynamic tests. RESULTS AND CONCLUSIONS: In our study there were no cases of pure urge incontinence nor were there any normal urodynamic situations; genuine stress incontinence was the most frequent urinary disorder. Moreover patients with grade 3-4 cystocele on the Baden-Walker scale had more difficulty in voiding than subjects with milder forms of cystocele. In fact the maximum and average flow rates of the former tended to decrease, flow and voiding times were longer and acceleration of flow rate were significantly lower. The maximum urethral closure pressure tended to diminish with an increase in the duration of menopause, whereas the pressure transmission ratio tended to decline significantly with an increase in cystocele severity. In conclusion, even when cystocele is the only alteration in pelvic statics, it determines significant urodynamic changes that must be carefully assessed so as to optimize the choice, mode and time of surgical, rehabilitative or pharmacological intervention.


Assuntos
Doenças da Bexiga Urinária/fisiopatologia , Urodinâmica/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Menopausa/fisiologia , Pessoa de Meia-Idade , Prolapso , Estudos Prospectivos , Fatores de Risco , Doenças da Bexiga Urinária/complicações , Incontinência Urinária por Estresse/epidemiologia , Incontinência Urinária por Estresse/etiologia , Transtornos Urinários/epidemiologia , Transtornos Urinários/etiologia
19.
Environ Int ; 28(7): 633-8, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12504160

RESUMO

Single-species tests allow the assessment of chronical effects of endocrine disruptors on organisms under laboratory conditions. In the current study, three-generation tests with Ceriodaphnia reticulata and Sida crystallina were carried out to examine the influence of the synthetic hormone 17alpha-ethinylestradiol (EE) on the reproduction of these cladoceran species. For each species, six different concentrations (10-500 microg/l EE) and two controls were tested with eight replicates for a duration of 4 weeks. The test was initiated by transferring one neonate individual into a test vessel which was incubated under standardized conditions. Every 2 days, the medium was renewed and life history parameters such as survivorship of the adults and juveniles, clutch size, first appearance and number of produced offspring were investigated. Acute toxicity tests showed that C. reticulata (EC50 (24 h) 1814 microg/l) was more sensitive towards the substance compared to S. crystallina (EC50 (24 h) >4100 microg/l). The juvenile phase of S. crystallina was significantly shorter at concentrations above 100 microg/l EE. For C. reticulata, 17alpha-ethinylestradiol caused a higher mortality of the newly hatched juveniles at EE concentrations above 200 microg/l. No effects were found for mortality of adult animals, birth rate, number of juveniles per female and net reproduction rate of S. crystallina and C. reticulata. Thus, sublethal effects on parental generation exposed to EE lead to disturbances in reproduction and to affection of their offspring. Negative consequences for the population dynamic cannot be excluded, e.g. the decrease of a population.


Assuntos
Cladocera/fisiologia , Congêneres do Estradiol/efeitos adversos , Etinilestradiol/efeitos adversos , Reprodução/efeitos dos fármacos , Poluentes Químicos da Água/efeitos adversos , Animais , Animais Recém-Nascidos , Coeficiente de Natalidade , Feminino , Dose Letal Mediana , Masculino , Sobrevida
20.
Environ Toxicol Chem ; 23(5): 1268-75, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15180379

RESUMO

We investigated the effect of 4-nonylphenol (NP) on nematode communities in the sediment of freshwater microcosms. Seven treatments were dosed with various concentrations of NP over a period of six weeks by using a controlled-release method (NPI-NP7; maximum sediment concentrations: 0.29-3.37 mg/kg dry wt). Four microcosms were not exposed to NP and served as controls. Nematode communities were analyzed over a period of 15 weeks, including sampling dates before, within, and after the NP application. Communities were characterized in terms of total nematode abundance and species diversity (Shannon index and evenness), as well as composition of species, feeding types, and different life-history strategists (maturity index [MI]). Species composition was analyzed by using a multivariate method (principal response curves). Total nematode abundance and species diversity were not affected in any of the NP-treated microcosms. However, in the highest dosed treatment, NP-induced changes in the nematode communities occurred. Species and feeding types composition, as well as the MI, were affected in the postapplication period, with species composition being altered most clearly. In the highest dosed treatment, deposit-feeding species, classified as colonizers (Eumonhystera), increased in dominance, whereas epistrate feeders and chewers (Prodesmodora and Tobrilus) decreased in relative abundance compared to the control.


Assuntos
Nematoides/efeitos dos fármacos , Fenóis/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Contagem de Colônia Microbiana , Dieta , Ecossistema , Água Doce , Estágios do Ciclo de Vida/efeitos dos fármacos , Estágios do Ciclo de Vida/fisiologia , Análise Multivariada , Nematoides/fisiologia , Dinâmica Populacional , Maturidade Sexual/efeitos dos fármacos , Maturidade Sexual/fisiologia , Especificidade da Espécie , Fatores de Tempo
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