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2.
Nat Ecol Evol ; 3(9): 1321-1330, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31477849

RESUMEN

Climate change vulnerability depends on whether organisms can disperse rapidly enough to keep pace with shifting temperatures and find suitable habitat along the way. Here, we develop a method to examine where and for which species shifting isotherms will outpace species dispersal using stream networks of the southern Appalachian Mountains (United States) and their highly speciose and endemic fish fauna as a model system. By exploring alternative tributary and mainstem dispersal pathways, we identify tributaries as slow-climate-velocity pathways along which some fish can successfully disperse and thus keep pace with climate change. Despite accessibility and thermal suitability, non-temperature habitat conditions in tributaries are unsuitable for some dispersing species, thus probably precluding establishment of persistent populations. Our findings demonstrate a trade-off shaping the efficacy of thermal refugia that depends on species-specific habitat associations and reveal individual-level dispersal behaviour, body size and stream network geometry as general correlates of climate change vulnerability.


Asunto(s)
Cambio Climático , Ríos , Animales , Ecosistema , Peces , Refugio de Fauna
3.
Ecotoxicol Environ Saf ; 161: 392-396, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29902619

RESUMEN

Isopods are macrodecomposers in terrestrial ecosystems, contributing to soil organic matter breakdown and nutrient cycling. They have been considered sensitive in laboratory tests designed to evaluate contaminants effects and are considered likely candidates to have a standardized protocol for ecotoxicity tests. For this purpose, a reference substance should be proposed as positive control in laboratory tests. This work aimed to evaluate the avoidance behaviour of the isopod species Porcellio dilatatus to boric acid (H3BO3; BA). Interlaboratory comparison tests were carried out based on the ISO guideline for earthworms, using tropical artificial soil as substrate, in the concentrations of 0, 125, 250, 500, 750, 1000, 1300 and 1800 mg BA kg-1 soil. Avoidance behaviour was evaluated in group (six organisms per replicate) and in individual tests (one organism per replicate), in dual-section plastic boxes, which received control soil (not contaminated) in one side and tested soil (with BA) in another one. The percentage of organisms in each side was recorded after 48 h, and data were analysed using Fisher exact test (p < 0.05) and t-test. Results showed significant avoidance response in individual tests at 250 mg kg-1 and in group tests at 500 mg kg-1. Limited habitat function (< 20% of organisms) for both tests and laboratories were observed at the highest tested concentration of 1800 mg kg-1, indicating the low sensitivity of this species to BA in avoidance tests, if compared to other substances in literature. Results showed that BA can be used as reference substance until a better option will be proposed.


Asunto(s)
Reacción de Prevención , Ácidos Bóricos/farmacología , Isópodos/efectos de los fármacos , Animales , Crustáceos , Estándares de Referencia , Suelo , Contaminantes del Suelo
4.
Chem Commun (Camb) ; 52(35): 5977-80, 2016 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-27058367

RESUMEN

A novel [2]catenane was synthesised by ring-closing metathesis from a Ca-bisphosphate template. The resulting interlocked structure features two chiral 1,1'-binaphthyl-phosphates, leading to a bifunctional catenane structure. Initial binding studies point at the applicability of such mechanically interlocked bisphosphates as artificial receptors for dicationic guest molecules.

5.
Z Gastroenterol ; 53(11): 1255-60, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26562399

RESUMEN

OBJECTIVE: There are just a few reports on Color Doppler Ultrasound-guided PTBD with and without metal stent implantation by endoscopic control. Ultrasound guidance facilitates percutaneous bile duct access and avoids severe adverse events. Internal biliary drainage rate in PTBD should be as high as possible as endoscopic ultrasound-guided cholangiodrainage (EUCD) offers internal drainage regularly. We report our prospective study analyzing success, internal drainage and adverse event rates. MATERIALS AND METHODS: Between June 2009 and November 2014 overall 63 PTBDs were performed prospectively in 37 patients (18 m, 19f; age on average: 72 years) with benign (9 %) and malignant (91 %) bile duct obstruction. Ultrasound was used in combination with fluoroscopic guidance. Whenever possible, primary or early secondary metal stent implantation via PTBD by endoscopic control was performed as a one step-procedure. RESULTS: 38 of 41 (93 %) initial PTBDs (in four patients PTBD was performed twice) were successful. 22 of 63 PTBDs were follow-up examinations with different interventions. In 34 of 38 successful (89 %) PTBDs, an internal drainage (or metal stent) was implanted. 12 metal stent implantations via PTBD were performed under endoscopic control. Just 2 (5 %) permanent external drainages were inserted. In 63 performed PTBDs 5 (7.9 %) early major adverse events (no severe intrahepatic bleeding) were documented and treated without any procedure related death. When metal stent implantation was performed via PTBD no adverse event was documented. CONCLUSION: Color Doppler guided PTBD is an effective and safe method for biliary drainage avoiding severe adverse events. Primary or early secondary metal stent implantation via PTBD reduces complication risks additionally. Endoscopic control of stent implantation via PTBD is helpful for optimal stent placement.


Asunto(s)
Colestasis/diagnóstico por imagen , Colestasis/cirugía , Drenaje/métodos , Endoscopía del Sistema Digestivo/métodos , Cirugía Asistida por Computador/métodos , Ultrasonografía Doppler en Color/métodos , Anciano , Anciano de 80 o más Años , Terapia Combinada/instrumentación , Terapia Combinada/métodos , Femenino , Humanos , Masculino , Metales , Persona de Mediana Edad , Estudios Prospectivos , Stents , Cirugía Asistida por Computador/instrumentación , Resultado del Tratamiento
6.
Dalton Trans ; 44(25): 11669, 2015 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-26067586

RESUMEN

Correction for 'Iminoborylene complexes: evaluation of synthetic routes towards BN-allenylidenes and unexpected reactivity towards carbodiimides' by J. Niemeyer et al., Dalton Trans., 2015, DOI: 10.1039/c5dt00131e.

7.
Dalton Trans ; 44(25): 11294-305, 2015 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-25710128

RESUMEN

The synthetic and reaction chemistries of cationic iminoborylene complexes [LnM=B=N=CR2](+), which feature a unique heterocumulene structure, have been systematically investigated. Precursors of the type CpFe(CO)2B(Cl)NCAr2 (Ar = p-Tol/Mes, 5c/d) have been generated by B-centred substitution chemistry using CpFe(CO)2BCl2 and suitable lithiated ketimines - a reaction which is found to be highly sensitive to the steric bulk at both the metal fragment and the ketimino group. Carbonyl/phosphine exchange (using PCy3 or PPh3), followed by halide abstraction allows for the generation of the cationic iminoborylenes [CpFe(PR3)(CO)(BNCAr2)](+)[BAr(X)4](-) (R = Cy, Ar = p-Tol/Mes, 12c/d; R = Ph, Ar = Mes, 13d; Ar(X) = 3,5-X2C6H3 where X = Cl, CF3) which have been characterized spectroscopically and by X-ray crystallography. The reactivity of these iminoborylene systems towards a range of nucleophiles and unsaturated substrates has been investigated. The latter includes the first examples of M=B metathesis reactivity with a carbodiimide, and results in Fe=B cleavage and formation of the isonitrile complexes [CpFe(PCy3)(CO)(CNR)](+)[BAr(Cl)4](-) (R = (i)Pr/Cy, 16/17).

8.
Z Gastroenterol ; 51(3): 290-5, 2013 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-23487358

RESUMEN

BACKGROUND: After the first case publication using the term "autoimmune pancreatitis" in 1995 and the successful treatment with steroids we now can distinguish between two clinical und histopathological forms of autoimmune pancreatitis. Type 1 autoimmune pancreatitis (AIP) is usually part of an IgG4-related systemic disease. AIP Typ 2 is an IgG4-independent pancreatic disease. For both entities pancreas cancer is the most important differential diagnosis. CASE REPORT: We report the case of an 82-year-old male patient who primarily presented with obstructive jaundice. Computed tomography (CT) revealed the typical image of a small cancer of the head of the pancreas with pulmonary metastases. After endoscopic drainage of the bile duct a CT-guided biopsy of a pulmonary nodule was performed in which cancer was ruled out. Next the patient was treated with steroids because of "tumour-associated cachexia". In the follow-up the mass in the head of the pancreas like the lung nodules had surprisingly disappeared. In the complete work-up the immune histochemical staining of the lung biopsy revealed subsequently a typical IgG4-associated inflammation. After termination of the therapy the disease relapsed as sclerosing cholangitis. CONCLUSION: The IgG4-related systemic disease with AIP can present as cancer of the pancreas with lung metastases. Extrapancreatic IgG4-positive histopathology and response to therapy with steroids can help to diagnose the disease in complex clinical presentations.


Asunto(s)
Enfermedades Autoinmunes/diagnóstico , Deficiencia de IgA/diagnóstico , Neoplasias Pulmonares/diagnóstico , Neoplasias Pancreáticas/diagnóstico , Pancreatitis/diagnóstico , Anciano de 80 o más Años , Enfermedades Autoinmunes/complicaciones , Diagnóstico Diferencial , Humanos , Deficiencia de IgA/complicaciones , Neoplasias Pulmonares/secundario , Masculino , Neoplasias Pancreáticas/complicaciones , Pancreatitis/complicaciones
9.
Ecotoxicol Environ Saf ; 86: 188-97, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23079741

RESUMEN

Ecological parameters (soil invertebrates, microbial activity, and plant community) were assessed in a metal contaminated site in an abandoned lead smelter and non-contaminated reference sites, as part of an ecological risk assessment (ERA). Vegetation cover inside the smelter area was lower and presented a more homogenous species composition than outside. A more simplified and less abundant vegetation community within the smelter area also simplified the habitat conditions, which in addition to metal toxicity, impaired the soil microbial and faunal communities. A significant reduction in the feeding activity was observed within the smelter area. Also a significant change in community composition of surface dwelling invertebrates was observed at those sites when compared to sites outside the smelter area. Moreover, basal respiration, microbial biomass C, dehydrogenase and phosphatase activity also decreased in several of these points under the smelter area. As a result, a significant impairment of organic material decomposition in the most contaminated sites was observed. Metal contamination affected the ecological status of the site, leading to a risk for ecosystem functioning and provisioning of ecosystem services like organic matter decomposition and nutrient cycling, even 17 years after the end of smelting activities. Regarding the sensitivity of the ecological parameters assessed, most were able to distinguish sites within the smelter area boundaries from those outside. However, only bait lamina (feeding activity), basal respiration and microbial biomass carbon presented high capacity to distinguish the level of soil contamination, since they were significantly correlated with metal loadings, and thus are promising candidates to be integrated in the Ecological Line of Evidence of an ERA.


Asunto(s)
Bacterias/efectos de los fármacos , Ecosistema , Invertebrados/efectos de los fármacos , Metales/toxicidad , Plantas/efectos de los fármacos , Contaminantes del Suelo/toxicidad , Animales , Biomasa , Metales/análisis , Suelo/química , Microbiología del Suelo , Contaminantes del Suelo/análisis , Clima Tropical
10.
J Perinatol ; 31(4): 251-7, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21233796

RESUMEN

OBJECTIVE: Strategies to reduce Retinopathy of Prematurity (ROP) have focused primarily on respiratory management. Hyperglycemia (HG) and insulin use, risk factors for adult diabetic retinopathy, as well as growth rates may be modifiable variables useful to reduce ROP. STUDY DESIGN: This was a retrospective chart review of all infants born at <30 weeks gestation from 2003 to 2007 who survived to discharge in our neonatal intensive care unit (NICU). All whole-blood glucose values (BG in mg dl(-1)) done in the first 29 days of life were collected for analysis. RESULT: BGs were done at least every 3 to 6 h for the first 48 to 96 h of life, then every 6 to 24 h thereafter, as long as infants remained on hyperalimentation. Hyperglycemia was defined as mild (BG 151 to 180), moderate (181 to 210) or severe (>210). Insulin use (given if BG>180 to 210) was also noted for each simultaneous BG. ROP was classified as none, mild (stage 1 to 2) or severe (stage 3 to 4). Growth velocity (g kg(-1) per day), length and head circumference were also analyzed. In all, 372 infants mean (s.d.) gestational age 27.6 (1.4) weeks, mean (s.d.) birth weight 994 (242)g had 18,649 BGs analyzed. 103 (28%) of the infants had mild ROP and 29 (8%) had severe ROP. 137 (37%) of the infants received at least 1 day of exogenous insulin (median days 9, range 1 to 26). Higher cumulative mean BG, more episodes of HG, and more insulin exposure were associated with an increased incidence and severity of ROP. Ordinal logistic regression identified lower gestational age, male gender, fetal growth restriction, slower NICU growth velocity, and higher BG as predictors for severity of ROP. However, insulin use was a stronger predictor than BG, and replaced it in the risk model. CONCLUSION: After adjusting for important risk factors, HG and especially insulin use in premature infants may increase the risk of ROP. In addition, slower NICU growth velocity, but not rates of head or length growth, was predictive of ROP.


Asunto(s)
Hiperglucemia/tratamiento farmacológico , Recién Nacido de muy Bajo Peso/sangre , Insulina/efectos adversos , Nutrición Parenteral Total/efectos adversos , Nacimiento Prematuro , Retinopatía de la Prematuridad , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Femenino , Retardo del Crecimiento Fetal/metabolismo , Edad Gestacional , Humanos , Hiperglucemia/etiología , Hiperglucemia/metabolismo , Recién Nacido , Insulina/administración & dosificación , Modelos Logísticos , Masculino , Monitoreo Fisiológico , Nacimiento Prematuro/metabolismo , Nacimiento Prematuro/fisiopatología , Nacimiento Prematuro/terapia , Retinopatía de la Prematuridad/sangre , Retinopatía de la Prematuridad/epidemiología , Retinopatía de la Prematuridad/etiología , Retinopatía de la Prematuridad/fisiopatología , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad
11.
Braz J Biol ; 69(1): 137-42, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19347156

RESUMEN

Reproduction of the isopod Cubaris murina was studied in the laboratory in order to observe the offspring number per brood, the number and duration of the incubation periods, and the influence of repeated mating on number of young per brood. An experiment was conducted with two different groups: female/male pairs and females that were isolated after mating. No significant difference was found between the two reproductive female groups for the mean number of young per brood (x = 25) and the duration of the incubation periods (x = 17 days). One mating was enough for at least five broods, with no reduction in brood size. There was no significant difference between the number of adult males and females. Low-density cultures had a significantly higher growth rate compared to high-density cultures. Furthermore, the experimental results for optimization isopod culture conditions for terrestrial ecotoxicity testing are reported.


Asunto(s)
Isópodos/fisiología , Animales , Femenino , Fertilidad/fisiología , Laboratorios , Masculino , Reproducción/fisiología , Razón de Masculinidad , Pruebas de Toxicidad/métodos
12.
Braz. j. biol ; Braz. j. biol;69(1): 137-142, Feb. 2009. graf, tab
Artículo en Inglés | LILACS | ID: lil-510133

RESUMEN

Reproduction of the isopod Cubaris murina was studied in the laboratory in order to observe the offspring number per brood, the number and duration of the incubation periods, and the influence of repeated mating on number of young per brood. An experiment was conducted with two different groups: female/male pairs and females that were isolated after mating. No significant difference was found between the two reproductive female groups for the mean number of young per brood (x = 25) and the duration of the incubation periods (x = 17 days). One mating was enough for at least five broods, with no reduction in brood size. There was no significant difference between the number of adult males and females. Low-density cultures had a significantly higher growth rate compared to high-density cultures. Furthermore, the experimental results for optimization isopod culture conditions for terrestrial ecotoxicity testing are reported.


A reprodução do isópodo Cubaris murina foi investigada em laboratório para observar: o número de filhotes por ninhada, número e duração dos períodos de incubação, e se repetidas cópulas influenciam o número de juvenis por ninhada. Um experimento foi conduzido com dois diferentes grupos: pares com uma fêmea e um macho e fêmeas mantidas individualmente depois da cópula. Não foram encontradas diferenças estatisticamente significantes entre os dois grupos de fêmeas em relação ao número de filhotes por ninhada (x = 25) e a duração dos períodos de incubação (x = 17 dias). Uma cópula foi suficiente para ao menos cinco ninhadas, sem redução em seu tamanho. A proporção sexual dos adultos de C. murina em laboratório não apresentou diferenças significativas entre a proporção de machos e fêmeas nos cultivos. A densidade influencia o crescimento dos isópodos de forma significativa: culturas com baixa densidade têm maior taxa de crescimento do que culturas com alta densidade. Os resultados experimentais sobre a eficiência dos cultivos em laboratório para ensaios ecotoxicológicos terrestres são apresentados.


Asunto(s)
Animales , Femenino , Masculino , Isópodos/fisiología , Fertilidad/fisiología , Laboratorios , Reproducción/fisiología , Razón de Masculinidad , Pruebas de Toxicidad/métodos
13.
Phys Rev Lett ; 91(19): 197002, 2003 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-14611603

RESUMEN

We observed current-voltage characteristics of superconducting single charge transistors with on-chip resistors of R approximately R(Q)=h/4e(2) approximately 6.45 kOmega, which are explained in terms of Cooper pair cotunneling. Both the effective strength of Josephson coupling and the cotunneling current are modulated by the gate-induced charge on the transistor island. For increasing values of the resistance R we found the Cooper pair current at small transport voltages to be dramatically suppressed.

14.
J Environ Radioact ; 63(3): 207-19, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12440510

RESUMEN

The application of solutions of the Advection-Dispersion-Equation (ADE) for soil profiles is sometimes questionable. An alternative method, based on the Weibull distribution, has been developed, which can approximate the vertical distribution of radiocesium (137Cs) and allows extrapolation to account for the complete inventory. The structure of the equation allows simple parameters describing the soil depth profile to be derived. Reliable estimates of the total 137Cs inventory can help to explain the lateral distribution. This equation was used to analyse the 137Cs-activities of Chernobyl fall-out measured on a slope under permanent pasture in Luxembourg.


Asunto(s)
Modelos Teóricos , Centrales Eléctricas , Ceniza Radiactiva , Liberación de Radiactividad Peligrosa , Contaminantes Radiactivos del Suelo/análisis , Radioisótopos de Cesio/análisis , Luxemburgo , Ucrania
15.
Inorg Chem ; 40(7): 1672-6, 2001 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-11261978

RESUMEN

The molecular structures and conformational properties of acetyl peroxynitrate (PAN, CH3C(O)OONO2) and trifluoroacetyl peroxynitrate (FPAN, CF3C(O)OONO2) were investigated in the gas phase by electron diffraction (GED), microwave spectroscopy (MW), and quantum chemical methods (HF/3-21G, HF/6-31G*, MP2/6-31G*, B3PW91/6-31G*, and B3PW91/6-311+G*). All experimental and theoretical methods show the syn conformer (C=O bond of acetyl group syn to O-O bond) to be strongly predominant relative to the anti conformer. The O-NO2 bonds are extremely long, 1.492(7) A in PAN and 1.526(10) A in FPAN, which correlates with their low bond energy and the easy formation of CX3C(O)OO* and *NO2 radicals in the atmosphere. The O-O bonds (1.418(12) A in PAN and 1.408(8) A in FPAN) are shorter than that in hydrogen peroxide (1.464 A). In both compounds the C-O-O-N dihedral angle is close to 85 degrees.

16.
Int J Legal Med ; 113(5): 259-62, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11009059

RESUMEN

A total of 65 consecutive cases of suicide by sharp force were investigated by evaluating the autopsy and prosecution department records. Suicides constituted 17% of all fatalities from sharp force autopsied between 1967 and 1996. Young males and persons with a psychiatric history predominated among the persons who chose this "hard" method of suicide. The most common implements used were knives (62%) and razor blades (15%). Cutting injuries in isolation were present in 26, stab injuries in isolation in 24 and a combination of both in 15 fatalities. The number of injuries per case varied from 1 to 37 but 1/3 showed one injury. More than 85% of the cutting injuries were located at the wrist, elbow crease or neck whereas 79% of the stab injuries involved the ventral aspect of the trunk. Perforation of clothing was present in 16 (52%) out of 31 stab injuries to the trunk. Injuries to more than one body region were observed in 34 (52%) cases. Tentative marks were present in 50 (77%) fatalities and the number varied from 1 to 60 per case. Superficial incisions of the fingers were found in 15% with razor blades constituting the weapon in half of these cases. Deviations from these typical patterns occurred not infrequently. The utter determination of the victim to carry it through or the use of unusual weapons resulted in a few bizarre cases which are outlined briefly.


Asunto(s)
Medicina Legal , Suicidio , Heridas Penetrantes , Traumatismos Abdominales , Adulto , Autopsia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Traumatismo Múltiple , Traumatismos del Cuello , Suicidio/legislación & jurisprudencia , Traumatismos Torácicos , Heridas Punzantes
17.
Int J Legal Med ; 112(3): 188-91, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10335884

RESUMEN

Cases of suicide from sharp pointed weapons (n = 12) witnessed by one or more persons are reported with regard to the potential for physical activity. One case each involved the ulnar artery, the great saphenous vein and the periphery of the lung and liver and the physical activity following these injuries lasted for several hours. In one case, the left carotid and vertebral arteries were transected and the physical activity lasted for approximately 10 s. An extraordinary case involved a protracted incapacitation due to heart tamponade from a small myocardial injury caused by a cannula. In the remaining seven cases, a stab wound to the heart was present. With regard to the physical activity, a long-term group (2-10 min, n = 4) can be differentiated from a short-term group (approximately 10 s, n = 2) and one case of immediate incapacitation. The size of the myocardial perforation was 7-10 mm in length in the long-term group compared to 1.4-2 cm in the short-term group. So small perforations of the heart or incisions of the carotid artery offer a potential for considerable physical activity. Large perforations of the heart or a transection of the carotid and vertebral arteries can result in short-term activity.


Asunto(s)
Suicidio , Heridas Penetrantes/fisiopatología , Adulto , Femenino , Medicina Legal , Humanos , Masculino , Persona de Mediana Edad , Movimiento , Factores de Tiempo
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