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1.
Nature ; 561(7721): E3, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29955153

RESUMEN

In equation (1) of this Letter, the closing bracket was missing; in Extended Data Fig. 1 and the accompanying legend, 'Φ(pd)' should have been 'Φ2(pd)', and in the Methods the text "Odd J assignments are uncertain by ±1." has been added. These errors have all been corrected online.

2.
Nature ; 557(7707): 687-690, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29795352

RESUMEN

Carbon burning powers scenarios that influence the fate of stars, such as the late evolutionary stages of massive stars 1 (exceeding eight solar masses) and superbursts from accreting neutron stars2,3. It proceeds through the 12C + 12C fusion reactions that produce an alpha particle and neon-20 or a proton and sodium-23-that is, 12C(12C, α)20Ne and 12C(12C, p)23Na-at temperatures greater than 0.4 × 109 kelvin, corresponding to astrophysical energies exceeding a megaelectronvolt, at which such nuclear reactions are more likely to occur in stars. The cross-sections 4 for those carbon fusion reactions (probabilities that are required to calculate the rate of the reactions) have hitherto not been measured at the Gamow peaks 4 below 2 megaelectronvolts because of exponential suppression arising from the Coulomb barrier. The reference rate 5 at temperatures below 1.2 × 109 kelvin relies on extrapolations that ignore the effects of possible low-lying resonances. Here we report the measurement of the 12C(12C, α0,1)20Ne and 12C(12C, p0,1)23Na reaction rates (where the subscripts 0 and 1 stand for the ground and first excited states of 20Ne and 23Na, respectively) at centre-of-mass energies from 2.7 to 0.8 megaelectronvolts using the Trojan Horse method6,7 and the deuteron in 14N. The cross-sections deduced exhibit several resonances that are responsible for very large increases of the reaction rate at relevant temperatures. In particular, around 5 × 108 kelvin, the reaction rate is boosted to more than 25 times larger than the reference value 5 . This finding may have implications such as lowering the temperatures and densities 8 required for the ignition of carbon burning in massive stars and decreasing the superburst ignition depth in accreting neutron stars to reconcile observations with theoretical models 3 .

3.
Phys Rev Lett ; 119(13): 132501, 2017 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-29341708

RESUMEN

The decay path of the Hoyle state in ^{12}C (E_{x}=7.654 MeV) has been studied with the ^{14}N(d,α_{2})^{12}C(7.654) reaction induced at 10.5 MeV. High resolution invariant mass spectroscopy techniques have allowed us to unambiguously disentangle direct and sequential decays of the state passing through the ground state of ^{8}Be. Thanks to the almost total absence of background and the attained resolution, a fully sequential decay contribution to the width of the state has been observed. The direct decay width is negligible, with an upper limit of 0.043% (95% C.L.). The precision of this result is about a factor 5 higher than previous studies. This has significant implications on nuclear structure, as it provides constraints to 3α cluster model calculations, where higher precision limits are needed.

4.
J Small Anim Pract ; 55(3): 170-3, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24345200

RESUMEN

A case of non-syndromic, complete syndactyly involving all four limbs is described in a three-month-old male crossbreed dog for the first time. Syndactyly is a rare condition in most animal species, in dogs it has been infrequently reported. Findings of clinical, radiographic and cytogenetic analyses are described and demonstrate probably for the first time that numerical and structural chromosome aberrations are not involved in the pathogenesis of this case of syndactyly.


Asunto(s)
Perros/anomalías , Sindactilia/veterinaria , Animales , Miembro Anterior/anomalías , Miembro Posterior/anomalías , Cariotipo , Masculino
6.
Reprod Domest Anim ; 46(1): 130-3, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20403132

RESUMEN

The aim of the study was to evaluate the use of laparoscopy for the assessment of the reproductive tract and stage of gonadal development of the tench (Tinca tinca). Laparoscopy was carried out from February to March 2009, on 30 anesthetized tenchs, 15 males and 15 females, of approximately 250 g bodyweight and 30 cm length, using a 1.9-mm rigid cystoscope. Male and female gonads, attached to the swim bladder, were visualized. Testes were orange with a striped appearance. Mature ovaries were cluster-shaped and whitish. Histological samples were collected, from the reproductive organs of both the sexes, with a forceps and showed the presence of gametes at different stages of maturity. The application of this minimally invasive diagnostic imaging technique could clinically be used as a powerful tool to evaluate the gender and to establish the reproductive status of tench and other fish.


Asunto(s)
Cyprinidae/anatomía & histología , Laparoscopía/veterinaria , Reproducción , Animales , Cyprinidae/cirugía , Femenino , Masculino , Oocitos , Ovario/anatomía & histología , Espermatocitos/ultraestructura , Testículo/anatomía & histología
7.
Anat Histol Embryol ; 40(2): 104-6, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21105902

RESUMEN

A case of unilateral hindlimb adactyly is described in a 3-month-old female Pointer dog. Clinical and radiographic findings are described. Adactyly or transverse hemimelia is a rare condition in most animal species. In dogs, this condition has been reported only three times as a deformity of the forelimb. To the authors' knowledge, the congenital pelvic limb deformity described here is the first case documented in a dog.


Asunto(s)
Ectromelia/veterinaria , Miembro Posterior/anomalías , Deformidades Congénitas de las Extremidades/veterinaria , Animales , Perros , Ectromelia/diagnóstico por imagen , Femenino , Miembro Posterior/diagnóstico por imagen , Deformidades Congénitas de las Extremidades/diagnóstico por imagen , Radiografía
8.
Anat Histol Embryol ; 38(5): 327-9, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19548891

RESUMEN

Cephalothoracopagus is a very rare form of conjoined twins and is characterized by fusion of heads and thoraxes with two separate spines, limbs and pelves. The aim of this study was to describe a case of female cephalothoracopagus kitten puppy. The most important gross findings involved the external body and some of the internal organs. Radiological features revealed main developmental abnormality of the head, spines and thorax. Authors discuss the pathogenic mechanisms of this condition, infrequently reported in veterinary practice, pointing out the importance of embryonic duplications commonly associated with dystocia.


Asunto(s)
Gatos/anomalías , Gemelos Siameses , Anomalías Múltiples/veterinaria , Animales , Femenino
9.
Phys Rev Lett ; 101(15): 152501, 2008 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-18999593

RESUMEN

The 18O(p,alpha)15N reaction is of primary importance in several astrophysical scenarios, including fluorine nucleosynthesis inside asymptotic giant branch stars as well as oxygen and nitrogen isotopic ratios in meteorite grains. Thus the indirect measurement of the low energy region of the 18O(p,alpha)15N reaction has been performed to reduce the nuclear uncertainty on theoretical predictions. In particular the strength of the 20 and 90 keV resonances has been deduced and the change in the reaction rate evaluated.

10.
Reprod Domest Anim ; 43(1): 121-3, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18199269

RESUMEN

We report two cases of bilateral malignant seminoma in the bursula testium of two mules, which had been slaughtered normally. Histologically, the testicular tumours consisted predominantly of large round to polyhedral cells with frequent mitotic figures. Metastases were found in the sublumbar lymph nodes. A final histopathological diagnosis of malignant seminoma with metastasis was made. To our knowledge, this paper appears to be the first report of two cases of bilateral malignant seminoma with metastases, in the mule.


Asunto(s)
Equidae , Seminoma/veterinaria , Neoplasias Testiculares/veterinaria , Animales , Inmunohistoquímica/veterinaria , Metástasis Linfática/diagnóstico , Metástasis Linfática/patología , Masculino , Seminoma/diagnóstico , Seminoma/patología , Neoplasias Testiculares/diagnóstico , Neoplasias Testiculares/patología
11.
Pol J Vet Sci ; 11(4): 385-8, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19227140

RESUMEN

A rare case of primary pleomorphic liposarcoma of the liver in an 8-year-old female German shepherd dog is described. The liver tumour, measuring 10x12x5 cm, was located in the right hepatic lobe. The diagnosis of pleomorphic liposarcoma was based on the morphological and immunohistochemical features of the tumour cells. To our knowledge, this is the second case of primary liposarcoma of the liver in the dog found in the veterinary literature.


Asunto(s)
Enfermedades de los Perros/patología , Liposarcoma/veterinaria , Neoplasias Hepáticas/veterinaria , Animales , Perros , Femenino , Liposarcoma/patología , Neoplasias Hepáticas/patología
12.
Phys Rev Lett ; 98(25): 252502, 2007 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-17678018

RESUMEN

Off-energy-shell effects in p - p scattering have been investigated at p - p relative energies from 600 down to 80 keV applying the Trojan horse method (THM) to the p + d --> p + p + n reaction at 5 MeV. In contrast with the on-energy-shell case, no Coulomb-nuclear interference minimum has been found in the extracted THM p - p cross section, due to the suppression of the Coulomb amplitude as predicted by the half-off-energy shell calculations. This hypothesis is strengthened by the agreement between THM p - p data and calculated on-energy-shell n + n, n + p and nuclear p + p cross sections.

13.
Reprod Domest Anim ; 42(1): 109-10, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17214784

RESUMEN

A rare case of a bilateral Leydig cells tumour located in the testis of a 15-year-old donkey slaughtered normally is presented. Histologically, the testicular tumour showed neoplastic Leydig cells arranged in solid growth as a pseudoadenomatous packet type. To our knowledge, this is the first bilateral Leydig cells tumour, a neoplasm never reported in the donkey.


Asunto(s)
Equidae , Tumor de Células de Leydig/veterinaria , Neoplasias Testiculares/veterinaria , Animales , Inmunohistoquímica/veterinaria , Tumor de Células de Leydig/patología , Masculino , Neoplasias Testiculares/patología
14.
Reprod Domest Anim ; 41(6): 568-70, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17107519

RESUMEN

A case of preputial glomangioma in an 8-year-old Springer Spaniel dog is reported. The dog presented a solitary nodular mass, approximately 3.5 x 5.2 cm in diameter, located on the lateral wall of the prepuce at the base of the penis. Histologically, the excised tumour mass consisted of proliferating round epithelioid cells arranged in a cordon-like structure around small blood vessels. The neoplastic cells were positive for alpha smooth muscle actin and negative for cytokeratin, desmin, S-100 protein and neurone-specific enolase. Based on these pathologic features, the tumour was diagnosed as glomangioma, a neoplasm extremely rare in dogs. To our knowledge, this is the first report of preputial glomangioma in the dog.


Asunto(s)
Enfermedades de los Perros/patología , Tumor Glómico/veterinaria , Neoplasias del Pene/veterinaria , Animales , Enfermedades de los Perros/diagnóstico , Enfermedades de los Perros/cirugía , Perros , Tumor Glómico/diagnóstico , Tumor Glómico/patología , Tumor Glómico/cirugía , Inmunohistoquímica/veterinaria , Masculino , Neoplasias del Pene/diagnóstico , Neoplasias del Pene/patología , Neoplasias del Pene/cirugía
17.
Reprod Domest Anim ; 39(1): 61-3, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15129924

RESUMEN

Here we present a case of preputial benign fibrous histiocytoma in a 7-year-old mule. This case was treated surgically. Pathologic analysis and diagnosis of these lesions were based on a combination of light microscopy and immunohistochemistry. Histologically, the tumour was composed primarily of a storiform pattern of fibroblastic and poligonal cells. In immunohistochemistry, except for consistent immunoreactivity for vimentin, nearly all tumour cells were positive for CD68, S-100 protein, pan-cytokeratin, alpha-smooth muscle actin, and desmin. Benign fibrous histiocytoma of the prepuce in mule is rarely reported in veterinary literature.


Asunto(s)
Histiocitoma Fibroso Benigno/veterinaria , Enfermedades de los Caballos/diagnóstico , Neoplasias del Pene/veterinaria , Animales , Diagnóstico Diferencial , Equidae , Histiocitoma Fibroso Benigno/diagnóstico , Enfermedades de los Caballos/patología , Enfermedades de los Caballos/cirugía , Caballos , Inmunohistoquímica/veterinaria , Masculino , Neoplasias del Pene/diagnóstico
18.
Reprod Domest Anim ; 38(5): 421-2, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12950697

RESUMEN

One case of interstitial cell tumour in the testicle of a New Zealand White rabbit was reported. The rabbit was 9-years old and had monolateral testicular lesion. There was enlargement of left testis and the lesion were seen on the cut surface. Light microscopy revealed intracytoplasmic crystals of Reinke that resembled to the features observed for this tumour in human. Immunohistochemically, this tumour was positive for vimentin.


Asunto(s)
Citoplasma/patología , Tumor de Células de Leydig/veterinaria , Conejos , Neoplasias Testiculares/veterinaria , Animales , Cristalización , Inmunohistoquímica , Tumor de Células de Leydig/metabolismo , Tumor de Células de Leydig/patología , Masculino , Neoplasias Testiculares/metabolismo , Neoplasias Testiculares/patología
19.
Clin Neurophysiol ; 113(10): 1536-43, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12350429

RESUMEN

OBJECTIVES: The objective of this study was to assess the sensitivity of motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) in demonstrating the possible subclinical impairment of the corticospinal pathway after recovery, in patients with a clinical history of pure motor stroke (PMS) due to a single lacunar infarct detectable by magnetic resonance imaging (MRI). METHODS: MEPs were recorded from the first dorsal interosseous muscle of 20 healthy subjects and 40 patients, 6 months or more after PMS onset. Patients were evaluated clinically by means of the NIH stroke scale, the Medical Research Council (MRC) scale and the Barthel Index. The patients with full hand strength recovery and the normal controls were also tested by means of the 9-hole peg test. RESULTS: Motor threshold (MT), MEP amplitude and central motor conduction time (CMCT) of the affected side were significantly different from those of the normal side and of the control subjects. MT, MEP amplitude and CMCT obtained after stimulation of the affected hemisphere were significantly correlated with the MRC scale values of the affected hand. Eighty-six percent of patients with persistent hand strength deficit showed MEP abnormalities. In 21 patients with complete clinical recovery, a significant increase in MT and decrease in MEP amplitude on the affected side were observed. CONCLUSIONS: After PMS, neurophysiological changes may persist despite complete clinical recovery. TMS represents a sensitive tool that enables to demonstrate objectively the clinical and subclinical impairment of the corticospinal pathway.


Asunto(s)
Encéfalo/efectos de la radiación , Hemiplejía/terapia , Actividad Motora/fisiología , Paresia/terapia , Accidente Cerebrovascular/terapia , Estimulación Magnética Transcraneal/uso terapéutico , Adulto , Anciano , Potenciales Evocados Motores/fisiología , Femenino , Lateralidad Funcional , Hemiplejía/etiología , Humanos , Masculino , Persona de Mediana Edad , Actividad Motora/efectos de la radiación , Paresia/etiología , Valores de Referencia , Estadísticas no Paramétricas , Accidente Cerebrovascular/fisiopatología
20.
Clin Neurophysiol ; 111(4): 630-5, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10727914

RESUMEN

OBJECTIVES: To evaluate central motor conduction to lower limbs in spinocerebellar ataxia type 2 (SCA2). METHODS: Transcranial magnetic stimulation was performed to study the corticospinal tracts of 18 patients with SCA2. RESULTS: Central motor conduction time (CMCT) to lower limbs and thresholds were abnormal in 8 patients (44%); CMCT and thresholds were significantly correlated with disease duration and disability. CONCLUSIONS: Corticospinal tract involvement is more frequent than previously reported in SCA2. Prolonged CMCT and increased threshold should not be used to differentiate between various type of autosomal dominant cerebellar ataxia. Similar to that reported in Friedreich's ataxia, we suggest that examining central motor conduction to the lower limbs may assist in evaluating the progressive steps of neurodegeneration in SCA2.


Asunto(s)
Conducción Nerviosa/fisiología , Tractos Piramidales/fisiopatología , Ataxias Espinocerebelosas/diagnóstico , Ataxias Espinocerebelosas/fisiopatología , Estimulación Magnética Transcraneal , Adulto , Anciano , Enfermedades Desmielinizantes/fisiopatología , Estimulación Eléctrica , Femenino , Estudios de Seguimiento , Humanos , Interneuronas/fisiología , Pierna/inervación , Pierna/fisiología , Masculino , Persona de Mediana Edad , Neuronas Motoras/fisiología , Tractos Piramidales/citología
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