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1.
Phys Rev Lett ; 131(3): 031802, 2023 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-37540851

RESUMEN

We report the direct observation of muon neutrino interactions with the SND@LHC detector at the Large Hadron Collider. A dataset of proton-proton collisions at sqrt[s]=13.6 TeV collected by SND@LHC in 2022 is used, corresponding to an integrated luminosity of 36.8 fb^{-1}. The search is based on information from the active electronic components of the SND@LHC detector, which covers the pseudorapidity region of 7.2<η<8.4, inaccessible to the other experiments at the collider. Muon neutrino candidates are identified through their charged-current interaction topology, with a track propagating through the entire length of the muon detector. After selection cuts, 8 ν_{µ} interaction candidate events remain with an estimated background of 0.086 events, yielding a significance of about 7 standard deviations for the observed ν_{µ} signal.

2.
Hum Mol Genet ; 27(22): 3827-3839, 2018 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-30007339

RESUMEN

Gain-of-function mutations in fibroblast growth factor receptors (FGFRs) cause congenital skeletal anomalies, including craniosynostosis (CS), which is characterized by the premature closure of craniofacial sutures. Apert syndrome (AS) is one of the severest forms of CS, and the only treatment is surgical expansion of prematurely fused sutures in infants. Previously, we demonstrated that the prolyl isomerase peptidyl-prolyl cis-trans isomerase interacting 1 (PIN1) plays a critical role in mediating FGFR signaling and that Pin1+/- mice exhibit delayed closure of cranial sutures. In this study, using both genetic and pharmacological approaches, we tested whether PIN1 modulation could be used as a therapeutic regimen against AS. In the genetic approach, we crossbred Fgfr2S252W/+, a mouse model of AS, and Pin1+/- mice. Downregulation of Pin1 gene dosage attenuated premature cranial suture closure and other phenotypes of AS in Fgfr2S252W/+ mutant mice. In the pharmacological approach, we intraperitoneally administered juglone, a PIN1 enzyme inhibitor, to pregnant Fgfr2S252W/+ mutant mice and found that this treatment successfully interrupted fetal development of AS phenotypes. Primary cultured osteoblasts from Fgfr2S252W/+ mutant mice expressed high levels of FGFR2 downstream target genes, but this phenotype was attenuated by PIN1 inhibition. Post-translational stabilization and activation of Runt-related transcription factor 2 (RUNX2) in Fgfr2S252W/+ osteoblasts were also attenuated by PIN1 inhibition. Based on these observations, we conclude that PIN1 enzyme activity is important for FGFR2-induced RUNX2 activation and craniofacial suture morphogenesis. Moreover, these findings highlight that juglone or other PIN1 inhibitors represent viable alternatives to surgical intervention for treatment of CS and other hyperostotic diseases.


Asunto(s)
Acrocefalosindactilia/genética , Subunidad alfa 1 del Factor de Unión al Sitio Principal/genética , Craneosinostosis/genética , Peptidilprolil Isomerasa de Interacción con NIMA/genética , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/genética , Acrocefalosindactilia/tratamiento farmacológico , Acrocefalosindactilia/fisiopatología , Animales , Suturas Craneales/fisiopatología , Craneosinostosis/tratamiento farmacológico , Craneosinostosis/fisiopatología , Modelos Animales de Enfermedad , Femenino , Mutación con Ganancia de Función/genética , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Ratones , Morfogénesis , Peptidilprolil Isomerasa de Interacción con NIMA/antagonistas & inhibidores , Naftoquinonas/administración & dosificación , Osteoblastos/efectos de los fármacos , Osteoblastos/metabolismo , Embarazo , Cultivo Primario de Células , Transducción de Señal
3.
Nat Mater ; 15(12): 1233-1236, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27525569

RESUMEN

The superconducting transition temperature (TC) in a FeSe monolayer on SrTiO3 is enhanced up to 100 K (refs ,,,). High TC is also found in bulk iron chalcogenides with similar electronic structure to that of monolayer FeSe, which suggests that higher TC may be achieved through electron doping, pushing the Fermi surface (FS) topology towards leaving only electron pockets. Such an observation, however, has been limited to chalcogenides, and is in contrast to the iron pnictides, for which the maximum TC is achieved with both hole and electron pockets forming considerable FS nesting instability. Here, we report angle-resolved photoemission characterization revealing a monotonic increase of TC from 24 to 41.5 K upon surface doping on optimally doped Ba(Fe1-xCox)2As2. The doping changes the overall FS topology towards that of chalcogenides through a rigid downward band shift. Our findings suggest that higher electron doping and concomitant changes in FS topology are favourable conditions for the superconductivity, not only for iron chalcogenides, but also for iron pnictides.

4.
Phys Rev Lett ; 119(3): 037201, 2017 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-28777603

RESUMEN

We report a ^{35}Cl nuclear magnetic resonance study in the honeycomb lattice α-RuCl_{3}, a material that has been suggested to potentially realize a Kitaev quantum spin liquid (QSL) ground state. Our results provide direct evidence that α-RuCl_{3} exhibits a magnetic-field-induced QSL. For fields larger than ∼10 T, a spin gap opens up while resonance lines remain sharp, evidencing that spins are quantum disordered and locally fluctuating. The spin gap increases linearly with an increasing magnetic field, reaching ∼50 K at 15 T, and is nearly isotropic with respect to the field direction. The unusual rapid increase of the spin gap with increasing field and its isotropic nature are incompatible with conventional magnetic ordering and, in particular, exclude that the ground state is a fully polarized ferromagnet. The presence of such a field-induced gapped QSL phase has indeed been predicted in the Kitaev model.

5.
Phys Rev Lett ; 119(22): 227202, 2017 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-29286817

RESUMEN

We report on terahertz spectroscopy of quantum spin dynamics in α-RuCl_{3}, a system proximate to the Kitaev honeycomb model, as a function of temperature and magnetic field. We follow the evolution of an extended magnetic continuum below the structural phase transition at T_{s2}=62 K. With the onset of a long-range magnetic order at T_{N}=6.5 K, spectral weight is transferred to a well-defined magnetic excitation at ℏω_{1}=2.48 meV, which is accompanied by a higher-energy band at ℏω_{2}=6.48 meV. Both excitations soften in a magnetic field, signaling a quantum phase transition close to B_{c}=7 T, where a broad continuum dominates the dynamical response. Above B_{c}, the long-range order is suppressed, and on top of the continuum, emergent magnetic excitations evolve. These excitations follow clear selection rules and exhibit distinct field dependencies, characterizing the dynamical properties of a possibly field-induced quantum spin liquid.

6.
Am J Phys Anthropol ; 159(4): 596-606, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26678538

RESUMEN

OBJECTIVE: As a chemical precursor to the hard tissue changes well-studied in bioarchaeological research, osteocalcin provides a unique opportunity to assess stress via fluctuations in bone metabolism. The main objectives of this research were 1) to successfully extract osteocalcin from the Black Friars skeletal population; 2) to assess the diagenetic change between individual bone samples; and 3) to compare osteocalcin concentrations across sex, age, time period and macroscopic indicators of stress. METHODS: Twenty adult individuals were selected from the 13th-17th centuries Black Friars skeletal population with bone samples taken from the clavicle and femur. Total protein was assessed through a MicroBCA analysis with osteocalcin quantified using a Human Quantikine ELISA kit. Diagenetic change was assessed using Fourier transform infrared spectroscopy and the attenuated total reflectance method. RESULTS: Osteocalcin concentrations showed no significant differences between sex or age groups; however, between time period the post-medieval individuals showed a significant reduction of osteocalcin in both the clavicle and the femur. There were no significant differences in osteocalcin concentrations between those with and without past stress indicators and only one significant difference among the chronic indicators. The diagenetic results demonstrated a similar degree of crystallinity between all samples. CONCLUSIONS: While preliminary in nature, this study was successful in demonstrating the potential use of osteocalcin in future health-related research and how the study of osteocalcin may contribute to a better understanding of how and when stress begins to affect the skeletal tissues.


Asunto(s)
Osteocalcina/análisis , Estrés Fisiológico/fisiología , Adolescente , Adulto , Antropología Física , Cementerios/historia , Clavícula/química , Femenino , Fémur/química , Historia del Siglo XV , Historia del Siglo XVI , Historia del Siglo XVII , Historia Medieval , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
7.
Int J Obes (Lond) ; 38(8): 1044-52, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24232498

RESUMEN

OBJECTIVES: Activation of the Wnt/ß-catenin signaling pathway inhibits adipogenesis by maintaining preadipocytes in an undifferentiated state. We investigated the effect of indirubin-3'-oxime (I3O), which was screened as an activator of the Wnt/ß-catenin signaling, on inhibiting the preadipocyte differentiation in vitro and in vivo. METHODS: 3T3L1 preadipocytes were differentiated with 0, 4 or 20 µM of I3O. The I3O effect on adipocyte differentiation was observed by Oil-red-O staining. Activation of Wnt/ß-catenin signaling in I3O-treated 3T3L1 cells was shown using immunocytochemical and immunoblotting analyses for ß-catenin. The regulation of adipogenic markers was analyzed via real-time reverse transcription-PCR (RT-PCR) and immunoblotting analyses. For the in vivo study, mice were divided into five different dietary groups: chow diet, high-fat diet (HFD), HFD supplemented with I3O at 5, 25 and 100 mg kg(-1). After 8 weeks, adipose and liver tissues were excised from the mice and subject to morphometry, real-time RT-PCR, immunoblotting and histological or immunohistochemical analyses. In addition, adipokine and insulin concentrations in serum of the mice were accessed by enzyme-linked immunosorbent assay. RESULTS: Using a cell-based approach to screen a library of pharmacologically active small molecules, we identified I3O as a Wnt/ß-catenin pathway activator. I3O inhibited the differentiation of 3T3-L1 cells into mature adipocytes and decreased the expression of adipocyte markers, CCAAT/enhancer-binding protein α and peroxisome proliferator-activated receptor γ, at both mRNA and protein levels. In vivo, I3O inhibited the development of obesity in HFD-fed mice by attenuating HFD-induced body weight gain and visceral fat accumulation without showing any significant toxicity. Factors associated with metabolic disorders such as hyperlipidemia and hyperglycemia were also improved by treatment of I3O. CONCLUSION: Activation of the Wnt/ß-catenin signaling pathway can be used as a therapeutic strategy for the treatment of obesity and metabolic syndrome and implicates I3O as a candidate anti-obesity agent.


Asunto(s)
Adipogénesis/efectos de los fármacos , Fármacos Antiobesidad/farmacología , Indoles/farmacología , Síndrome Metabólico/metabolismo , Obesidad/metabolismo , Oximas/farmacología , Vía de Señalización Wnt/efectos de los fármacos , Células 3T3-L1/efectos de los fármacos , Adipocitos/efectos de los fármacos , Adipocitos/metabolismo , Animales , Diferenciación Celular/efectos de los fármacos , Dieta Alta en Grasa , Masculino , Medicina Tradicional China , Síndrome Metabólico/tratamiento farmacológico , Ratones , Obesidad/tratamiento farmacológico , Reacción en Cadena de la Polimerasa/métodos
8.
Phys Rev Lett ; 110(11): 117204, 2013 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-25166571

RESUMEN

In the spin ladder compound BiCu(2)PO(6), there exists a decisive dynamics of spin excitations that we classify and characterize using inelastic light scattering. We observe an interladder singlet bound mode at 24 cm(-1) and two intraladder bound states at 62 and 108 cm(-1) in the leg (bb) and the rung (cc) polarization as well as a broad triplon continuum extending from 36 cm(-1) to 700 cm(-1). Though isolated spin ladder physics can roughly account for the observed excitations at high energies, frustration and interladder interactions need to be considered to fully describe the spectral distribution and scattering selection rules at low and intermediate energies. In addition, we attribute the rich spectrum of singlet bound modes to a melting of a dimer crystal. Our study provides evidence for a Z(2) quantum phase transition from a dimer to a resonating valence bond state driven by singlet fluctuations.

9.
Phys Rev Lett ; 111(21): 217001, 2013 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-24313517

RESUMEN

We performed temperature dependent x-ray linear dichroism (XLD) experiments on an iron pnictide system, Ba(Fe(1-x)Co(x))2As2 with x=0.00, 0.05, 0.08, and 0.10 to experimentally verify the existence of orbital ordering (OO). Substantial XLD was observed in polarization dependent x-ray absorption spectra of Fe L edges. By exploiting the difference in the temperature dependent behaviors, OO, and structure contributions to XLD could be clearly separated. The observed OO signal indicates different occupation numbers for d(yz) and d(zx) orbitals and supports the existence of ferro-OO. The results are also consistent with the theoretical prediction. Moreover, we find substantial OO signal well above the structural and magnetic transition temperatures, which suggests the existence of strong OO fluctuations up to high temperatures.

10.
Nat Commun ; 14(1): 7405, 2023 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-37974022

RESUMEN

Kondo impurities provide a nontrivial probe to unravel the character of the excitations of a quantum spin liquid. In the S = 1/2 Kitaev model on the honeycomb lattice, Kondo impurities embedded in the spin-liquid host can be screened by itinerant Majorana fermions via gauge-flux binding. Here, we report experimental signatures of metallic-like Kondo screening at intermediate temperatures in the Kitaev honeycomb material α-RuCl3 with dilute Cr3+ (S = 3/2) impurities. The static magnetic susceptibility, the muon Knight shift, and the muon spin-relaxation rate all feature logarithmic divergences, a hallmark of a metallic Kondo effect. Concurrently, the linear coefficient of the magnetic specific heat is large in the same temperature regime, indicating the presence of a host Majorana metal. This observation opens new avenues for exploring uncharted Kondo physics in insulating quantum magnets.

11.
Phys Rev Lett ; 108(6): 067206, 2012 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-22401119

RESUMEN

We report on coherent manipulation of electron spins in an antiferromagnetically coupled spin triangle {Cu3-X} (X=As, Sb) impregnated in freestanding nanoporous silicon (NS) by using 240 GHz microwave pulses. Rabi oscillations are observed and the spin coherence time is found to be T(2)=1066 ns at 1.5 K. This demonstrates that the {Cu3-X}:NS hybrid material provides a promising scheme for implementing spin-based quantum gates. By measuring the spin relaxation times of samples with different symmetries and environments we give evidence that a spin chirality is the main decoherence source of spin triangle molecules.

12.
Dis Esophagus ; 25(1): 17-25, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21668570

RESUMEN

Bolus transit through the esophagus has not been validated by videoesophagram in patients with dysphagia and changes in impedance with abnormal barium transit have not been described in those patients. The aim of this study was to compare esophageal impedance findings with barium esophagram measurements in patients with dysphagia. The consecutive patients with dysphagia underwent conventional multichannel esophageal impedance manometry, after which a barium videoesophagram was performed simultaneously with multichannel esophageal impedance manometry using a mean of three swallows of barium. Esophageal emptying patterns shown in the esophagogram were classified by the degree of intraesophageal stasis and presence of intraesophageal reflux. Bolus transit patterns in impedance were classified as complete and incomplete transit. Sixteen patients (M : F = 8 : 8, mean age, 47 years) were enrolled. Their manometric diagnosis were normal (n= 6), ineffective esophageal motility (n= 1), diffuse esophageal spasm (DES; n= 2), and achalasia (n= 7). Sixty-three swallows were analyzed. According to impedance analysis, 21/22 swallows with normal barium emptying showed complete transit (96%) and 31/32 swallows with severe stasis showed incomplete transit (97%). Nine swallows with mild stasis showed either complete or incomplete transit patterns in impedance. Swallows with mild barium stasis and complete transit in impedance were observed in patients who had received treatment (two patients with achalasia with history of esophageal balloonplasty and a patient with DES after nifedipine administration). Impedance reflected severe stasis with retrograde barium movement and described typical bolus transit patterns in patients with achalasia and DES. In conclusion, impedance-barium esophagram concordance is high for swallows with normal esophageal emptying and for severe barium stasis in patients with dysphagia.


Asunto(s)
Trastornos de Deglución/diagnóstico por imagen , Deglución , Impedancia Eléctrica , Esófago/diagnóstico por imagen , Tránsito Gastrointestinal , Adulto , Sulfato de Bario , Trastornos de Deglución/fisiopatología , Esófago/fisiopatología , Femenino , Humanos , Masculino , Manometría , Persona de Mediana Edad , Radiografía , Grabación en Video
13.
Hong Kong Med J ; 18(5): 407-11, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23018068

RESUMEN

OBJECTIVES. To clarify the use of ultrasonography by determining the frequency of developmental dysplasia of the hip among breech-presented Chinese neonates in Hong Kong. DESIGN. Prospective case series. SETTING. Regional hospital, Hong Kong. PATIENTS. All breech-presented Chinese neonates born during January 2008 to June 2009 were included (except premature neonates). They were examined clinically from birth till the age of 1 year. Ultrasound of the hips was performed at the age of 2 weeks, and X-ray of the pelvis at the age of 1 year. RESULTS. A total of 209 breech-presented neonates were born during the study period; 110 neonates completed all necessary investigations and follow-up. Among the latter, there were three neonates with developmental dysplasia of the hip warranting treatment, which amounted to a frequency of 2.7%. CONCLUSION. Developmental dysplasia of the hip among breech-presented Chinese babies is only slightly less common than in corresponding populations in other regions in the world. Since early diagnosis is important, ultrasonography screening in high-risk cases such as those with breech presentation may be useful.


Asunto(s)
Presentación de Nalgas , Luxación Congénita de la Cadera/epidemiología , Tamizaje Neonatal/métodos , Femenino , Estudios de Seguimiento , Luxación Congénita de la Cadera/diagnóstico por imagen , Hong Kong/epidemiología , Humanos , Lactante , Recién Nacido , Masculino , Embarazo , Estudios Prospectivos , Ultrasonografía
14.
Hong Kong Med J ; 17(2): 96-104, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21471588

RESUMEN

OBJECTIVE: To identify predictive factors for mortality of patients with upper limb necrotising fasciitis. DESIGN: Retrospective study. SETTING: Six hospitals in Hong Kong. PATIENTS: Clinical records of 29 patients treated in the hospitals were traced and analysed. MAIN OUTCOME MEASURES: Possible predictive factors for mortality as evaluated by application of Fisher's test. RESULTS: Overall mortality was 28%. Digital infections conferred a lower mortality, but progressive necrosis necessitated amputation. Vibrio vulnificus was the commonest organism identified in association with marine injury and in patients with cirrhosis. Prognostic indicators with decreasing significance include deranged renal and liver function, thrombocytopaenia, proximal involvement (elbow or above) initially, and presence of hypotension upon admission. CONCLUSION: With a P value of less than 0.05, deranged renal and liver function, thrombocytopaenia, initial proximal involvement, and hypotension on admission were predictors of mortality in necrotising fasciitis affecting the upper limbs. The ALERTS (Abnormal Liver function, Extent of infection, Renal impairment, Thrombocytopenia, and Shock) score with a cutoff of 3 appeared to predict mortality.


Asunto(s)
Fascitis Necrotizante/mortalidad , Fascitis Necrotizante/complicaciones , Fascitis Necrotizante/tratamiento farmacológico , Femenino , Hong Kong , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento , Extremidad Superior
15.
Gene Ther ; 17(8): 1052-61, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20485381

RESUMEN

Cell-permeable peptides (CPPs) promote the transduction of nonpermissive cells by recombinant adenovirus (rAd) to improve the therapeutic efficacy of rAd. In this study, branched oligomerization of CPPs significantly enhanced the transduction of human mesenchymal stem cells (MSCs) by rAd in a CPP type-independent manner. In particular, tetrameric CPPs increased transduction efficiency at 3000-5000-fold lower concentrations than did monomeric CPPs. Although branched oligomerization of CPPs also increases cytotoxicity, optimal concentrations of tetrameric CPPs required for maximum transduction are at least 300-1000-fold lower than those causing 50% cytotoxicity. Furthermore, although only approximately 60% of MSCs were maximally transduced at 500 muM of monomeric CPPs, >95% of MSCs were transduced with 0.1 muM of tetrameric CPPs. Tetrameric CPPs also significantly increased the formation and net surface charge of CPP/rAd complexes, as well as the binding of rAd to cell membranes at a greater degree than did monomeric CPPs, followed by rapid internalization into MSCs. In a critical-size calvarial defect model, the inclusion of tetrameric CPPs in ex vivo transduction of rAd expressing bone morphogenetic protein 2 into MSCs promoted highly mineralized bone formation. In addition, MSCs that were transduced with rAd expressing brain-derived neurotrophic factor in the presence of tetrameric CPPs improved functional recovery in a spinal cord injury model. These results demonstrated the potential for tetrameric CPPs to provide an innovative tool for MSC-based gene therapy and for in vitro gene delivery to MSCs.


Asunto(s)
Adenoviridae/genética , Péptidos de Penetración Celular/química , Terapia Genética/métodos , Células Madre Mesenquimatosas/metabolismo , Transducción Genética/métodos , Animales , Enfermedades Óseas/genética , Enfermedades Óseas/terapia , Proteína Morfogenética Ósea 2/genética , Técnicas de Transferencia de Gen , Vectores Genéticos , Humanos , Masculino , Células Madre Mesenquimatosas/citología , Osteogénesis/genética , Ratas , Ratas Sprague-Dawley , Cráneo/crecimiento & desarrollo
16.
Minim Invasive Neurosurg ; 53(1): 25-8, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20376741

RESUMEN

INTRODUCTION: Because of the increasing use of magnetic resonance imaging (MRI), thoracic soft disc herniations are being easily detected in the early stages. To avoid a high morbidity rate and other complications that are associated with the conventional approach, the authors have applied a percutaneous endoscopic technique. METHODS: From May 2001 to July 2007, fourteen patients with soft lateral or central thoracic disc herniation (TDH) underwent percutaneous endoscopic thoracic discectomy. Under local anesthesia with intravenous sedation, the authors removed the herniated disc through the thoracic intervertebral foramen after performing a foraminoplasty, which is the enlargement of the foramen by cutting the lateral and inferior part of the superior facet with a round cutter. The clinical outcome was evaluated using the visual analogue scale (VAS) and Oswestry disability index (ODI). RESULTS Six patients were male and eight were female, aged 21-75 years (mean: 48.1 years). Mean follow-up period was 60.2 months (15-89 months), mean operative time was 61 min. The mean VAS improved from 6.5 to 3.0 for back pain and 5.8 to 2.5 for leg pain at the final follow-up. The mean ODI scores also improved from 58.1 before surgery to 24.5 at the final follow-up. Conversion to an open procedure was not required for any of the patients. DISCUSSION: As it has been proven to lessen the morbidity rate, this percutaneous endoscopic thoracic discectomy (PETD) technique for symptomatic soft TDH is a safe and effective method that provides a direct route to the lesion under local anesthesia.


Asunto(s)
Discectomía Percutánea/métodos , Desplazamiento del Disco Intervertebral/cirugía , Neuroendoscopía/métodos , Vértebras Torácicas/cirugía , Adulto , Anciano , Diagnóstico Precoz , Femenino , Fluoroscopía , Estudios de Seguimiento , Humanos , Procesamiento de Imagen Asistido por Computador , Desplazamiento del Disco Intervertebral/diagnóstico , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Vértebras Torácicas/patología , Tomografía Computarizada por Rayos X , Adulto Joven
17.
J Obstet Gynaecol ; 30(5): 439-43, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20604642

RESUMEN

This study was conducted to examine the behaviour and facial expressions of the fetus after birth by 4-dimensional (4-D) ultrasonography, and the association of the biophysical profile (BPP) with the Doppler scale. A total of 40 singleton pregnancies were included. All 4-D ultrasonographies were performed using the Accuvix XQ (Medison Co. Ltd, Seoul, Republic of Korea). The BPP and Doppler were performed on gravidas using 2-D ultrasonography. We recorded the newborn while awake no later than 48 h after delivery. The most frequent movement in fetuses and newborn was yawning and isolated arm movements, respectively. Sucking, swallowing (r = 0.78) and isolated limb movements (r = 0.72) in fetuses as observed by 4-D ultrasonography had a relationship with isolated limb movements in the newborn. Because of the limitation of ultrasonography, an overall comparison could not be made. There was a high correlation between sucking, swallowing, and isolated limb movements in fetuses and newborn.


Asunto(s)
Cara/diagnóstico por imagen , Expresión Facial , Movimiento Fetal , Conducta del Lactante , Ultrasonografía Prenatal/métodos , Femenino , Humanos , Recién Nacido , Embarazo
18.
Anal Chem ; 81(6): 2043-52, 2009 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-19231844

RESUMEN

In many settings, molecular testing is needed but unavailable due to complexity and cost. Simple, rapid, and specific DNA detection technologies would provide important alternatives to existing detection methods. Here we report a novel, rapid nucleic acid detection method based on the accelerated photobleaching of the light-sensitive cyanine dye, 3,3'-diethylthiacarbocyanine iodide (DiSC(2)(3) I(-)), in the presence of a target genomic DNA and a complementary peptide nucleic acid (PNA) probe. On the basis of the UV-vis, circular dichroism, and fluorescence spectra of DiSC(2)(3) with PNA-DNA oligomer duplexes and on characterization of a product of photolysis of DiSC(2)(3) I(-), a possible reaction mechanism is proposed. We propose that (1) a novel complex forms between dye, PNA, and DNA, (2) this complex functions as a photosensitizer producing (1)O(2), and (3) the (1)O(2) produced promotes photobleaching of dye molecules in the mixture. Similar cyanine dyes (DiSC(3)(3), DiSC(4)(3), DiSC(5)(3), and DiSC(py)(3)) interact with preformed PNA-DNA oligomer duplexes but do not demonstrate an equivalent accelerated photobleaching effect in the presence of PNA and target genomic DNA. The feasibility of developing molecular diagnostic assays based on the accelerated photobleaching (the smartDNA assay) that results from the novel complex formed between DiSC(2)(3) and PNA-DNA is under way.


Asunto(s)
Benzotiazoles/química , Carbocianinas/química , Colorantes/química , Sondas de Oligonucleótidos/química , Ácidos Nucleicos de Péptidos/química , Fotoblanqueo , Análisis de Secuencia de ADN/métodos , Catálisis , Dicroismo Circular , ADN/química , Técnicas de Diagnóstico Molecular , Espectrofotometría Ultravioleta
19.
Science ; 266(5186): 763-70, 1994 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-7973627

RESUMEN

The three-dimensional structure of a ternary complex of the purine repressor, PurR, bound to both its corepressor, hypoxanthine, and the 16-base pair purF operator site has been solved at 2.7 A resolution by x-ray crystallography. The bipartite structure of PurR consists of an amino-terminal DNA-binding domain and a larger carboxyl-terminal corepressor binding and dimerization domain that is similar to that of the bacterial periplasmic binding proteins. The DNA-binding domain contains a helix-turn-helix motif that makes base-specific contacts in the major groove of the DNA. Base contacts are also made by residues of symmetry-related alpha helices, the "hinge" helices, which bind deeply in the minor groove. Critical to hinge helix-minor groove binding is the intercalation of the side chains of Leu54 and its symmetry-related mate, Leu54', into the central CpG-base pair step. These residues thereby act as "leucine levers" to pry open the minor groove and kink the purF operator by 45 degrees.


Asunto(s)
Proteínas Bacterianas/química , Proteínas de Unión al ADN/química , ADN/metabolismo , Proteínas de Escherichia coli , Regiones Operadoras Genéticas , Proteínas Represoras/química , Secuencia de Aminoácidos , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Secuencia de Bases , Sitios de Unión , Gráficos por Computador , Cristalografía por Rayos X , ADN/química , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Enlace de Hidrógeno , Hipoxantina , Hipoxantinas/metabolismo , Represoras Lac , Modelos Moleculares , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , Conformación Proteica , Estructura Secundaria de Proteína , Proteínas Represoras/genética , Proteínas Represoras/metabolismo
20.
Science ; 248(4951): 64-6, 1990 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-2157285

RESUMEN

A complementary DNA (cDNA) clone that encodes inositol 1,4,5-trisphosphate 3-kinase was isolated from a rat brain cDNA expression library with the use of monoclonal antibodies. This clone had an open reading frame that would direct the synthesis of a protein consisting of 449 amino acids and with a molecular mass of 49,853 daltons. The putative protein revealed a potential calmodulin-binding site and six regions with amino acid compositions (PEST regions) common to proteins that are susceptible to calpain. Expression of the cDNA in COS cells resulted in an approximately 150-fold increase in inositol 1,4,5-trisphosphate 3-kinase activity of these cells.


Asunto(s)
Clonación Molecular , ADN/genética , Expresión Génica , Fosfotransferasas (Aceptor de Grupo Alcohol) , Fosfotransferasas/genética , Secuencia de Aminoácidos , Animales , Sitios de Unión , Encéfalo/enzimología , Calcio/metabolismo , Calmodulina/metabolismo , Calpaína/antagonistas & inhibidores , Calpaína/farmacología , Línea Celular , Codón , Datos de Secuencia Molecular , Peso Molecular , Fosfotransferasas/metabolismo , Plásmidos , Ratas , Transfección
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