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1.
Nature ; 620(7976): 965-970, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37648757

RESUMEN

Subjecting a physical system to extreme conditions is one of the means often used to obtain a better understanding and deeper insight into its organization and structure. In the case of the atomic nucleus, one such approach is to investigate isotopes that have very different neutron-to-proton (N/Z) ratios than in stable nuclei. Light, neutron-rich isotopes exhibit the most asymmetric N/Z ratios and those lying beyond the limits of binding, which undergo spontaneous neutron emission and exist only as very short-lived resonances (about 10-21 s), provide the most stringent tests of modern nuclear-structure theories. Here we report on the first observation of 28O and 27O through their decay into 24O and four and three neutrons, respectively. The 28O nucleus is of particular interest as, with the Z = 8 and N = 20 magic numbers1,2, it is expected in the standard shell-model picture of nuclear structure to be one of a relatively small number of so-called 'doubly magic' nuclei. Both 27O and 28O were found to exist as narrow, low-lying resonances and their decay energies are compared here to the results of sophisticated theoretical modelling, including a large-scale shell-model calculation and a newly developed statistical approach. In both cases, the underlying nuclear interactions were derived from effective field theories of quantum chromodynamics. Finally, it is shown that the cross-section for the production of 28O from a 29F beam is consistent with it not exhibiting a closed N = 20 shell structure.

2.
Nature ; 580(7803): 350-354, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32296190

RESUMEN

Quantum computers are expected to outperform conventional computers in several important applications, from molecular simulation to search algorithms, once they can be scaled up to large numbers-typically millions-of quantum bits (qubits)1-3. For most solid-state qubit technologies-for example, those using superconducting circuits or semiconductor spins-scaling poses a considerable challenge because every additional qubit increases the heat generated, whereas the cooling power of dilution refrigerators is severely limited at their operating temperature (less than 100 millikelvin)4-6. Here we demonstrate the operation of a scalable silicon quantum processor unit cell comprising two qubits confined to quantum dots at about 1.5 kelvin. We achieve this by isolating the quantum dots from the electron reservoir, and then initializing and reading the qubits solely via tunnelling of electrons between the two quantum dots7-9. We coherently control the qubits using electrically driven spin resonance10,11 in isotopically enriched silicon12 28Si, attaining single-qubit gate fidelities of 98.6 per cent and a coherence time of 2 microseconds during 'hot' operation, comparable to those of spin qubits in natural silicon at millikelvin temperatures13-16. Furthermore, we show that the unit cell can be operated at magnetic fields as low as 0.1 tesla, corresponding to a qubit control frequency of 3.5 gigahertz, where the qubit energy is well below the thermal energy. The unit cell constitutes the core building block of a full-scale silicon quantum computer and satisfies layout constraints required by error-correction architectures8,17. Our work indicates that a spin-based quantum computer could be operated at increased temperatures in a simple pumped 4He system (which provides cooling power orders of magnitude higher than that of dilution refrigerators), thus potentially enabling the integration of classical control electronics with the qubit array18,19.

3.
Nature ; 569(7757): 532-536, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-31086337

RESUMEN

Universal quantum computation will require qubit technology based on a scalable platform1, together with quantum error correction protocols that place strict limits on the maximum infidelities for one- and two-qubit gate operations2,3. Although various qubit systems have shown high fidelities at the one-qubit level4-10, the only solid-state qubits manufactured using standard lithographic techniques that have demonstrated two-qubit fidelities near the fault-tolerance threshold6 have been in superconductor systems. Silicon-based quantum dot qubits are also amenable to large-scale fabrication and can achieve high single-qubit gate fidelities (exceeding 99.9 per cent) using isotopically enriched silicon11,12. Two-qubit gates have now been demonstrated in a number of systems13-15, but as yet an accurate assessment of their fidelities using Clifford-based randomized benchmarking, which uses sequences of randomly chosen gates to measure the error, has not been achieved. Here, for qubits encoded on the electron spin states of gate-defined quantum dots, we demonstrate Bell state tomography with fidelities ranging from 80 to 89 per cent, and two-qubit randomized benchmarking with an average Clifford gate fidelity of 94.7 per cent and an average controlled-rotation fidelity of 98 per cent. These fidelities are found to be limited by the relatively long gate times used here compared with the decoherence times of the qubits. Silicon qubit designs employing fast gate operations with high Rabi frequencies16,17, together with advanced pulsing techniques18, should therefore enable much higher fidelities in the near future.

4.
Phys Rev Lett ; 133(1): 012501, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-39042802

RESUMEN

To search for low-energy resonant structures in isospin T=3/2 three-body systems, we have performed the experiments ^{3}H(t,^{3}He)3n and ^{3}He(^{3}He,t)3p at intermediate energies. For the 3n experiment, we have newly developed a thick Ti-^{3}H target that has the largest tritium thickness among targets of this type ever made. The 3n experiment for the first time covered the momentum-transfer region as low as 15 MeV/c, which provides ideal conditions for producing fragile systems. However, in the excitation-energy spectra we obtained, we did not observe any distinct peak structures. This is in sharp contrast to tetraneutron spectra. The distributions of the 3n and 3p spectra are found to be similar, except for the displacement in energy due to Coulomb repulsion. Comparisons with theoretical calculations suggest that three-body correlations exist in the 3n and 3p systems, although not enough to produce a resonant peak.

5.
Phys Rev Lett ; 133(8): 082501, 2024 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-39241734

RESUMEN

The neutron-rich unbound fluorine isotope ^{30}F_{21} has been observed for the first time by measuring its neutron decay at the SAMURAI spectrometer (RIBF, RIKEN) in the quasifree proton knockout reaction of ^{31}Ne nuclei at 235 MeV/nucleon. The mass and thus one-neutron-separation energy of ^{30}F has been determined to be S_{n}=-472±58(stat)±33(sys) keV from the measurement of its invariant-mass spectrum. The absence of a sharp drop in S_{n}(^{30}F) shows that the "magic" N=20 shell gap is not restored close to ^{28}O, which is in agreement with our shell-model calculations that predict a near degeneracy between the neutron d and fp orbitals, with the 1p_{3/2} and 1p_{1/2} orbitals becoming more bound than the 0f_{7/2} one. This degeneracy and reordering of orbitals has two potential consequences: ^{28}O behaves like a strongly superfluid nucleus with neutron pairs scattering across shells, and both ^{29,31}F appear to be good two-neutron halo-nucleus candidates.

6.
Nanotechnology ; 35(33)2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38763138

RESUMEN

Oxide/metal/oxide multilayers as a transparent conducting electrode (TCE) have been developed to replace metals due to their high transparency and low sheet resistance. Nickel oxide (NiO) film with a high work function was used as an oxide to form NiO/Ag/NiO (NAN) TCE, therefore a high barrier height between NAN/zinc oxide (ZnO) interface. In the study, NAN TCE was deposited on ZnO surface to fabricate metal-semiconductor-metal (MSM) photodetectors (PDs) and study its carrier transport mechanism. The NAN TCE has a low sheet resistance of 6.5 Ω/sq. and transmittance more than 40% in a 300-1000 nm wavelength range. Such issues result in the figure-of-merit is higher (2.3 × 10-4Ω-1) than that (2.5 × 10-7Ω-1) of pure single NiO thin film. As compared to the conventional Au/ZnO MSM-PDs, the NAN/ZnO MSM-PDs demonstrates a lower leakage current as a result of Ni atoms diffusing into ZnO and passivating the defects. Due to the high work function of NiO, the NAN/ZnO interface exhibits a barrier height as high as 0.91 eV. The Au/ZnO MSM-PDs reveals only one carrier conduction of ohmic due to the electrons tunnel form Au into ZnO through the surface defects. In contrast, two distinct carrier transport mechanisms were observed in the NAN/ZnO MSM-PDs. At low-voltage forV⩽0.64 V, ohmic conduction dominates and the electrons inject from NAN to ZnO, trapped by the defect states of ZnO. At high-voltage for V⩾0.64 V, the trapped electrons acquire enough energy and emit from trap to conduction band, entering Poole-Frankel emission transport.

8.
Clin Radiol ; 79(1): e73-e79, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37914602

RESUMEN

AIM: To evaluate inter-reader agreement between novice and expert radiologists in assessing contrast-enhanced ultrasonography (CEUS) and magnetic resonance imaging (MRI) images for detecting viable tumours with different sizes after conventional transarterial chemoembolisation (cTACE). MATERIALS AND METHODS: This prospective study included patients who had less than five hepatomas and who underwent cTACE. Hepatomas with one or two feeding arteries were selected as target lesions. CEUS and MRI were performed within 1 week after cTACE to evaluate viable tumours. RESULTS: The expert group had higher kappa values in evaluating all tumour sizes via CEUS compared with MRI. The novice group had similar kappa values. In patients with tumours measuring ≤3 cm, the expert group had higher kappa values in reading CEUS compared with MRI images; however, in the novice group, the kappa value was lower in evaluating CEUS compared with MRI images. In patients with tumours measuring >3 cm, the expert and novice groups had good to excellent kappa values. The confidence level of the two groups in reading MRI images was high; however, the novice group had a lower confidence level. CONCLUSION: CEUS is a convenient, cost-effective, and easy to apply imaging tool that can help interventionists perform early detection of viable hepatocellular carcinoma post-TACE. It has a higher inter-rater agreement in interpreting CEUS images compared with MRI images among expert radiologists even when they are extremely familiar with post-cTACE MRI images. In novice radiologists, there may be a learning curve to achieve good consistency in CEUS interpretation.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/terapia , Carcinoma Hepatocelular/irrigación sanguínea , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/terapia , Neoplasias Hepáticas/irrigación sanguínea , Estudios Prospectivos , Medios de Contraste , Ultrasonografía/métodos , Imagen por Resonancia Magnética
9.
Anaesthesia ; 78(1): 64-72, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36198200

RESUMEN

Unanticipated difficult laryngoscopy is associated with serious airway-related complications. We aimed to develop and test a convolutional neural network-based deep-learning model that uses lateral cervical spine radiographs to predict Cormack-Lehane grade 3 or 4 direct laryngoscopy views of the glottis. We analysed the radiographs of 5939 thyroid surgery patients at our hospital, 253 (4%) of whom had grade 3 or 4 glottic views. We used 10 randomly sampled datasets to train a model. We compared the new model with six similar models (VGG, ResNet, Xception, ResNext, DenseNet and SENet). The Brier score (95%CI) of the new model, 0.023 (0.021-0.025), was lower ('better') than the other models: VGG, 0.034 (0.034-0.035); ResNet, 0.033 (0.033-0.035); Xception, 0.032 (0.031-0.033); ResNext, 0.033 (0.032-0.033); DenseNet, 0.030 (0.029-0.032); SENet, 0.031 (0.029-0.032), all p < 0.001. We calculated mean (95%CI) of the new model for: R2 , 0.428 (0.388-0.468); mean squared error, 0.023 (0.021-0.025); mean absolute error, 0.048 (0.046-0.049); balanced accuracy, 0.713 (0.684-0.742); and area under the receiver operating characteristic curve, 0.965 (0.962-0.969). Radiographic features around the hyoid bone, pharynx and cervical spine were associated with grade 3 and 4 glottic views.


Asunto(s)
Aprendizaje Profundo , Humanos
10.
Nature ; 526(7573): 410-4, 2015 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-26436453

RESUMEN

Quantum computation requires qubits that can be coupled in a scalable manner, together with universal and high-fidelity one- and two-qubit logic gates. Many physical realizations of qubits exist, including single photons, trapped ions, superconducting circuits, single defects or atoms in diamond and silicon, and semiconductor quantum dots, with single-qubit fidelities that exceed the stringent thresholds required for fault-tolerant quantum computing. Despite this, high-fidelity two-qubit gates in the solid state that can be manufactured using standard lithographic techniques have so far been limited to superconducting qubits, owing to the difficulties of coupling qubits and dephasing in semiconductor systems. Here we present a two-qubit logic gate, which uses single spins in isotopically enriched silicon and is realized by performing single- and two-qubit operations in a quantum dot system using the exchange interaction, as envisaged in the Loss-DiVincenzo proposal. We realize CNOT gates via controlled-phase operations combined with single-qubit operations. Direct gate-voltage control provides single-qubit addressability, together with a switchable exchange interaction that is used in the two-qubit controlled-phase gate. By independently reading out both qubits, we measure clear anticorrelations in the two-spin probabilities of the CNOT gate.

11.
Clin Radiol ; 76(2): 156.e19-156.e26, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33256975

RESUMEN

AIM: To investigate the image quality and radiation dose of ultralow-dose (ULD) and low-dose (LD) lower-extremity computed tomography (CT) angiography (LE-CTA) using the advanced modelled iterative reconstruction (ADMIRE) algorithm to detect peripheral arterial disease (PAD) in comparison with standard-dose (SD) CT. MATERIALS AND METHODS: One hundred and seven consecutive patients were examined using LE-CTA at 70 kVp and a dual-source scanner to achieve three image sets using 30% (ULD), 70% (LD), and 100% (SD) tube loads. Qualitative analysis was conducted by examining the three image sets for overall quality. The image quality of arterial segments was analysed by two independent readers. In addition, the CT dose index (CTDIvol) was measured in the three image sets. RESULTS: The mean overall quality scores were 3.4±0.6 for ULD CT, 3.9±0.3 for LD CT, and 3.9±0.2 for SD CT. Both readers scored the arterial segments as 2-4 (adequate-excellent) in the three image sets. In addition, 89.4% (93/104) and 54.8% (57/104) segments of PAD with calcified plaques were scored 4 between SD and LD CT and between SD and ULD CT, respectively, and 45.2% (47/104) segments had a lower score by one point in ULD CT compared with SD CT. The mean CTDIvol was 4.1±1.1 mGy for SD CT, 2.9±0.8 mGy for LD CT, and 1.2±0.3 mGy for ULD CT. CONCLUSIONS: LD/ULD CT at 70 kVp using ADMIRE reconstruction enables a reduction in the radiation dose while enabling adequate evaluation or follow-up of PAD based on LE-CTA.


Asunto(s)
Angiografía por Tomografía Computarizada/métodos , Extremidad Inferior/diagnóstico por imagen , Enfermedad Arterial Periférica/diagnóstico por imagen , Dosis de Radiación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Estudios Retrospectivos , Adulto Joven
12.
Phys Rev Lett ; 125(24): 247703, 2020 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-33412043

RESUMEN

Intermediate band solar cells (IBSCs) promise high efficiencies while maintaining a low device structural complexity. A high efficiency can be obtained by harvesting below-band-gap photons, thus increasing the current, while at the same time preserving a high voltage. Here, we provide experimental proof that below-band-gap photons can be used to produce nonzero electrical work in an IBSC without compromising the voltage. For this, we manufacture a GaSb/GaAs quantum-dot IBSC. We use light biasing and make our cell operate at the maximum power point at 9 K. We measure the photocurrent response to absorption of photons with an energy of less than 1.15 eV while the cell is operating at 1.15 V. We also show that this result implies the existence of three quasi-Fermi levels linked to the three electronic bands in our device, as demanded by the IBSC theory to preserve the output voltage of the cell.

13.
Phys Rev Lett ; 124(15): 152502, 2020 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-32357034

RESUMEN

Detailed spectroscopy of the neutron-unbound nucleus ^{28}F has been performed for the first time following proton/neutron removal from ^{29}Ne/^{29}F beams at energies around 230 MeV/nucleon. The invariant-mass spectra were reconstructed for both the ^{27}F^{(*)}+n and ^{26}F^{(*)}+2n coincidences and revealed a series of well-defined resonances. A near-threshold state was observed in both reactions and is identified as the ^{28}F ground state, with S_{n}(^{28}F)=-199(6) keV, while analysis of the 2n decay channel allowed a considerably improved S_{n}(^{27}F)=1620(60) keV to be deduced. Comparison with shell-model predictions and eikonal-model reaction calculations have allowed spin-parity assignments to be proposed for some of the lower-lying levels of ^{28}F. Importantly, in the case of the ground state, the reconstructed ^{27}F+n momentum distribution following neutron removal from ^{29}F indicates that it arises mainly from the 1p_{3/2} neutron intruder configuration. This demonstrates that the island of inversion around N=20 includes ^{28}F, and most probably ^{29}F, and suggests that ^{28}O is not doubly magic.

14.
Phys Rev Lett ; 124(21): 212503, 2020 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-32530691

RESUMEN

The heaviest bound isotope of boron ^{19}B has been investigated using exclusive measurements of its Coulomb dissociation, into ^{17}B and two neutrons, in collisions with Pb at 220 MeV/nucleon. Enhanced electric dipole (E1) strength is observed just above the two-neutron decay threshold with an integrated E1 strength of B(E1)=1.64±0.06(stat)±0.12(sys) e^{2} fm^{2} for relative energies below 6 MeV. This feature, known as a soft E1 excitation, provides the first firm evidence that ^{19}B has a prominent two-neutron halo. Three-body calculations that reproduce the energy spectrum indicate that the valence neutrons have a significant s-wave configuration and exhibit a dineutronlike correlation.

15.
Nanotechnology ; 31(34): 345205, 2020 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-32403098

RESUMEN

Conventionally, p-NiO/n-Si (p-n) heterojunction photodiodes (HPDs) exhibit a larger visible response than the ultraviolet response due to the thick Si substrate; hence, it is used as a broadband photodetector with a poor ultraviolet (UV)-to-visible rejection ratio. Herein, an intrinsic NiO (i-NiO) layer is inserted between the p-NiO and the n-Si substrate to fabricate p-NiO/i-NiO/n-Si (p-i-n) HPDs, significantly suppressing leakage current and visible response. Compared with the conventional p-n HPDs, the insertion of the i-NiO layer significantly reduces leakage current by approximately 241 times and enhances the rectification ratio from 13.8 to 3228 for the p-n and p-i-n HPDs. The insertion of an i-NiO layer not only increases the UV-response but also suppresses the visible response. These issues enhance the UV-to-visible rejection ratio from 72.2 in p-n HPDs to 915.3 in p-i-n HPDs. The p-NiO reveals a poorer crystalline structure than the i-NiO film because the Ag dopants accumulate at the grain boundary and inhibit crystalline growth. The Ag diffusion in the Si substrate causes defect states within the Si bandgap, whereas it is retarded by the i-NiO layer in the p-i-n HPDs. The poor crystallinity in the p-NiO and defect states within the Si bandgap contributes to a high leakage current and visible response in p-n HPDs. The p-i-n HPDs demonstrate a higher UV-response due to absorption by the i-NiO layer. Because visible light cannot be absorbed by the i-NiO layer, visible response is suppressed in p-i-n HPDs.

16.
J Appl Microbiol ; 129(2): 287-295, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32145045

RESUMEN

AIMS: Emergence and rapid dissemination of antibiotic-resistant bacteria is becoming a severe problem to public health. The search for antimicrobial substitutes for antibiotics is necessary. Lactoferricin B like peptide (LBLP) is a 23-mer antimicrobial peptide (AMP), derived from the big centipede Scolopendra subspinipes mutilans. Although its antifungal effect and its mechanism have been reported, the antibacterial activity has not yet been elucidated. METHOD AND RESULTS: In this study, we investigated antibacterial activity of LBLP and its mode of action. LBLP showed potent antibacterial effect against pathogenic bacteria Escherichia coli and did not show haemolytic activity against human erythrocyte. The general antimicrobial mechanism of AMP is to disrupt the cell membrane, however, LBLP exerted its antibacterial activity by causing apoptosis-like death through reactive oxygen species (ROS) generation. LBLP-treated E. coli cells exhibited hallmarks of apoptosis, such as membrane depolarization, DNA fragmentation, caspase-like protein activation and phosphatidylserine exposure. These apoptotic features were attenuated by pretreatment of NAC, a representative ROS scavenger. CONCLUSIONS: These results demonstrate that LBLP exerted its antibacterial activity by generating ROS and inducing apoptosis-like death in E. coli. LBLP is not membrane destructive per se, but essentially a metabolic inhibitor. SIGNIFICANCE AND IMPACT OF THE STUDY: Lactoferricin B like peptide is potential candidate to replace conventional antibiotics that are less effective because of its unique properties.


Asunto(s)
Antibacterianos/farmacología , Apoptosis/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Lactoferrina/farmacología , Especies Reactivas de Oxígeno/metabolismo , Animales , Antibacterianos/química , Artrópodos/química , Escherichia coli/metabolismo , Humanos , Lactoferrina/química , Péptidos/química , Péptidos/farmacología
17.
J Appl Microbiol ; 128(5): 1524-1531, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31883170

RESUMEN

AIMS: As cell-adapted foot-and-mouth disease virus (FMDV) with H56R mutation in VP3 has reduced thermostability, this study aimed to investigate the effect of thermostabilizers on cell-adapted FMDV for vaccine production. METHODS AND RESULTS: We examined the effect of 3% sucrose, 10% (or 25%) glycerol or 10% FBS on cell-adapted FMDV O/SKR/JC/2014, containing H56R mutation in VP3, as vaccine seed virus at -80, 4, 25 or 37°C for 2, 4 or 7 days. The stabilizing effect of 3% sucrose on O/SKR/JC/2014 was observed at 25, 37°C, and after repeated freeze-thaw cycles. Additionally, we tested the effect of 3% sucrose on the growth of FMDV or cells and did not observe any decrease in either viral growth or cell viability. CONCLUSIONS: Our study showed the protective effect of 3% sucrose on FMDV infectivity at various temperatures; this virus stock in 3% sucrose could be used for infecting cells without the removal of sucrose. SIGNIFICANCE AND IMPACT OF THE STUDY: We suggest that 3% sucrose-containing medium could be beneficial for the stable storage and transport of cell-adapted FMDV.


Asunto(s)
Virus de la Fiebre Aftosa/crecimiento & desarrollo , Sacarosa/análisis , Excipientes de Vacunas/análisis , Vacunas Virales/química , Animales , Proteínas de la Cápside/genética , Supervivencia Celular/efectos de los fármacos , Fiebre Aftosa/virología , Virus de la Fiebre Aftosa/efectos de los fármacos , Virus de la Fiebre Aftosa/genética , Virus de la Fiebre Aftosa/inmunología , Mutación , Sacarosa/farmacología , Temperatura , Excipientes de Vacunas/farmacología , Potencia de la Vacuna
18.
Anaesthesia ; 75(2): 179-186, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31631314

RESUMEN

The aim of this study was to evaluate the effectiveness of cricoid and paralaryngeal force for oesophageal entrance occlusion during induction of anaesthesia. Seventy-four patients were included in this randomised, crossover study. The relative position of the glottis and outer anteroposterior diameter of the upper oesophageal entrance were assessed at baseline, after the application of 30 N cricoid and paralaryngeal force, and after induction of anaesthesia. The occlusion rate of the oesophageal entrance with cricoid and paralaryngeal force was assessed during direct laryngoscopy. The relative position of the upper oesophageal entrance to the glottis changed in 45 out of 74 patients after induction of anaesthesia and during direct laryngoscopy compared with the awake state. The application of cricoid and paralaryngeal force decreased the mean (SD) diameter of the upper oesophageal entrance to a similar degree in awake (8.5 (2.1) mm to 6.4 (1.7) mm and 6.5 (1.6) mm, respectively; p < 0.001) and anaesthetised (8.7 (2.2) mm to 6.5 (1.7) mm and (6.7 (1.9) mm, respectively; p < 0.001) states. During direct laryngoscopy, the occlusion rate of the oesophageal entrance was greater with cricoid compared with paralaryngeal force (46/74 vs. 26/74, respectively; p = 0.002). The relative position of the upper oesophageal entrance to the glottis may change after induction of anaesthesia and during direct laryngoscopy. Cricoid and paralaryngeal force both decrease the diameter of the upper oesophageal entrance in awake and anaesthetised states. Occlusion of the oesophageal entrance is achieved more frequently with cricoid force compared with paralaryngeal force during direct laryngoscopy.


Asunto(s)
Anestesia/métodos , Cartílago Cricoides/anatomía & histología , Esófago/anatomía & histología , Laringoscopía/métodos , Laringe/anatomía & histología , Ultrasonografía/métodos , Estudios Cruzados , Femenino , Humanos , Intubación Intratraqueal/métodos , Masculino , Persona de Mediana Edad , Presión
19.
Anaesthesist ; 69(5): 352-358, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32152737

RESUMEN

BACKGROUND: Intense noxious input from the periphery may result in central sensitization and hyperexcitability, thus accentuating subsequent postoperative pain. Parturients who undergo emergency cesarean section (C-sec) after experiencing labor pain often develop labor pain-induced sensitization. OBJECTIVE: This retrospective study evaluated whether parturients without epidural labor analgesia (ELA) who underwent emergency C­sec, experienced more severe postoperative pain and required more rescue analgesics during the postoperative period. METHODS: The institution's medical database was searched for parturients who underwent emergency C­sec under spinal anesthesia for any reason between January 2013 and December 2016. Those who underwent elective C­sec under spinal anesthesia were included as the reference arm. Parturients were divided into three groups: ELA, no-ELA and elective. Characteristics of patients and perioperative outcomes were evaluated. As primary outcomes, numerical rating scale (NRS) for postoperative pain (0-10) was recorded up to 96 h postoperatively, and use of rescue analgesics was evaluated at 6, 24, and 48 h postoperatively. RESULTS: In the ELA, no-ELA, and elective groups, 61, 73, and 88 parturients, respectively, were ultimately enrolled. The NRS for pain were similar among the three groups, except at 6 h postoperatively. Parturients in the no-ELA group demonstrated significantly higher NRS at 6 h postoperatively than those in the ELA group (P = 0.01).More patients in the no-ELA group required rescue analgesics than in the ELA (P = 0.001) and elective groups (P < 0.001) at 6-24 h postoperatively. Moreover, the proportion of patients requiring rescue analgesics ≥2 times was also significantly higher in the no-ELA group (vs. the ELA group, P = 0.004; vs. the elective group, P < 0.001). CONCLUSION: Parturients undergoing emergency C­sec without ELA management during labor experienced greater postoperative pain and a greater use of rescue analgesics during the postoperative period. The findings suggest that administration of ELA before emergency C­sec may act as pre-emptive analgesia against postoperative pain.


Asunto(s)
Analgesia Epidural , Anestesia Obstétrica , Cesárea , Dolor Postoperatorio/tratamiento farmacológico , Adulto , Analgésicos , Anestesia Epidural , Anestesia Raquidea , Anestésicos Locales/administración & dosificación , Femenino , Humanos , Embarazo , Estudios Retrospectivos
20.
Nutr Metab Cardiovasc Dis ; 29(1): 30-38, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30545672

RESUMEN

BACKGROUND AND AIM: Hyperuricemia (HUA) is associated with the prevalence of metabolic syndrome (MetS) and cardiovascular risks in various populations. HUA is also able to induce cardiomyocyte hypertrophy in mouse models. However, the dose-response effects of serum uric acid (SUA) on the prevalence of MetS and electrocardiographic left ventricular hypertrophy (LVH) are unclear. METHODS AND RESULTS: We retrospectively collected data from 18,932 individuals who underwent an annual health examination between 1/1/2016 and 12/31/2016. We excluded those with systemic diseases or missing questionnaires. The primary study endpoints were the prevalence of MetS and LVH, which were defined by the criteria for the Taiwanese population and the "SPRINT" trial. The cohort consisted of 17,913 individuals with a mean age of 31.2 years (SD 7.4) and a mean body mass index of 24.6 kg/m2 (SD 3.6); 87.1% of the individuals were men. The prevalence rates of HUA, MetS, and LVH were 29.5%, 9.4%, and 0.32%, respectively, in the overall study population. The HUA group was predominantly male and had significantly poorer lifestyle choices and greater laboratory cardiometabolic biomarker values than did the normouricemic group. However, the frequencies of physical activity were comparable between the two groups. After adjusting for confounders, SUA was associated with MetS (OR:1.473, 95% CI:1.408-1.540, P < 0.001) and LVH (OR:1.301, 95% CI:1.064-1.591, P = 0.01). CONCLUSION: We demonstrated that the dose-response effects of SUA are associated with the prevalence of MetS and electrocardiographic LVH in healthy individuals from Taiwan. Based on this evidence, future studies should investigate urate-lowering therapy and cardiovascular benefits in individuals with HUA (ClinicalTrials.gov number NCT03473951).


Asunto(s)
Electrocardiografía , Hipertrofia Ventricular Izquierda/epidemiología , Hiperuricemia/epidemiología , Síndrome Metabólico/epidemiología , Ácido Úrico/sangre , Adulto , Biomarcadores/sangre , Femenino , Humanos , Hipertrofia Ventricular Izquierda/diagnóstico , Hiperuricemia/sangre , Hiperuricemia/diagnóstico , Masculino , Síndrome Metabólico/sangre , Síndrome Metabólico/diagnóstico , Valor Predictivo de las Pruebas , Prevalencia , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Taiwán/epidemiología , Adulto Joven
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