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OBJECTIVES: To evaluate the feasibility of using deep-learning algorithms to classify as normal or abnormal sonographic images of the fetal brain obtained in standard axial planes. METHODS: We included in the study images retrieved from a large hospital database from 10 251 normal and 2529 abnormal pregnancies. Abnormal cases were confirmed by neonatal ultrasound, follow-up examination or autopsy. After a series of pretraining data processing steps, 15 372 normal and 14 047 abnormal fetal brain images in standard axial planes were obtained. These were divided into training and test datasets (at case level rather than image level), at a ratio of approximately 8:2. The training data were used to train the algorithms for three purposes: performance of image segmentation along the fetal skull, classification of the image as normal or abnormal and localization of the lesion. The accuracy was then tested on the test datasets, with performance of segmentation being assessed using precision, recall and Dice's coefficient (DICE), calculated to measure the extent of overlap between human-labeled and machine-segmented regions. We assessed classification accuracy by calculating the sensitivity and specificity for abnormal images. Additionally, for 2491 abnormal images, we determined how well each lesion had been localized by overlaying heat maps created by an algorithm on the segmented ultrasound images; an expert judged these in terms of how satisfactory was the lesion localization by the algorithm, classifying this as having been done precisely, closely or irrelevantly. RESULTS: Segmentation precision, recall and DICE were 97.9%, 90.9% and 94.1%, respectively. For classification, the overall accuracy was 96.3%. The sensitivity and specificity for identification of abnormal images were 96.9% and 95.9%, respectively, and the area under the receiver-operating-characteristics curve was 0.989 (95% CI, 0.986-0.991). The algorithms located lesions precisely in 61.6% (1535/2491) of the abnormal images, closely in 24.6% (614/2491) and irrelevantly in 13.7% (342/2491). CONCLUSIONS: Deep-learning algorithms can be trained for segmentation and classification of normal and abnormal fetal brain ultrasound images in standard axial planes and can provide heat maps for lesion localization. This study lays the foundation for further research on the differential diagnosis of fetal intracranial abnormalities. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.
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Encéfalo/diagnóstico por imagem , Aprendizado Profundo , Feto/diagnóstico por imagem , Malformações do Sistema Nervoso/diagnóstico por imagem , Ultrassonografia Pré-Natal/classificação , Encéfalo/anormalidades , Encéfalo/embriologia , Diagnóstico Diferencial , Estudos de Viabilidade , Feminino , Feto/anormalidades , Feto/embriologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Malformações do Sistema Nervoso/embriologia , Gravidez , Curva ROC , Sensibilidade e EspecificidadeRESUMO
Communication is closely related to safe practice and patient outcomes. Given that most clinicians fall into routines when communicating with patients, it is important to address communication issues early. This study explores Taiwanese nursing students' experiences of communication with patients with cancer and their families. Senior nursing students who had cared for cancer patients were recruited to participate in focus group interviews. These semi-structured interviews were recorded and transcribed for content analysis. Among the 45 participants, about 36% of them never received any communication training. Up to 76% of the participants stated that their communication with cancer patients was difficult and caused them emotional stress. Subsequent data analysis revealed four themes: disengagement, reluctance, regression and transition. Students' negative communication experiences were related to the patients' terminally ill situation; the students' lack of training, low self-efficacy and power status, poor emotional regulation, and cultural considerations. The findings of this study provide a deeper understanding of nursing students' communication experiences in oncology settings within the cultural context. Early and appropriate communication training is necessary to help students regulate their emotions and establish effective communication skills. Further studies are needed to examine the relationship among students' emotional labour, communication skills and outcomes.
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Barreiras de Comunicação , Neoplasias/enfermagem , Relações Enfermeiro-Paciente , Estudantes de Enfermagem/psicologia , Aprendizagem da Esquiva , Cuidadores , Medo/psicologia , Feminino , Humanos , Masculino , Neoplasias/psicologia , Rejeição em Psicologia , Autoeficácia , Adulto JovemRESUMO
The demand for molecular analysis of aquatic microbial communities in freshwater has highlighted the need for efficient methods of DNA extraction. The centrifugation method and filtration-membrane method are 2 widely used methods for extracting DNA. The objective of this study was to compare the extraction efficiency of 3 methods, including the centrifugation method, filtration-membrane method, and modified filtration-membrane method, by evaluating the quantity and purity of DNA extracts obtained from water. DNA extraction was analyzed by agarose gel electrophoresis, ultraviolet-spectroscopy, restriction enzyme digestion, and polymerase chain reaction. The results showed that the modified filtration-membrane method was the most efficient for extracting microbial DNA from freshwater with high integrity and purity and is suitable for molecular applications.
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Bactérias/isolamento & purificação , Centrifugação/métodos , Cromatografia em Gel/métodos , DNA Bacteriano/isolamento & purificação , Bactérias/genética , DNA Bacteriano/genética , Água Doce/microbiologiaRESUMO
The generalized tight-binding model with exact diagonalization method is developed to calculate the optical properties of monolayer graphene in the presence of composite magnetic fields. The ratio of the uniform magnetic field and the modulated one accounts for a strong influence on the structure, number, intensity and frequency of absorption peaks, and thus the extra selection rules that are subsequently induced can be explained. When the modulated field increases, each symmetric peak, under a uniform magnetic field, splits into a pair of asymmetric peaks with lower intensities. The threshold absorption frequency exhibits an obvious evolution in terms of a redshift. These absorption peaks obey the same selection rule that is followed by Landau level transitions. Moreover, at a sufficiently strong modulation strength, the extra peaks in the absorption spectrum might arise from different selection rules.
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Using lattice simulations, we study the infrared behavior of a particularly interesting SU(2) gauge theory, with six massless Dirac fermions in the fundamental representation. We compute the running gauge coupling derived nonperturbatively from the Schrödinger functional of the theory, finding no evidence for an infrared fixed point up through gauge couplings g(2) of order 20. This implies that the theory either is governed in the infrared by a fixed point of considerable strength, unseen so far in nonsupersymmetric gauge theories, or breaks its global chiral symmetries producing a large number of composite Nambu-Goldstone bosons relative to the number of underlying degrees of freedom. Thus either of these phases exhibits novel behavior.
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Objective: To assess the clinical features and effectiveness of antiviral therapy in newborns with sensorineural hearing loss (SNHL) caused by congenital congenital cytomegalovirus (cCMV) infection, and to speculate the risk factors for poor hearing outcomes. Methods: A multicenter prospective cohort study wasconducted, enrolling 176 newborns diagnosed with cCMV at four research centers in Zhejiang Province from March 1, 2021, to April 30, 2024. Clinical characteristics at birth were recorded and hearing was followed up. The children were divided into groups based on their condition at birth, specifically into asymptomatic, mild symptom, and moderate to severe symptom groups. Additionally, they were divided into SNHL and normal hearing groups based on the results of air conduction brainstem audiometry at birth. And they were also divided into treatment and untreated groups according to antiviral treatment. Mann Whitney U test, and chi square test were used for inter group comparison to analyze the differences in clinical features between different disease groups, and to analyze the effects of clinical features, antiviral therapy, and other factors on hearing improvement. Logistic regression analysis was employed to identify the risk factors influencing hearing outcomes. Results: Among the cohort of 176 children diagnosed infection with cCMV, 90 cases were male and 86 cases were female. Of these, 79 cases were asymptomatic, 12 cases classified as mild cCMV and 85 cases as moderate to severe cCMV. Fifty cases belonged to SNHL group, with different degrees of severity, including 30 cases of mild, 9 cases of moderate, 5 cases of severe, and 6 cases of extremely severe SNHL. Among the 121 cases in the normal hearing group, 2 cases (1.7%) exhibited late-onset hearing loss despite having normal hearing at birth. Among 81 cases (46.0%) who completed the hearing follow-up, 71 cases (87.7%) had good hearing outcomes and 10 cases (12.3%) had poor hearing outcomes. Among the 81 children, 29 cases (35.8%) had SNHL at birth. During follow-up, the hearing threshold improved in 19 cases (65.5%), remained stable in 7 cases (24.1%) and progressed in 3 cases (10.3%). A total of 26 cases in the treatment group and 55 cases in the untreated group completed the hearing follow-up assessment. The rate of hearing improvement in the treatment group was found to be higher compared to the untreated group (13 cases (50.0%) vs. 6 cases (10.9%), χ2=15.00, P<0.01), with individuals in the treatment group having a 4.58 times greater likelihood of experiencing hearing improvement (RR=4.58,95%CI 1.96-10.70, P<0.05). However, no statistically significant difference was observed in hearing outcomes between the antiviral treatment group and the untreated group (RR=0.90, 95%CI 0.57-1.41, P=0.517). Multivariate analysis further confirmed SNHL (OR=11.58, 95%CI 2.10-63.93, P=0.005) and preterm birth (OR=4.98, 95%CI 1.06-23.41, P=0.042) as independent risk factors for poor hearing outcomes. Conclusions: SNHL resulting from cCMV infection presents symptoms at birth and can be improved by antiviral therapy. Poor hearing outcomes are associated with SNHL and prematurity.
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Antivirais , Infecções por Citomegalovirus , Perda Auditiva Neurossensorial , Humanos , Infecções por Citomegalovirus/congênito , Infecções por Citomegalovirus/complicações , Masculino , Feminino , Recém-Nascido , Estudos Prospectivos , Perda Auditiva Neurossensorial/virologia , Perda Auditiva Neurossensorial/etiologia , Antivirais/uso terapêutico , Fatores de Risco , Citomegalovirus , Lactente , Modelos LogísticosRESUMO
Attosecond-pump/attosecond-probe experiments have long been sought as the most straightforward method for observing electron dynamics in real time. Although there has been much success with overlapped near-infrared femtosecond and extreme ultraviolet attosecond pulses combined with theory, true attosecond-pump/attosecond-probe experiments have been limited. We used a synchronized attosecond x-ray pulse pair from an x-ray free-electron laser to study the electronic response to valence ionization in liquid water through all x-ray attosecond transient absorption spectroscopy (AX-ATAS). Our analysis showed that the AX-ATAS response is confined to the subfemtosecond timescale, eliminating any hydrogen atom motion and demonstrating experimentally that the 1b1 splitting in the x-ray emission spectrum is related to dynamics and is not evidence of two structural motifs in ambient liquid water.
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Electrocyclic reactions are characterized by the concerted formation and cleavage of both σ and π bonds through a cyclic structure. This structure is known as a pericyclic transition state for thermal reactions and a pericyclic minimum in the excited state for photochemical reactions. However, the structure of the pericyclic geometry has yet to be observed experimentally. We use a combination of ultrafast electron diffraction and excited state wavepacket simulations to image structural dynamics through the pericyclic minimum of a photochemical electrocyclic ring-opening reaction in the molecule α-terpinene. The structural motion into the pericyclic minimum is dominated by rehybridization of two carbon atoms, which is required for the transformation from two to three conjugated π bonds. The σ bond dissociation largely happens after internal conversion from the pericyclic minimum to the electronic ground state. These findings may be transferrable to electrocyclic reactions in general.
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Superconductivity and charge density waves (CDWs) are competitive, yet coexisting, orders in cuprate superconductors. To understand their microscopic interdependence, a probe capable of discerning their interaction on its natural length and time scale is necessary. We use ultrafast resonant soft x-ray scattering to track the transient evolution of CDW correlations in YBa2Cu3O6+x after the quench of superconductivity by an infrared laser pulse. We observe a nonthermal response of the CDW order characterized by a near doubling of the correlation length within ≈1 picosecond of the superconducting quench. Our results are consistent with a model in which the interaction between superconductivity and CDWs manifests inhomogeneously through disruption of spatial coherence, with superconductivity playing the dominant role in stabilizing CDW topological defects, such as discommensurations.
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Optical selection rules for one-dimensional graphene nanoribbons are explored based on the tight-binding model. A theoretical explanation, through analyzing the velocity matrix elements and the features of the wavefunctions, can account for the selection rules, which depend on the edge structure of the nanoribbon, i.e., armchair or zigzag edges. The selection rule of armchair nanoribbons is ΔJ = Jc - Jv = 0, and the optical transitions occur from the conduction to the valence subbands of the same index. Such a selection rule originates in the relationships between two sublattices and between the conduction and valence subbands. On the other hand, zigzag nanoribbons exhibit the selection rule |ΔJ| = odd, which results from the alternatively changing symmetry property as the subband index increases. Furthermore, an efficient theoretical prediction on transition energies is obtained by the application of selection rules, and the energies of the band-edge states become experimentally attainable via optical measurements.
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We describe a lattice simulation of the masses and decay constants of the lowest-lying vector and axial resonances, and the electroweak S parameter, in an SU(3) gauge theory with N(f)=2 and 6 fermions in the fundamental representation. The spectrum becomes more parity doubled and the S parameter per electroweak doublet decreases when N(f) is increased from 2 to 6, motivating study of these trends as N(f) is increased further, toward the critical value for transition from confinement to infrared conformality.
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The radiolysis of water is ubiquitous in nature and plays a critical role in numerous biochemical and technological applications. Although the elementary reaction pathways for ionized water have been studied, the short-lived intermediate complex and structural dynamic response after the proton transfer reaction remain poorly understood. Using a liquid-phase ultrafast electron diffraction technique to measure the intermolecular oxygen···oxygen and oxygen···hydrogen bonds, we captured the short-lived radical-cation complex OH(H3O+) that was formed within 140 femtoseconds through a direct oxygen···oxygen bond contraction and proton transfer, followed by the radical-cation pair dissociation and the subsequent structural relaxation of water within 250 femtoseconds. These measurements provide direct evidence of capturing this metastable radical-cation complex before separation, thereby improving our fundamental understanding of elementary reaction dynamics in ionized liquid water.
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A candidate antimicrobial peptide (AmAMP1) was identified by searching the whole genome sequence of Acropora millepora for short (<125AA) cysteine-rich predicted proteins with an N-terminal signal peptide but lacking clear homologs in the SwissProt database. It resembled but was not closely related to damicornin, the only other known AMP from a coral, and was shown to be active against both Gram-negative and Gram-positive bacteria. These proteins define a family of AMPs present in corals and their close relatives, the Corallimorpharia, and are synthesised as preproproteins in which the C-terminal mature peptide contains a conserved arrangement of six cysteine residues. Consistent with the idea of a common origin for AMPs and toxins, this Cys motif is shared between the coral AMPs and the Shk neurotoxins of sea anemones. AmAMP1 is expressed at late stages of coral development, in ectodermal cells that resemble the "ganglion neurons" of Hydra, in which it has recently been demonstrated that a distinct AMP known as NDA-1 is expressed.
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Antozoários/imunologia , Peptídeos Antimicrobianos/genética , Cnidários/imunologia , Venenos de Cnidários/genética , Ectoderma/metabolismo , Anêmonas-do-Mar/imunologia , Animais , Peptídeos Antimicrobianos/metabolismo , Sequência Conservada , Cisteína/genética , Filogenia , Especificidade da Espécie , Homologia Estrutural de ProteínaRESUMO
Conformational isomers (conformers) of molecules play a decisive role in biology and organic chemistry. However, experimental methods for investigating chemical reaction dynamics are typically not conformer-sensitive. We report on a gas-phase megaelectronvolt ultrafast electron diffraction investigation of α-phellandrene undergoing an electrocyclic ring-opening reaction. We directly imaged the evolution of a specific set of α-phellandrene conformers into the product isomer predicted by the Woodward-Hoffmann rules in real space and time. Our experimental results are in quantitative agreement with nonadiabatic quantum molecular dynamics simulations, which provide considerable detail of how conformation influences the time scale and quantum efficiency of photoinduced ring-opening reactions.
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Developing femtosecond resolution methods for directly observing structural dynamics is critical to understanding complex photochemical reaction mechanisms in solution. We have used two recent developments, ultrafast mega-electron-volt electron sources and vacuum compatible sub-micron thick liquid sheet jets, to enable liquid-phase ultrafast electron diffraction (LUED). We have demonstrated the viability of LUED by investigating the photodissociation of tri-iodide initiated with a 400 nm laser pulse. This has enabled the average speed of the bond expansion to be measured during the first 750 fs of dissociation and the geminate recombination to be directly captured on the picosecond time scale.
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The low-energy magnetoelectronic structures of nanographene ribbons under a modulated magnetic field are investigated by the Peierls tight-binding model. They are dominated by the field strength, period, phase, the ribbon width, and edge structure. The modulated magnetic field could add state degeneracy, modify energy dispersions, alter subband spacings, affect carrier-density distributions, create additional band-edge states, and cause semiconductor-metal transitions. The main features of energy bands are directly reflected in density of states, such as the position, height, structure, and number of the prominent peaks. These results immensely differ from those in a uniform magnetic field. Significant differences between a 1D graphene ribbon and a 2D electron gas are also found.
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AIMS: To compare bacterial populations and antimicrobial resistance patterns between clinical and sewage isolates from a regional hospital in northern Taiwan. The dissemination of antibiotic-resistant bacteria from hospital compartments to the hospital sewage treatment plant was examined. METHODS AND RESULTS: A total of 1020 clinical isolates and 435 sewage isolates were collected between July and September 2005. The percentages of Gram-negative bacteria from the clinical and sewage isolates were 87.2% and 91.0%, respectively (P = 0.033). Escherichia coli were the leading bacterial isolates in both groups. Antimicrobial susceptibility testing showed a significant difference (P < 0.001) in resistance to ampicillin (85.6% vs 94.1%), ampicillin/sulbactam (31.7% vs 55.4%), cefazolin (29.2% vs 71.5%) and cefuroxime (20.7% vs 61.9%) between clinical and sewage coliform isolates, respectively. CONCLUSIONS: The sewage isolates had higher antimicrobial resistance rates than the clinical isolates from the same hospital. SIGNIFICANCE AND IMPACT OF THE STUDY: The low efficacy of the hospital sewage treatment may contribute to the dissemination of multidrug resistant bacteria from this hospital compartments to the environment. Practices which limit the disposal of antimicrobial agents into the wastewater system may be the possible measure to prevent the selection of multidrug-resistant bacteria from sewage treatment plants.
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Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Bacterianas/microbiologia , Farmacorresistência Bacteriana Múltipla , Esgotos/microbiologia , Bactérias/isolamento & purificação , Hospitais de Ensino , Humanos , TaiwanRESUMO
The growth and progression of prostate cancer are dependent on androgens and androgen receptor (AR), which act by modulating gene expression. Utilizing a gene microarray approach, we have identified the alpha1-subunit gene of soluble guanylyl cyclase (sGC) as a novel androgen-regulated gene. A heterodimeric cytoplasmic protein composed of one alpha and one beta subunit, sGC mediates the widespread cellular effects of nitric oxide (NO). We report here that, in prostate cancer cells, androgens stimulate the expression of sGCalpha1. A cloned human sGCalpha1 promoter is activated by androgen in an AR-dependent manner, suggesting that sGCalpha1 may be a direct AR target gene. Disruption of sGCalpha1 expression severely compromises the growth of both androgen-dependent and androgen-independent AR-positive prostate cancer cells. Overexpression of sGCalpha1 alone is sufficient for stimulating prostate cancer cell proliferation. Interestingly, the major growth effect of sGCalpha1 is independent of NO and cyclic guanosine monophosphate, a major mediator of the sGC enzyme. These data strongly suggest that sGCalpha1 acts in prostate cancer via a novel pathway that does not depend on sGCbeta1. Tissue studies show that sGCalpha1 expression is significantly elevated in advanced prostate cancer. Thus, sGCalpha1 may be an important mediator of the procarcinogenic effects of androgens.