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1.
Nature ; 570(7761): 344-348, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31217601

RESUMO

In 1928, Dirac proposed a wave equation to describe relativistic electrons1. Shortly afterwards, Klein solved a simple potential step problem for the Dirac equation and encountered an apparent paradox: the potential barrier becomes transparent when its height is larger than the electron energy. For massless particles, backscattering is completely forbidden in Klein tunnelling, leading to perfect transmission through any potential barrier2,3. The recent advent of condensed-matter systems with Dirac-like excitations, such as graphene and topological insulators, has opened up the possibility of observing Klein tunnelling experimentally4-6. In the surface states of topological insulators, fermions are bound by spin-momentum locking and are thus immune from backscattering, which is prohibited by time-reversal symmetry. Here we report the observation of perfect Andreev reflection in point-contact spectroscopy-a clear signature of Klein tunnelling and a manifestation of the underlying 'relativistic' physics of a proximity-induced superconducting state in a topological Kondo insulator. Our findings shed light on a previously overlooked aspect of topological superconductivity and can serve as the basis for a unique family of spintronic and superconducting devices, the interface transport phenomena of which are completely governed by their helical topological states.

2.
J Ultrasound Med ; 43(5): 923-930, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38298028

RESUMO

PURPOSE: To explore prenatal ultrasonic features and prognosis of the persistent left superior vena cava (PLSVC) complicated with mild narrow aorta. MATERIALS AND METHODS: A retrospective study was conducted involving 1348 fetuses diagnosed with PLSVC prenatally between January 2016 and December 2019. Forty-five fetuses with PLSVC associated with mild narrow aorta were selected from the cohort as the study group and 79 fetuses with isolated PLSCV were recruited randomly as the control group. All clinical and ultrasound results, including images and parameters of cardiac structures, were reviewed retrospectively. General conditions, ultrasound (US) measurements, and fetal prognosis were compared between the groups. RESULTS: Aorta valve diameter (AOD), Z-score of aorta valve (AODz-score), aortic isthmus diameter (AOIsD), and pulmonary diameter (PAD)/AOD were significantly different in study group than control group no matter in the second or third trimester. Thirty-eight fetuses in study group were born with favorable outcomes after long-term follow-up. A total of 13.16% (5/38) remain mild narrow aorta and 3 of them showed smaller left ventricle after 3 years follow up. Prenatal AODz-score in infants remains mild narrow aorta after 2 years aged was higher than ones' aorta return to normal (P = .01), especially when AODz-score >1.725. Moreover, when prenatal ratio of AOIsD/left subclavian artery was <1.12, it was more likely that the aorta would remain mildly narrow at age 2. CONCLUSION: Fetuses diagnosed with PLSVC with mild narrow aorta had favorable prognosis. AODz-score and AOIsD/left subclavian artery may be two predictors that reveal the risk of a mildly narrowed aorta remaining after birth.


Assuntos
Veia Cava Superior Esquerda Persistente , Gravidez , Feminino , Lactente , Humanos , Idoso , Pré-Escolar , Estudos de Coortes , Estudos Retrospectivos , Veia Cava Superior/diagnóstico por imagem , Ultrassonografia Pré-Natal/métodos , Diagnóstico Pré-Natal , Aorta/diagnóstico por imagem
3.
Am J Perinatol ; 2023 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-37068514

RESUMO

OBJECTIVE: This study aimed to explore the efficiency of ultrasound (US) in prenatal diagnosis and prognosis of Pierre Robin sequence (PRS) of 18 cases. STUDY DESIGN: A total of 79,305 women admitted for prenatal US examinations were recruited from January 2017 to December 2020. Eighteen cases of PRS fetuses were selected form the cohort and 40 cases of isolated micrognathia were recruited randomly as control group. All the clinical and imaging results were retrospectively reviewed. General condition, US measurements, and prognosis of fetuses were compared between groups. RESULTS: Cleft palate, glossoptosis, and micrognathia were found in all 18 fetuses with PRS by prenatal US. Compared with the isolated micrognathia group, there were no significant differences in the PRS group in examination of maternal age, gestational weeks at assessment, and gender of fetuses, but significant lower measures in inferior facial angle, jaw index, and frontal nasal-mental angle (each p < 0.05). Twelve fetuses were defined to have other associated malformations. Ear malformations were the most common associated malformations with a prevalence of 44.4% (8/18). All of the18 cases were confirmed with PRS after delivery or autopsy. Two delivered infants were found bucking easily, one baby was spitting up frequently but growth showed normal. CONCLUSION: Prenatal detection of PRS with US examination is highly efficient. Even with the triad of malformations, isolated PRS had good outcomes following initial stabilization and management in the neonatal period. Prenatal detection of Pierre Robin syndrome with targeted US examination is efficient in discerning characteristics of this rare syndrome. Even with the triad of malformations, isolated PRS had good outcomes following initial stabilization and management in the neonatal period. KEY POINTS: · Prenatal diagnosis of fetal PRS is of great clinical importance.. · Micrognathia has been identified as the primary feature of PRS.. · Posterior displacement of the tongue may cause acute neonatal respiratory distress.. · Even with triad malformation, isolated PRS seemed to have good outcomes..

4.
Luminescence ; 38(8): 1521-1528, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37296519

RESUMO

To obtain optimal luminescence, 0.12 g of GdVO4 :3%Eu3+ nanocrystals (NCs) and different volumes of nitrogen-doped carbon dots (N-CDs) crude solution were used as precursors, and the composite synthesized using the hydrothermal deposition method showed optimal luminescence when 11 ml (2.45 mmol) crude solution was used. In addition, similar composites with the same molar ratio as GVE/cCDs(11) were also prepared with the hydrothermal and physical mixing processes. Based on the test results of XRD, XPS, and PL spectra, for the composite GVE/cCDs(11), the highest (lowest) peak intensity of the C-C/C=C (C=O/C=N) bond, which was 1.18 (0.75) times that of GVE/cCDs-m, indicated most N-CDs deposition and led to their highest emission intensity under 365 nm excitation, although nitrogen atoms in the composite were shed slightly during the deposition process. Finally, as can be seen from the patterns designed for security applications that the optimally luminescent composite is one of the most promising candidates in the anti-counterfeiting field.


Assuntos
Luminescência , Nanopartículas , Carbono/química , Nitrogênio/química
5.
Ultraschall Med ; 44(1): e39-e46, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34015837

RESUMO

PURPOSE: To determine the association between levator avulsion and urinary stress incontinence (USI) by 3/4D transperineal ultrasound. MATERIALS AND METHODS: 842 patients who were admitted to our hospital from 2016 to 2019 were recruited for our study. 3D/4D transperineal ultrasound was performed. After standard interview and clinical evaluation, general conditions and levator hiatus data were collected and measured to compare with each group. The odds ratio (OR) of USI symptoms or ultrasound features with levator avulsion were calculated. RESULTS: A total of 593 women were studied: 204 suffered from levator avulsion (96 cases of left-side avulsion, 80 cases of right-side avulsion and 28 cases of bilateral avulsion) and 389 women had no avulsion. The gravidity and episiotomy conditions of the avulsion groups were significantly different from the no-avulsion group. Significant differences were found in the transverse diameters and anteroposterior diameters between the levator avulsion group and the no-avulsion group, but there was no difference among the avulsion groups, regardless of whether the patient was at rest or performing the Valsalva maneuver. Interestingly, a significant difference was found in the presence of USI symptoms between the uni-avulsion group and the no-avulsion group. The odds ratio (OR) of USI symptoms in the uni-avulsion group is 2.786 (95 %CI, 1.663-4.669), but 0.939 (95 %CI, 0.276-3.199) for the bilateral avulsion and no-avulsion groups. CONCLUSION: Unilateral levator avulsion may be a risk factor for urinary stress incontinence.


Assuntos
Incontinência Urinária por Estresse , Humanos , Feminino , Gravidez , Parto Obstétrico , Ultrassonografia , Imageamento Tridimensional , Fatores de Risco
6.
Sensors (Basel) ; 23(11)2023 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-37299857

RESUMO

Tunable Diode Laser Absorption Spectroscopy (TDLAS) has been widely applied in in situ and real-time monitoring of trace gas concentrations. In this paper, an advanced TDLAS-based optical gas sensing system with laser linewidth analysis and filtering/fitting algorithms is proposed and experimentally demonstrated. The linewidth of the laser pulse spectrum is innovatively considered and analyzed in the harmonic detection of the TDLAS model. The adaptive Variational Mode Decomposition-Savitzky Golay (VMD-SG) filtering algorithm is developed to process the raw data and could significantly eliminate the background noise variance by about 31% and signal jitters by about 12.5%. Furthermore, the Radial Basis Function (RBF) neural network is also incorporated and applied to improve the fitting accuracy of the gas sensor. Compared with traditional linear fitting or least squares method (LSM), the RBF neural network brings along the enhanced fitting accuracy within a large dynamic range, achieving an absolute error of below 50 ppmv (about 0.6%) for the maximum 8000 ppmv methane. The proposed technique in this paper is universal and compatible with TDLAS-based gas sensors without hardware modification, allowing direct improvement and optimization for current optical gas sensors.


Assuntos
Lasers Semicondutores , Dispositivos Ópticos , Algoritmos , Análise Espectral , Redes Neurais de Computação
7.
Phys Rev Lett ; 129(1): 010502, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35841558

RESUMO

Superconducting qubits provide a promising path toward building large-scale quantum computers. The simple and robust transmon qubit has been the leading platform, achieving multiple milestones. However, fault-tolerant quantum computing calls for qubit operations at error rates significantly lower than those exhibited in the state of the art. Consequently, alternative superconducting qubits with better error protection have attracted increasing interest. Among them, fluxonium is a particularly promising candidate, featuring large anharmonicity and long coherence times. Here, we engineer a fluxonium-based quantum processor that integrates high qubit coherence, fast frequency tunability, and individual-qubit addressability for reset, readout, and gates. With simple and fast gate schemes, we achieve an average single-qubit gate fidelity of 99.97% and a two-qubit gate fidelity of up to 99.72%. This performance is comparable to the highest values reported in the literature of superconducting circuits. Thus our work, within the realm of superconducting qubits, reveals an alternative qubit platform that is competitive with the transmon system.

8.
Eur Phys J E Soft Matter ; 44(10): 126, 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34633556

RESUMO

This study investigates phase separation behavior and pattern formation in a binary fluid with chemical reaction controlled by thermal diffusion. By incorporating the Arrhenius equation into the lattice Boltzmann method (LBM), the coupling effects of the pre-exponential factor K, viscosity [Formula: see text], and thermal diffusion D on phase separation were successfully evaluated. The effect of the competition between thermal diffusion and concentration on the phase separation morphology and dynamics of binary mixtures under a chemically reacting controlled by slow cooling is assessed based on the extended LBM. The calculations indicated that increases in viscosity and thermal diffusion can obtain interconnected structures (ISs) and lamellar structures (LSs) for cases with small K. However, concentric phase-separated structures (CSs) were observed in cases with large K. The increase in the degree and efficiency of phase separation were significantly greater in cases with decreased viscosity and increased thermal diffusion.

9.
Environ Res ; 194: 110622, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33359699

RESUMO

Halogenated methyl sulfonic acid (HMSAs) is a new type of disinfection by-product recently reported, and there are few relevant studies, so its source and harm are still unclear. This study mainly discusses the source of halogenated methyl sulfonic acid from the macroscopic level and evaluates the harm to human health. This study clarified that chlorine disinfection is one of the main ways of generating halogenated methyl sulfonic acids (HMSAs) in drinking water. The macroscopic properties of HMSA precursors were analyzed through liquid chromatograph-mass spectrometry (LC-MS/MS), 3D fluorescence, and Fourier transform infrared spectrometry. The results showed that polar and positively charged organic compounds with molecular weights of >3 KDa or <0.5 KDa can readily generate HMSAs. By analyzing the main components of natural organic compounds in water and comparing them with the characteristics of organic compounds such as dimethyl sulfoxide and ethyl mercaptan, it meant that natural organic compounds are easily degraded. Humic and fulvic acids contribute the most to HMSA generation. This study lasted for three years and collected water samples from 102 waterworks in 24 cities in China, and the existence of HMSAs in drinking water in different cities was analyzed. The potential health risks associated with HMSAs were used by the United States Environmental Protection Agency (U.S. EPA) health risk assessment model. The average and maximum concentrations of HMSAs in tap water from key cities in China were taken as evaluation objects. The results showed that the carcinogenic risk coefficient (R) value of both concentrations was far lower than the lowest acceptable carcinogenic risk (1.0 × 10-6) provided by U.S. EPA. Therefore, HMSAs in drinking water in China currently pose no human health risks.


Assuntos
Água Potável , Poluentes Químicos da Água , Purificação da Água , China , Cromatografia Líquida , Cidades , Desinfecção , Humanos , Ácidos Sulfônicos , Espectrometria de Massas em Tandem , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
10.
Arch Gynecol Obstet ; 303(3): 811-820, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33394142

RESUMO

PURPOSE: Our objective was to establish a random forest model and to evaluate its predictive capability of the treatment effect of neoadjuvant chemotherapy-radiation therapy. METHODS: This retrospective study included 82 patients with locally advanced cervical cancer who underwent scanning from March 2013 to May 2018. The random forest model was established and optimised based on the open source toolkit scikit-learn. Byoptimising of the number of decision trees in the random forest, the criteria for selecting the final partition index and the minimum number of samples partitioned by each node, the performance of random forest in the prediction of the treatment effect of neoadjuvant chemotherapy-radiation therapy on advanced cervical cancer (> IIb) was evaluated. RESULTS: The number of decision trees in the random forests influenced the model performance. When the number of decision trees was set to 10, 25, 40, 55, 70, 85 and 100, the performance of random forest model exhibited an increasing trend first and then a decreasing one. The criteria for the selection of final partition index showed significant effects on the generation of decision trees. The Gini index demonstrated a better effect compared with information gain index. The area under the receiver operating curve for Gini index attained a value of 0.917. CONCLUSION: The random forest model showed potential in predicting the treatment effect of neoadjuvant chemotherapy-radiation therapy based on high-resolution T2WIs for advanced cervical cancer (> IIb).


Assuntos
Colo do Útero/efeitos dos fármacos , Colo do Útero/efeitos da radiação , Quimiorradioterapia/métodos , Terapia Neoadjuvante/métodos , Neoplasias do Colo do Útero/terapia , Adulto , Colo do Útero/diagnóstico por imagem , Árvores de Decisões , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Avaliação de Resultados em Cuidados de Saúde , Estudos Retrospectivos , Neoplasias do Colo do Útero/patologia
11.
Fetal Diagn Ther ; 48(9): 641-650, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34510037

RESUMO

OBJECTIVE: The aim of the study was to evaluate whether fetal ultrasound could determine bronchial isomerism and distinguish left isomerism from right isomerism. METHODS: We identified 110 healthy fetuses and 28 fetuses with isomerism. The outer angle between the tracheal midline and the inner margin of the bronchus is measured. The bronchial angles and the ratio of left/right bronchial angle were used to differentiate bronchial morphology and confirm the presence of bronchial isomerism in pathological cases. RESULTS: The normal angles of the left and right bronchi were 146.98° (95% CI, 145.15-147.81°) and 167.37° (95% CI, 166.30-168.44°), separately. The cutoff bronchial angle of 156.5° was used to distinguish left bronchus from right bronchus. The bronchial isomerism could be identified in all pathological cases by autopsy and bronchial-atrial concordance occurred in 27 pathological cases (96.4%). In 21 pathological cases, the bilateral bronchial angle was <156.5 versus >156.5 differentiated left from right isomerism, respectively. The ratio of the left/right bronchial angle of >0.935 identified 92.9% (26/28) of all pathological cases, with a sensitivity of 89.7%. CONCLUSIONS: Fetal ultrasound can detect the bronchial morphology and the presence of bronchial isomerism in fetuses with isomerism according to bronchial angles and the ratio of left/right bronchial angle.


Assuntos
Síndrome de Heterotaxia , Ultrassom , Brônquios/diagnóstico por imagem , Feminino , Feto/diagnóstico por imagem , Humanos , Isomerismo
12.
J Clin Ultrasound ; 49(7): 770-773, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33885168

RESUMO

Right ventricular aneurysm is a rare congenital defect that can be diagnosed with fetal echocardiography. Information on etiology of right ventricular aneurysm is limited and its prognosis remains variable from asymptomatic forms to severe cases. Here we report three cases of fetal right ventricular aneurysms that could have been related to coronary artery disorders and needed regular monitoring of progression in size and signs of cardiac decompensation.


Assuntos
Aneurisma Cardíaco , Cardiopatias Congênitas , Adulto , Ecocardiografia , Feminino , Feto , Aneurisma Cardíaco/diagnóstico por imagem , Cardiopatias Congênitas/diagnóstico por imagem , Humanos , Gravidez , Diagnóstico Pré-Natal , Ultrassonografia Pré-Natal
13.
Nano Lett ; 17(5): 2825-2832, 2017 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-28418675

RESUMO

Electric-field (E-field) control of magnetism enabled by multiferroic materials has the potential to revolutionize the landscape of present memory devices plagued with high energy dissipation. To date, this E-field controlled multiferroic scheme has only been demonstrated at room temperature using BiFeO3 films grown on DyScO3, a unique and expensive substrate, which gives rise to a particular ferroelectric domain pattern in BiFeO3. Here, we demonstrate reversible electric-field-induced switching of the magnetic state of the Co layer in Co/BiFeO3 (BFO) (001) thin film heterostructures fabricated on (001) SrTiO3 (STO) substrates. The angular dependence of the coercivity and the remanent magnetization of the Co layer indicates that its easy axis reversibly switches back and forth 45° between the (100) and the (110) crystallographic directions of STO as a result of alternating application of positive and negative voltage pulses between the patterned top Co electrode layer and the (001) SrRuO3 (SRO) layer on which the ferroelectric BFO is epitaxially grown. The coercivity (HC) of the Co layer exhibits a hysteretic behavior between two states as a function of voltage. A mechanism based on the intrinsic magnetoelectric coupling in multiferroic BFO involving projection of antiferromagnetic G-type domains is used to explain the observation. We have also measured the exact canting angle of the G-type domain in strained BFO films for the first time using neutron diffraction. These results suggest a pathway to integrating BFO-based devices on Si wafers for implementing low power consumption and nonvolatile magnetoelectronic devices.

14.
Int J Cancer ; 138(11): 2713-23, 2016 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-26773960

RESUMO

Tumors can induce the generation and accumulation of immunosuppressive cells such as myeloid-derived suppressor cells (MDSCs) in a tumor microenvironment, contributing to tumor escape from immunological attack. Although dendritic cell-based cancer vaccines can initiate antitumor immune responses, tumor-educated dendritic cells (TEDCs) involved in the tolerance induction have attracted much attention recently. In this study, we investigated the effect of ß-glucan on TEDCs and found that ß-glucan treatment could promote the maturation and migration of TEDCs and that the suppressive function of TEDCs was significantly decreased. Treatment with ß-glucan drastically decreased the levels of regulatory T (Treg) cells but increased the infiltration of macrophages, granulocytes and DCs in tumor masses, thus elicited Th1 differentiation and cytotoxic T-lymphocyte responses and led to a delay in tumor progression. These findings reveal that ß-glucan can inhibit the regulatory function of TEDCs, therefore revealing a novel function for ß-glucan in immunotherapy and suggesting its potential clinical benefit. ß-Glucan directly abrogated tumor-educated dendritic cells-associated immune suppression, promoted Th1 differentiation and cytotoxic T-lymphocyte priming and improved antitumor responses.


Assuntos
Vacinas Anticâncer/imunologia , Células Dendríticas/imunologia , Imunidade Celular , Células Mieloides/imunologia , Neoplasias/imunologia , Vacinas Anticâncer/uso terapêutico , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Humanos , Imunoterapia , Macrófagos/imunologia , Neoplasias/terapia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Reguladores/imunologia , Microambiente Tumoral/imunologia , beta-Glucanas/imunologia , beta-Glucanas/farmacologia
15.
BMC Cancer ; 16: 158, 2016 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-26917546

RESUMO

BACKGROUND: Combined hepatocellular-cholangiocarcinoma (cHCC-CC) is an uncommon primary liver malignancy and little known about the clinical and imaging characteristics of cHCC-CC. We aim to define the demographics, imaging features of cHCC-CC on contrast-enhanced ultrasound (CEUS) and contrast-enhanced computed tomography (CT) in this study. METHODS: From January 2005 to December 2014, 45 patients with pathologically proven cHCC-CC who underwent preoperative CEUS and 43 patients who had additional CT scan in our institution were included. A retrospective review of the imaging studies and clinical data in these patients was conducted. RESULTS: In our series, cHCC-CC accounted for 1.6 % of all primary liver malignancy. Mean age of patient with cHCC-CC was 52.8 year (range: 28-74 year) and 88.9 % (40/45) of patients were male. Thirty of forty five patients (66.7 %) had cirrhosis and 20 % (9/45) of patients had chronic hepatitis B without cirrhosis. Alpha--fetoprotein (AFP) was elevated in 62.2 % (28/45) of patients and carbohydrate antigen 19-9 (CA19-9) elevated in 22.2 % (10/45) of patients). Both AFP and CA19-9 were simultaneously elevated in 15.6 % (7/45) of patients. Enhancement pattern resembling cholangiocarcinoma (CC) was noted in 53.3 % (24/45) of patients (on CEUS and in 30.2 % (13/43) of patients at CT. Enhancement pattern resembling hepatocellular carcinoma (HCC) was observed in 42.2 % (19/45) of patients on CEUS and in 58.1 % (25/43) of patients at CT. The percentage of tumors showing CC enhancement pattern (27.9 %, 12/43) was comparable with that of tumors showing HCC enhancement pattern (44.2 %, 19/43) on both CEUS and CT (p = 0.116). Simultaneous elevation of tumor markers (AFP and CA19-9) or tumor marker elevation (AFP or CA19-9) in discordance with enhancement pattern on CEUS was demonstrated in 51.1 % (23/45) of patients and on CT in 53.5 % (23/43) of patients, which was significantly more than simultaneous elevation of tumor markers (AFP and CA19-9) alone (p = 0.000). CONCLUSIONS: The clinical characteristics of cHCC-CC are similar to those of HCC. The cHCC-CC tumors display enhancement patterns resembling CC or HCC in comparable proportion on both CEUS and CT. Combination of simultaneous elevation of tumor makers (AFP and CA19-9) and tumor mark elevation (AFP or CA19-9) in discordance with presumptive imaging findings on CEUS or CT may lead significantly more patients to be suspicious of the diagnosis of cHCC-CC.


Assuntos
Carcinoma Hepatocelular/diagnóstico , Colangiocarcinoma/diagnóstico , Aumento da Imagem , Neoplasias Hepáticas/diagnóstico , Fenótipo , Tomografia Computadorizada por Raios X , Ultrassonografia , Adulto , Idoso , Biomarcadores Tumorais , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/patologia , Colangiocarcinoma/sangue , Colangiocarcinoma/patologia , Comorbidade , Feminino , Humanos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X/métodos , Carga Tumoral , Ultrassonografia/métodos
16.
J Chem Phys ; 144(9): 094302, 2016 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-26957164

RESUMO

We present a joint experimental and theoretical study on the desolvation of Ba(+) cations in (4)He nanodroplets excited via the 6p ← 6s transition. The experiments reveal an efficient desolvation process yielding mainly bare Ba(+) cations and Ba(+)Hen exciplexes with n = 1 and 2. The speed distributions of the ions are well described by Maxwell-Boltzmann distributions with temperatures ranging from 60 to 178 K depending on the excitation frequency and Ba(+) Hen exciplex size. These results have been analyzed by calculations based on a time-dependent density functional description for the helium droplet combined with classical dynamics for the Ba(+). In agreement with experiment, the calculations reveal the dynamical formation of exciplexes following excitation of the Ba(+) cation. In contrast to experimental observation, the calculations do not reveal desolvation of excited Ba(+) cations or exciplexes, even when relaxation pathways to lower lying states are included.

17.
J Chem Phys ; 140(13): 131101, 2014 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-24712773

RESUMO

Whereas most of the phenomena associated with superfluidity have been observed in finite-size helium systems, the nucleation of quantized vortices has proven elusive. Here we show using time-dependent density functional simulations that the solvation of a Ba(+) ion created by photoionization of neutral Ba at the surface of a (4)He nanodroplet leads to the nucleation of a quantized ring vortex. The vortex is nucleated on a 10 ps timescale at the equator of a solid-like solvation structure that forms around the Ba(+) ion. The process is expected to be quite general and very efficient under standard experimental conditions.

18.
Planta Med ; 80(12): 1036-44, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25144675

RESUMO

Antitumor activity has been reported for turmeric, the dried rhizome of Curcuma longa. This study proposes a new feature selection method for the identification of the antitumor compounds in turmeric total extracts. The chemical composition of turmeric total extracts was analyzed by gas chromatography-mass spectrometry (21 ingredients) and high-performance liquid chromatography-mass spectrometry (22 ingredients), and their cytotoxicity was detected through an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay against HeLa cells. A support vector machine for regression and a generalized regression neural network were used to research the composition-activity relationship and were later combined with the mean impact value to identify the antitumor compounds. The results showed that six volatile constituents (three terpenes and three ketones) and seven nonvolatile constituents (five curcuminoids and two unknown ingredients) with high absolute mean impact values exhibited a significant correlation with the cytotoxicity against HeLa cells. With the exception of the two unknown ingredients, the identified 11 constituents have been reported to exhibit cytotoxicity. This finding indicates that the feature selection method may be a supplementary tool for the identification of active compounds from herbs.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Curcumina/uso terapêutico , Cetonas/uso terapêutico , Fitoterapia , Extratos Vegetais/uso terapêutico , Terpenos/uso terapêutico , Neoplasias do Colo do Útero/tratamento farmacológico , Antineoplásicos Fitogênicos/análise , Antineoplásicos Fitogênicos/farmacologia , Cromatografia Líquida , Curcuma/química , Curcumina/análise , Curcumina/farmacologia , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Células HeLa , Humanos , Cetonas/análise , Cetonas/farmacologia , Óleos Voláteis/análise , Óleos Voláteis/farmacologia , Óleos Voláteis/uso terapêutico , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Rizoma , Terpenos/análise , Terpenos/farmacologia , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/farmacologia , Compostos Orgânicos Voláteis/uso terapêutico
19.
Medicine (Baltimore) ; 103(26): e38668, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38941409

RESUMO

BACKGROUND: Chaihu-Shugan-San (CSS), a Traditional Chinese Medicine formula, has been widely used for treating depression since the Ming Dynasty, as recorded in Jingyue Quanshu, but its effectiveness and safety lack comprehensive and objective evaluation. Based on our meta-analysis, we aimed to adequately evaluate the efficacy and risk of CSS by considering the latest clinical literature. METHODS: Multiple databases, including PubMed, Embase, Web of Science, SinoMed, China National Knowledge Infrastructure, Chongqing VIP, and Wanfang, were used to collect clinical data. The quality of the included clinical studies was assessed using the Cochrane Risk of Bias Tool, and the data were meta-analyzed using Review Manager 5.0 and Stata 17. The data were obtained from a genome-wide association study, and Mendelian randomization (MR) was performed using R Software 4.3.2 with the TwoSampleMR and MR Pleiotropy RESidual Sum and Outlier packages. RESULTS: A total of 15 studies with 1034 patients and 6 antidepressant drugs were included in this work. Meta-analyses revealed that drug combinations of CSS and antidepressants significantly improved depressive symptoms (weighted mean difference = -4.21; 95% confidence interval [CI]: -5.62--2.81), increased the effective rate (odds ratio [OR] = 3.82; 95% CI: 2.44-6.83), and reduced side effects (OR = -3.55; 95% CI: -5.66--1.43) compared with antidepressant monotherapy. Additionally, compared with antidepressant monotherapy, CSS alone exhibited fewer side effects (95% CI:-9.25--6.95). Like antidepressants, CSS also improved depressive symptoms (weighted mean difference = -0.05; 95% CI: -0.63--0.52) and increased the effective rate (OR = 1.07; 95% CI: 0.52-2.20). Additionally, MR was used to evaluate the safety of traditional antidepressants, as there was a causal association between amitriptyline and body mass index. CONCLUSION: This analysis demonstrated that compared with traditional antidepressants, CSS combined with antidepressants was more effective and safer for treating depressed patients. MR showed that a causal relationship may exist between amitriptyline and body mass index. Therefore, clinicians should carefully consider the advantages and potential drawbacks of Traditional Chinese Medicine and classic drugs to serve patients better.


Assuntos
Antidepressivos , Depressão , Humanos , Antidepressivos/uso terapêutico , Antidepressivos/efeitos adversos , Depressão/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Extratos Vegetais/efeitos adversos , Medicamentos de Ervas Chinesas/uso terapêutico , Medicamentos de Ervas Chinesas/efeitos adversos , Resultado do Tratamento
20.
Orphanet J Rare Dis ; 19(1): 100, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38444029

RESUMO

OBJECTIVE: Poor fetal and perinatal outcomes in fetuses associated with umbilical artery thrombosis (UAT), such as severe intrauterine growth restriction (IUGR) and intrauterine asphyxia have been reported by some case series. Its hemodynamic impact remains unclear. The aim of this study was to evaluate the hemodynamic changes and perinatal outcome in UAT fetuses with a relatively large sample. METHODS: We included singleton fetuses diagnosed with UAT and with at least one available Doppler evaluation before the end of pregnancy in our center from 2016 to 2023. Fetuses with structural abnormalities and with no follow-up results were excluded. Doppler waveforms from the Umbilical artery (UA), middle cerebral artery (MCA), ductus venosus (DV) and uterine artery (UtA) were routinely evaluated according to ISUOG Practice Guidelines from diagnosis. The same sample of GA-matched normal fetuses with Doppler measurements during the same period were randomly selected as control group. RESULTS: Eighty-nine singleton fetuses with UAT with at least one Doppler evaluation before the end of pregnancy were identified, 13 fetuses with no follow-up results were excluded. After comprehensive prenatal counseling, 14 cases received urgent cesarean section, the remaining 55 cases received expectant management, the median day between GA at diagnosis and end of pregnancy was 13 (5-53) days (range, 2-159). 7 (7/76, 9.2%) cases occurred stillbirth, and the incidence of IUGR and Neonatal Intensive Care Unit (NICU) admission were 18.4% (14/76) and 13.2% (10/76) respectively. 49 fetuses (49/76, 64.5%) combined with Doppler abnormalities. UA abnormalities (35/76, 46.1%) and MCA abnormalities (34/76, 44.7%) were the most changes at presentation. Compared to control group, UA-EDV was significantly increased in UAT fetuses [21.84 (15.59-26.64) vs. 16.40 (12.43-20.70) cm/s, p < 0.001], UA-PI and UA-RI significantly decreased [0.68 (0.57-0.84) vs. 0.92 (0.79-1.11), p<0.001; 0.51 (0.44-0.59) vs. 0.62 (0.55-0.68), p < 0.001, respectively]. Both the MCA-PSV and MCA-EDV were significantly higher in UAT fetuses [54.60 (48.00-61.34) vs. 44.47 (29.66-57.60) cm/s, p < 0.001; 11.19 (7.84-17.60) vs. 8.22 (5.21-12.00) cm/s, p < 0.001, respectively], this led to a lower MCA-PI and MCA-RI. Meanwhile, DV-PIV was significantly higher in UAT fetuses [0.6 (0.47-0.87) vs. 0.45 (0.37-0.55), p < 0.001], CPR and UtA-PI were no significant difference between these two groups. Multivariate logistic regression analysis showed that DV-PIV was an independent risk factor for adverse pregnancy outcomes (OR 161.922, p<0.001), the area under the ROC curve (AUC) was 0.792 (95% CI 0.668-0.917; p < 0.001). CONCLUSION: Our data showed serious adverse pregnancy consequences are combined with UAT fetuses. Hemodynamic changes in UAT fetuses showed the remaining artery for compensation and brain perfusion derangement. With a comprehensive and standardized Doppler evaluation, progression of fetal deterioration may be detailed presented.


Assuntos
Trombose , Artérias Umbilicais , Recém-Nascido , Gravidez , Humanos , Feminino , Artérias Umbilicais/diagnóstico por imagem , Estudos Retrospectivos , Cesárea , Feto , Retardo do Crescimento Fetal
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