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1.
Clin Chem ; 70(6): 820-829, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38517460

RESUMO

BACKGROUND: Optical genome mapping (OGM) is a novel assay for detecting structural variants (SVs) and has been retrospectively evaluated for its performance. However, its prospective evaluation in prenatal diagnosis remains unreported. This study aimed to prospectively assess the technical concordance of OGM with standard of care (SOC) testing in prenatal diagnosis. METHODS: A prospective cohort of 204 pregnant women was enrolled in this study. Amniotic fluid samples from these women were subjected to OGM and SOC testing, which included chromosomal microarray analysis (CMA) and karyotyping (KT) in parallel. The diagnostic yield of OGM was evaluated, and the technical concordance between OGM and SOC testing was assessed. RESULTS: OGM successfully analyzed 204 cultured amniocyte samples, even with a cell count as low as 0.24 million. In total, 60 reportable SVs were identified through combined OGM and SOC testing, with 22 SVs detected by all 3 techniques. The diagnostic yield for OGM, CMA, and KT was 25% (51/204), 22.06% (45/204), and 18.14% (37/204), respectively. The highest diagnostic yield (29.41%, 60/204) was achieved when OGM and KT were used together. OGM demonstrated a concordance of 95.56% with CMA and 75.68% with KT in this cohort study. CONCLUSIONS: Our findings suggest that OGM can be effectively applied in prenatal diagnosis using cultured amniocytes and exhibits high concordance with SOC testing. The combined use of OGM and KT appears to yield the most promising diagnostic outcomes.


Assuntos
Diagnóstico Pré-Natal , Humanos , Feminino , Gravidez , Estudos Prospectivos , Diagnóstico Pré-Natal/métodos , Adulto , Cariotipagem , Mapeamento Cromossômico , Líquido Amniótico/química , Líquido Amniótico/citologia
2.
Appl Opt ; 63(8): 2030-2035, 2024 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-38568644

RESUMO

Multimode power splitters are the fundamental building blocks in mode division multiplexing systems. In this paper, we propose a low-loss and compact, dual-mode, 3-dB power splitter for the two lowest TE modes combining three different structures, including a directional coupler, a multimode interferometer, and a Y-junction. The coupling length of the proposed device is only 7.2 µm. For both T E 0 and T E 1 modes, the numerical simulation shows that the insertion loss is only less than 0.1 dB and crosstalk is less than -20d B at the wavelength range of 1520-1580 nm. The working bandwidth can cover the entire C-band. It offers a potential solution for a 3-dB power splitter of the two lowest TE modes.

3.
Opt Express ; 30(19): 34835-34847, 2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-36242487

RESUMO

We investigate the propagation dynamics of the Pearcey-Gaussian (PG) pulses in the presence of time-dependent potentials in a linear medium both theoretically and numerically. We demonstrate that the combination of the linear potential and the initial chirp of PG pulses can flexibly control the propagation trajectory and inherent focusing properties of the PG pulses. When the parabolic potential is taken into account, the chirped PG pulses are periodically focused and reversed. By adjusting the parabolic potential and the pulse chirp, the characteristics of the focal points, such as position, intensity, and spacing between focal points, can be manipulated effectively. The interaction of two temporally separated PG pulses still shows a periodic evolution with controllable focusing characteristics. These results can broaden the application range of PG pulses and provide some inspiration for the control of PG pulses under nonlinear conditions.

4.
Opt Express ; 30(24): 43815-43825, 2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36523072

RESUMO

In recent years, high-power, tunable terahertz (THZ) radiation sources have become the key areas of research in the world. The method of THZ waves by nonlinear optical difference frequency generation (DFG) has the advantages of wide tuning, high power, room temperature operation, and compact structure. However, the conversion efficiency of the current difference frequency method is low, which needs a trade-off between conversion efficiency and tuning range. We apply the nonlinear optical cascade difference frequency conversion theory based on stimulated Raman adiabatic passage (STIRAP) and propose a theoretical scheme to generate THZ waves. Numerical simulation investigates the cascaded difference frequency process of generating THZ waves with the help of the nonlinear medium lithium niobate (LN) crystal. The theoretical analysis shows that the maximum quantum conversion efficiency from signal laser to THZ waves is 43.2 % when the wavelength of the tuned signal laser varies between 1.044 - 1.065 µm with the fixed two pump laser wavelengths constant. The tunable THZ waves of 0.48 - 5.0 THz can be obtained and the maximum output intensity of THZ waves is 2.17 MW/cm2, and the method is robust to temperature variations. It also provides a novel idea for the cascaded difference frequency generation of THZ waves.

5.
Appl Opt ; 61(25): 7443-7448, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36256047

RESUMO

Zinc citrate (ZC) has been widely used in food as an important nutritional supplement. Accurate detection of ZC in food is important for health and safety. In this study, THz time-domain spectroscopy (THz-TDS) is used to quantitatively detect ZC in flour and milk powder mixtures. In our research, 15 different contents of ZC in flour and milk powder mixtures were prepared and measured by THz-TDS. A partial least squares (PLS) model was established based on the quantitative analysis of the absorption coefficient data of these two mixtures at 0.5-3.0 THz. The R2 and rms error (RMSE) given by the PLS model prediction were, respectively, 0.999 and 0.14% ZC in flour and 0.999 and 0.20% ZC in milk mixtures, indicating the predictions of the PLS model are in excellent agreement with the experimental measurements. The results show that combining THz-TDS with the PLS model can be used for accurate, quantitative analyses of ZC in food mixtures.


Assuntos
Espectroscopia Terahertz , Animais , Citratos , Farinha , Leite , Pós , Espectroscopia Terahertz/métodos , Zinco
6.
Zhongguo Dang Dai Er Ke Za Zhi ; 24(11): 1219-1225, 2022 Nov 15.
Artigo em Chinês | MEDLINE | ID: mdl-36398547

RESUMO

OBJECTIVES: To develop the birth weight curves of the Chinese Han (26-41 weeks of gestation) and Zhuang (28-41 weeks of gestation) singleton neonates in 11 cities of China, as well as the birth weight means of full-term neonates of 14 Chinese ethnic groups. METHODS: The live singleton neonates who were born in 11 maternal and child health care hospitals from 11 cities of China between January 2017 and December 2020 were classified according to the mother's ethnic group. Birth weight means were calculated for the full-term neonates of each ethnic group. For the Han and Zhuang singleton neonates with a large sample size, the Lambda-Mu-Sigma (LMS) method was used to establish the birth weight percentile curves of the Han and Zhuang singleton neonates with different gestational ages. RESULTS: A total of 105 365 live singleton neonates were included, among whom the Han neonates had the highest number of 84 851 (26-41 weeks of gestation), followed by the Zhuang neonates (12 803 neonates with a gestational age of 28-41 weeks). The neonates of the other Chinese ethnic groups enrolled were live full-term singleton neonates, with a sample size of more than 100 neonates for each ethnic group. The 3rd-97th percentile curves of birth weight were established for the Han singleton neonates with a gestational age of 26-41 weeks and the Zhuang singleton neonates with a gestational age of 28-41 weeks. The birth weight curves of the Han singleton neonates at each gestational age were higher than those of the Zhuang singleton neonates. Birth weight means (3 199-3 499 g) and standard deviations were determined for 14 Chinese ethnic groups, i.e., Li, Mulao, Zhuang, Yao, Dong, Miao, Han, Buyi, Mongolian, Tujia, Yi, Hui, Man, and Korean ethnic groups. The Li ethnic group had the lowest birth weight, followed by the Mulao, Zhuang, Yao, Dong, Miao, Han, Buyi, Mongolian, Tujia, Yi, Hui, Man, and Korean ethnic groups. CONCLUSIONS: The 3rd-97th percentile curves of birth weight are developed for the Han (26-41 weeks of gestation) and Zhuang (28-41 weeks of gestation) singleton neonates in 11 cities of China, and birth weight means are determined for the full-term neonates of 14 Chinese ethnic groups in 11 cities of China, which provides a reference for evaluating the intrauterine growth of neonates in these ethnic groups.


Assuntos
Etnicidade , Recém-Nascido , Masculino , Criança , Humanos , Lactente , Peso ao Nascer , Cidades , Idade Gestacional , China
7.
Zhongguo Dang Dai Er Ke Za Zhi ; 24(8): 899-907, 2022 Aug 15.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-36036129

RESUMO

OBJECTIVES: To develop the birth weight curve of twin neonates with a gestational age of 25-40 weeks, and to investigate the regional differences of the birth weight curve. METHODS: A total of 11 maternal and child health care hospitals with more than 7 000 neonates delivered annually were selected in 11 cities of China (Haikou, Guangzhou, Liuzhou, Guilin, Quanzhou, Shenzhen, Chongqing, Chengdu, Changsha, Ningbo, and Lianyungang), and all live twin neonates delivered in the 11 hospitals from January 1, 2017 to December 31, 2020 were enrolled for the development of birth weight curves. RESULTS: A total of 17 256 twin neonates with a gestational age of 25-40 weeks from the 11 cities were included in the study. The reference values of the 3rd-97th percentiles of birth weight of twin neonates for the total of the 11 cities and for each of the 11 cities in China were established, and the birth weight percentile curves were drawn. The birth weight curve level of twin neonates in Liuzhou was lower than the average level of the 11 cities; the birth weight curve level of twin neonates in Ningbo was higher than the average level of the 11 cities; the birth weight curve level of twin neonates in Lianyungang was obviously higher than the average level of the 11 cities; the birth weight curve level of twin neonates in other 8 cities was almost the same as the average level of the 11 cities. CONCLUSIONS: The reference values of the 3rd-97th percentiles of birth weight of twin neonates for the total of the 11 cities and for each of the 11 cities are developed, which can be used as a reference for evaluating the intrauterine growth of twin neonates in the region. The level of intrauterine growth of twin neonates in some cities is different from the average level of the 11 cities of China.


Assuntos
Gêmeos , Peso ao Nascer , Criança , China , Cidades , Idade Gestacional , Humanos , Lactente , Recém-Nascido
8.
Pestic Biochem Physiol ; 145: 100-107, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29482725

RESUMO

Acetohydroxyacid synthase (AHAS, EC: 2.2.1.6) is a target for the development of novel herbicides. Two series of N-nitrophenyl derivatives, type-A and type-B, were designed and synthesized based on the active site of the AHAS structure. All the structures of newly prepared compounds were thorough characterized by IR, and 1H NMR spectrums. The IC50 values of all synthesized target compounds against AHAS enzyme and EC50 values for herbicidal activity against Brassica campestris L., Amaranthus mangostanus L. and Sorghum sudanense were determined. The bioactive assay results showed that the type-B compounds exhibited highly improved inhibitory activity against the AHAS enzyme and the tested plants comparing to type-A compounds. The IC50 values of most type-B compounds against the AHAS enzyme were between 25-177µM. The EC50 values of several type-B compounds against Sorghum sudanense reached 5.0mg/L. The differences in the biological activity between type-A and type-B compounds were attributed to two structural features - the orthogonal bend at the N-nitro amides group and the common plane structure of another phenyl with chain bridge. With the structure of the target compounds and the IC50 values for AHAS enzyme, a statistically significant CoMFA model with high predict abilities (q2=0.606, r2=0.982, N=4, SEE=0.058, F=280.255) was obtained, and its reliability was verified. The model will provide a theoretical basis for the further structural optimization.


Assuntos
Acetolactato Sintase/química , Herbicidas/química , Herbicidas/farmacologia , Nitrofenóis/química , Nitrofenóis/farmacologia , Acetolactato Sintase/antagonistas & inibidores , Amaranthus/efeitos dos fármacos , Brassica/efeitos dos fármacos , Herbicidas/síntese química , Simulação de Acoplamento Molecular , Nitrofenóis/síntese química , Conformação Proteica , Espectroscopia de Prótons por Ressonância Magnética , Relação Quantitativa Estrutura-Atividade , Sorghum/efeitos dos fármacos , Espectrofotometria Infravermelho
9.
J Phys Chem A ; 119(16): 3753-61, 2015 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-25798659

RESUMO

Most material properties can be traced to electronic structures. Black silicon produced from SF6 or sulfur powder via irradiation with femtosecond laser pulses displays decreased infrared absorption after annealing, with almost no corresponding change in visible light absorption. The high-intensity laser pulses destroy the original crystal structure, and the doping element changes the material performance. In this work, the structural and electronic properties of several sulfur-doped silicon systems are investigated using first principle calculations. Depending on the sulfur concentration (level of doping) and the behavior of the sulfur atoms in the silicon lattice, different states or an absence of states are exhibited, compared with the undoped system. Moreover, the visible-infrared light absorption intensities are structure specific. The results of our theoretical calculations show that the conversion efficiency of sulfur-doped silicon solar cells depends on the sulfur concentrations. Additionally, two types of defect configurations exhibit light absorption characteristics that differ from the other configurations. These two structures produce a rapid increase in the theoretical photoelectric conversion efficiency in the range of the specific chemical potential studied. By controlling the positions of the atomic sulfur and the sulfur concentration in the preparation process, an efficient photovoltaic (PV) material may be obtainable.

10.
Pestic Biochem Physiol ; 122: 22-8, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26071803

RESUMO

Bacterial leaf blight, caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases of rice worldwide. N-acetylglucosamine-1-phosphate uridyltransferase (GlmU) was an attractive target for the development of antimicrobial agents. To develop novel, more potent and even more selective inhibitors of the uridyltransferase activity of Xanthomonas oryzae pv. oryzae GlmU (Xo-GlmU), three types of novel target compounds were optimized and synthesized based on the Xo-GlmU structure in this study. The biological testing results showed that all of the target compounds displayed the higher inhibition than the lead compound with the IC50 values in the 10.82-23.31 µM range, and the inhibition rates were increased by 30%-67%. The binding mode and the possible inhibitory mechanism of the target compounds in the active site were also analyzed by the molecular docking based on the uridyltransferase active site of Xo-GlmU.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Nucleotidiltransferases/antagonistas & inibidores , Nucleotidiltransferases/química , Xanthomonas/efeitos dos fármacos , Antibacterianos/síntese química , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Domínio Catalítico , Técnicas de Química Sintética , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Concentração Inibidora 50 , Simulação de Acoplamento Molecular , Estrutura Molecular , Terapia de Alvo Molecular , Nucleotidiltransferases/metabolismo , Oryza/microbiologia , Relação Estrutura-Atividade , Xanthomonas/metabolismo
11.
Bioorg Med Chem Lett ; 24(12): 2734-6, 2014 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-24794106

RESUMO

A series of novel chiral esters derived from tetrafluorobenzyl alcohol were designed and prepared via asymmetric synthesis. The target molecules have been identified on the basis of analytical spectra data. All newly synthesized compounds have been screened their potential insecticidal activity against Plutella xylostella compared with those of fenvalerate and d-trans-phenothrin by standard method, and the respective pairs of enantiomers (3-B1-R/S, 3-C1-R/S, 3-D1-R/S) indicated significantly different activities.


Assuntos
Álcoois Benzílicos/síntese química , Ésteres/síntese química , Fluorbenzenos/química , Inseticidas , Lepidópteros , Animais , Álcoois Benzílicos/química , Álcoois Benzílicos/farmacologia , Ésteres/química , Ésteres/farmacologia , Inseticidas/síntese química , Inseticidas/química , Piretrinas/química , Estereoisomerismo
12.
J Matern Fetal Neonatal Med ; 37(1): 2338440, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38604949

RESUMO

BACKGROUND: Noninvasive prenatal testing (NIPT) is the most common method for prenatal aneuploidy screening. Low fetal fraction (LFF) is the primary reason for NIPT failure. Consequently, factors associated with LFF should be elucidated for optimal clinical implementation of NIPT. METHODS: In this study, NIPT data from January 2019 to December 2022 from the laboratory records and obstetrical and neonatal data from the electronic medical records were collected and analyzed. Subjects with FF >3.50% were assigned to the control group, subjects with FF <3.50% once were assigned to the LFF group, and subjects with FF <3.50% twice were assigned to the repetitive low fetal fraction (RLFF) group. Factors, including body mass index (BMI), gestational age, maternal age, twin pregnancy, and in vitro fertilization (IVF) known to be associated with LFF were assessed by Kruskal-Wallis H test and logistic regression. Clinical data on first trimester pregnancy-associated plasma protein-A (PAPP-A), beta-human chorionic gonadotropin (ß-hCG), gestational age at delivery, birth weight at delivery, and maternal diseases were obtained from the hospital's prenatal and neonatal screening systems (twin pregnancy was not included in the data on gestational age at delivery and the control group did not include data on maternal diseases.), and were analyzed using Kruskal-Wallis H test and Chi-square test. RESULTS: Among the total of 63,883 subjects, 63,605 subjects were assigned to the control group, 197 subjects were assigned to the LFF group, and 81 subjects were assigned to the RLFF group. The median of BMI in the three groups was 22.43 kg/m2 (control), 25.71 kg/m2 (LFF), and 24.54 kg/m2 (RLFF). The median gestational age in the three groups was 130 days (control), 126 days (LFF), and 122/133 days (RLFF). The median maternal age in the three groups was 29 (control), 29 (LFF), and 33-years-old (RLFF). The proportion of twin pregnancies in the three groups was 3.3% (control), 10.7% (LFF), and 11.7% (RLFF). The proportion of IVF in the three groups was 4.7% (control), 11.7% (LFF), and 21.3% (RLFF). The factors significantly associated with LFF included BMI [2.18, (1.94, 2.45), p < 0.0001], gestational age [0.76, (0.67, 0.87), p < 0.0001], twin pregnancy [1.62, (1.02, 2.52), p = 0.0353], and IVF [2.68, (1.82, 3.86), p < 0.0001]. The factors associated with RLFF included maternal age [1.54, (1.17, 2.05), p = 0.0023] and IVF [2.55, (1.19, 5.54), p = 0.016]. Multiples of the median (MOM) value of ß-hCG and pregnant persons' gestational age at delivery were significantly decreased in the LFF and RLFF groups compared to the control group. CONCLUSION: According to our findings based on the OR value, factors associated strongly with LFF include a high BMI and the use of IVF. Factors associated less strongly with LFF include early gestational age and twin pregnancy, while advanced maternal age and IVF were independent risk factors for a second LFF result.


Body mass index, gestational age, maternal age, twin pregnancy, and in vitro fertilization are associated with fetal fraction. We added the repetitive low fetal fraction population and used a large normal population as a control to identify the main factors associated with low fetal fraction.


Assuntos
Ácidos Nucleicos Livres , Teste Pré-Natal não Invasivo , Gravidez , Recém-Nascido , Feminino , Humanos , Gonadotropina Coriônica Humana Subunidade beta , Diagnóstico Pré-Natal/métodos , Primeiro Trimestre da Gravidez , DNA , Proteína Plasmática A Associada à Gravidez
13.
Front Pediatr ; 12: 1366891, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38577637

RESUMO

Background: Neonatal screening for inherited metabolic diseases (IMDs) has been revolutionized by tandem mass spectrometry (MS/MS). This study aimed to enhance neonatal screening for IMDs using machine learning (ML) techniques. Methods: The study involved the analysis of a comprehensive dataset comprising 309,102 neonatal screening records collected in the Ningbo region, China. An advanced ML system model, encompassing nine distinct algorithms, was employed for the purpose of predicting the presence of 31 different IMDs. The model was compared with traditional cutoff schemes to assess its diagnostic efficacy. Additionally, 180 suspected positive cases underwent further evaluation. Results: The ML system exhibited a significantly reduced positive rate, from 1.17% to 0.33%, compared to cutoff schemes in the initial screening, minimizing unnecessary recalls and associated stress. In suspected positive cases, the ML system identified 142 true positives with high sensitivity (93.42%) and improved specificity (78.57%) compared to the cutoff scheme. While false negatives emerged, particularly in heterozygous carriers, our study revealed the potential of the ML system to detect asymptomatic cases. Conclusion: This research provides valuable insights into the potential of ML in pediatric medicine for IMD diagnosis through neonatal screening, emphasizing the need for accurate carrier detection and further research in this domain.

14.
Lasers Med Sci ; 28(2): 621-5, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22618158

RESUMO

The radiotherapy-related types of nasopharyngeal carcinoma (NPC) have been established, which give the most effective treatment for NPC patients using the individual therapy. To diagnose the types of NPC, we assess the general NPC cell lines CNE1, CNE2 and normal nasopharyngeal cell line NP69 using optical coherence tomography (OCT) in two steps: firstly, the OCT images of the three different types of cell pellets are captured. Secondly, by fitting Beer's law to the averaged A-scans in these OCT datasets, the attenuation coefficients (µ t ) of the cells can be extracted. The median attenuation coefficients (interquartile range) of CNE1, CNE2, and NP69 are 5.58 mm(-1) (IQR 5.55 to 5.65 mm(-1)), 5.91 mm(-1) (IQR 5.82 to 5.88 mm(-1)), and 8.96 mm(-1) (IQR 8.80 to 9.47 mm(-1)), respectively. The distinguishable quantitative OCT analysis (by µ t ) shows that the types of NPC could potentially be differentiated in real time and noninvasive.


Assuntos
Neoplasias Nasofaríngeas/patologia , Tomografia de Coerência Óptica/métodos , Carcinoma , Linhagem Celular , Linhagem Celular Tumoral , Humanos , Processamento de Imagem Assistida por Computador/métodos , Carcinoma Nasofaríngeo , Nasofaringe/citologia
15.
Arch Biochem Biophys ; 522(2): 125-9, 2012 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-22525523

RESUMO

The aim was to test whether the typical NPC cell lines of 5-8F (high tumorigenesis and metastasis) and 6-10B (low tumorigenesis and metastasis) could be differentiated by polarization sensitive optical coherence tomography (PS-OCT). We imaged the two types of low cellular differentiated NPC cell lines 5-8F and 6-10B pellets using PS-OCT; then extracted the optical parameters of attenuate coefficient and anisotropy from the A-scan lines based on the multiple scattering model; and compared their phase retardation. The fitting scattering coefficients were µs=10.91±0.45 and µs=11.33±0.27 cm(-1) for 5-8F and 6-10B pellets (p<0.05), respectively; and the anisotropy factors were g=0.900±0.013 and g=0.885±0.008 for 5-8F and 6-10B pellets (p<0.01), respectively. While the phase retardation of 6-10B was a little faster than 5-8F. These results indicated that PS-OCT could differentiate the two cell lines, and had the potential ability for typing the tissue of NPC.


Assuntos
Neoplasias/patologia , Tomografia de Coerência Óptica/métodos , Linhagem Celular , Linhagem Celular Tumoral , Humanos , Metástase Neoplásica
16.
Nanomaterials (Basel) ; 10(12)2020 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-33339400

RESUMO

We propose a nonvolatile, reconfigurable, and narrowband mid-infrared bandpass filter based on surface lattice resonance in phase-change material Ge2Sb2Te5. The proposed filter is composed of a two-dimensional gold nanorod array embedded in a thick Ge2Sb2Te5 film. Results show that when Ge2Sb2Te5 transits from the amorphous state to the crystalline state, the narrowband reflection spectrum of the proposed filter is tuned from 3.197 µm to 4.795 µm, covering the majority of the mid-infrared regime, the peak reflectance decreases from 72.6% to 25.8%, and the corresponding quality factor decreases from 19.6 to 10.3. We show that the spectral tuning range can be adjusted by varying the incidence angle or the lattice period. By properly designing the gold nanorod sizes, we also show that the quality factor can be greatly increased to 70 at the cost of relatively smaller peak reflection efficiencies, and that the peak reflection efficiency can be further increased to 80% at the cost of relatively smaller quality factors. We expect that this work will advance the engineering of Ge2Sb2Te5-based nonvalatile tunable surface lattice resonances and will promote their applications especially in reconfigurable narrowband filters.

17.
Front Hum Neurosci ; 12: 85, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29556184

RESUMO

Hemodynamic response to motor execution (ME) and motor imagery (MI) was investigated using functional near-infrared spectroscopy (fNIRS). We used a 31 channel fNIRS system which allows non-invasive monitoring of cerebral oxygenation changes induced by cortical activation. Sixteen healthy subjects (mean-age 24.5 yeas) were recruited and the changes in concentration of hemoglobin were examined during right and left hand finger tapping tasks and kinesthetic MI. To suppress the systemic physiological interference, we developed a preprocessing procedure which prevents over-activated reporting in NIRS-SPM. In the condition of ME, more activation was observed in the anterior part of the motor cortex including the pre-motor and supplementary motor area (pre-motor and SMA), primary motor cortex (M1) and somatosensory motor cortex (SMC; t(15) > 2.27), however, in the condition of MI, more activation was found in the posterior part of motor cortex including SMC (t(15) > 1.81), which is in line with previous observations with functional magnetic resonance imaging (fMRI).

18.
Neurosci Lett ; 683: 94-99, 2018 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-29935269

RESUMO

Functional near-infrared spectroscopy (fNIRS) was used to investigate the stability of resting state functional connectivity (RSFC) in the prefrontal cortex. In a longitudinal study for investigating the stability of RSFC with time, we recruited 6 healthy adult subjects to undergo a 10-min resting state fNIRS scan once per day for 7 consecutive days. In a cross-sectional study, 62 healthy subjects underwent a single 10-min RSFC measurement. Three regions-of-interest (ROIs) were studied, the superior frontal gyrus (SFG), the middle frontal gyrus (MFG), and the inferior frontal gyrus (IFG). Homologous RSFC between the left and right hemisphere was computed for each ROI. The longitudinal RSFC study showed no significant variation with time in each ROI, implying that a one-time scan was sufficient for evaluating RSFC for an individual. The cross-sectional study showed significant difference in RSFC between SFG and MFG/IFG. Based on these observations, a lower bound of RSFC with an 85% confidence level for healthy adults was given for each gender: in IFG, 0.6894 (male) and 0.5392 (female), in MFG, 0.6487 (male) and 0.5713 (female), and in SFG: 0.8042(male) and 0.7436(female). To test ability of the lower bound to differentiate between healthy adults and adults with neurological disorders (showing weaker RSFC), 15 patients with affective disorders or sleep disorder were recruited for the resting state scan. The results showed that IFG was the most predictive ROI. This study may help to establish a quantitative range of RSFC for healthy adults and serve as a reference for screening patients with neurological disorders.


Assuntos
Mapeamento Encefálico/métodos , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/fisiopatologia , Descanso/fisiologia , Adulto , Estudos Transversais , Feminino , Humanos , Estudos Longitudinais , Masculino , Doenças do Sistema Nervoso/diagnóstico , Doenças do Sistema Nervoso/metabolismo , Doenças do Sistema Nervoso/fisiopatologia , Vias Neurais/metabolismo , Vias Neurais/fisiopatologia , Distribuição Aleatória , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Adulto Jovem
19.
Sci Rep ; 6: 32654, 2016 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-27585479

RESUMO

A series of novel peptidomimetics bearing dehydroepiandrosterone moiety were designed, synthesized, and evaluated for their inhibition activities against cell proliferation. According to the preliminary studies on inhibitory activities, some of the newly prepared compounds indicated significantly inhibition activities against human hepatoma cancer (HepG2), human lung cancer (A549), human melanoma (A875) cell lines compared with the control 5-fluorouracil. Especially, compounds Ii (IC50 < 14 µM) and Ik (IC50 < 13 µM) exhibited obvious inhibition activities against all tested cell lines. The highly potential compound Ik induced apoptosis in HepG2 cells were analyzed by flow cytometry, and the apoptotic effects of compound Ik were further evaluated using Annexin V-FITC/propidium iodide dual staining assay, which revealed these highly potential compounds induced cell death in HepG2 cells at least partly by apoptosis.


Assuntos
Desidroepiandrosterona/química , Desidroepiandrosterona/farmacologia , Peptidomiméticos/química , Peptidomiméticos/farmacologia , Anexina A5/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desidroepiandrosterona/síntese química , Relação Dose-Resposta a Droga , Desenho de Fármacos , Citometria de Fluxo , Fluoresceína-5-Isotiocianato/metabolismo , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Peptidomiméticos/síntese química , Relação Estrutura-Atividade
20.
J Biomed Opt ; 20(3): 037004, 2015 03.
Artigo em Inglês | MEDLINE | ID: mdl-25756306

RESUMO

We have recently applied the technique of drop coating deposition Raman (DCDR) spectroscopy for colorectal cancer (CRC) detection using blood plasma. The aim of this study was to develop a more convenient and stable method based on blood plasma for noninvasive CRC detection. Significant differences are observed in DCDR spectra between healthy (n = 105) and cancer (n = 75) plasma from 15 CRC patients and 21 volunteers, particularly in the spectra that are related to proteins, nucleic acids, and ß-carotene. The multivariate analysis principal components analysis and the linear discriminate analysis, together with leave-one-out, cross validation were used on DCDR spectra and yielded a sensitivity of 100% (75/75) and specificity of 98.1% (103/105) for detection of CRC. This study demonstrates that DCDR spectroscopy of blood plasma associated with multivariate statistical algorithms has the potential for the noninvasive detection of CRC.


Assuntos
Neoplasias Colorretais/sangue , Neoplasias Colorretais/diagnóstico por imagem , Análise Espectral Raman/métodos , Estudos de Casos e Controles , Análise Discriminante , Humanos , Proteínas de Neoplasias/análise , Ácidos Nucleicos/análise , Análise de Componente Principal , beta Caroteno/análise
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