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1.
Anim Microbiome ; 6(1): 23, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38702785

RESUMO

BACKGROUND: Living things from microbes to their hosts (plants, animals and humans) interact with each other, and their relationships may be described with complex network models. The present study focuses on the critical network structures, specifically the core/periphery nodes and backbones (paths of high-salience skeletons) in animal gastrointestinal microbiomes (AGMs) networks. The core/periphery network (CPN) mirrors nearly ubiquitous nestedness in ecological communities, particularly dividing the network as densely interconnected core-species and periphery-species that only sparsely linked to the core. Complementarily, the high-salience skeleton network (HSN) mirrors the pervasive asymmetrical species interactions (strictly microbial species correlations), particularly forming heterogenous pathways in AGM networks with both "backbones" and "rural roads" (regular or weak links). While the cores and backbones can act as critical functional structures, the periphery nodes and weak links may stabilize network functionalities through redundancy. RESULTS: Here, we build and analyze 36 pairs of CPN/HSN for the AGMs based on 4903 gastrointestinal-microbiome samples containing 473,359 microbial species collected from 318 animal species covering all vertebrate and four major invertebrate classes. The network analyses were performed at host species, order, class, phylum, kingdom scales and diet types with selected and comparative taxon pairs. Besides diet types, the influence of host phylogeny, measured with phylogenetic (evolutionary) timeline or "age", were integrated into the analyses. For example, it was found that the evolutionary trends of three primary microbial phyla (Bacteroidetes/Firmicutes/Proteobacteria) and their pairwise abundance-ratios in animals do not mirror the patterns in modern humans phylogenetically, although they are consistent in terms of diet types. CONCLUSIONS: Overall, the critical network structures of AGMs are qualitatively and structurally similar to those of the human gut microbiomes. Nevertheless, it appears that the critical composition (the three phyla of Bacteroidetes, Firmicutes, and Proteobacteria) in human gut microbiomes has broken the evolutionary trend from animals to humans, possibly attributable to the Anthropocene epoch and reflecting the far-reaching influences of agriculture and industrial revolution on the human gut microbiomes. The influences may have led to the deviations between modern humans and our hunter-gather ancestors and animals.

2.
Sensors (Basel) ; 24(4)2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38400261

RESUMO

In the field of inter-satellite laser communication, achieving high-quality communication and compensating for the Doppler frequency shift caused by relative motion necessitate lasers with narrow linewidths, low phase noise, and the ability to achieve mode-hop-free tuning within a specific range. To this end, this paper investigates a novel external cavity diode laser (ECDL) with a frequency-selective F-P etalon structure, leveraging the external cavity F-P etalon structure in conjunction with an auxiliary filter to achieve single longitudinal mode selection. The laser undergoes linewidth testing using a delayed self-heterodyne beating method, followed by the testing of its phase noise and frequency noise characteristics using a noise analyzer, yielding beat spectra and noise power spectral density profiles. Furthermore, the paper introduces an innovative bidirectional temperature-scanning laser method to achieve optimal laser-operating point selection and mode-hop-free tuning. The experimental results showcase that the single longitudinal mode spectral side-mode suppression ratio (SMSR) is around 70 dB, and the output power exceeds 10 mW. Enhancing the precision of the F-P etalon leads to a more pronounced suppression of low-frequency phase noise, reducing the Lorentzian linewidth from the initial 10 kHz level to a remarkable 5 kHz level. The bidirectional temperature-scanning laser method not only allows for the selection of the optimal operating point but also enables mode-hop-free tuning within 160 pm.

3.
Molecules ; 27(23)2022 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-36500291

RESUMO

Eleven highly oxidized withanolides, chantriolides F-P (1-11), together with six known analogues (12-17), were isolated from the rhizomes of Tacca chantrieri. Their structures were established on the basis of comprehensive spectroscopic data analysis and comparison with published NMR data, and their absolute configurations were further confirmed by experimental ECD data and single crystal X-ray diffraction analysis. The structures of compounds 5-8 contained a chlorine atom substituted at C-3. Compounds 1 and 12 are a pair of epimers isomerized at C-24 and C-25, while compounds 9 and 16 are isomerized at C-1, C-7, C-24, and C-25. Next, the hepatoprotective effect of all the isolates was evaluated on tert-butyl hydroperoxide (t-BHP)-injured AML12 hepatocytes. Compounds 5-11 and 16 significantly enhanced cell viability. Compound 8 decreased reactive oxygen species accumulation and increased glutathione level in t-BHP injured AML12 hepatocytes through promoting nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2).


Assuntos
Dioscoreaceae , Vitanolídeos , Vitanolídeos/farmacologia , Dioscoreaceae/química , Rizoma/química , terc-Butil Hidroperóxido/farmacologia , Espécies Reativas de Oxigênio/análise , Estresse Oxidativo
4.
Int. j. morphol ; 40(6): 1530-1535, dic. 2022. ilus, tab
Artigo em Espanhol | LILACS | ID: biblio-1421801

RESUMO

La anastomosis de Hyrtl's (AH), vaso único con amplia variabilidad anatómica, comunica las arterias umbilicales cerca de la inserción del cordón umbilical en las placentas humanas. El objetivo del presente trabajo fue determinar si existe relación entre las características morfométricas de la placenta y la presencia de anastomosis y analizar si esta tiene influencia en la eficiencia placentaria. Estudio descriptivo. Se analizaron 60 placentas provenientes de madres que aceptaron participar en la investigación, embarazo único, a término (entre 37,0 y 41,6 semanas), con edades entre 18 y 37 años, con al menos cuatro visitas a control prenatal, sin comorbilidades. Las características placentarias de peso, diámetros y grosor se tomaron en fresco. Una vez fijadas con formaldehido al 10 %, mediante disección se ubicó, clasificó y fotografió la anastomosis. El peso de la placenta fue 494,4 ± 87,1 gramos, el grosor central correspondió a 1,7 ± 0,4 cm, DM 19,9 ± 2,0 cm y Dm 18,4 ± 1,7 cm. La inserción de cordón predominante fue excéntrica (65 %) y la forma discoidea u ovalada (60 %). En 51 placentas se ubicó la presencia de anastomosis (85 %). En el grupo de placentas con presencia AH se encontró un peso placentario más bajo al compararlo con el grupo que no presentó AH, el resto de las características morfométricas de la placenta, incluido el tipo de inserción de cordón umbilical no presentaron relación con la anastomosis. La eficiencia placentaria expresada con la relación entre peso neonato/peso placenta presentó diferencias significativas en el grupo con presencia de anastomosis, con mayores valores comparados con el grupo sin anastomosis. La presencia de AH contribuye positivamente a la eficiencia placentaria. Sin embargo, el incremento del peso placentario puede ser un efecto compensador de la placenta y no siempre indica una mayor eficiencia funcional del órgano.


SUMMARY: Hyrtl's anastomosis (HA), a single vessel, with wide anatomical variability, communicates the umbilical arteries, near the insertion of the umbilical cord in human placentas. The objective of this study was to determine if there is a relationship between the morphometric characteristics of the placenta and the presence of the anastomosis and to analyze if this influences the placental efficiency. Descriptive study. We analyzed 60 placentas from mothers who agreed to participate in the study, single pregnancy, term (between 37.0 and 41.6 weeks), aged between 18 and 37 years with at least four visits to prenatal control, without comorbidities. The placental characteristics of weight, diameters and thickness were taken fresh. Once fixed with 10 % formaldehyde, the anastomosis was located, classified, and photographed by dissection. The weight of the placenta was 494.4 ± 87.1 g, the central thickness corresponded to 1.7 ± 0.4 cm, the MD 19.9 ± 2.0 cm and Dm 18.4 ± 1.7 cm: The predominant cord insertion was eccentric, with 65 % and the discoid or oval shape with 60 %. In 51 placentas the presence of anastomosis was found (85 %). In the group of placentas with AH presence, a lower placental weight was found when compared to the group that did not present AH, the rest of the morphometric characteristics of the placenta, including the type of umbilical cord insertion, were not related to the anastomosis. Placental efficiency expressed as the neonatal weight/placental weight ratio showed significant differences in the group with presence of anastomosis, with higher values compared to the group without anastomosis. The presence of HA contributes positively to placental efficiency. However, the increase in placental weight may be a compensatory effect of the placenta and does not always indicate a greater functional efficiency of the organ.


Assuntos
Humanos , Feminino , Adolescente , Adulto , Adulto Jovem , Placenta/anatomia & histologia , Artérias Umbilicais/anatomia & histologia , Tamanho do Órgão , Placenta/irrigação sanguínea , Peso ao Nascer
5.
Sensors (Basel) ; 22(20)2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36298075

RESUMO

With the rapid development of photo-communication technologies, avalanche photodiode (APD) will play an increasingly important role in the future due to its high quantum efficiency, low power consumption, and small size. The monolithic integration of optical components and signal processing electronics on silicon substrate chips is crucial to driving cost reduction and performance improvement; thus, the technical research on InGaAs/Si APD is of great significance. This work is the first to demonstrate the use of a photon-trapping (PT) structure to improve the performance of the InGaAs/Si APD based on an SOI substrate, which exhibits very high absorption efficiency at 1310 nm wavelength while the thickness of the absorption layer is kept at 800 nm. Based on the optical and electrical simulations, an optimized InGaAs/Si PT-APD is proposed, which exhibits a better performance and a higher responsivity compared to the original InGaAs/Si APD.

6.
Sensors (Basel) ; 21(19)2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34640690

RESUMO

To resolve the problem of miscellaneous peaks and improve the accuracy of data processing in micro-ring resonators (MRRs), we propose an optical transmission model based on a Fabry-Perot (F-P) resonance effect in a Si3N4 add-drop MRR-waveguide structure, which is analyzed using a coupled mode theory and stationary interference method. The analysis indicates the experimentally obtained miscellaneous peaks are mainly induced by the multiple reflections between the two end grating couplers, which form a F-P cavity. In addition, an anti-reflection film on the interface of the grating couplers is proposed to reduce the F-P resonance effect. This work could be useful to analyze optical transmission properties of other MRR-based structures.

7.
Sensors (Basel) ; 21(12)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203744

RESUMO

Optical fiber sensors (OFS) are a potential candidate for monitoring physical parameters in nuclear environments. However, under an irradiation field the optical response of the OFS is modified via three primary mechanisms: (i) radiation-induced attenuation (RIA), (ii) radiation-induced emission (RIE), and (iii) radiation-induced compaction (RIC). For resonance-based sensors, RIC plays a significant role in modifying their performance characteristics. In this paper, we numerically investigate independently the effects of RIC and RIA on three types of OFS widely considered for radiation environments: fiber Bragg grating (FBG), long-period grating (LPG), and Fabry-Perot (F-P) sensors. In our RIC modeling, experimentally calculated refractive index (RI) changes due to low-dose radiation are extrapolated using a power law to calculate density changes at high doses. The changes in RI and length are subsequently calculated using the Lorentz-Lorenz relation and an established empirical equation, respectively. The effects of both the change in the RI and length contraction on OFS are modeled for both low and high doses using FIMMWAVE, a commercially available vectorial mode solver. An in-depth understanding of how radiation affects OFS may reveal various potential OFS applications in several types of radiation environments, such as nuclear reactors or in space.

8.
J Obstet Gynaecol Res ; 47(3): 1040-1051, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33401341

RESUMO

AIM: Our aim was to examine whether serum levels of placental growth factor (PlGF) and soluble endoglin (sEng) at 19-25 and 26-31 weeks of gestation were associated with the occurrence of the 9-block categorization of placenta weight (PW) and fetal/placenta ratio (F/P ratio). METHODS: We performed a retrospective cohort study in 1391 women with singleton pregnancy. Serum levels of PlGF and sEng were measured by enzyme immunosorbent assay. A light placenta was defined as PW ZS < -1.28 SD. Based on the PW (light, normal, and heavy) and F/P ratio (relatively heavy, balanced growth, and relatively small), 9-block categorization were performed. Multivariable logistic regression analyses were performed. RESULTS: Low PlGF at 26-31 weeks was an independent risk factor for the birth of infants belonging to Block A (light placenta and relatively heavy infant), after adjusting for prepregnancy body mass index and serum levels of sEng. High sEng at 26-31 weeks was an independent risk factor for the birth of infants belonging to Block D (light placenta and balanced growth of infant), after adjusting for past history of either preeclampsia or gestational hypertension, high pulsatility index of uterine artery flow velocity waveforms in the second trimester, and serum level of PlGF. CONCLUSIONS: Low PlGF levels at 26-31 weeks of gestation may precede a light placenta and relatively heavy infant (Block A), and high sEng levels at 26-31 weeks of gestation may precede a light placenta and balanced growth of infant (Block D).


Assuntos
Endoglina/sangue , Fator de Crescimento Placentário/sangue , Pré-Eclâmpsia , Proteínas da Gravidez , Antígenos CD , Biomarcadores , Peso ao Nascer , Feminino , Humanos , Recém-Nascido , Placenta , Gravidez , Receptores de Superfície Celular , Estudos Retrospectivos , Receptor 1 de Fatores de Crescimento do Endotélio Vascular
9.
Drug Test Anal ; 13(1): 74-90, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32678962

RESUMO

Due to the dynamic market involving synthetic cannabinoids (SCs), the determination of analytical targets is challenging in clinical and forensic toxicology. SCs usually undergo extensive metabolism, and therefore their main metabolites must be identified for the detection in biological matrices, particularly in urine. Controlled human studies are usually not possible for ethical reasons; thus, alternative models must be used. The aim of this work was to predict the in vitro and in vivo metabolic patterns of 7-azaindole-derived SCs using 1-(5-fluoropentyl)-N-(2-phenylpropan-2-yl)-1H-pyrollo[2,3-b]pyridin-3-carboxamide (cumyl-5F-P7AICA) as an example. Different in vitro (pooled human liver S9 fraction, pooled human liver microsomes, and pig liver microsomes) and in vivo (rat and pig) systems were compared. Monooxygenase isoenzymes responsible for the most abundant phase I steps, namely oxidative defluorination (OF) followed by carboxylation, monohydroxylation, and ketone formation, were identified. In both in vivo models, OF/carboxylation and N-dealkylation/monohydroxylation/sulfation could be detected. Regarding pHS9 and pig urine, monohydroxylation/sulfation or glucuronidation was also abundant. Furthermore, the parent compound could still be detected in all models. Initial monooxygenase activity screening revealed the involvement of CYP2C19, CYP3A4, and CYP3A5. Therefore, in addition to the parent compound, the OF/carboxylated and monohydroxylated (and sulfated or glucuronidated) metabolites can be recommended as urinary targets. In comparison to literature, the pig model predicts best the human metabolic pattern of cumyl-5F-P7AICA. Furthermore, the pig model should be suitable to mirror the time-dependent excretion pattern of parent compounds and metabolites.


Assuntos
Canabinoides/metabolismo , Indóis/metabolismo , Microssomos Hepáticos/metabolismo , Animais , Canabinoides/administração & dosagem , Canabinoides/análise , Humanos , Indóis/administração & dosagem , Indóis/análise , Masculino , Redes e Vias Metabólicas , Ratos , Ratos Wistar , Suínos
10.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-822298

RESUMO

@#The coronavirus disease 2019 (COVID-19) is highly infectious, with the current pandemic causing significant morbidity and mortality worldwide. As large numbers of frontline healthcare workers (HCWs) have also been infected and several have died, there is much global concern about protective measures for them, particularly those performing surgery or other procedures with close patient contact. Since the beginning of the pandemic, there has been and there remains a shortage in the supply of personal protective equipment (PPE), including the N95 filtering facepiece (FFP) respirator, for HCWs. N95 respirators have filtration efficiency of 95% of aerosol particles. Surgical N95 respirators are used where fluid resistance is also required together with respiratory protection, e.g. during surgery or interventional procedures. The shortage of N95 respirators may be overcome by extended use and reuse - comprising rotation and decontamination by approved techniques. The additional role of powered air-purifying respirators (PAPR) is also discussed.

11.
Sensors (Basel) ; 19(7)2019 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-30934942

RESUMO

A novel Fabry⁻Perot (F⁻P) interferometer model based on the ultra-small gradient-index (GRIN) fiber probe is investigated. The signal arm of the F⁻P interferometer is organically combined with the ultra-small GRIN fiber probe to establish the theoretical model of the novel F⁻P interferometer. An interferometer experimental system for vibration measurements was built to measure the performance of the novel F⁻P interferometer system. The experimental results show that under the given conditions, the output voltage of the novel interferometer is 3.9 V at the working distance of 0.506 mm, which is significantly higher than the output voltage 0.48 V of the single-mode fiber (SMF) F⁻P interferometer at this position. In the range of 0.1⁻2 mm cavity length, the novel interferometer has a higher output voltage than an SMF F⁻P interferometer. Therefore, the novel F⁻P interferometer is available for further study of the precise measurement of micro vibrations and displacements in narrow spaces.

12.
J Nucl Med ; 60(1): 16-22, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29853651

RESUMO

N-(2-(diethylamino)-ethyl)-18F-5-fluoropicolinamide (18F-P3BZA) is a radiotracer that demonstrates high binding selectivity and affinity in melanoma. The aim of the present study was to estimate the biodistribution and clinical radiation dosimetry of 18F-P3BZA in healthy volunteers and perform a preliminary clinical application for PET/CT imaging in melanoma patients. Methods:18F-P3BZA was produced efficiently with a radiosynthesizer. Six healthy volunteers were injected with 18F-P3BZA (211.7 ± 15.4 MBq) followed by serial whole-body PET/CT scans and blood tests to assess biodistribution, pharmacokinetic, and radiation dosimetry at 10 min, 1 h, 2 h, and 4 h after injection. The vital signs of volunteers were recorded in regular intervals during the imaging sessions. The effective dose for each subject after the medical internal radiation dosimetry schema was calculated with OLINDA/EXM software. For the preliminary clinical application, 5 patients with suspected melanomas underwent 18F-P3BZA PET/CT imaging at 10 min and 1 h after injection. All patients also underwent 18F-FDG PET/CT scans on the third day to compare the potential diagnostic ability of 18F-P3BZA with 18F-FDG. Results: The radiochemistry yield of 18F-P3BZA labeling was 12.3% ± 3.9%, and the purity of 18F-P3BZA after purification and formulation was higher than 99.5%. The highest uptake of 18F-P3BZA was in the liver with an SUVmean of 8.3 ± 1.0 at 10 min after injection. The resultant whole-body effective dose was 0.0193 mSv/MBq. 18F-P3BZA showed high uptake and suggested an ability for specific imaging of melanoma and its metastasis in patients. The average SUVmean of 18F-P3BZA and 18F-FDG in tumors was 19.7 ± 5.3 and 10.8 ± 2.7 at 60 min after injection. Conclusion: Our study suggests that 18F-P3BZA is safe and compatible for clinical use. The first-in-human clinical application to melanoma showed favorable delineated tumors in patients, demonstrating the potential of 18F-P3BZA for diagnostic PET imaging of melanoma.


Assuntos
Melaninas/metabolismo , Ácidos Picolínicos/farmacocinética , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Melanoma/diagnóstico por imagem , Melanoma/metabolismo , Pessoa de Meia-Idade , Ácidos Picolínicos/efeitos adversos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/efeitos adversos , Radiometria , Segurança , Distribuição Tecidual , Imagem Corporal Total
13.
Int J Med Sci ; 15(5): 484-491, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29559837

RESUMO

Objective: To classify the infants into 9 blocks based on the deviation of both placental weight (PW) and fetal/placental weight ratio (F/P) Z score and compared the incident rate of perinatal death in each of the small for date (SFD) vs. appropriate for date (AFD) vs. heavy for date (HFD) groups. Methods: The study population consisted of 93,034 placentas/infants from women who vaginally delivered a singleton infant. They were classified into 3 groups according to infants' weight: SFD (n=3,379), AFD (n=81,143) and HFD (n=8,512). The population was classified into 9 blocks according to the combination of i) low vs. middle vs. high placental weight (PW: a sex-, parity- and gestational-age-specific placental weight) and ii) low vs. middle vs. high F/P. In both i) and ii), ± 1.28 standard deviations in the in the Z scores was used for classifying low vs. middle vs. high, with 3x3 making 9 blocks. We then determined whether or not the perinatal death in each block differed among the three groups (SFD vs. AFD vs. HFD). Results: (1) The proportions of 'balanced growth of placenta and infant' (appropriate PW and F/P based on Z-score) were 37.6% in the SFD group, 78.8% in the AFD group, and 51.2% in HFD group. (2) The proportion of 'inappropriately heavy placenta' in the SFD group and that of 'inappropriately light placenta' in the HFD group were 0.3 and 0.4%, respectively, a very rare phenomenon. The proportions of 'inappropriately heavy placenta' and 'inappropriately light placenta' accounted for 4.1 and 5.5% in AFD group, respectively. (3) The rates of perinatal death in those with 'balanced growth of placenta and infant' were lowest in the SFD and AFD groups. Conclusion: By showing the fact that perinatal death was lowest in cases with balanced fetal/ placental growth, we conclude that 9-block categorization of PW and F/P based on deviation in the Z-score may be a candidate factor employable for understanding fetal and placental growth and perinatal deaths.


Assuntos
Desenvolvimento Fetal/fisiologia , Recém-Nascido Pequeno para a Idade Gestacional/fisiologia , Placenta/fisiologia , Adulto , Peso ao Nascer/fisiologia , Feminino , Feto/fisiologia , Idade Gestacional , Humanos , Recém-Nascido , Tamanho do Órgão , Paridade/fisiologia , Gravidez
14.
Sensors (Basel) ; 18(1)2018 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-29329225

RESUMO

In order to access the fretting damage of the steam generator tube (SGT), a fast fiber Fabry-Perot (F-P) non-scanning correlation demodulation system based on a super luminescent light emitting diode (SLED) was performed. By demodulating the light signal coming out from the F-P force sensor, the radial collision force between the SGT and the tube support plate (TSP) was interrogated. For higher demodulation accuracy, the effects of the center wavelength, bandwidth, and spectrum noise of SLED were discussed in detail. Specially, a piezoelectric ceramic transducer (PZT) modulation method was developed to get rid of the interference of mode coupling induced by different types of fiber optics in the demodulation system. The reflectivity of optical wedge and F-P sensor was optimized. Finally, the demodulation system worked well in a 1:1 steam generator test loop and successfully demodulated a force signal of 32 N with a collision time of 2 ms.

15.
Spectrochim Acta A Mol Biomol Spectrosc ; 194: 117-125, 2018 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-29331812

RESUMO

A simple change from alkyl group to alkene in side chain of imidazolium cation with same anion resulted in a drastic impact on physical properties (e.g., melting point) from bmimPF6 IL to cmimPF6 IL. The underlying reasons have been elucidated by structural and interaction studies with the help of DSC, SCXRD, vibrational and multi-nuclear NMR spectroscopic techniques. Experiments reveal existence of new weak interactions involving the carbon and π cloud of the imidazolium aromatic ring with fluoride of PF6 anion (i.e., C2--F-P and π--F-P) in cmimPF6 but are absent in structurally similar prototype IL, bmimPF6. Though weak, these interactions helped to form ladder type supramolecular arrangement, resulting in quite high melting point for cmimPF6 IL compared to bmimPF6 IL. These findings emphasize that an IL system can behave uniquely because of the existence of uncommon weak interactions.

16.
Adv Mater ; 29(4)2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27748535

RESUMO

Ultrasensitive pressure sensors are constructed with few-layer MoS2 films. As-designed Fabry-Perot (F-P) sensors exhibit nearly synchronous pressure-deflection responses with a very high sensitivity (89.3 nm Pa-1 ), which is three orders of magnitude higher than those of conventional diaphragm materials (e.g., silica, silver films). This kind of F-P sensor may open up new avenues for 2D materials in biomedical and environmental applications.

17.
Sensors (Basel) ; 16(9)2016 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-27598173

RESUMO

We review our works on Fabry-Perot (F-P) interferometric fiber-optic sensors with various applications. We give a general model of F-P interferometric optical fiber sensors including diffraction loss caused by the beam divergence and the Gouy phase shift. Based on different structures of an F-P cavity formed on the end of a single-mode fiber, the F-P interferometric optical sensor has been extended to measurements of the refractive index (RI) of liquids and solids, temperature as well as small displacement. The RI of liquids and solids can be obtained by monitoring the fringe contrast related to Fresnel reflections, while the ambient temperature and small displacement can be obtained by monitoring the wavelength shift of the interference fringes. The F-P interferometric fiber-optic sensors can be used for many scientific and technological applications.

18.
Front Physiol ; 7: 28, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26903878

RESUMO

Appropriate fetal growth relies upon adequate placental nutrient transfer. Birthweight:placental weight ratio (BW:PW ratio) is often used as a proxy for placental efficiency, defined as the grams of fetus produced per gram placenta. An elevated BW:PW ratio in an appropriately grown fetus (small placenta) is assumed to be due to up-regulated placental nutrient transfer capacity i.e., a higher nutrient net flux per gram placenta. In fetal growth restriction (FGR), where a fetus fails to achieve its genetically pre-determined growth potential, placental weight and BW:PW ratio are often reduced which may indicate a placenta that fails to adapt its nutrient transfer capacity to compensate for its small size. This review considers the literature on BW:PW ratio in both large cohort studies of normal pregnancies and those studies offering insight into the relationship between BW:PW ratio and outcome measures including stillbirth, FGR, and subsequent postnatal consequences. The core of this review is the question of whether BW:PW ratio is truly indicative of altered placental efficiency, and whether changes in BW:PW ratio reflect those placentas which adapt their nutrient transfer according to their size. We consider this question using data from mice and humans, focusing upon studies that have measured the activity of the well characterized placental system A amino acid transporter, both in uncomplicated pregnancies and in FGR. Evidence suggests that BW:PW ratio is reduced both in FGR and in pregnancies resulting in a small for gestational age (SGA, birthweight < 10th centile) infant but this effect is more pronounced earlier in gestation (<28 weeks). In mice, there is a clear association between increased BW:PW ratio and increased placental system A activity. Additionally, there is good evidence in wild-type mice that small placentas upregulate placental nutrient transfer to prevent fetal undergrowth. In humans, this association between BW:PW ratio and placental system A activity is less clear and is worthy of further consideration, both in terms of system A and other placental nutrient transfer processes. This knowledge would help decide the value of measuring BW:PW ratio in terms of determining the risk of poor health outcomes, both in the neonatal period and long term.

19.
Int J Med Sci ; 12(4): 301-5, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25897290

RESUMO

PURPOSE: The "inappropriately heavy placenta" has been considered to be associated with various pregnancy disorders; however, data is scarce what factors affect it. To determine whether the following three affect it; (1) infant gender and mother's parity, (2) growth restriction, and (3) preeclampsia. METHODS: We employed fetal/placental weight ratio (F/P). Subjects consisted of 53,650 infants and their placentas from women who vaginally delivered singleton live term infants. First, we examined whether F/P differs among the infant's gender or mother's parity. We classified the population into 4 categories according to gender and parity: male, nulliparous (n=7,431), male, multiparous (n=7,859), female, nulliparous (n=7,559), female, multiparous (n=7,800), and, compared F/P among the four groups. Next, we determined whether F/P differs in "small" or "large" for gestational age (SGA or LGA) infants, compared with appropriate for gestational age infants. Last, we determined whether preeclampsia (representative disorder of SGA) affects F/P. RESULTS: (1) F/P significantly differed according to infant gender and parity: female and nulliparity had significantly smaller F/P. F/P was significantly smaller in (2) SGA infants, and (3) infants from preeclamptic mothers. CONCLUSION: We for the first time showed that in Japanese term vaginally-delivered singleton population, the following three had significantly smaller F/P than controls thus had "inappropriately heavy placenta": (1) female gender and nulliparity, (2) SGA infants, and (3) infants from preeclamptic mothers. We recommend that these factors should be taken into account in evaluating placental weight. These data may also be useful for further clarifying the fetal-placental pathophysiology in these conditions.


Assuntos
Feto/anatomia & histologia , Placenta/anatomia & histologia , Povo Asiático , Peso ao Nascer , Estudos de Coortes , Feminino , Retardo do Crescimento Fetal/patologia , Humanos , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Japão , Masculino , Tamanho do Órgão , Paridade , Placenta/patologia , Pré-Eclâmpsia/patologia , Gravidez , Estudos Retrospectivos , Caracteres Sexuais
20.
Eur J Med Chem ; 80: 562-568, 2014 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-24832612

RESUMO

Cyclooxygenase-1 (COX-1), but not COX-2, is expressed at high levels in the early stages of human epithelial ovarian cancer where it seems to play a key role in cancer onset and progression. As a consequence, COX-1 is an ideal biomarker for early ovarian cancer detection. A series of novel fluorinated COX-1-targeted imaging agents derived from P6 was developed by using a highly selective COX-1 inhibitor as a lead compound. Among these new compounds, designed by structural modification of P6, 3-(5-chlorofuran-2-yl)-5-(fluoromethyl)-4-phenylisoxazole ([(18/19)F]-P6) is the most promising derivative [IC50 = 2.0 µM (purified oCOX-1) and 1.37 µM (hOVCAR-3 cell COX-1)]. Its tosylate precursor was also prepared and, a method for radio[(18)F]chemistry was developed and optimized. The radiochemistry was carried out using a carrier-free K(18)F/Kryptofix 2.2.2 complex, that afforded [(18)F]-P6 in good radiochemical yield (18%) and high purity (>95%). In vivo PET/CT imaging data showed that the radiotracer [(18)F]-P6 was selectively taken up by COX-1-expressing ovarian carcinoma (OVCAR 3) tumor xenografts as compared with the normal leg muscle. Our results suggest that [(18)F]-P6 might be an useful radiotracer in preclinical and clinical settings for in vivo PET-CT imaging of tissues that express elevated levels of COX-1.


Assuntos
Biomarcadores Tumorais/metabolismo , Ciclo-Oxigenase 1/metabolismo , Radioisótopos de Flúor , Furanos , Isoxazóis , Neoplasias Ovarianas/diagnóstico por imagem , Neoplasias Ovarianas/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Animais , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Inibidores de Ciclo-Oxigenase/química , Inibidores de Ciclo-Oxigenase/farmacologia , Feminino , Furanos/química , Furanos/farmacologia , Humanos , Isoxazóis/química , Isoxazóis/farmacologia , Camundongos , Neoplasias Ovarianas/patologia , Traçadores Radioativos , Radioquímica , Tomografia Computadorizada por Raios X
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