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1.
Cardiol Young ; : 1-12, 2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-34986918

RESUMO

OBJECTIVES: To evaluate the impact of fetal haemodynamics on surgical and neurodevelopmental outcomes in severe Ebstein anomaly and tricuspid valve dysplasia. METHODS: Thirty-four fetuses with Ebstein anomaly/tricuspid valve dysplasia were referred from 2013 to 2019 for fetal echocardiography and clinical management. Nineteen fetuses with Ebstein anomaly/tricuspid valve dysplasia and 30 controls underwent cardiovascular magnetic resonance to quantify the fetal blood flow and to calculate cerebral oxygen delivery (cDO2) and consumption (cVO2). The 3D steady-state free precession acquisition was used to measure fetal brain volume. Surgical outcome, brain MRI, and neurodevelopmental follow-up were reviewed. RESULTS: Twenty-six fetuses were live born (76%) and survival (65%) at a mean follow-up of 4 years. Nine fetuses had a brain MRI before discharge, and all had clinically silent injuries and volume loss. At 18 months, five single-ventricle patients had a neurodevelopmental delay in cognition and language (mean percentile: 11th), with gross-motor skills more affected than fine-motor skills (mean percentiles: 4th and 34th). Fetuses with Ebstein anomaly/tricuspid valve dysplasia had smaller brains, lower combined ventricular output, ascending aorta, superior caval vien and umbilical vein flows, lower oxygen saturation in ascending aorta and superior caval vien, lower cDO2 and cVO2 (p < 0.05). Superior caval vien/combined ventricular output and descending aorta/combined ventricular output ratios were lower in fetuses with circular shunt (p < 0.05). Fetuses requiring the Starnes procedure tended to have smaller brains, lower combined ventricular output, superior caval vien, descending aorta, and umbilical vein flows. CONCLUSIONS: All patients with Ebstein anomaly/tricuspid valve dysplasia are at high risk of neurodevelopmental delay and warrant follow-up. Fetal cardiovascular magnetic resonance revealed impaired brain growth with diminished cerebral blood flow and cDO2, the extenting dependent on the severity of the haemodynamic compromise.

2.
Sci Total Environ ; 806(Pt 1): 150479, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34583081

RESUMO

Excessive ammonia-nitrogen (N) in aquifers has caused groundwater pollution on the Dongting Plain (DTP), which seriously threatens the safety of drinking water. It is urgent and necessary to determine the sources and enrichment mechanisms of ammonia-N in groundwater. Carrying out water and soil collaborative research on a three-dimensional scale can more comprehensively analyze the sources of N, including natural and anthropogenic sources. In this study, surface and groundwater quality characteristics were examined from a total of 77 sites on the DTP. Two subsequent boreholes were drilled in the high ammonia concentration area and normal groundwater area, respectively, to compare the effects of anthropogenic activities. Indicators from hydrogeochemical and pedogeochemical analyses, as well as various isotopes, including δ15N-NH4+, δ15N-TON, δ15N-NO3-, δ18O-NO3-, δ18O-H2O, δD-H2O, and δ13C-TOC were used to identify ammonium sources and transformation mechanisms in the strata. We found that the sediments were contaminated by manure and sewage in the aquifers, and part of the shallow groundwater was additionally contaminated by nitrogen fertilizers. Excessive ammonium-N was also detected in the deep aquitards and sediments, which were mainly dominated by mineralization. Ammonia oxidation (with weak hydroxylamine oxidation) is an important biogeochemical process in which ammonia and nitrate do not accumulate in oxidizing groundwater environments. However, heterotrophic nitrification (HN) and anaerobic ammonium oxidation (ANAMMOX) are the release mechanisms for excessive ammonium-N under reducing conditions. In addition, organic matter (OM) on the DTP had a wide range of biogeochemical proxies generated by phytoplankton within a lake, and the comparatively resilient terrestrial organic residues washed in from the surrounding terrestrial area. This study breaks through the conventional mechanisms for the release of excessive ammonium from sediments to aquifers, which provides new ideas for research on ammonium in sediments and ammonia in groundwater.


Assuntos
Compostos de Amônio , Água Subterrânea , Poluentes Químicos da Água , China , Monitoramento Ambiental , Nitratos/análise , Isótopos de Nitrogênio/análise , Poluentes Químicos da Água/análise
3.
Front Public Health ; 9: 705354, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34733814

RESUMO

Objective: Frontline health-care workers and patients with COVID-19 have been identified as high-risk groups for psychological problems. Experience of working or staying in quarantine wards generated psychological stressors for health-care workers and patients with COVID-19. The present study aimed to investigate the psychological symptoms of hospitalized patients with COVID-19 and the health-care workers treating them during the outbreak period, examine the effects of psychological stressors on mental health in both populations and perceived coping resources for both sides. Methods: Three hundred and eleven health-care workers working in a COVID-19 designated hospital in Wuhan, China, and 148 hospitalized patients with COVID-19 in the same hospital participated in this cross-sectional survey conducted in February 2020. Psychological symptoms, psychological stressors, and perceived coping resources were reported by both groups. Results: Thirty-three percent of health-care workers and 35.2% of patients with COVID-19 had significant psychological symptoms that were indicative of a high risk for psychological disorders. Pandemic-related psychological stressors contributed to psychological symptoms for both populations. Concern about patients was one aspect of psychological stressors of frontline health-care workers and both groups perceived support from the opposite side as an important external coping resource. Conclusion: The results shed light on the need to provide psychological support to both frontline health-care workers and patients with COVID-19 and suggest enhancing the treatment alliance might be effective to improve mental health for both populations during the crisis.


Assuntos
COVID-19 , Quarentena , Estudos Transversais , Hospitais , Humanos , Pacientes Internados , SARS-CoV-2
4.
Materials (Basel) ; 14(19)2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34639998

RESUMO

Biological matter evolution provides an idea for the human design and synthesis of new materials. However, biomimetic materials only stay in laboratory-scale models, and their large-scale industrial applications are yet to be realized. Here, inspired by nacre's architecture, we report a continuous, large-scale method to fabricate phosphogypsum composites by reactive extrusion strategy. After curing for seven days, with more than 50 wt% of beta-hemihydrate phosphogypsum (ß-HPG), the compressive strength and softening coefficient were 24.98 MPa and 0.78, increasing by 110.0% and 20.0%, respectively, compared to the pouring method. The results show that the screw extrusion process can improve the mechanical strength and waterproof properties of ß-HPG hydration specimens without any special chemical admixtures and cements.

5.
Transl Pediatr ; 10(8): 2182-2196, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34584890

RESUMO

Following the improvements in the clinical management of patients with congenital heart disease (CHD) and their increased survival, neurodevelopmental outcome has become an emerging priority in pediatric cardiology. Large-scale efforts have been made to protect the brain during the postnatal, surgical, and postoperative period; however, the presence of brain immaturity and injury at birth suggests in utero and peripartum disturbances. Over the past decade, there has been considerable interest and investigations on fetal brain growth in the setting of CHD. Advancements in fetal brain imaging have identified abnormal brain development in fetuses with CHD from the macrostructural (brain volumes and cortical folding) down to the microstructural (biochemistry and water diffusivity) scale, with more severe forms of CHD showing worse disturbances and brain abnormalities starting as early as the first trimester. Anomalies in common genetic developmental pathways and diminished cerebral substrate delivery secondary to altered cardiovascular physiology are the forefront hypotheses, but other factors such as impaired placental function and maternal psychological stress have surfaced as important contributors to fetal brain immaturity in CHD. The characterization and timing of fetal brain disturbances and their associated mechanisms are important steps for determining preventative prenatal interventions, which may provide a stronger foundation for the developing brain during childhood.

6.
Transl Pediatr ; 10(8): 2197-2209, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34584891

RESUMO

The importance of prenatal diagnosis and fetal intervention has been increasing as a preventative strategy for improving the morbidity and mortality in congenital heart disease (CHD). The advancements in medical imaging technology have greatly enhanced our understanding of disease progression, assessment, and impact in those with CHD. In particular, there has been a growing focus on improving the morbidity and mortality of fetuses diagnosed with left-sided lesions. The disruption of fetal hemodynamics resulting from poor structural developmental of the left outflow tract during cardiogenesis is considered a major factor in the progressive lethal underdevelopment of the left ventricle (LV). This positive feedback cycle of inadequate flow and underdevelopment of the LV leads to a disrupted fetal circulation, which has been described to impact fetal brain growth where systemic outflow is poor and, in some cases, the fetal lungs in the setting of a restrictive interatrial communication. For the past decade, maternal hyperoxygenation (MH) has been investigated as a diagnostic tool to assess the pulmonary vasculature and a therapeutic agent to improve the development of the heart and brain in fetuses with CHD with a focus on left-sided cardiac defects. This review discusses the findings of these studies as well as the utility of acute and chronic administration of MH in CHD.

7.
Appl Opt ; 60(15): 4305-4314, 2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-34143117

RESUMO

We reformulate the coordinate transformation method (C method) for gratings with a vertical facet or overhanging profile (overhanging gratings), in which no tensor concept is involved, only the knowledge of elementary mathematics and Maxwell's equations in the rectangular coordinate system is used, and we provide a detailed recipe for programming. This formulation is easy to understand and implement. It adopts the strategy of a rotating coordinate system from Plumey et al. [J. Opt. Soc. Am. A14, 610 (1997)JOAOD60740-323210.1364/JOSAA.14.000610] and expresses it with the method of changing variables from Li et al. [Appl. Opt.38, 304 (1999)APOPAI0003-693510.1364/AO.38.000304]. We investigate several typical overhanging gratings by the reformulated C method, and we validate and compare the results with the Fourier modal method, which shows that it is superior, especially for metal deep smooth gratings. This reformulation can facilitate the research in light couplers for optical engineers.

8.
Opt Express ; 29(8): 11683-11692, 2021 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-33984944

RESUMO

We present a novel approach based on dual-sideband heterodyne phase-sensitive detection of dispersion spectroscopy to realize simultaneous measurement of the gas absorption signal and corresponding path length. The details of heterodyne phase-sensitive detection of dispersion spectroscopy are derived. A standard Mach-Zehnder intensity modulator (MZM) is adopted to generate a spectrum of a carrier and two sidebands. Phase shift of the beatnote signal generated by the two sidebands is detected to retrieve the path length as well as the gas absorption signal. The measurement range of the path length can be adapted by changing the modulation frequency. Proof-of-principle experiments are conducted with methane (CH4) as the absorber which is filled into a gas cell with a variable path length. We also utilize this approach to evaluate the path length of a White cell and meanwhile calibrate the experimental system with different concentrations of methane. The proposed method has a great potential for detecting the path length and gas absorption in multipass cells and the open path environment.

9.
Spectrochim Acta A Mol Biomol Spectrosc ; 254: 119601, 2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-33676345

RESUMO

In this paper, we proposed the technique of Natural Logarithm Wavelength Modulation Spectroscopy (ln-WMS). Unlike conventional WMS, the amplitudes of the harmonics are linear to the absorbance regardless how large it is. The treating method used in ln-WMS is taking the natural logarithm of the transmitted intensity. The key to ln-WMS is to find out the demodulation phase. We introduced the η-seeking algorithm, which works to find the demodulation phase η so that the 1st harmonic of the unabsorbed intensity comes to zero. Then the nth harmonic of the absorbed intensity is demodulated at phase nη. With simulations, we validated the effectiveness of ln-WMS as well as illustrated the shapes of 1st, 2nd and 3rd harmonics. Then we utilized ln-WMS for measuring water vapor experimentally. It turns out that the linearity is established between the amplitudes of the 1st, 2nd and 3rd harmonics and concentration, although the absorbance is as large as 0.76. We evaluated the stability of the system with coefficient of variation and Allan deviation analysis, proved the effectiveness of the η-seeking algorithm and investigated how the modulation amplitude influenced the amplitudes of the harmonics.

10.
Physiol Rep ; 9(5): e14742, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33650787

RESUMO

Artificial placenta (AP) technology aims to maintain fetal circulation, while promoting the physiologic development of organs. Recent reports of experiments performed in sheep indicate the intrauterine environment can be recreated through the cannulation of umbilical vessels, replacement of the placenta with a low-resistance membrane oxygenator, and incubation of the fetus in fluid. However, it remains to be seen whether animal fetuses similar in size to the extremely preterm human infant that have been proposed as a potential target for this technology can be supported in this way. Preterm Yucatan miniature piglets are similar in size to extremely preterm human infants and share similar umbilical cord anatomy, raising the possibility to serve as a good model to investigate the AP. To characterize fetal cardiovascular physiology, the carotid artery (n = 24) was cannulated in utero and umbilical vein (UV) and umbilical artery were sampled. Fetal UV flow was measured by MRI (n = 16). Piglets were delivered at 98 ± 4 days gestation (term = 115 days), cannulated, and supported on the AP (n = 12) for 684 ± 228 min (range 195-3077 min). UV flow was subphysiologic (p = .002), while heart rate was elevated on the AP compared with in utero controls (p = .0007). We observed an inverse relationship between heart rate and UV flow (r2  = .4527; p < .001) with progressive right ventricular enlargement that was associated with reduced contractility and ultimately hydrops and circulatory collapse. We attribute this to excessive afterload imposed by supraphysiologic circuit resistance and augmented sympathetic activity. We conclude that short-term support of the preterm piglet on the AP is feasible, although we have not been able to attain normal fetal physiology. In the future, we propose to investigate the feasibility of an AP circuit that incorporates a centrifugal pump in our miniature pig model.

11.
Spectrochim Acta A Mol Biomol Spectrosc ; 255: 119661, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-33751961

RESUMO

Wavelength Modulation United Absorption Spectroscopy (WM-UAS), which is virtually an extension of Wavelength Modulation Spectroscopy (WMS), for measuring multi-component broadband absorbers is proposed and demonstrated in this paper. "Broadband absorbers" indicates matters that do not exhibit resolved absorption spectra within a certain wavelength range. WM-UAS requires the assistance of a kind of probe substance which exhibits a series of narrow absorption profiles to measure broadband absorbers. An improved WMS technique is first introduced, with which the limitation of low absorbance in conventional WMS is broken through. On this basis, the mathematical expression for WM-UAS is deduced step-by-step. Simulations and experiments are conducted so that the procedures as well as the validity of WM-UAS is presented. In the experiment, water vapor is selected as the probe substance while methanol vapor and ethanol vapor are simultaneously measured. According to Allan deviation analysis, the optimal average time of the system is 150.18 s and the corresponding detection limit is 19.38 ppm·m for ethanol and 14.85 ppm·m for methanol.

12.
Appl Psychol Health Well Being ; 13(4): 745-760, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33742781

RESUMO

The present study aimed to examine the effect of perceived organizational support on the PTSD symptoms of frontline healthcare workers, and to examine the mediating effects of coping self-efficacy and coping strategies in this relationship. A short-term longitudinal study design was used to conduct two waves of online surveys in March and April 2020. Participants comprised 107 medical staff in both waves of investigation. Self-efficacy, coping strategies, and perceived organizational support were reported at Wave 1, and PTSD symptoms were reported at Wave 2. Results indicated that (1) The prevalence of probable PTSD was 9.3% and 4.7% on the Chinese version of the Impact of Events Scale-Revised of 33 and 35, respectively. Local healthcare workers had greater risks of PTSD than the members of medical rescue teams. Doctors reported higher PTSD symptoms than nurses. (2) Perceived organizational support had a significant indirect effect on PTSD symptoms through the mediation of problem-focused coping strategies and the sequential mediating effect of coping self-efficacy and problem-focused coping strategies. The findings highlight the importance of providing adequate organizational support to reduce PTSD symptoms in frontline medical staff during the COVID-19 pandemic.


Assuntos
COVID-19 , Transtornos de Estresse Pós-Traumáticos , Adaptação Psicológica , Estudos Transversais , Surtos de Doenças , Pessoal de Saúde , Humanos , Estudos Longitudinais , Pandemias , SARS-CoV-2 , Autoeficácia , Transtornos de Estresse Pós-Traumáticos/epidemiologia
13.
Asia Pac J Clin Nutr ; 30(1): 15-21, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33787036

RESUMO

BACKGROUND AND OBJECTIVES: The novel coronavirus disease (COVID-19) epidemic is spreading all over the world. With the number of cases increasing rapidly, the epidemiological data on the nutritional practice is scarce. In this study, we aim to describe the clinical characteristics and nutritional practice in a cohort of critically ill COVID-19 patients. METHODS AND STUDY DESIGN: This is a multicenter, ambidirectional cohort study conducted at 11 hospitals in Hubei Province, China. All eligible critical COVID-19 patients in the study hospital intensive care units at 00:00, March 6th, 2020, were included. Data collection was performed via written case report forms. RESULTS: A total of 44 patients were identified and enrolled, of whom eight died during the 28-day outcome follow- up period. The median interval between hospital admission and the study day was 24 (interquartile range, 13- 26) days and 52.2% (23 of 44) of patients were on invasive mechanical ventilation. The median nutrition risk in critically ill (mNUTRIC) score was 3 (interquartile range, 2-5) on the study day. During the enrolment day, 68.2% (30 of 44) of patients received enteral nutrition (EN), while 6.8% (3 of 44) received parenteral nutrition (PN) alone. Nausea and aspiration were uncommon, with a prevalence of 11.4% (5 of 44) and 6.8% (3 of 44), respectively. As for energy delivery, 69.7% (23 of 33) of patients receiving EN and/or PN were achieving their prescribed targets. CONCLUSIONS: The study showed that EN was frequently applied in critical COVID-19 patients. Energy delivery may be suboptimal in this study requiring more attention.


Assuntos
COVID-19/epidemiologia , COVID-19/terapia , Estado Terminal/epidemiologia , Estado Nutricional , Apoio Nutricional , Idoso , China/epidemiologia , Estudos de Coortes , Nutrição Enteral/estatística & dados numéricos , Feminino , Hospitalização , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Nutrição Parenteral/estatística & dados numéricos , SARS-CoV-2
14.
Sci Total Environ ; 774: 145131, 2021 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-33610997

RESUMO

Excessive inorganic nitrogen (IN) compound content in groundwater is generally attributed to anthropogenic activities. Here, natural nitrogen sources in Quaternary sediments from aquifers and aquitards of Jianghan Plain (JHP), China were identified. Ammonium and nitrate content in groundwater samples collected from 129 well sites were determined through chemical analysis. Subsequent 4 boreholes were drilled at areas with high nitrogen concentration in the Quaternary aquifer. Indicators from hydrochemistry and soil geochemistry analysis, as well as optically stimulated luminescence dating and various of radioactive isotope δ14C-CO2 and stable isotopes including δ15N-NH4+, δ15N-total organic nitrogen (TON), δ15N-NO3-, δ18O-NO3-, δ18O-H2O, δD-H2O, and δ13C-total organic carbon (TOC) were used to identify high-concentration N compound sources and transformation mechanisms (NO3-: 0.02-770 mg L-1; NH4-N: 0-30.5 mg L-1) in the porous media. The thick clay layer protected the underlying media. Paleo-precipitation characteristics were preserved in the porewater; that is, it had not been affected by anthropogenic activities. The high nitrate concentration in the shallow oxidized aquifer was mostly attributed to manure and sewage (δ15N-NO3- was 14‰). The ammonium-N in the deep strata and part of ammonium-N in the shallow strata (aquifers and aquitards) were from natural sources, mainly from natural TON mineralization. Adsorption was an auxiliary factor for ammonium enrichment in the shallow strata, as were dissimilatory nitrate reduction to ammonium (DNRA) and low ammonia volatilization. Organic matter (OM) involved in mineralization was a mixture of lacustrine algae and terrigenous clastic sediments (from river upstream). The algae were traced to lake formation and frequent evolutionary changes in river environments, as indicated by alterations in sedimentary facies. The present findings may encourage researchers to consider natural IN sources' contribution to N contamination using quantitative models. They also serve as a valuable reference for understanding other pollutants' transformation mechanism in similar environments and provide research ideas for similar areas.

15.
Spectrochim Acta A Mol Biomol Spectrosc ; 247: 119127, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33161262

RESUMO

Molecules without well-resolved absorption spectra within a certain spectral range can be called broadband absorbers. Inspired by Wavelength Modulation Spectroscopy (WMS), we came up the idea of Wavelength Modulation United Absorption Spectroscopy (WM-UAS) for measuring broadband absorbers. WM-UAS commonly involves two gases, one is the probe gas, another is the target broadband absorber. The only request for implementing WM-UAS is that, within the spectral envelope of the broadband absorber, there exists more than one well-resolved absorption peak of the probe gas. To validate the effectiveness of WM-UAS, methanol was experimentally measured with water vapor as the probe gas. According to Allan deviation analysis, the detection limit was estimated as 1.7 ppm during the optimal average time of 5.4 s. For standard methanol vapor with a concentration of 100.9 ppm, the measurement error was about 1.3%@5.4 s, and for high purity nitrogen, the measurement result was 3.56 ppm@5.4 s.

16.
J Magn Reson Imaging ; 53(2): 540-551, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32815242

RESUMO

BACKGROUND: Phase contrast MRI in the great vessels is a potential clinical tool for managing fetal pathologies. One challenge is the uncontrollable fetal motion, potentially corrupting flow quantifications. PURPOSE: To demonstrate improvements in fetal blood flow quantification in great vessels using retrospectively motion-corrected golden-angle radial phase contrast MRI relative to Cartesian phase contrast MRI. STUDY TYPE: Method comparison. PHANTOM/SUBJECTS: Computer simulation. Seventeen pregnant volunteers. FIELD STRENGTH/SEQUENCE: 1.5T and 3T. Cartesian and golden-angle radial phase contrast MRI. ASSESSMENT: Through computer simulations, radial (with and without retrospective motion correction) and Cartesian phase contrast MRI were compared using flow deviations. in vivo Cartesian and radial phase contrast MRI measurements and reconstruction qualities were compared in pregnancies. Cartesian data were reconstructed into gated reconstructions (CINEs) after cardiac gating with metric optimized gating (MOG). For radial data, real-time reconstructions were performed for motion correction and MOG followed by CINE reconstructions. STATISTICAL TESTS: Wilcoxon signed-rank test. Linear regression. Bland-Altman plots. Student's t-test. RESULTS: Simulations showed significant improvements (P < 0.05) in flow accuracy and reconstruction quality with motion correction ([mean/peak] flow errors with ±5 mm motion corruption: Cartesian [35 ± 1/115 ± 7] mL/s, motion uncorrected radial [25 ± 1/75 ± 2] mL/s and motion-corrected radial [1.0 ± 0.5/-5 ± 1] mL/s). in vivo Cartesian reconstructions without motion correction had lower quality than the motion-corrected radial reconstructions (P < 0.05). Across all fetal mean flow measurements, the bias [limits of agreement] between the two measurements were -0.2 [-76, 75] mL/min/kg, while the linear regression coefficients were (Mradial = 0.81 × MCartesian + 29.8 [mL/min/kg], r2 = 0.67). The corresponding measures for the peak fetal flows were -23 [-214, 167] mL/min/kg and (Pradial = 0.95 × PCartesian -1.2 [mL/min/kg], r2 = 0.80). Cartesian reconstructions of low quality showed significantly higher estimated mean and peak (P < 0.05) flows than the corresponding radial reconstructions. DATA CONCLUSION: Simulations showed that radial phase contrast MRI with motion compensation improved flow accuracy. For fetal measurements, motion-corrected radial reconstructions showed better image quality than, and different flow values from, Cartesian reconstructions. Level of Evidence 1. Technical Efficacy Stage 1. J. MAGN. RESON. IMAGING 2021;53:540-551.


Assuntos
Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Simulação por Computador , Feminino , Humanos , Movimento (Física) , Gravidez , Reprodutibilidade dos Testes , Estudos Retrospectivos
17.
Nat Commun ; 11(1): 5366, 2020 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-33097712

RESUMO

The world has experienced dramatic urbanization in recent decades. However, we still lack information about the characteristics of urbanization in large cities throughout the world. After analyzing 841 large cities with built-up areas (BUAs) of over 100 km2 from 2001 to 2018, here we found an uneven distribution of urbanization at different economic levels. On average, large cities in the low-income and lower-middle-income countries had the highest urban population growth, and BUA expansion in the upper-middle-income countries was more than three times that of the high-income countries. Globally, more than 10% of BUAs in 325 large cities showed significant greening (P < 0.05) from 2001 to 2018. In particular, China accounted for 32% of greening BUAs in the 841 large cities, where about 108 million people lived. Our quantitative results provide information for future urban sustainable development, especially for rational urbanization of the developing world.

18.
Huan Jing Ke Xue ; 41(9): 4333-4344, 2020 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-33124315

RESUMO

Nitrogen plays a vital role in biological activities as the basic element of organic molecules and the main nutrient of soil. In the study of nitrogen pollution, the first step is to understand the transformation mechanism of various nitrogen forms. Based on the transformation process and the mechanism of nitrogen in the ecosystem, this review summarizes the research methods of nitrogen source analysis and nitrogen isotope fractionation in soil and water, and categorically reviews the applications of nitrogen source identification in surface water and groundwater. We showed that it is more effective to identify the sources of soil and water nitrogen pollution by combining hydrochemical methods with the multi-isotope approach. The importance of primary nitrogen sources should also be quantified to study groundwater pollution. A new approach to determine the source of oxygen atoms during nitrosation was also presented, and the enrichment principle of δ18O-NO3- during secondary oxidation was explained. Finally, the contribution of primary ammonium nitrogen to groundwater pollution was discussed, and innovative research ideas were provided.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Ecossistema , Monitoramento Ambiental , Nitratos/análise , Nitrogênio/análise , Isótopos de Nitrogênio/análise , Solo , Água , Poluentes Químicos da Água/análise
19.
Am J Physiol Cell Physiol ; 319(6): C967-C979, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-32667865

RESUMO

Necrotizing enterocolitis (NEC) is an acute intestinal condition accounting for severe mortality and morbidity in preterm infants. This study aimed to identify the possible roles of let-7d-5p in neonatal rats with NEC. The differentially expressed genes (DEGs) related to NEC were initially screened in silico. After establishment of NEC rat models, measurement of the expression of let-7d-5p, galectin-3 (LGALS3), Toll-like receptor 4 (TLR4), and nuclear factor-κB (NF-κB) as well as proinflammatory cytokines (TNF-α, IL-1ß, and IL-6) was conducted. The interaction between let-7d-5p and LGALS3 or argonaute-2 (AGO2) was identified. Gain- and loss-of-function approaches were then performed in an attempt to investigate the regulatory roles of let-7d-5p and LGALS3 in inflammation and cell apoptosis in NEC neonatal rats. Let-7d-5p was poorly expressed, whereas LGALS3, TLR4, and NF-κB were highly expressed, in the intestinal tissues of NEC rats. Overexpression of let-7d-5p resulted in decreased levels of proinflammatory factors in the intestinal tissues of NEC rats. Through sequential experimentation, let-7d-5p was identified to target LGALS3 and bind to AGO2. In addition, LGALS3 silencing or LPS treatment blocked the TLR4/NF-κB signaling pathway, thereby suppressing intestinal epithelial cell apoptosis and inflammation in NEC. Collectively, let-7d-5p might exercise its inhibitory properties in the inflammatory response and intestinal epithelial cell apoptosis in NEC neonatal rats via inactivation of the LGALS3-dependent TLR4/NF-κB signaling pathway.


Assuntos
Enterocolite Necrosante/genética , Galectina 3/genética , Inflamação/genética , MicroRNAs/genética , NF-kappa B/genética , Transdução de Sinais/genética , Receptor 4 Toll-Like/genética , Animais , Animais Recém-Nascidos , Apoptose/genética , Citocinas/genética , Enterocolite Necrosante/patologia , Células Epiteliais/patologia , Feminino , Recém-Nascido Prematuro , Inflamação/patologia , Mucosa Intestinal/patologia , Intestinos/patologia , Ratos , Ratos Sprague-Dawley
20.
J Physiol ; 598(15): 3259-3281, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32372463

RESUMO

KEY POINTS: Human fetal Doppler ultrasound and invasive blood gas measurements obtained by cordocentesis or at the time of delivery reveal similarities with sheep (an extensively used model for human fetal cardiovascular physiology). Oxygen saturation (SO2 ) measurements in human fetuses have been limited to the umbilical and scalp vessels, providing little information about normal regional SO2 differences in the fetus. Blood T2 MRI relaxometry presents a non-invasive measure of SO2 in the major fetal vessels. This study presents the first in vivo validation of fetal vessel T2 oximetry against the in vitro T2-SO2 relationship using catheterized sheep fetuses and compares the normal SO2 in the major vessels between the human and sheep fetal circulations. Human fetal vessel SO2 by T2 MRI confirms many similarities with the sheep fetal circulation and is able to demonstrate regional differences in SO2 ; in particular the significantly higher SO2 in the left versus right heart. ABSTRACT: Blood T2 magnetic resonance imaging (MRI) relaxometry non-invasively measures oxygen saturation (SO2 ) in major vessels but has not been validated in fetuses in vivo. We compared the blood T2-SO2 relationship in vitro (tubes) and in vivo (vessels) in sheep, and measured SO2 across the normal human and sheep fetal circulations by T2. Singleton pregnant ewes underwent surgery to implant vascular catheters. In vitro and in vivo sheep blood T2 measurements were related to corresponding SO2 measured using a blood gas analyser, as well as relating T2 and SO2 of human fetal blood in vitro. MRI oximetry was performed in the major vessels of 30 human fetuses at 36 weeks (term, 40 weeks) and 10 fetal sheep (125 days; term, 150 days). The fidelity of in vivo fetal T2 oximetry was confirmed through comparison of in vitro and in vivo sheep blood T2-SO2 relationships (P = 0.1). SO2 was similar between human and sheep fetuses, as was the fetal oxygen extraction fraction (human, 33 ± 11%; sheep, 34 ± 7%; P = 0.798). The presence of streaming in the human fetal circulation was demonstrated by the SO2 gradient between the ascending aorta (68 ± 10%) and the main pulmonary artery (49 ± 9%; P < 0.001). Human and sheep fetal vessel MRI oximetry based on T2 is a validated approach that confirms the presence of streaming of umbilical venous blood towards the heart and brain. Streaming is important in ensuring oxygen delivery to these organs and its disruption may have important implications for organ development, especially in conditions such as congenital heart disease and fetal growth restriction.


Assuntos
Feto , Imageamento por Ressonância Magnética , Animais , Gasometria , Feminino , Sangue Fetal , Feto/diagnóstico por imagem , Humanos , Oxigênio , Ovinos
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