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1.
Nature ; 577(7788): 74-78, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31894145

RESUMO

To address global challenges1-4, 193 countries have committed to the 17 United Nations Sustainable Development Goals (SDGs)5. Quantifying progress towards achieving the SDGs is essential to track global efforts towards sustainable development and guide policy development and implementation. However, systematic methods for assessing spatio-temporal progress towards achieving the SDGs are lacking. Here we develop and test systematic methods to quantify progress towards the 17 SDGs at national and subnational levels in China. Our analyses indicate that China's SDG Index score (an aggregate score representing the overall performance towards achieving all 17 SDGs) increased at the national level from 2000 to 2015. Every province also increased its SDG Index score over this period. There were large spatio-temporal variations across regions. For example, eastern China had a higher SDG Index score than western China in the 2000s, and southern China had a higher SDG Index score than northern China in 2015. At the national level, the scores of 13 of the 17 SDGs improved over time, but the scores of four SDGs declined. This study suggests the need to track the spatio-temporal dynamics of progress towards SDGs at the global level and in other nations.


Assuntos
Desenvolvimento Sustentável/tendências , China , Tempo
2.
Proc Natl Acad Sci U S A ; 119(26): e2101388119, 2022 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-35733266

RESUMO

The 2015/16 El Niño brought severe drought and record-breaking temperatures in the tropics. Here, using satellite-based L-band microwave vegetation optical depth, we mapped changes of above-ground biomass (AGB) during the drought and in subsequent years up to 2019. Over more than 60% of drought-affected intact forests, AGB reduced during the drought, except in the wettest part of the central Amazon, where it declined 1 y later. By the end of 2019, only 40% of AGB reduced intact forests had fully recovered to the predrought level. Using random-forest models, we found that the magnitude of AGB losses during the drought was mainly associated with regionally distinct patterns of soil water deficits and soil clay content. For the AGB recovery, we found strong influences of AGB losses during the drought and of [Formula: see text]. [Formula: see text] is a parameter related to canopy structure and is defined as the ratio of two relative height (RH) metrics of Geoscience Laser Altimeter System (GLAS) waveform data-RH25 (25% energy return height) and RH100 (100% energy return height; i.e., top canopy height). A high [Formula: see text] may reflect forests with a tall understory, thick and closed canopy, and/or without degradation. Such forests with a high [Formula: see text] ([Formula: see text] ≥ 0.3) appear to have a stronger capacity to recover than low-[Formula: see text] ones. Our results highlight the importance of forest structure when predicting the consequences of future drought stress in the tropics.


Assuntos
Biomassa , Secas , El Niño Oscilação Sul , Floresta Úmida , Solo , Clima Tropical , Água
3.
J Bioenerg Biomembr ; 56(3): 273-284, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38427129

RESUMO

Tetramethylpyrazine (TMP) is one of the active ingredients of Chuan Xiong that has been reported to have effects on numerous diseases, including diabetic nephropathy (DN). Whereas, related molecular mechanisms are not fully elucidated. We aimed to explore circACTR2's role in TMP-mediated protective effects on DN. In vitro DN condition was established in human kidney cells (HK-2) by treating high glucose (HG). CCK-8 assay and flow cytometry assay were used to observe cell viability and survival. Oxidative stress was determined by the associated markers using kits. The release of inflammatory factors was detected using ELISA kits. Quantitative real-time PCR (qPCR) and western blot were utilized for expression analysis of cricACTR2, miR-140-5p, and GLI pathogenesis-related 2 (GLIPR2). The binding between miR-140-5p and circACTR2 or GLIPR2 was confirmed by dual-luciferase, RIP, and pull-down studies. HG largely induced HK-2 cell apoptosis, oxidative stress, and inflammation, which were alleviated by TMP. CircACTR2's expression was enhanced in HG-treated HK-2 cells but attenuated in HG + TMP-treated HK-2 cells. CircACTR2 overexpression attenuated the functional effects of TMP and thus restored HG-induced cell apoptosis, oxidative stress, and inflammation. CircACTR2 bound to miR-140-5p to enhance the expression of GLIPR2. MiR-140-5p restoration or GLIPR2 inhibition reversed the role of circACTR2 overexpression. CircACTR2 attenuated the protective effects of TMP on HG-induced HK-2 cell damages by regulating the miR-140-5p/GLIPR2 network, indicating that circACTR2 was involved in the functional network of TMP in DN.


Assuntos
Pirazinas , Humanos , Pirazinas/farmacologia , MicroRNAs/metabolismo , Estresse Oxidativo/efeitos dos fármacos , RNA Circular/metabolismo , Rim/metabolismo , Rim/efeitos dos fármacos , Rim/patologia , Linhagem Celular , Apoptose/efeitos dos fármacos , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/patologia
4.
Glob Chang Biol ; 30(8): e17454, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39132898

RESUMO

Tropical and subtropical evergreen broadleaved forests (TEFs) contribute more than one-third of terrestrial gross primary productivity (GPP). However, the continental-scale leaf phenology-photosynthesis nexus over TEFs is still poorly understood to date. This knowledge gap hinders most light use efficiency (LUE) models from accurately simulating the GPP seasonality in TEFs. Leaf age is the crucial plant trait to link the dynamics of leaf phenology with GPP seasonality. Thus, here we incorporated the seasonal leaf area index of different leaf age cohorts into a widely used LUE model (i.e., EC-LUE) and proposed a novel leaf age-dependent LUE model (denoted as LA-LUE model). At the site level, the LA-LUE model (average R2 = .59, average root-mean-square error [RMSE] = 1.23 gC m-2 day-1) performs better than the EC-LUE model in simulating the GPP seasonality across the nine TEFs sites (average R2 = .18; average RMSE = 1.87 gC m-2 day-1). At the continental scale, the monthly GPP estimates from the LA-LUE model are consistent with FLUXCOM GPP data (R2 = .80; average RMSE = 1.74 gC m-2 day-1), and satellite-based GPP data retrieved from the global Orbiting Carbon Observatory-2 (OCO-2) based solar-induced chlorophyll fluorescence (SIF) product (GOSIF) (R2 = .64; average RMSE = 1.90 gC m-2 day-1) and the reconstructed TROPOspheric Monitoring Instrument SIF dataset using machine learning algorithms (RTSIF) (R2 = .78; average RMSE = 1.88 gC m-2 day-1). Typically, the estimated monthly GPP not only successfully represents the unimodal GPP seasonality near the Tropics of Cancer and Capricorn, but also captures well the bimodal GPP seasonality near the Equator. Overall, this study for the first time integrates the leaf age information into the satellite-based LUE model and provides a feasible implementation for mapping the continental-scale GPP seasonality over the entire TEFs.


Assuntos
Florestas , Folhas de Planta , Tecnologia de Sensoriamento Remoto , Estações do Ano , Folhas de Planta/crescimento & desenvolvimento , Fotossíntese , Modelos Teóricos , Luz , Árvores/crescimento & desenvolvimento , Modelos Biológicos , Clima Tropical
5.
Glob Chang Biol ; 30(7): e17423, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39010751

RESUMO

The extreme dry and hot 2015/16 El Niño episode caused large losses in tropical live aboveground carbon (AGC) stocks. Followed by climatic conditions conducive to high vegetation productivity since 2016, tropical AGC are expected to recover from large losses during the El Niño episode; however, the recovery rate and its spatial distribution remain unknown. Here, we used low-frequency microwave satellite data to track AGC changes, and showed that tropical AGC stocks returned to pre-El Niño levels by the end of 2020, resulting in an AGC sink of 0.18 0.14 0.26 $$ {0.18}_{0.14}^{0.26} $$ Pg C year-1 during 2014-2020. This sink was dominated by strong AGC increases ( 0.61 0.49 0.84 $$ {0.61}_{0.49}^{0.84} $$ Pg C year-1) in non-forest woody vegetation during 2016-2020, compensating the forest AGC losses attributed to the El Niño event, forest loss, and degradation. Our findings highlight that non-forest woody vegetation is an increasingly important contributor to interannual to decadal variability in the global carbon cycle.


Assuntos
Carbono , El Niño Oscilação Sul , Clima Tropical , Carbono/metabolismo , Carbono/análise , Ciclo do Carbono , Florestas , Sequestro de Carbono , Mudança Climática
6.
Glob Chang Biol ; 28(4): 1583-1595, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34854168

RESUMO

Our limited understanding of the impacts of drought on tropical forests significantly impedes our ability in accurately predicting the impacts of climate change on this biome. Here, we investigated the impact of drought on the dynamics of forest canopies with different heights using time-series records of remotely sensed Ku-band vegetation optical depth (Ku-VOD), a proxy of top-canopy foliar mass and water content, and separated the signal of Ku-VOD changes into drought-induced reductions and subsequent non-drought gains. Both drought-induced reductions and non-drought increases in Ku-VOD varied significantly with canopy height. Taller tropical forests experienced greater relative Ku-VOD reductions during drought and larger non-drought increases than shorter forests, but the net effect of drought was more negative in the taller forests. Meta-analysis of in situ hydraulic traits supports the hypothesis that taller tropical forests are more vulnerable to drought stress due to smaller xylem-transport safety margins. Additionally, Ku-VOD of taller forests showed larger reductions due to increased atmospheric dryness, as assessed by vapor pressure deficit, and showed larger gains in response to enhanced water supply than shorter forests. Including the height-dependent variation of hydraulic transport in ecosystem models will improve the simulated response of tropical forests to drought.


Assuntos
Secas , Ecossistema , Mudança Climática , Florestas , Árvores , Clima Tropical
8.
J Environ Manage ; 303: 114167, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34861505

RESUMO

In recent decades, rapid urbanization and intensified global climate change have resulted in a significant difference of environment and resources distribution on space, which would cause trouble for accurate assessment of regional ecological sustainable development, especially in the large urban agglomerations. The parameters used in previous assessment methods have normally ignored spatial heterogeneity, leading to deviations in the evaluation accuracies against the context above. By incorporating remote sensing technology, this study proposed an improved emergy ecological footprint (EEF) method and a novel ecological sustainability index to comprehensively analyze the variability of ecological security states (ESS) from 1994 to 2018 in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) and to predict its sustainable growth potential based on a combined factorial decomposition and scenario analysis. Results showed that the pixel-based emergy analysis revealed significant heterogeneity over time and space under the impact of climate change and intense land use activities during the study period. The emergy carrying capacity per capita (ecc) and the emergy ecological footprint per capita (eef) also showed a significant difference between the nine cities in the GBA. In addition, the traditional EEF method, which does not consider the spatiotemporal variation, has indeed overestimated the GBA's ecc by 15% compared with our results. The ESS of the GBA gradually worsened from slight insecurity in the 1990s to moderate insecurity in 2018. If the current trends in socio-economic activities and climate change continue according to the RCP8.5 scenario in the IPCC, the ESS of the GBA will reach the extreme insecurity state in 2050. However, our scenarios show that industrial structure adjustment, energy structure optimization, and especially biological resource conservation can reduce the EFI by approximately 6.52%, 23.4%, and 30.6%, respectively. Consequently, effective implementation of the above measures can limit the increase both in emergy ecological deficit and emergy ecological footprint intensity (EFI) and, together, contribute to a higher security status in the GBA in 2050.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , China , Hong Kong , Macau , Estudos Prospectivos , Estudos Retrospectivos
9.
Glob Chang Biol ; 27(2): 215-217, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33098149

RESUMO

To limit global temperature rise, scientists have proposed significant potentials for climate change mitigation from protecting and managing natural systems. However, depending on the time taken for technology deployment and natural carbon gain, actual mitigation can be dramatically delayed, and total mitigation by 2030 or 2050 can be more than halved compared to the estimated potential. Delayed or lack of action on implementation would push back the timeline to reduce greenhouse gas emissions, largely undermining the Paris goals. Launching actions now and learning from past experience can help deliver climate mitigation and sustainable development goals.


Assuntos
Mudança Climática , Gases de Efeito Estufa , Paris
10.
Sensors (Basel) ; 20(20)2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33050173

RESUMO

Numerous vehicle detection methods have been proposed to obtain trustworthy traffic data for the development of intelligent traffic systems. Most of these methods perform sufficiently well under common scenarios, such as sunny or cloudy days; however, the detection accuracy drastically decreases under various bad weather conditions, such as rainy days or days with glare, which normally happens during sunset. This study proposes a vehicle detection system with a visibility complementation module that improves detection accuracy under various bad weather conditions. Furthermore, the proposed system can be implemented without retraining the deep learning models for object detection under different weather conditions. The complementation of the visibility was obtained through the use of a dark channel prior and a convolutional encoder-decoder deep learning network with dual residual blocks to resolve different effects from different bad weather conditions. We validated our system on multiple surveillance videos by detecting vehicles with the You Only Look Once (YOLOv3) deep learning model and demonstrated that the computational time of our system could reach 30 fps on average; moreover, the accuracy increased not only by nearly 5% under low-contrast scene conditions but also 50% under rainy scene conditions. The results of our demonstrations indicate that our approach is able to detect vehicles under various bad weather conditions without the need to retrain a new model.

11.
Sensors (Basel) ; 18(9)2018 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-30213128

RESUMO

Dynamic voltage and frequency scaling (DVFS) is a well-known method for saving energy consumption. Several DVFS studies have applied learning-based methods to implement the DVFS prediction model instead of complicated mathematical models. This paper proposes a lightweight learning-directed DVFS method that involves using counter propagation networks to sense and classify the task behavior and predict the best voltage/frequency setting for the system. An intelligent adjustment mechanism for performance is also provided to users under various performance requirements. The comparative experimental results of the proposed algorithms and other competitive techniques are evaluated on the NVIDIA JETSON Tegra K1 multicore platform and Intel PXA270 embedded platforms. The results demonstrate that the learning-directed DVFS method can accurately predict the suitable central processing unit (CPU) frequency, given the runtime statistical information of a running program, and achieve an energy savings rate up to 42%. Through this method, users can easily achieve effective energy consumption and performance by specifying the factors of performance loss.

12.
Int J Technol Assess Health Care ; 33(2): 206-214, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28583223

RESUMO

OBJECTIVES: The aim of this study was to evaluate the universal newborn hearing screening (UNHS) and intervention program in Shanghai, China. METHODS: This study included the quantitative analyses of the UNHS-Shanghai database in 2002-12 and qualitative assessment of the program. The Otoacoustic Emissions and the Automated Auditory Brainstem Evoked Responses tests were conducted in screening. The costs and benefits were calculated based on the number of participants in each stage. The short-term and long-term periods were defined as from birth to 15 years of age or to death (82-year-olds), respectively. Sensitivity analyses were conducted. RESULTS: A total 1,574,380 newborns were included, representing 93.6 percent of all eligible babies in Shanghai during the study period. The prevalence of newborn hearing loss was 1.66‰. The short-term/long-term program costs were ¥488.5 million (US$75.52 million)/¥1.08 billion (US$167.12 million), and the short-term/long-term program benefit was ¥980.1 million (US$151.53 million)/¥8.13 billion (US$1.26 billion). The program benefit was greater than its cost if the proportion of hearing-loss children enrolled in regular schools was no less than 41.4 percent of all hearing impaired children, as well as if the wage growth rate ranged from 3 percent to 8 percent. Qualitative results also suggested that stakeholders strongly supported this program. CONCLUSIONS: The universal newborn hearing screening and intervention program in Shanghai is justified in terms of the resource input in the long run, although there is still room for further improvement with respect to educational rehabilitation and a better infrastructure system.


Assuntos
Potenciais Evocados Auditivos do Tronco Encefálico , Transtornos da Audição/diagnóstico , Triagem Neonatal , China , Testes Auditivos , Humanos , Recém-Nascido , Emissões Otoacústicas Espontâneas
13.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(2): 477-82, 2014 Feb.
Artigo em Zh | MEDLINE | ID: mdl-24822424

RESUMO

The main objectives of the research described in the present paper are to develop a semi-analysis model of water clarity for case 2 waters without inputting the absorption and scattering coefficient, which are not easy to be obtained for offshore marine areas so far. Based on the Zsd (Secchi depth)inversion theory, a simple semi-analysis spectra model was established for offshore seawater clarity by analyzing the relationship between vertical diffuse attenuation coefficient K(d) (490) and the beam attenuation coefficient c(490) with remote sensing reflectance. This semi-analysis spectra model needed two band reflectance ratios on- ly, while tidal correction was produced for this model to improve the precision of the retrieving results. The semi-analysis spectra model was applied to ASD hyperspectral reflectance data measured in the Pearl River Estuary Ecological Zone (October 21, 23, 2012, November 2, 2012; N=20) and the Xuwen Coral Reef Protection Zone (January 13, 14, 2013, N=25) which covered different water body of tidal times and different pollution sources. The results indicated that the changing tendency of predicted values was consistent with the synchronous measurement values after comparing them. However, water clarity calculated by the ASD hyperspectral reflectance measured in spring tidal time, generated 0. 4 m deviation compared with in-situ water clarity, while water clarity calculated by the ASD hyperspectral reflectance measured in neap tidal time is close to the in-situ water clarity. So the tidal correction coefficient of 0.4 was further applied for the model. After modification, the coefficient of determination between the inversed and measured water clarity was 0. 663, the average absolute error was 0. 14 m and the average relative error was 19.5%. Research demonstrated that this semi-analysis inversion algorithm just needs two band reflectance ratio to complete the inversion of water clarity, which is simple and works relatively well for lower clarity (less than 2 meters) waters compared to He' (2004) and Doron' (2011) algorithms.

14.
iScience ; 27(2): 108974, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38327790

RESUMO

In 2016, the Yangtze River Protection Strategy was proposed and a series of measures were applied to restore the health and function of the Yangtze River ecosystem. However, the impact of these measures on the carbon (C) sink capacity of the Yangtze River estuary wetlands has not been exhaustively studied. In this work, the effects of these measures on the C sink capacity of Yangtze River estuary wetlands were examined through the long-term monitoring of C fluxes, soil respiration, plant growth and water quality. The C flux of the Yangtze River estuary wetlands has become increasingly negative after the implementation of these measures, mainly owing to reduction in soil CO2 emission. The decrease in the chemical fertilizer release and returning farmland to wetland had led to the improvement of water quality in the estuary area, which further reduced soil heterotrophic microbial activity, and ultimately decreasing soil CO2 emissions of estuary wetlands.

15.
Front Med (Lausanne) ; 11: 1301312, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38405190

RESUMO

Objectives: Coronavirus disease-19 (COVID-19)/influenza poses unprecedented challenges to the global economy and healthcare services. Numerous studies have described alterations in the microbiome of COVID-19/influenza patients, but further investigation is needed to understand the relationship between the microbiome and these diseases. Herein, through systematic comparison between COVID-19 patients, long COVID-19 patients, influenza patients, no COVID-19/influenza controls and no COVID-19/influenza patients, we conducted a comprehensive review to describe the microbial change of respiratory tract/digestive tract in COVID-19/influenza patients. Methods: We systematically reviewed relevant literature by searching the PubMed, Embase, and Cochrane Library databases from inception to August 12, 2023. We conducted a comprehensive review to explore microbial alterations in patients with COVID-19/influenza. In addition, the data on α-diversity were summarized and analyzed by meta-analysis. Results: A total of 134 studies comparing COVID-19 patients with controls and 18 studies comparing influenza patients with controls were included. The Shannon indices of the gut and respiratory tract microbiome were slightly decreased in COVID-19/influenza patients compared to no COVID-19/influenza controls. Meanwhile, COVID-19 patients with more severe symptoms also exhibited a lower Shannon index versus COVID-19 patients with milder symptoms. The intestinal microbiome of COVID-19 patients was characterized by elevated opportunistic pathogens along with reduced short-chain fatty acid (SCFAs)-producing microbiota. Moreover, Enterobacteriaceae (including Escherichia and Enterococcus) and Lactococcus, were enriched in the gut and respiratory tract of COVID-19 patients. Conversely, Haemophilus and Neisseria showed reduced abundance in the respiratory tract of both COVID-19 and influenza patients. Conclusion: In this systematic review, we identified the microbiome in COVID-19/influenza patients in comparison with controls. The microbial changes in influenza and COVID-19 are partly similar.

16.
Nat Commun ; 15(1): 2251, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38480716

RESUMO

Accelerating efforts for the Sustainable Development Goals requires understanding their synergies and trade-offs at the national and sub-national levels, which will help identify the key hurdles and opportunities to prioritize them in an indivisible manner for a country. Here, we present the importance of the 17 goals through synergy and trade-off networks. Our results reveal that 19 provinces show the highest trade-offs in SDG13 (Combating Climate Change) or SDG5 (Gender Equality) consistent with the national level, with other 12 provinces varying. 24 provinces show the highest synergies in SDG1 (No Poverty) or SDG6 (Clean Water and Sanitation) consistent with the national level, with the remaining 7 provinces varying. These common but differentiated SDG priorities reflect that to ensure a coordinated national response, China should pay more attention to the provincial situation, so that provincial governments can formulate more targeted policies in line with their own priorities towards accelerating sustainable development.


Assuntos
Políticas , Desenvolvimento Sustentável , China , Pobreza , Mudança Climática
17.
Sci Bull (Beijing) ; 69(1): 114-124, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-37989675

RESUMO

As one of the world's largest emitters of greenhouse gases, China has set itself the ambitious goal of achieving carbon peaking and carbon neutrality. Therefore, it is crucial to quantify the magnitude and trend of sources and sinks of atmospheric carbon dioxide (CO2), and to monitor China's progress toward these goals. Using state-of-the-art datasets and models, this study comprehensively estimated the anthropogenic CO2 emissions from energy, industrial processes and product use, and waste along with natural sources and sinks of CO2 for all of China during 1980-2021. To recognize the differences among various methods of estimating greenhouse emissions, the estimates are compared with China's National Greenhouse Gas Inventories (NGHGIs) for 1994, 2005, 2010, 2012, and 2014. Anthropogenic CO2 emissions in China have increased by 7.39 times from 1980 to 12.77 Gt CO2 a-1 in 2021. While benefiting from ecological projects (e.g., Three Norths Shelter Forest System Project), the land carbon sink in China has reached 1.65 Gt CO2 a-1 averaged through 2010-2021, which is almost 15.81 times that of the carbon sink in the 1980s. On average, China's terrestrial ecosystems offset 14.69% ± 2.49% of anthropogenic CO2 emissions through 2010-2021. Two provincial-level administrative regions of China, Xizang and Qinghai, have achieved carbon neutrality according to our estimates, but nearly half of the administrative regions of China have terrestrial carbon sink offsets of less than 10% of anthropogenic CO2 emissions. This study indicated a high level of consistency between NGHGIs and various datasets used for estimating fossil CO2 emissions, but found notable differences for land carbon sinks. Future estimates of the terrestrial carbon sinks of NGHGIs urgently need to be verified with process-based models which integrate the comprehensive carbon cycle processes.

18.
J Pharm Sci ; 112(11): 2863-2868, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37336264

RESUMO

Two routes of the dehydration process of theophylline monohydrate have been proposed in this work from mid-frequency Raman difference spectra (MFRDS) results and experiments. MFRDS can establish short-range order correlations among various theophylline crystal forms. MFRDS results indicate that the short-range order of metastable Form III is most similar to that of monohydrate, which explains that Form III is the main dehydration products in the mild dehydration process. The phenomenon that unstable amorphous theophylline intermediate phase would appear during the dehydration process of theophylline monohydrate was confirmed indirectly by Powder X-ray Diffraction (PXRD) and optical microscope and reported in the previous reports, which could cause the nucleation of Form II, as MFRDS results indicate short-range order of amorphous solid dispersion of theophylline is most similar to that of Form II. MFRDS analysis shows the advantages in studying the phase transformation of small organic molecule crystals.

19.
Environ Int ; 172: 107762, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36689865

RESUMO

Estuarine wetlands with high organic carbon (OC) accumulation rates due to their high plant biomass and interception of tide-derived OC are generally considered as large CO2 sinks. However, our previous study found that tidal OC input seems to stimulate soil CO2 emissions, potentially weakening CO2 sequestration in estuarine wetlands. To further verify this phenomenon, we first established a structural equation model, which confirmed a positive correlation between tidal OC input and soil organic carbon (SOC) and soil respiration. We then performed trace analysis to determine the stability of SOC derived from different sources and its effect on soil CO2 emissions by analyzing the input and retention of OC derived from tides and plants in the Yangtze Estuary wetlands. From upstream to downstream, as tidal OC input decreased, the relative retention ratio of the tidal OC in wetland soil increased from 1.259 to 2.148, whereas the relative retention ratio of plant OC in the soil decreased from 61.5% to 14.8%. Our findings indicated that the degradability of tidal OC was higher upstream than that downstream, but both inhibited plant OC degradation, thus providing an important reason for the higher CO2 emissions upstream of wetlands (with higher tidal OC input). In addition, the primarily contributor to CO2 (δ13) emissions' transforming from plant SOC (81.35%) to tidal SOC (91.18%) was an increase in organic matter input from the tide in a microcosm system. Consequently, a higher CO2 output than CO2 input (plant OC) due to the ready degradation of tidal OC consequently weakens the CO2 sequestration capacity of the estuarine wetlands. This phenomenon is cause for concern regarding the CO2 sink function of estuarine wetlands intercepting large amounts of organic matter.


Assuntos
Carbono , Áreas Alagadas , Carbono/análise , Dióxido de Carbono , Solo/química , Biomassa , Plantas , Sequestro de Carbono , China
20.
Appl Spectrosc ; 77(6): 652-665, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37218159

RESUMO

Amorphous simvastatin (amorphous SIM) and Form I of SIM were prepared separately from SIM acetone (AC)/ethyl acetate (ETAC)/ethanol (ET) solutions by simply controlling the solvent evaporation rate, and the kinetic formation of amorphous SIM from SIM AC/ETAC/ET solutions was explained using mid-frequency Raman difference spectra analysis. The mid-frequency Raman difference spectra analysis results indicate that the amorphous phase has close connections with solutions and might be the bridge, playing an important role in the intermediate phase, between solutions and their outcome polymorphs.


Assuntos
Sinvastatina , Sinvastatina/química , Cristalização , Difração de Raios X
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