Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
Más filtros













Base de datos
Intervalo de año de publicación
1.
Anal Chem ; 95(29): 10895-10902, 2023 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-37433088

RESUMEN

Conjugate vaccines have been demonstrated to be a promising strategy for immunotherapeutic intervention in substance use disorder, wherein a hapten structurally similar to the target drug is conjugated to an immunogenic carrier protein. The antibodies generated following immunization with these species can provide long-lasting protection against overdose through sequestration of the abused drug in the periphery, which mitigates its ability to cross the blood-brain barrier. However, these antibodies exhibit a high degree of heterogeneity in structure. The resultant variations in chemical and structural compositions have not yet been clearly linked to the stability that directly affects their in vivo functional performance. In this work, we describe a rapid mass-spectrometry-based analytical workflow capable of simultaneous and comprehensive interrogation of the carrier protein-dependent heterogeneity and stability of crude polyclonal antibodies in response to conjugate vaccines. Quantitative collision-induced unfolding-ion mobility-mass spectrometry with an all-ion mode is adapted to rapidly assess the conformational heterogeneity and stability of crude serum antibodies collected from four different vaccine conditions, in an unprecedented manner. A series of bottom-up glycoproteomic experiments was performed to reveal the driving force underlying these observed heterogeneities. Overall, this study not only presents a generally applicable workflow for fast assessment of crude antibody conformational stability and heterogeneity at the intact protein level but also leverages carrier protein optimization as a simple solution to antibody quality control.


Asunto(s)
Anticuerpos , Inmunización , Haptenos , Vacunas Conjugadas/química , Proteínas Portadoras
2.
Chem Sci ; 14(22): 5936-5944, 2023 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-37293657

RESUMEN

Growing evidence supports the confident association between distinct amyloid beta (Aß) isoforms and Alzheimer's Disease (AD) pathogenesis. As such, critical investigations seeking to uncover the translational factors contributing to Aß toxicity represent a venture of significant value. Herein, we comprehensively assess full-length Aß42 stereochemistry, with a specific focus on models that consider naturally-occurring isomerization of Asp and Ser residues. We customize various forms of d-isomerized Aß as natural mimics, ranging from fragments containing a single d residue to full length Aß42 that includes multiple isomerized residues, systematically evaluating their cytotoxicity against a neuronal cell line. Combining multidimensional ion mobility-mass spectrometry experimental data with replica exchange molecular dynamics simulations, we confirm that co-d-epimerization at Asp and Ser residues within Aß42 in both N-terminal and core regions effectively reduces its cytotoxicity. We provide evidence that this rescuing effect is associated with the differential and domain-specific compaction and remodeling of Aß42 secondary structure.

3.
Animals (Basel) ; 13(12)2023 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-37370439

RESUMEN

Waterbird monitoring is the foundation of conservation and management strategies in almost all types of wetland ecosystems. China's improved wetland protection infrastructure, which includes remote devices for the collection of larger quantities of acoustic and visual data on wildlife species, increased the need for data filtration and analysis techniques. Object detection based on deep learning has emerged as a basic solution for big data analysis that has been tested in several application fields. However, these deep learning techniques have not yet been tested for small waterbird detection from real-time surveillance videos, which can address the challenge of waterbird monitoring in real time. We propose an improved detection method by adding an extra prediction head, SimAM attention module, and sequential frame to YOLOv7, termed as YOLOv7-waterbird, for real-time video surveillance devices to identify attention regions and perform waterbird monitoring tasks. With the Waterbird Dataset, the mean average precision (mAP) value of YOLOv7-waterbird was 67.3%, which was approximately 5% higher than that of the baseline model. Furthermore, the improved method achieved a recall of 87.9% (precision = 85%) and 79.1% for small waterbirds (defined as pixels less than 40 × 40), suggesting a better performance for small object detection than the original method. This algorithm could be used by the administration of protected areas or other groups to monitor waterbirds with higher accuracy using existing surveillance cameras and can aid in wildlife conservation to some extent.

4.
J Cardiothorac Surg ; 18(1): 118, 2023 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-37038166

RESUMEN

INTRODUCTION: Multiple rib fractures (≥ 3 displaced rib fractures and/or flail chest) are severe chest trauma with high morbidity and mortality. Rib fixation has become the first choice for multiple rib fracture treatment. However, the timing of surgical rib fixation is unclear. MATERIALS AND METHODS: The present study explored whether early rib fracture fixation can improve the outcome of multiple rib fractures. The present research included patients who were hospitalized in three Jiangsu hospitals following diagnosis with multiple rib fractures. Patients received early rib fracture fixation (≤ 48 h) or delayed rib fracture fixation (> 48 h) utilizing computer-based random sequencing (in a 1:1 ratio). The primary outcome measures included hospital length of stay, intensive care unit (ICU) stay, mechanical ventilation, inflammatory cytokine levels, infection marker levels, infection, and mortality. RESULTS: A total of 403 individuals were classified into two groups, namely, the early group (n = 201) and the delayed group (n = 202). Patients belonging to the two groups had similar baseline clinical data, and there were no statistically significant differences between them. Early rib fracture fixation greatly decreased the length of stay in the ICU (4.63 days vs. 6.72 days, p < 0.001), overall hospital stay (10.15 days vs. 12.43 days, p < 0.001), ventilation days (3.67 days vs. 4.55 days, p < 0.001), and hospitalization cost (6900 USD vs. 7600 USD, p = 0.008). Early rib fracture fixation can decrease inflammatory cytokine levels and infection marker levels, prevent hyperinflammation and improve infection in patients with multiple rib fractures. The timing of rib fracture fixation does not influence the surgical procedure time, operative blood loss, 30-day all-cause mortality, or surgical site infection. CONCLUSION: The findings from the present research indicated that early rib fracture fixation (≤ 48 h) is a safe, rational, effective and economical strategy and worth clinical promotion.


Asunto(s)
Tórax Paradójico , Fracturas de las Costillas , Traumatismos Torácicos , Humanos , Fracturas de las Costillas/cirugía , Fijación Interna de Fracturas/métodos , Tórax Paradójico/cirugía , Traumatismos Torácicos/terapia , Hospitalización , Tiempo de Internación , Estudios Retrospectivos
5.
Clin Exp Pharmacol Physiol ; 49(11): 1209-1220, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36184488

RESUMEN

Circular RNA (circRNAs) Fibronectin Type III Domain Containing 3B (FNDC3B) (circFNDC3B) has been revealed to be involved in the progression of oesophageal squamous cell carcinoma (ESCC). Hence, the potential regulatory network of circFNDC3B in ESCC was further investigated. Levels of genes and proteins were examined by qRT-PCR and Western blot. In vitro assays were performed using colony formation assay, 5-Ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry, wound healing assay, and transwell assay. The target relationship between miR-214-3p and circFNDC3B or cell division cycle 25 homologue A (CDC25A) was verified by dual-luciferase reporter and RIP assays. In vivo assay was carried out using the xenograft nude mice model. CircFNDC3B was highly expressed in ESCC, and high circFNDC3B expression was tightly associated with poor prognosis in ESCC patients. Functionally, circFNDC3B knockdown not only suppressed ESCC cell growth, migration and invasion in vitro, but hindered ESCC tumour growth in vivo. Mechanistically, circFNDC3B acted as a sponge for miR-214-3p to up-regulate the expression of its target CDC25A. Rescue experiments showed that miR-214-3p inhibitor reversed the anticancer effects of circFNDC3B knockdown. Moreover, forced expression of miR-214-3p suppressed the malignant phenotypes mentioned above, while this condition was abolished by CDC25A overexpression. CircFNDC3B silencing restrains the tumorigenesis of oesophageal squamous cell carcinoma through miR-214-3p/CDC25A axis, which opens a new window to the development of novel therapeutic strategy for ESCC patients.


Asunto(s)
Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , MicroARNs , Animales , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas de Esófago/patología , Regulación Neoplásica de la Expresión Génica , Humanos , Ratones , Ratones Desnudos , MicroARNs/genética , MicroARNs/metabolismo , ARN Circular/genética , Fosfatasas cdc25/genética , Fosfatasas cdc25/metabolismo
6.
Int J Biol Macromol ; 220: 1532-1544, 2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-36096258

RESUMEN

Gut microbial ß-glucuronidases (GUSs) inhibition is a new approach for managing some diseases and medication therapy. However, the structural and functional complexity of GUSs have posed tremendous challenges to discover specific or broad-spectrum GUSs inhibitors using Escherichia coli GUS (EcoGUS) alone. This study first assessed the effects of twenty-one dietary flavones employing three Loop 1-type GUSs of different taxonomic origins, which were considered to be the main GUSs involved in deglucuronidation of small molecules, on p-nitrophenyl-ß-D-glucuronide hydrolysis and a structure-activity relationship is preliminarily proposed based on both in vitro assays and a docking study with representative compounds. EcoGUS and Staphylococcus pasteuri GUS showed largely similar inhibition propensities with potencies positively correlating with the total hydroxyl groups and those at ring B of flavones, while docking results revealed strong interactions developed via ring A and/or C. Streptococcus agalactiae GUS (SagaGUS) exhibited distinct inhibition propensities, displaying late-onset inhibition and steep dose-response profiles with most tested compounds. The α-helix in loop 1 region of SagaGUS which causes spatial hindrance but offers a hydrophobic surface for contacting with the carbonyl group on ring C of flavones is believed to be essential for the allosteric inhibition of SagaGUS. Taken together, the study with a series of flavones revealed varied preferences for GUSs belonging to the same Loop 1-type, highlighting the necessity of adopting multi-GUSs instead of EcoGUS alone for screening broad-spectrum GUSs inhibitors or tailoring the inhibition based on specific GUS structure.


Asunto(s)
Flavonas , Microbioma Gastrointestinal , Inhibidores Enzimáticos/farmacología , Escherichia coli/metabolismo , Flavonas/farmacología , Microbioma Gastrointestinal/fisiología , Glucuronidasa/química , Glucurónidos , Humanos , Relación Estructura-Actividad
7.
Environ Pollut ; 285: 117455, 2021 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-34090070

RESUMEN

Studies of algal bloom early warning systems have rarely paid attention to the dynamics of excessive proliferation of phytoplankton (EPP), which occurs prior to algal blooms, or to the sensitivity of a lake to EPP based on multiple environmental factors. In this study, we investigated EPP dynamics in large lakes and identified major factors that influenced the lake's vulnerability to EPP, to improve algal bloom early warning systems. High temporal moderate resolution imaging spectroradiometer (MODIS) images and multi-source daily site monitoring data of large lakes in the middle-lower Yangtze River basin were analyzed. Then, the floating algal index (FAI) and resource use efficiency (RUE) by phytoplankton were used to investigate the EPP dynamics and lake's vulnerability to EPP, respectively. Moreover, generalized linear models were used to assess the relative importance of environmental factors on RUE. The results indicate that the lakes freely connected (FC) to the Yangtze River (Dongting Lake and Poyang Lake) had lower FAIs but higher RUEs than the non-connected lakes (NC; Chaohu Lake and Taihu Lake). The key factors affecting RUE-FC were standard deviation of water level within 30 days(WL30), particulate matter <10 µm(PM10), and relative humidity(Hum), which explained 15.91% of the variations in RUE. The key factors affecting RUE-NC were ozone(O3), basin normalized difference vegetation index standard deviation(BNDVISD), and dissolved oxygen(DO), which explained 35.28% of the variations in RUE. These results emphasize the importance of air quality in influencing or reflecting EPP risks in large lakes. In addition, basin vegetation and hydrological rhythms can influence NH4+ through non-point source loading. Algal bloom early warning systems can be improved by routine monitoring and forecasting of potential environmental factors such as air quality and basin vegetation.


Asunto(s)
Contaminación del Aire , Lagos , China , Monitoreo del Ambiente , Eutrofización , Ríos
8.
Biochem Pharmacol ; 190: 114566, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33865833

RESUMEN

Bacterial ß-glucuronidase enzymes (BGUSs) are at the interface of host-microbial metabolic symbiosis, playing an important role in health and disease as well as medication outcomes (efficacy or toxicity) by deconjugating a large number of endogenous and exogenous glucuronides. In recent years, BGUSs inhibition has emerged as a new approach to manage diseases and medication therapy and attracted an increasing research interest. However, a growing body of evidence underlines great genetic diversity, functional promiscuity and varied inhibition propensity of BGUSs, which have posed big challenges to identifying BGUSs involved in a specific pathophysiological or pharmacological process and developing effective inhibition. In this article, we offered a general introduction of the function, in particular the physiological, pathological and pharmacological roles, of BGUSs and their taxonomic distribution in human gut microbiota, highlighting the structural features (active sites and adjacent loop structures) that affecting the protein-substrate (inhibitor) interactions. Recent advances in BGUSs-mediated deconjugation of drugs and carcinogens and the discovery and applications of BGUS inhibitors in management of medication therapy, typically, irinotecan-induced diarrhea and non-steroidal anti-inflammatory drugs (NSAIDs)-induced enteropathy, were also reviewed. At the end, we discussed the perspectives and the challenges of tailoring BGUS inhibition towards precision medicine.


Asunto(s)
Microbioma Gastrointestinal/efectos de los fármacos , Tracto Gastrointestinal/enzimología , Glucuronidasa/antagonistas & inhibidores , Glicoproteínas/farmacología , Medicina de Precisión/métodos , Animales , Antiinflamatorios no Esteroideos/efectos adversos , Antiinflamatorios no Esteroideos/farmacología , Diarrea/inducido químicamente , Microbioma Gastrointestinal/fisiología , Tracto Gastrointestinal/efectos de los fármacos , Glucuronidasa/metabolismo , Glicoproteínas/efectos adversos , Humanos , Irinotecán/efectos adversos , Irinotecán/farmacología , Medicina de Precisión/tendencias , Estructura Secundaria de Proteína , Inhibidores de Topoisomerasa I/efectos adversos , Inhibidores de Topoisomerasa I/farmacología
9.
Ecol Evol ; 10(20): 11237-11250, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33144961

RESUMEN

Geographical gradients in species diversity have long fascinated biogeographers and ecologists. However, the extent and generality of the effects of the important factors governing functional diversity (FD) patterns are still debated, especially for the freshwater domain. We examined the relationship between lake productivity and functional diversity of waterbirds sampled from 35 lakes and reservoirs in northern China with a geographic coverage of over 5 million km2. We used structural equation modeling (SEM) to explore the causal relationships between geographic position, climate, lake productivity, and waterbird FD. We found unambiguous altitudinal and longitudinal gradients in lake productivity and waterbird FD, which were strongly mediated by local environmental factors. Specifically, we found (a) lake productivity increased northeast and decreased with altitude. The observed geographic and altitudinal gradients were driven by climatic conditions and nutrient availability, which collectively explained 93% of the variations in lake productivity; (b) waterbird FD showed similar geographic and altitudinal gradients; the environmental factors which had direct and/or indirect effects on these gradients included climate and lake area, which collectively explained more than 39% of the variation in waterbird FD; and 3) a significant (p = .029) causality between lake productivity and waterbird FD was confirmed. Nevertheless, the causality link was relatively weak in comparison with climate and lake area (the standardized path coefficient was 0.55, 0.23, and 0.03 for climate, lake area, and productivity, respectively). Our study demonstrates how the application of multivariate technique (e.g., SEM) enables the illustration of complex causal paths in ecosystems, enhancing mechanistic explanations that underlie the observed broadscale biodiversity gradients.

10.
Pharmacol Res ; 159: 104919, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32464324

RESUMEN

Ferroptosis is a new kind of regulated cell death that is characterized by highly iron-dependent lipid peroxidation. Ferroptosis involves various biology processes, such as iron metabolism, lipid metabolism, oxidative stress and biosynthesis of nicotinamide adenine dinucleotide phosphate (NADPH), glutathione (GSH) and coenzyme Q10 (CoQ10). A growing body of evidence suggests that ferroptosis is associated with cancer and neurodegenerative diseases (Alzheimer's disease, Parkinson's disease and Huntington's disease). This finding has helped develop a novel cytoprotective strategy to protect cells in neurodegenerative, blood and heart diseases by inhibiting ferroptosis. Meanwhile, the selective induction of ferroptosis has been adopted as a potential treatment strategy in some kinds of cancer. This review aims to summarize the mechanism of ferroptosis regulation and relevance to pathological physiology.


Asunto(s)
Ferroptosis , Hierro/metabolismo , Peroxidación de Lípido , Neoplasias/patología , Enfermedades Neurodegenerativas/patología , Animales , Antineoplásicos/uso terapéutico , Ferroptosis/efectos de los fármacos , Humanos , Peroxidación de Lípido/efectos de los fármacos , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Enfermedades Neurodegenerativas/tratamiento farmacológico , Enfermedades Neurodegenerativas/metabolismo , Fármacos Neuroprotectores/uso terapéutico , Especies Reactivas de Oxígeno/metabolismo
11.
Int J Biometeorol ; 64(1): 115-122, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31654197

RESUMEN

Plateau zokor (Myospalax baileyi) and plateau pika (Ochotona curzoniae) are endemic fossorial vertebrates in the Qinghai-Tibetan Plateau alpine meadow ecosystem. Their different burrowing activities together transform soil structure and then significantly change the landscape of meadow ecosystem. However, how their burrowing activities impact greenhouse gas (GHG) emissions and the pattern of GHG emissions between different types of tunnel burrowing still remain obscure. In this study, we conducted in situ measurements quantitatively investigating the impacts of the different burrowing activities of zokors and pikas on three main GHG CO2, CH4, and N2O from an alpine meadow ecosystem in southeastern Qinghai-Tibetan Plateau. Our results showed that zokor hummocks and pika burrows were sources of CO2 and N2O and sinks of CH4. Zokors burrowing increased N2O in the atmosphere, decreased CO2, and enhanced CH4 absorbing, while pikas burrowing increased N2O in the atmosphere and enhanced CH4 absorbing. Considering the controversial role of fossorial vertebrates in Qinghai-Tibetan Plateau, this study also shed lights on effective management of animal activities with the aim of stabilizing or increasing ecosystem carbon sequestration.


Asunto(s)
Ecosistema , Gases de Efecto Invernadero , Animales , Pradera , Suelo , Tibet
12.
Artículo en Inglés | MEDLINE | ID: mdl-30935053

RESUMEN

Most migratory birds depend on stopover sites, which are essential for refueling during migration and affect their population dynamics. In the East Asian⁻Australasian Flyway (EAAF), however, the stopover ecology of migratory waterfowl is severely under-studied. The knowledge gaps regarding the timing, intensity and duration of stopover site usages prevent the development of effective and full annual cycle conservation strategies for migratory waterfowl in EAAF. In this study, we obtained a total of 33,493 relocations and visualized 33 completed spring migratory paths of five geese species using satellite tracking devices. We delineated 2,192,823 ha as the key stopover sites along the migration routes and found that croplands were the largest land use type within the stopover sites, followed by wetlands and natural grasslands (62.94%, 17.86% and 15.48% respectively). We further identified the conservation gaps by overlapping the stopover sites with the World Database on Protected Areas (PA). The results showed that only 15.63% (or 342,757 ha) of the stopover sites are covered by the current PA network. Our findings fulfil some key knowledge gaps for the conservation of the migratory waterbirds along the EAAF, thus enabling an integrative conservation strategy for migratory water birds in the flyway.


Asunto(s)
Migración Animal , Conservación de los Recursos Naturales , Gansos , Animales , Sistemas de Información Geográfica , Pradera , Dinámica Poblacional , Comunicaciones por Satélite , Estaciones del Año , Humedales
13.
ACS Appl Mater Interfaces ; 10(48): 41592-41598, 2018 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-30406985

RESUMEN

By introducing six triarylamine groups to a hexaphenylbenzene (HPB) or a hexakis(2-thienyl)benzene (HTB) core, two propeller-shaped, triarylamine-rich, and low-cost hole-transporting materials (HTMs), which are termed as HPB-OMe and HTB-OMe, respectively, with considerable hole mobility, were obtained by easy synthetic routes. Solid-state planar perovskite CH3NH3PbI3 solar cells (PSCs) with two new HTMs showed high power conversion efficiencies (12.9% for HPB-OMe and 17.3% for HTB-OMe in forward scans) under standard 100 mW cm-2 AM 1.5G illumination without doping. A comparison of matched-degree of energy levels, hole-transporting ability, photovoltaic conversion efficiencies, and recombination of the two HTMs indicated that developing multi-triarylamine- and thiophene-rich molecules provides candidate and efficient dopant-free HTMs for PSCs.

14.
ACS Omega ; 3(9): 10791-10797, 2018 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-31459193

RESUMEN

The simpler the design, the better and more effective it is. Two novel conjugated triarylamine derivatives in donor-π-donor structure employing biphenyl core and pyrene core as π-bridges, which are termed as Bp-OMe and Py-OMe, have been synthesized and characterized and then applied to perovskite solar cells (PSCs) as hole-transport materials (HTMs) successfully. Using 2,2',7,7'-tetrakis(N,N-di-p-methoxy-phenylamine)-9,9'-spirobiuorene (spiro-OMeTAD) as a relative reference, Py-OMe-based PSCs showed the best power conversion efficiency (PCE) of 19.28% under AM 1.5 G illumination at 100 mW cm-2, which is comparable to that of PSCs based on spiro-OMeTAD with a best PCE of 18.57% with doping. Although Bp-OMe-based PSCs performed with relatively poor PCEs (best PCE of 15.06%) than those of Py-OMe-based PSCs, attributing to the poor planarity and hole mobility, taking the cost into consideration, Bp-OMe and Py-OMe are much more likely to be promising efficient HTMs for PSCs.

15.
J Obstet Gynaecol Res ; 44(3): 495-502, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29271025

RESUMEN

AIM: This study explored chlamydia trachomatis (CT), ureaplasma urealyticum (UU) and/or neisseria gonorrhoeae (NG) in 5893 women with urinary tract infections (UTIs) in Shanghai. METHODS: From January 2009 to December 2014, 5893 women with UTIs in Shanghai were selected to undergo CT, UU and NG detection. Baseline characteristics including age, education level, occupation, reproductive history, sexual behavior and contraceptive method were obtained for epidemiological analysis. RESULTS: The total CT, UU and/or NG infection rate in the urine samples of 5893 patients was 50.69% (2987/5893), while the infection rate in vaginal secretion samples was 56.22% (3313/5893). The two detection methods were consistent. Patients aged 21-30, service personnel and unemployed persons had the highest rates of CT, UU and/or NG infection, while patients with higher education levels exhibited lower rates. As the number of previous pregnancies, natural births, abortions, sexual partners and the frequency of sexual intercourse increased, the rates of CT, UU and/or NG infection were elevated. Sexual intercourse during the menstruation period, a lack of cleaning before sexual intercourse and the use of intrauterine devices could all lead to an increased rate of CT, UU and/or NG infection. CONCLUSIONS: These data revealed that the rate of CT, UU and/or NG infection may be associated with age, education level, occupation, reproductive history, sexual behavior and type of contraceptive method in female patients with UTI in Shanghai.


Asunto(s)
Infecciones por Chlamydia/epidemiología , Chlamydia trachomatis/patogenicidad , Gonorrea/epidemiología , Neisseria gonorrhoeae/patogenicidad , Infecciones por Ureaplasma/epidemiología , Ureaplasma urealyticum/patogenicidad , Infecciones Urinarias/epidemiología , Adolescente , Adulto , China/epidemiología , Estudios Transversales , Femenino , Humanos , Persona de Mediana Edad , Adulto Joven
16.
Zhongguo Zhong Yao Za Zhi ; 42(12): 2298-2304, 2017 Jun.
Artículo en Chino | MEDLINE | ID: mdl-28822183

RESUMEN

Near infrared model established under a certain condition can be applied to the new samples status, environmental conditions or instrument status through the model transfer. Spectral background correction and model update are two types of data process methods of NIR quantitative model transfer, and orthogonal signal regression (OSR) is a method based on spectra background correction, in which virtual standard spectra is used to fit a linear relation between master batches spectra and slave batches spectra, and map the slave batches spectra to the master batch spectra to realize the transfer of near infrared quantitative model. However, the above data processing method requires the represent activeness of the virtual standard spectra, otherwise the big error will occur in the process of regression. Therefore, direct orthogonal signal correction-slope and bias correction (DOSC-SBC) method was proposed in this paper to solve the problem of PLS model's failure to predict accurately the content of target components in the formula of different batches, analyze the difference between the spectra background of the samples from different sources and the prediction error of PLS models. DOSC method was used to eliminate the difference of spectral background unrelated to target value, and after being combined with SBC method, the system errors between the different batches of samples were corrected to make the NIR quantitative model transferred between different batches. After DOSC-SBC method was used in the preparation process of water extraction and ethanol precipitation of Lonicerae Japonicae Flos in this paper, the prediction error of new batches of samples was decreased to 7.30% from 32.3% and to 4.34% from 237%, with significantly improved prediction accuracy, so that the target component in the new batch samples can be quickly quantified. DOSC-SBC model transfer method has realized the transfer of NIR quantitative model between different batches, and this method does not need the standard samples. It is helpful to promote the application of NIR technology in the preparation process of Chinese medicines, and provides references for real-time monitoring of effective components in the preparation process of Chinese medicines.


Asunto(s)
Medicamentos Herbarios Chinos/normas , Espectroscopía Infrarroja Corta , Calibración , Lonicera/química , Control de Calidad , Agua
18.
Front Plant Sci ; 8: 2196, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29312423

RESUMEN

Floodplain wetlands are valuable ecosystems for maintaining biodiversity, but are vulnerable to hydrological modification and climatic extremes. The floodplain wetlands in the middle Yangtze region are biodiversity hotspots, particularly important for wintering migratory waterbirds. In recent years, extremely low winter water level events frequently occurred in the middle Yangtze River. The hydrological droughts greatly impacted the development and distribution of the wet meadows, one of the most important ecological components in the floodplains, which is vital for the survival of many migratory waterbirds wintering in the Yangtze region. To effectively manage the wet meadows, it is critical to pinpoint the drivers for their deterioration. In this study, we assessed the effects of hydrological connectivity on the ecological stability of wet meadow in Poyang Lake for the period of 2000 to 2016. We used the time series of MODIS EVI (Enhanced Vegetation Index) as a proxy for productivity to infer the ecological stability of wet meadows in terms of resistance and resilience. Our results showed that (1) the wet meadows developed in freely connected lakes had significantly higher resilience; (2) wet meadows colonizing controlled lakes had higher resistance to water level anomalies; (3) there was no difference in the resistance to rainfall anomaly between the two types of lakes; (4) the wet meadow in freely connected lakes might approach a tipping point and a regime shift might be imminent. Our findings suggest that adaptive management at regional- (i.e., operation of Three Gorges Dam) and site-scale (e.g., regulating sand mining) are needed to safeguard the long-term ecological stability of the system, which in term has strong implications for local, regional and global biodiversity conservation.

19.
Sci Total Environ ; 573: 645-660, 2016 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-27592464

RESUMEN

An alteration in the hydrological connectivity reduces the synergistic processes and interactions between rivers and their floodplains, and changes the distribution of waterbirds that rely on floodplains as foraging grounds. Recent river and wetland conservation and restoration efforts have been partially focused on reinstating the natural river-floodplain connectivity to ameliorate the ecological effects of regulation in river systems. However, in regions where human well-being is tightly linked with the cultivation of the floodplain (such as fisheries), management options are constrained and trade-offs among competing social, economic and ecological goals may be necessary for the wise use of wetlands. Poyang Lake in east central China includes numerous sub-lakes with different types of hydrological regulation; therefore, this lake may provide a useful context for exploring the likelihood of such trade-offs. In this study, we used multiyear simultaneous waterbird survey data together with habitat maps derived from satellite imagery for Poyang Lake to examine the variations in waterbird community structure and abundance within sub-lakes with different types of hydrological regulation. Using a Bayesian Markov chain Monte Carlo approach, we built generalized linear mixed models to explore the differences in wetland composition and waterbird abundance/diversity among three lake types (i.e. isolated, freely connected, and controlled) at community, guild and species levels. The results showed hydrological connectivity alteration clearly affects wintering waterbirds; in addition, the ecological benefits of a natural flow regime were most unambiguous at the community level. Nevertheless, little evidence exists to indicate that the lakes' ecological values as waterbird foraging grounds were compromised by partial regulation. That is, species richness and population size were comparable in naturally connected and controlled lakes. Our results suggest that, with carefully designed management plans, a delicate balance between waterbird conservation and development can be accomplished in large river floodplains.


Asunto(s)
Aves/fisiología , Conservación de los Recursos Naturales , Humedales , Animales , Teorema de Bayes , Biota , China , Hidrología , Lagos , Modelos Lineales , Cadenas de Markov , Método de Montecarlo , Densidad de Población , Estaciones del Año
20.
PLoS One ; 8(6): e65843, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23823943

RESUMEN

The study of habitat selection and diet has a long history in ecology. This is often used to assess the functional roles of wetland in biodiversity conservation. Shifting habitat and diet may be one of the survival strategies during extremely adverse conditions. Therefore, sudden changes in habitat selection may indicate the deterioration of the habitat quality, and management interventions are necessary. Siberian crane (Grus leucogeranus) became critically endangered due to loss of habitat, and is currently a global conservation focus. Every winter, more than 95% of the species' global population congregates at Poyang Lake, and feeds on tubers of Vallisneria spiralis in shallow water and mudflat habitat. In this study, we reported the first sighting of large numbers of Siberian cranes foraging at wet meadows, where they fed on a different plant, Potentilla limprichtii due to extreme scarcity of their preferred tuber. To understand how well the cranes adapted to such unusual habitat, field surveys to assess the distribution of cranes across different habitats, and food availability in each habitat were carried out in the winter of 2011. Field observations on crane behaviors at different habitats were also conducted. Results show that cranes displayed significantly different behavior patterns when using the wet meadow, compared to the crane's optimal habitat - shallow water and mudflat. Both juveniles and adults spent significantly less time foraging, and more time alerting in meadows than in shallow waters and mudflats. These results indicated that the meadow might be a suboptimal wintering ground for Siberian crane, which helped the cranes survive from extreme unfavorable conditions. To some degree, this finding alleviates the general concern over the fluctuating of its food resources which was caused by hydrological disturbances. However, more studies are needed to assess the consequences of such diet and habitat shift for crane survival.


Asunto(s)
Aves/fisiología , Conservación de los Recursos Naturales , Dieta , Ecosistema , Conducta Alimentaria , Animales , Lagos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA