Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 65
Filtrar
1.
BMC Neurol ; 23(1): 15, 2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36639620

RESUMO

BACKGROUND: Parkinson's disease (PD) is a neurodegenerative disease and is clinically characterized by a series of motor symptoms (MS) and nonmotor symptoms (NMS). NMS often appear before MS, while cognitive impairment mostly occurs within a few years after the diagnosis of PD. Therefore, we aimed to predict the risk factors for cognitive impairment (CI) in PD patients based on transcranial sonography, clinical symptoms, and demographic characteristics. METHODS: Based on the occurrence time of CI, a total of 172 PD patients were divided into non-CI (N-CI, n = 48), CI at the first treatment (F-CI, n = 58), and CI at the last treatment (L-CI, n = 66) groups. Clinical data (including MS and NMS) and ultrasonic data of all patients at the first treatment and the last treatment were collected retrospectively. Independent samples t tests were used to compare continuous data, and chi-square tests were used to compare categorical data. The risk factors for CI and Parkinson's disease dementia were identified by logistic regression analysis, and an ROC curve was established to explore the diagnostic efficacy. RESULTS: 1) The age of onset, first treatment and smoking history of CI patients were significantly different from those of N-CI patients. When age of first treatment ≥61 years was considered the boundary value to diagnose CI, the sensitivity and specificity were 77.40 and 66.70%, respectively. 2) The severity of depression was significantly different between F-CI and N-CI patients at the first treatment, while the cumulative and new or aggravated memory deficit was significantly different between the L-CI and N-CI patients at the last treatment. 3) There was a significant difference in TCS grading between the first and last treatment in L-CI patients. 4) Depression, sexual dysfunction, and olfactory dysfunction in NMS were independent risk factors for CI during the last treatment. 5) The sensitivity and specificity of predicting CI in PD patients were 81.80 and 64.60%, respectively. CONCLUSIONS: PD patients with CI were older, and most of them had a history of smoking. Furthermore, there was good diagnostic efficiency for predicting CI in PD via TCS combined with clinical characteristics (especially NMS).


Assuntos
Disfunção Cognitiva , Demência , Doenças Neurodegenerativas , Doença de Parkinson , Humanos , Pessoa de Meia-Idade , Estudos Longitudinais , Demência/etiologia , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/epidemiologia , Estudos Retrospectivos , Doenças Neurodegenerativas/complicações , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/epidemiologia , Demografia
2.
J Environ Manage ; 344: 118416, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37331315

RESUMO

Knowledge on relationship and determinants of water and carbon dioxide (CO2) exchange is crucial to land managers and policy makers especially for the desertified land restoration. However, there remains highly uncertain in terms of water use and carbon sequestration for artificial plantation in desert. Here, continuous water and carbon fluxes were measured using eddy covariance (EC) in conjunction with hydrometeorological measurements over an artificial C4 shrub, Haloxylon ammodendron (C. A. Mey.) Bunge, from July 2020 to 2021 in Tengger Desert, China. Throughout 2021, evapotranspiration (ET) was 189.5 mm, of which 85% (150 mm) occurred during growing season, that was comparable with the summation of precipitation (132.2 mm), dew (33.5 mm) and potential other sources (e.g. deep subsoil water). This ecosystem was a strong carbon sink with net ecosystem production (NEP) up to 446.4 g C m-2 yr-1, much higher than surrounding sites. Gross primary production (GPP, 598.7 g C m-2 yr-1) in this shrubland was comparable with that of other shrublands, whereas ecosystem respiration (Re, 152.3 g C m-2 yr-1) was lower. Random Forest showed that environmental factors can explain 71.56% and 80.07% variation of GPP and ET, respectively. Interestingly, environmental factors have divergent effect on water and carbon exchange, i.e., soil hydrothermic factors (soil moisture content and soil temperature) determine the magnitude and seasonal pattern of ET and Re, while aerodynamics factors (net radiation, atmospheric temperature and wind speed) determine GPP and NEP. As such, divergent response of abiotic factors resulted in the decoupling of water and carbon exchange. Our results suggest that H. ammodendron is a suitable species for large-scale afforestation in dryland given its low water use but high carbon sequestration. Therefore, we infer that artificial planting H. ammodendron in dryland could provide an opportunity for climate change mitigation, and the long-term time series data is needed to confirm its sustainable role of carbon sequestration in the future.


Assuntos
Ecossistema , Água , Ciclo do Carbono , Sequestro de Carbono , Solo , Estações do Ano , Dióxido de Carbono/análise
3.
BMC Neurosci ; 23(1): 80, 2022 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-36575381

RESUMO

BACKGROUND: In the treatment of ischemic cerebral stroke (ICS), most conventional treatments, including carotid endarterectomy and carotid artery stenting, may cause cerebral ischemia-reperfusion injury (CIRI). For treated ICS patients, changes in cerebral blood flow are directly related to brain function. At present, computed tomography perfusion, dynamic susceptibility contrast-enhanced perfusion weighted imaging and magnetic resonance arterial spin labeling perfusion imaging are used to monitor cerebral blood flow, but they still have some limitations. Our study aimed to monitor the changes in cerebral cortical blood flow by laser speckle contrast imaging (LSCI) in CIRI model mice and to propose a new method for predicting outcomes after CIRI. C57BL/6 N mice were used to establish a mouse CIRI model based on a modified thread-occlusion method and divided into a good outcome group and a poor outcome group according to survival within 7 days. The cerebral cortical blood flow of the area supplied by the left middle cerebral artery was monitored by LSCI at baseline (before modeling), 1 h after ischemia, immediately after reperfusion and 24 h after reperfusion. Then, the brains of the mice were removed immediately and stained with hematoxylin and eosin to observe the pathological changes in brain neurons. RESULTS: The cerebral cortical blood flow in the poor outcome group was obviously reduced compared with that less in the good outcome group at 24 h after reperfusion (180.8 ± 20.9 vs. 113.9 ± 6.4, p = 0.001), and at 24 h after reperfusion, the cerebral cortical blood flow was negatively correlated with the severity of brain tissue injury (p = - 0.710, p = 0.010). CONCLUSIONS: LSCI can monitor the changes in cerebral cortical blood flow during CIRI in mice and could be used as a feasible method for predicting outcomes after CIRI in mice.


Assuntos
Isquemia Encefálica , Estenose das Carótidas , Traumatismo por Reperfusão , Camundongos , Animais , Imagem de Contraste de Manchas a Laser , Estenose das Carótidas/diagnóstico por imagem , Camundongos Endogâmicos C57BL , Stents , Traumatismo por Reperfusão/patologia
4.
Nanotechnology ; 33(48)2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-35901665

RESUMO

Designing in-plane supercapacitors with high electrode materials selectivity is an indispensable approach to improve electrochemical performance. In this work, a facile template method was employed to fabricate in-plane supercapacitors. This template method could select any electrochemical active materials as electrode materials of in-plane supercapacitors. Hence, a high electrochemical performance material Mn-Co LDO-2S with optimized metal-sulfur bonds proportion and abundant sulfur vacancies was employed as electrode material of symmetrical in-plane supercapacitor (SPS). SPS exhibits excellent electrochemical performance finally, and has considerable area energy density 55.0µWh cm-2with an area power density of 0.7 mW cm-2. As a result, introducing sulfur atoms and sulfur vacancies are efficient approaches to improve electrode materials' electrochemical performance, and template method that proposed in this work is a promising approach to widen selectivity of in-plane supercapacitors' electrode materials.

5.
BMC Cancer ; 19(1): 147, 2019 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-30760229

RESUMO

BACKGROUND: The patient satisfaction of symptoms improvement and disease factors that may affect long-term treatment efficacy of radiofrequency ablation (RFA) for non-functioning solid benign thyroid nodules (TNs) over a 2-year follow up study was investigated. METHODS: This retrospective study evaluated 194 non-functioning solid benign TNs of 103 patients. The TNs were categorized as small (≤5 ml), medium (5.1 to 13 ml), intermediate (13.1 to 30 ml) and large (over 30 ml) according to the initial volume of TNs before ablation. Clinical evaluation and contrast-enhanced ultrasound (CEUS) were carried out before ablation and the follow up at 1, 3, 6 months and every 6 months after ablation. All patients were asked to assess the cosmetic score (1-4 scores) and symptom score (0-10 scores) before ablation and every follow up after ablation. RESULTS: All patients underwent RFA without any major complications. The mean treatment sessions were 1.5 ± 0.6. 98 nodules required a single session (98/194, 50.5%), 87 required two sessions (87/194, 44.9%), 9 required three sessions (9/194, 4.6%). The average follow up months were 16.3 ± 5.6 (range, 6-24 months) and no nodule regrew in our study. After RFA treatment, the TNs volume significantly decreased (P < 0.001). The small group of nodules shrunk larger compared to the medium, intermediate and large groups (P < 0.001). Cosmetic signs and pressure symptoms were significantly improved, particularly in the intermediate and large groups (P < 0.05). CONCLUSIONS: RFA is effective for treating non-functioning solid benign TNs and controlling clinical symptoms with a low complication rate during 2 years follow up. The reduction rate was related to the initial volume of nodules. Patients were satisfied with cosmetic signs and pressure symptoms improvement, particularly in the intermediate and large groups. However, multiple RFA treatments should be used in larger nodules to achieve the desired clinical outcomes.


Assuntos
Neoplasias/terapia , Satisfação do Paciente/estatística & dados numéricos , Ablação por Radiofrequência , Nódulo da Glândula Tireoide/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/epidemiologia , Nódulo da Glândula Tireoide/epidemiologia , Resultado do Tratamento , Adulto Jovem
6.
Biol Pharm Bull ; 42(2): 194-200, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30464092

RESUMO

Seventeen 13,28-epoxy triterpenoid saponins obtained from Ardisia gigantifolia STAPF. were evaluated their anti-proliferative activities on MCF-7 cells. The structure-activity relationship analysis indicated that CH3 group at C-30, four saccharide units with L-rhamnose at R6 in the sugar units are crucial for the cytotoxic activity on MCF-7. Compounds 1, 2, 6, 7, 12, and 14 were selected to identify the anti-proliferative activity on the other three breast cancer cell lines (T47D, MDA-MB-231 and SK-BR-3). Compounds 2, 6, and 7 with good activity on MCF-7 also showed activity on T47D, MDA-MB-231, and SK-BR-3. Compounds 12 and 14 without cytotoxic activity on MCF-7 almost showed no activities on the other three cell lines. For the triple-negative breast cancer MDA-MB-231, Saponins 7 and 14 showed selective cytotoxic activity, 7 showed much more activity than 14, suggesting the six saccharide units in sugar units and CH3 on C-30 were the key moieties for the anti-proliferative activities. Further molecular mechanism of saponin 7 was studied on inhibiting cell proliferation of MDA-MB-231 cells. Saponin 7 could enhance apoptosis, arrest cell cycles, decrease mitochondrial membrane potentials (MMPs), and considered the involvement of reactive oxygen species (ROS) may explain this conundrum.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Ardisia/química , Neoplasias da Mama/tratamento farmacológico , Saponinas/farmacologia , Triterpenos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Células MCF-7 , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Saponinas/química , Saponinas/isolamento & purificação , Triterpenos/química , Triterpenos/isolamento & purificação
7.
Am J Emerg Med ; 36(9): 1627-1630, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29502976

RESUMO

BACKGROUND: Real-time ultrasound elastography (RTE) is used to examine liver fibrosis and benign and malignant lesions, but its use for the diagnosis of liver trauma has not been examined. The purpose of this study was to examine the use of RTE for the evaluation of differential penetrating liver trauma in a rabbit model. MATERIAL AND METHODS: Eighty New Zealand rabbits were divided into 2 groups. In one group, a single incision (type "-" lesion) was made, and in the other group a hash mark incision (type "#" lesion) was made (about 0.5cm in depth; 1.0-2.0cm in length). RTE was performed at 10, 30, and 60min after injury. RESULTS: There were no differences in mean RTE scores between the 2 types of lesions at 10 and 30min. However, the mean values for the 2 types of lesions increased from 10min to 60min (type '-' lesion: 0.88±0.32 to 2.06±0.88; type '#' lesion: 0.89±0.34 to 2.63±1.16). At 60min, the mean elasticity score in the type '#' lesion group was significantly higher than in the type '-' lesion group (P<.001). Strain ratios were not different between the groups at each time point, but in each group the values decreased from the 10min time point to the 60min time point (P-value for the trends, <.001). CONCLUSIONS: RTE may be able to distinguish mild or severe penetrating liver trauma at 60min or more after injury.


Assuntos
Técnicas de Imagem por Elasticidade/métodos , Fígado/lesões , Ferimentos Penetrantes/diagnóstico por imagem , Animais , Masculino , Coelhos , Estresse Mecânico , Fatores de Tempo , Vasodilatação/fisiologia , Ferimentos Penetrantes/fisiopatologia
8.
Mol Microbiol ; 96(6): 1257-71, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25786547

RESUMO

The control of secondary production in streptomycetes involves the funneling of environmental and physiological signals to the cluster-situated (transcriptional) regulators (CSRs) of the biosynthetic genes. For some systems, the binding of biosynthetic products to the CSR has been shown to provide negative feedback. Here we show for the production of lidamycin (C-1027), a clinically relevant antitumor agent, by Streptomyces globisporus that negative feedback can extend to a point higher in the regulatory cascade. We show that the DNA-binding activity of the S. globisporus orthologue of AtrA, which was initially described as a transcriptional activator of actinorhodin biosynthesis in S. coelicolor, is inhibited by the binding of heptaene, a biosynthetic intermediate of lidamycin. Additional experiments described here show that S. globisporus AtrA binds in vivo as well as in vitro to the promoter region of the gene encoding SgcR1, one of the CSRs of lidamycin production. The feedback to the pleiotropic regulator AtrA is likely to provide a mechanism for coordinating the production of lidamycin with that of other secondary metabolites. The activity of AtrA is also regulated by actinorhodin. As AtrA is evolutionarily conserved, negative feedback of the type described here may be widespread within the streptomycetes.


Assuntos
Aminoglicosídeos/biossíntese , Streptomyces/metabolismo , Fatores de Transcrição/metabolismo , Anti-Infecciosos/metabolismo , Antibióticos Antineoplásicos/biossíntese , Proteínas de Bactérias/metabolismo , Proteínas de Ligação a DNA/metabolismo , Enedi-Inos , Regiões Promotoras Genéticas , Ligação Proteica
9.
BMC Neurol ; 16(1): 183, 2016 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-27660100

RESUMO

BACKGROUND: Past studies found that cerebral developmental venous anomaly (DVA) is often concurrent with cavernous malformation (CM). But the reason of the concurrency remains unknown. The purpose of this study was to confirm whether angioarchitectural factors relate to the concurrence and which angioarchitectural factors can induce the concurrency. METHODS: DVA cases were selected from the records of the same 3.0 T MR. The DVA cases was divided into two group which are DVA group and DVA concurrent with CM group. 8 angioarchitectural factors of the DVAs were selected and measured. Statistical analysis was performed by the Pearson chi-square statistic,analysis of variance (ANOVA) and multi-factor logistic regression analysis. RESULTS: Five hundred three DVA lesions were found and 76 CM lesions coexisting with DVA. In the single factor analysis, all the 8 angioarchitectural factors of DVA were related to the concurrency. In the multivariate analysis, 6 angioarchitectural factors. Result of multi-factor logistic regression analysis is Logit(P) = -4.858-0.932(Location) + 1.616(Direction) + 1.757(Torsion) + 0.237(Number) + 2.119(Stenosis rate of medullary vein)-0.015(Angle), goodness of fit is 90.1 %. CONCLUSIONS: The angioarchitectural factors of DVA are related to the concurrency of DVA and CM. 6 angioarchitectural factors may induce the concurrency.

10.
Med Sci Monit ; 21: 1648-55, 2015 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-26049721

RESUMO

BACKGROUND: The purpose of this study was to evaluate tongue movements during swallowing in healthy adults using the B+M-mode ultrasonography, and to determine a common feature in the M-mode traces for quantitative measurement and individual comparison of tongue movements. MATERIAL AND METHODS: Ninety healthy subjects were divided into 3 groups according to age (20-39, 40-59, and 60-80 years). The tongue movements during 3 saliva swallows were examined using real-time B+M-mode ultrasonography. The M-mode traces of tongue movements were recorded and evaluated. RESULTS: Both intra-individual and inter-individual differences were detected in the M-mode traces during the 3 saliva swallows. Characteristic types were seen during the individual swallowing phases of M-mode traces: 2 activity types in phase I, 2 types in phase IIb, and 3 types in phase III. However, no variations were seen during phase IIa, in which all subjects displayed a continuous upsloping trace. The average range of swallow-related tongue radial displacement during phase IIa decreased gradually with age, while the average duration of tongue movement during phase IIa increased gradually with age. These 2 trends were not statistically significant across age groups. However, differences between sexes were found in both the range of tongue radial displacement and the duration of deglutitive lingual actions during phase IIa in all 3 age groups (P<0.05). CONCLUSIONS: B+M-mode ultrasonography may offer a quick and safe alternative for the preliminary evaluation of deglutitive tongue movements.


Assuntos
Deglutição/fisiologia , Língua/fisiologia , Ultrassonografia/métodos , Adulto , Fatores Etários , Idoso , Análise de Variância , Humanos , Pessoa de Meia-Idade , Língua/diagnóstico por imagem
11.
Environ Monit Assess ; 187(11): 705, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26502726

RESUMO

Water use efficiency (WUE) is an important trait associated with plant acclimation caused by water deficits, and δ13C is a good surrogate of WUE under conditions of water deficits. Water deficiency also enhances the accumulation of compatible solutes in the leaves. In this study, variations in foliar δ(13)C values and main osmotic solutes were investigated. Those included total soluble sugar (TSS), sucrose, free proline, glycine betaine (GB), and inorganic ionic (K+, Ca2+, and Cl-) content of Populus euphratica for different groundwater depths in a Ejina desert riparian forest, China. Results indicated that foliar δ13C values in the P. euphratica for different groundwater depths ranged from -29.14±0.06 to -25.84±0.04 ‰. Foliar δ13C signatures became richer as groundwater levels declined. TSS, sucrose, free proline, GB, and K+ were accumulated in P. euphratica foliage with developing plant growth and increasing groundwater depth. Ca2+ and Cl- content increased under stronger P. euphratica transpiration rates for shallower groundwater depths (1-2.5 m) and decreased for deeper groundwater depths (greater than 3.0 m). Moreover, correlations between δ13C, osmotic solutes, and groundwater depths showed that the primary osmotic solutes were TSS, sucrose, proline, GB, and K+. Correlations also showed that δ13C was not only a useful measure for P. euphratica-integrated WUE but also could be used as an indicator reflecting some physiological osmotic indexes.


Assuntos
Isótopos de Carbono/análise , Monitoramento Ambiental , Água Subterrânea/química , Folhas de Planta/química , Populus/química , China , Meio Ambiente , Folhas de Planta/fisiologia , Populus/crescimento & desenvolvimento
12.
Environ Monit Assess ; 188(10): 561, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27624743

RESUMO

Hysteresis, related to tree sap flow and associated environmental variables, plays a critical ecological role in the comprehensive understanding of forest water use dynamics. Nevertheless, only limited researches related to this unique ecological phenomenon have been conducted to date in desert riparian forests under extreme arid regions. Populus euphratica Oliv sap flow velocity (VS) was measured during the 2012 growing season using the heat ratio method, at the same time as environmental variables, such as photosynthetically active radiation (PAR), vapor pressure deficit (VPD), and leaf water potential. We found clockwise patterns of hysteresis between VS and VPD but anticlockwise patterns between VS and PAR. Pronounced hysteretic VS lag time, a function of PAR and VPD, was approximately 1.0~1.5 and -0.5 h, respectively. Hysteresis was primarily caused by the biophysical declining in canopy conductance. Sigmoid response of VS to synthetic meteorological variables was enhanced by approximately 56 % after hysteresis calibration to sunny days. Consequently, hysteresis can be seen as a protection mechanism for plants to avoid the overlapping of peak VS and environmental variables. Furthermore, the consistent presence of hysteresis suggested that estimating of plant water use in large temporal and spatial models may require certain provisions to different VS responses to variables between morning and afternoon and between seasons.


Assuntos
Populus/fisiologia , Árvores/fisiologia , Água/metabolismo , China , Clima Desértico , Monitoramento Ambiental , Florestas , Fotossíntese , Folhas de Planta , Rios , Estações do Ano
13.
BMC Neurol ; 14: 50, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24628866

RESUMO

BACKGROUND: Some studies reported that cerebral developmental venous anomaly (DVA) is often concurrent with cavernous malformation (CM). But there is lack of statistical evidence and study of bulk cases. The factors associated with concurrency are still unknown. The purpose of this study was to determine the prevalence of concomitant DVA and CM using observational data on Chinese patients and analyze the factors associated with the concurrency. METHODS: The records of all cranial magnetic resonance imaging (MRI) performed between January 2001 and December 2012 in Beijing Tiantan Hospital were reviewed retrospectively. The DVA and CM cases were selected according to imaging reports that met diagnostic criteria. Statistical analysis was performed using the Pearson chi-square statistic for binary variables and multivariable logistic regression analysis for predictors associated with the concurrent CM. RESULTS: We reviewed a total of 165,230 cranial MR images performed during the previous 12 year period, and identified 1,839 cases that met DVA radiographic criteria. There were 205 patients who presented concomitant CM among the 1,839 DVAs. The CM prevalence in DVA cases (11.1%) was significantly higher than that in the non-DVA cases (2.3%) (P<0.01). In the multivariate analysis, we found that DVAs with three or more medullary veins in the same MRI section (adjusted OR = 2.37, 95% CI: 1.73-3.24), infratentorial DVAs (adjusted OR = 1.71, 95% CI: 1.26-2.33) and multiple DVAs (adjusted OR = 2.08, 95% CI: 1.04-4.16) have a higher likelihood of being concomitant with CM. CONCLUSIONS: CM are prone to coexisting with DVA. There is a higher chance of concurrent CM with DVA when the DVA has three or more medullary veins in the same MRI scanning section, when the DVA is infratentorial, and when there are multiple DVAs. When diagnosing DVA cases, physicians should be alerted to the possibility of concurrent CM.


Assuntos
Veias Cerebrais/anormalidades , Veias Cerebrais/crescimento & desenvolvimento , Hemangioma Cavernoso do Sistema Nervoso Central/diagnóstico , Imageamento por Ressonância Magnética/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Estudos Transversais , Feminino , Hemangioma Cavernoso do Sistema Nervoso Central/epidemiologia , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Adulto Jovem
14.
Environ Monit Assess ; 186(9): 5469-77, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24816539

RESUMO

Desert riparian forests are the main body of natural oases in the lower reaches of inland rivers; its growth and distribution are closely related to water use sources. However, how does the desert riparian forest obtains a stable water source and which water sources it uses to effectively avoid or overcome water stress to survive? This paper describes an analysis of the water sources, using the stable oxygen isotope technique and the linear mixed model of the isotopic values and of desert riparian Populus euphratica forests growing at sites with different groundwater depths and conditions. The results showed that the main water source of Populus euphratica changes from water in a single soil layer or groundwater to deep subsoil water and groundwater as the depth of groundwater increases. This appears to be an adaptive selection to arid and water-deficient conditions and is a primary reason for the long-term survival of P. euphratica in the desert riparian forest of an extremely arid region. Water contributions from the various soil layers and from groundwater differed and the desert riparian P. euphratica forests in different habitats had dissimilar water use strategies.


Assuntos
Ecossistema , Água Subterrânea/análise , Populus/fisiologia , Recursos Hídricos/estatística & dados numéricos , Clima Desértico , Meio Ambiente , Monitoramento Ambiental , Populus/crescimento & desenvolvimento , Rios , Solo , Árvores/crescimento & desenvolvimento
15.
Zhongguo Zhong Yao Za Zhi ; 39(11): 1972-5, 2014 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-25272824

RESUMO

Aconitum, as a kind of common traditional Chinese medicine, contains multiple biological active substances, with a very high medicinal value but high toxicity. Its major toxic ingredients are aconitine, mesaconitine and hypaconitine, which are also efficient ingredients. Therefore, the safety of its clinical application has aroused wide attention. With the constant deepening of drug development studies, people want to learn about its toxic mechanism and the regularity of its emergence and development of its toxicology, so as to make a scientific and rational assessment for its safety. Therefore, toxicokinetics and metabonomics have gradually become important content in the new drug assessment. During the development of drug performance, it is crucial to establish a scientific, objective and standardized Aconitum safety evaluation system and correctly assess and utilize its toxicity. Having summarized studies on metabonomics and toxicokinetics of Aconitum drugs in recent years, authors proposed to strengthen the studies on Aconitum drug safety assessment and establish a scientific and standardized safety evaluation system as soon as possible, in order to make the national treasure more useful.


Assuntos
Aconitum/toxicidade , Medicamentos de Ervas Chinesas/farmacocinética , Medicamentos de Ervas Chinesas/toxicidade , Aconitum/química , Animais , Humanos , Metabolômica
16.
Cell Signal ; 120: 111218, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38734194

RESUMO

Glioblastoma multiforme (GBM) is the most common and aggressive primary malignant human brain tumor. Although comprehensive therapies, including chemotherapy and radiotherapy following surgery, have shown promise in prolonging survival, the prognosis for GBM patients remains poor, with an overall survival rate of only 14.6 months. Chemoresistance is a major obstacle to successful treatment and contributes to relapse and poor survival rates in glioma patients. Therefore, there is an urgent need for novel strategies to overcome chemoresistance and improve treatment outcomes for human glioma patients. Recent studies have shown that the tumor microenvironment plays a key role in chemoresistance. Our study demonstrates that upregulation of HAS2 and subsequent hyaluronan secretion promotes glioma cell proliferation, invasion, and chemoresistance in vitro and in vivo through the c-myc pathway. Targeting HAS2 sensitizes glioma cells to chemotherapeutic agents. Additionally, we found that hypoxia-inducible factor HIF1α regulates HAS2 expression. Together, our findings provide insights into the dysregulation of HAS2 and its role in chemoresistance and suggest potential therapeutic strategies for GBM.


Assuntos
Proliferação de Células , Resistencia a Medicamentos Antineoplásicos , Subunidade alfa do Fator 1 Induzível por Hipóxia , Proteínas Proto-Oncogênicas c-myc , Regulação para Cima , Animais , Humanos , Camundongos , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/genética , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Glioblastoma/metabolismo , Glioblastoma/patologia , Glioblastoma/genética , Glioma/patologia , Glioma/metabolismo , Glioma/genética , Hialuronan Sintases/metabolismo , Hialuronan Sintases/genética , Ácido Hialurônico/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Camundongos Nus , Proteínas Proto-Oncogênicas c-myc/metabolismo
17.
Adv Mater ; : e2406128, 2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38940075

RESUMO

The 329-type bismuth (Bi)-based metal halide (MH) polycrystalline films have potential to be applied in the new generation of X-ray imaging technology owing to high X-ray absorption coefficients and excellent detection properties. However, the mutually independent [Bi2X9]3- units and numerous grain boundaries in the material lead to low carrier transport and collection capabilities, severe ion migration, large dark currents, and poor response uniformity. Here, a new multi-phenyl ring methyltriphenylphosphonium (MTP) is designed to optimize the energy band structure. For the first time, the coupling between the A-site cation and [Bi2X9]3- is realized, making it the main contributor to the conduction band minimum (CBM), getting rid of dilemma that carrier transport is confined to [Bi2X9]3-. Further, the preparation of MTP3Bi2I9 amorphous large-area wafer is achieved by melt-quenching; the steric hindrance effect improves stability, increases ion migration energy, and promotes response uniformity (14%). Moreover, the amorphous structure takes advantage of A-site cation participation in the conductivity, achieving a record sensitivity (7601 µC Gy-1 cm-2) and low dark current (≈0.11 nA) in the field of amorphous X-ray detection, and features low-temperature large-area preparation. Ultimately, designing amorphous array imaging devices that exhibit excellent response uniformity and potential imaging capabilities is succeeded here.

18.
Environ Manage ; 52(1): 209-20, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23716005

RESUMO

The Ecological Water Transfer and Rehabilitation Project in the arid inland area of northwest China is an important measure in restoring a deteriorated ecosystem. However, the sustainability of the project is affected by many socio-economic factors. This article examines the attitudes of the local populace toward the project, its impact on the livelihood of the people, and the positive effects of water-efficient agricultural practices in Ejina County. Related data were collected through questionnaire surveys and group discussions. The results identified three critical issues that may influence the sustainability of the project in the study area. The first issue relates to the impact of the project on the livelihood of local herdsmen. The potential for the sustainability of the project is compromised because the livelihood of the herdsmen greatly depends on the compensation awarded by the project. The second issue is that the project did not raise the water resource utilization ratio, which may undermine its final purpose. Finally, the compensation provided by the project considers losses in agriculture, but neglects the externalities and public benefit of eco-water. Thus, appropriate compensation mechanisms should be established and adopted according to local economic, environmental, and social conditions. Some recommendations for improving the sustainability of the project are provided based on the results of this study.


Assuntos
Conservação dos Recursos Naturais , Rios , Abastecimento de Água , Adolescente , Adulto , Idoso , Agricultura , Atitude , China , Ecossistema , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Adulto Jovem
19.
Sci Total Environ ; 904: 166669, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37657550

RESUMO

Rapid urbanization and climate changes result in frequent occurrence of urban waterlogging disasters, which cause serious economic damage and pose a threat to residents' safety. Understanding the spatial characteristic and the key influencing factors of urban waterlogging has significant implications for mitigating waterlogging. In this study, the officially issued representative waterlogging points were obtained, as well as the topographic factors and land cover characteristics were selected to compare their impacts on the waterlogging event density in a highly urbanized area at urban functional zone (UFZ) scale, and to quantify the contributions of the key influencing factors on urban waterlogging events. Results showed the average density of urban waterlogging events in the study area is 9.2 points/km2, and 38.4 % of the waterlogging events are distributed in REZ. The distribution of waterlogging points in the study area revealed a significant multi-core and multilevel spatial aggregation pattern, and 12.1 % of the study area was high-density waterlogging area. In the total UFZs, the correlation coefficients of topographic indices with waterlogging density were relatively weaker than the other land cover characteristic metrics. The impervious surface ratio had significant contributions in all UFZ types. The larger ratio of impervious surface significantly increased the density of waterlogging events. The increase in the ratio of green space can effectively decrease the density of urban waterlogging. In the total UFZs, the top 3 key influencing factors of urban waterlogging were PR (35.9 %), COHESION (32.5 %) and DIVISION (11.8 %). The higher connectivity of landscape patches in REZ, INZ and COZ, as well as the increase of landscape dispersion or diversity in REZ, EGZ, INZ and GSZ can effectively reduce the occurrence of urban waterlogging. This study provides a better understanding of the formation mechanism of urban waterlogging disasters and potential implications for prioritized waterlogging mitigation strategies.

20.
Adv Mater ; 35(9): e2208414, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36541158

RESUMO

Precise and on-demand release of sufficient hydrogen (H2 ) to tumor sites remains a key challenge for emerging H2 -oncotherapy, and little is known about the physiological effects of "abundant" H2 on complex tumor microenvironments (TME). Here, a highly efficient and cost-effective imaging-guided/-assessed H2 -therapy of tumors based on a joint electrochemo-sonodynamic treatment (H2 -EC/SD co-therapy) with strong "domino effect" triggered by endogenous H2 generation at tumor sites is reported to speedily eliminate tumor tissue (≤80 mm3 ) within 1 day. Adequate H2 is controllably generated in tumor sites through mild electrochemistry in vivo due to acidic TME by using clinical acupuncture Fe needles as electrodes. Besides starvation damage due to gas blockage/destruction of vessels, nano-/micro-bubbles of H2 formed in situ can elevate the tumor's internal temperature and burst vessels to further destroy the tumor under ultrasound irradiation. Remarkably, vulnerable homeostasis of TME is disturbed as H2 also participates in the physiological activity of tumor cells, leading to tumor dysfunction. Last but not least, the body's inflammatory response to cancer is reduced after the treatment, which is beneficial for the body's immune system during post-treatment recovery. Based on all of these merits, the H2 -EC/SD co-therapy provides a potentially safe and viable therapeutic strategy for future clinical applications.


Assuntos
Neoplasias , Humanos , Neoplasias/terapia , Hidrogênio , Diagnóstico por Imagem , Linhagem Celular Tumoral , Microambiente Tumoral
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa