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1.
Nature ; 568(7751): 212-215, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30944471

RESUMO

Lasers have both ubiquitous applications and roles as model systems in which non-equilibrium and cooperative phenomena can be elucidated1. The introduction of novel concepts in laser operation thus has potential to lead to both new applications and fundamental insights2. Spintronics3, in which both the spin and the charge of the electron are used, has led to the development of spin-lasers, in which charge-carrier spin and photon spin are exploited. Here we show experimentally that the coupling between carrier spin and light polarization in common semiconductor lasers can enable room-temperature modulation frequencies above 200 gigahertz, exceeding by nearly an order of magnitude the best conventional semiconductor lasers. Surprisingly, this ultrafast operation of the resultant spin-laser relies on a short carrier spin relaxation time and a large anisotropy of the refractive index, both of which are commonly viewed as detrimental in spintronics3 and conventional lasers4. Our results overcome the key speed limitations of conventional directly modulated lasers and offer a prospect for the next generation of low-energy ultrafast optical communication.

2.
BMC Plant Biol ; 24(1): 494, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38831264

RESUMO

BACKGROUND ACMELLA RADICANS: (Jacquin) R.K. Jansen is a new invasive species record for Yunnan Province, China. Native to Central America, it has also been recently recorded invading other parts of Asia. To prevent this weed from becoming a serious issue, an assessment of its ecological impacts and potential distribution is needed. We predicted the potential distribution of A. radicans in China using the MaxEnt model and its ecological impacts on local plant communities and soil nutrients were explored. RESULTS: Simulated training using model parameters produced an area under curve value of 0.974, providing a high degree of confidence in model predictions. Environmental variables with the greatest predictive power were precipitation of wettest month, isothermality, topsoil TEB (total exchangeable bases), and precipitation seasonality, with a cumulative contribution of more than 72.70% and a cumulative permutation importance of more than 69.20%. The predicted potential suitable area of A. radicans in China is concentrated in the southern region. Projected areas of A. radicans ranked as high and moderately suitable comprised 5425 and 26,338 km2, accounting for 0.06 and 0.27% of the Chinese mainland area, respectively. Over the 5 years of monitoring, the population density of A. radicans increased while at the same time the population density and importance values of most other plant species declined markedly. Community species richness, diversity, and evenness values significantly declined. Soil organic matter, total N, total P, available N, and available P concentrations decreased significantly with increasing plant cover of A. radicans, whereas pH, total K and available K increased. CONCLUSION: Our study was the first to show that A. radicans is predicted to expand its range in China and may profoundly affect plant communities, species diversity, and the soil environment. Early warning and monitoring of A. radicans must be pursued with greater vigilance in southern China to prevent its further spread.


Assuntos
Espécies Introduzidas , China , Solo/química , Ecossistema
3.
J Comput Assist Tomogr ; 46(3): 406-412, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35405718

RESUMO

OBJECTIVE: We aimed to prospectively investigate intravoxel incoherent motion parameters to predict the response to chemotherapy in locally advanced non-small cell lung cancer (NSCLC) patients. METHODS: From July 2016 to March 2018, 30 advanced NSCLC patients were enrolled and underwent chest intravoxel incoherent motion-diffusion-weighted imaging at Siemens 3T magnetic resonance imaging before and at the end of the first cycle of chemotherapy. Regions of interest were drawn including the whole tumor volume to derive the apparent diffusion coefficient value, D, D*, and f, respectively. Time-dependent receiver operating characteristic curves were generated to evaluate the cutoff values of continuous variables. A Cox proportional hazards model was used to assess the independent predictors of progression-free survival (PFS) and overall survival (OS). Kaplan-Meier curves and log-rank test were generated. RESULTS: Among the 30 patients, 28 cases (93.3%) died and 2 cases (6.7%) survived till the closeout date. Univariate Cox regression analyses revealed that the significant predictors of PFS and OS were the tumor size reduction rate, the change rates of D and apparent diffusion coefficient values, and the D value before therapy (PFS: P = 0.015, hazard ratio [HR] = 2.841; P < 0.001, HR = 5.840; P = 0.044, HR = 2.457; and P = 0.027, HR = 2.715; OS: P = 0.008, HR = 2.987; P < 0.001, HR = 4.357; P = 0.006, HR = 3.313; and P = 0.013, HR = 2.941, respectively). Multivariate Cox regression analysis suggested that △D% was identified as independent predictors of both PFS and OS (P = 0.003, HR = 9.200 and P = 0.016, HR = 4.617). In addition, the cutoff value of △D% was 21.06% calculated by receiver operating characteristic curve analysis. In the Kaplan-Meier analysis, the PFS and OS were significantly greater in the group of patients with △D% larger than 21.06% (log-rank test, χ2 = 16.453, P < 0.001; χ2 = 13.952, P < 0.001). CONCLUSIONS: Intravoxel incoherent motion-diffusion-weighted imaging was preferred for predicting the prognosis of advanced NSCLC patients treated with chemotherapy. A D increase more than 21.06% at 1 month was associated with a lower rate of disease progression and death.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Imagem de Difusão por Ressonância Magnética/métodos , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/tratamento farmacológico , Imageamento por Ressonância Magnética , Movimento (Física)
4.
J Magn Reson Imaging ; 54(5): 1529-1540, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34291852

RESUMO

BACKGROUND: T1 mapping can potentially quantitatively assess the intrinsic properties of tumors. B1 correction can reduce the magnetic field inhomogeneity. PURPOSE: To assess the repeatability and reproducibility of B1 -corrected T1 mapping for lung cancer and the ability to identify pathological types. STUDY TYPE: Prospective reproducibility study. POPULATION: Sixty lung cancer patients (22 with emphysema) with a total of 60 lesions (adenocarcinoma [n = 23], squamous cell carcinoma [n = 19], and small-cell lung cancer [SCLC] [n = 18]). FIELD STRENGTH/SEQUENCE: A 3 T/B1 -corrected 3D variable flip angle T1 mapping and free-breathing diffusion-weighted imaging. ASSESSMENT: Intraobserver, interobserver, and test-retest reproducibility of minimum, maximum, mean, and SD of lung tumor T1 values were assessed. The correlation between mean T1 and apparent diffusion coefficient (ADC) and differences between different histological types of lung cancer were evaluated. STATISTICAL TESTS: Intraclass correlation coefficients (ICCs), within-subject coefficients of variation (WCVs), Bland-Altman plots, Pearson's correlation coefficient (r), and analysis of variance (ANOVA). A P value <0.05 was considered to be statistically significant. RESULTS: No significant differences were found in minimum, maximum, mean, and SD T1 values for repeated measurements (intraobserver and interobserver) and repeated examinations (P = 0.103-0.979). All parameters showed good intraobserver, interobserver and test-retest reproducibility (ICC, 0.780-0.978), except the maximum T1 value (ICC, 0.645-0.922). The mean T1 exhibited the best reproducibility and repeatability, with an average difference <6% for repeated measurements, <8% for repeated scans in lung cancer patients, and<10% for repeated scans in those with emphysema. The mean T1 correlated moderately with ADC (r = -0.580, -0.516, and -0.511 for observers A, B, and C). Both mean T1 and mean ADC were significantly different in SCLC patients compared with those in adenocarcinoma and squamous cell carcinoma patients. DATA CONCLUSION: The mean T1 from B1 -corrected T1 mapping is a repeatable parameter with the potential to identify histological types of lung cancer and thus may be a promising imaging biomarker for characterizing lung cancer. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.


Assuntos
Imagem de Difusão por Ressonância Magnética , Neoplasias Pulmonares , Biomarcadores , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Estudos Prospectivos , Reprodutibilidade dos Testes
5.
Physiol Plant ; 173(3): 911-919, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34164817

RESUMO

Mikania micrantha Kunth is a serious invasive alien plant characterized by the formation of an adventitious root system in its prostrate growth form. Unlike the initial roots from seed germination, adventitious roots gradually appear above the stem and branch nodes. Little is known about adventitious roots play on plant growth and population expansion of M. micrantha. We hypothesized that adventitious roots provide an advantage for plant growth and nutrient availability. To test this hypothesis, plant growth, physiology, and nutrition characteristics of M. micrantha were measured under four soil surface conditions allowing various plant parts to touch the soil to stimulate variable adventitious root formation. The results showed that the biomass, stem length, branch number, and adventitious root biomass of M. micrantha were significantly increased (P < 0.05) with increasing nodes bearing adventitious roots. As the number of nodes with adventitious roots increased, the net photosynthetic rate, antioxidant enzyme activities like superoxide dismutase, catalase, peroxidase, and malondialdehyde, chlorophyll content, and plant nutrient contents (N, P, and K) of M. micrantha were increased (P < 0.05), with higher values in main stem leaves than in those of branch leaves. The concentrations of soil organic matter, total N, total P, total K, available N, available P, and available K were greater (P < 0.05) in initial soil (CK) than in treatment soil (with M. micrantha) and were significantly reduced by adventitious roots. Our study was the first to show that plant growth, physiology and nutrition status of M. micrantha were strongly promoted by adventitious roots in the prostrate growth form.


Assuntos
Mikania , Biomassa , Fotossíntese , Folhas de Planta , Raízes de Plantas , Solo
6.
Phys Rev Lett ; 125(15): 157402, 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33095598

RESUMO

In many atomically thin materials, their optical absorption is dominated by excitonic transitions. It was recently found that optical selection rules in these materials are influenced by the band topology near the valleys. We propose that gate-controlled band ordering in a single atomic monolayer, through changes in the valley winding number and excitonic transitions, can be probed in helicity-resolved absorption and photoluminescence. This predicted tunable band topology is confirmed by combining an effective Hamiltonian and a Bethe-Salpeter equation for an accurate description of excitons, with first-principles calculations suggesting its realization in Sb-based monolayers.

7.
Phys Rev Lett ; 119(12): 127403, 2017 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-29341642

RESUMO

The two-dimensional character and reduced screening in monolayer transition-metal dichalcogenides (TMDs) lead to the ubiquitous formation of robust excitons with binding energies orders of magnitude larger than in bulk semiconductors. Focusing on neutral excitons, bound electron-hole pairs that dominate the optical response in TMDs, it is shown that they can provide fingerprints for magnetic proximity effects in magnetic heterostructures. These proximity effects cannot be described by the widely used single-particle description but instead reveal the possibility of a conversion between optically inactive and active excitons by rotating the magnetization of the magnetic substrate. With recent breakthroughs in fabricating Mo- and W-based magnetic TMD heterostructures, this emergent optical response can be directly tested experimentally.

8.
Neurochem Res ; 41(7): 1684-90, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27003587

RESUMO

Glioma is a severe and highly lethal brain cancer, a malignancy largely stemming from growing in a relatively restrained area of the brain. Hence, the understanding of the molecular regulation of the growth of glioma is critical for improving its treatment. MicroRNA has become a hotspot in research on diseases, especially in the initiation and progression of different types of cancer. However, the molecular function and mechanisms of miR-508-5p in gliomagenesis are still unclear. The aim of this study was to investigate miR-508-5p expression in glioma and determine its effects on proliferation. miR-508-5p expression levels, both in glioma cell lines and in tissue, were significantly lower than in a normal human astrocyte cell line or adjacent tissues. Cell growth was analyzed using a MTT assay and over-expression of miR-508-5p was found to decrease glioma cell growth. Moreover, a bioinformatic analysis was performed, showing that glycoprotein non-metastatic melanoma B (GPNMB) was a direct target for miR-508-5p in glioma cells. Furthermore, in vivo treatment with miR-508-5p reduced GPNMB protein levels in the tumor. Additionally, overexpression of GPNMB without 3'-UTR partially reversed the cell growth arrest induced by miR-508-5p over-expression in glioma cells. In conclusion, these results indicate that increased expression of miR-508-5p might be related to glioma progression, indicating a potential role of miR-508-5p for clinical therapy.


Assuntos
Neoplasias Encefálicas/metabolismo , Progressão da Doença , Glioma/metabolismo , Glicoproteínas de Membrana/biossíntese , MicroRNAs/biossíntese , Animais , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/prevenção & controle , Linhagem Celular Tumoral , Marcação de Genes/métodos , Glioma/patologia , Glioma/prevenção & controle , Humanos , Glicoproteínas de Membrana/antagonistas & inibidores , Camundongos , Camundongos Nus , MicroRNAs/administração & dosagem , Carga Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
9.
BMC Ecol ; 16: 30, 2016 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-27323798

RESUMO

BACKGROUND: As a means of biologically controlling Mikania micrantha H.B.K. in Yunnan, China, the influence of sweet potato [Ipomoea batatas (L.) Lam.] on its reproductive characteristics was studied. The trial utilized a de Wit replacement series incorporating six ratios of sweet potato and M. micrantha plants in 25 m(2) plots over 2 years. RESULTS: Budding of M. micrantha occurred at the end of September; flowering and fruiting occurred from October to February. Flowering phenology of M. micrantha was delayed (P < 0.05), duration of flowering and fruiting was reduced (P < 0.05) and duration of bud formation was increased (P < 0.05) with increasing proportions of sweet potato. Reproductive allocation, reproductive investment and reproductive index of M. micrantha were significantly reduced (P < 0.05) with increasing sweet potato densities. Apidae bees, and Calliphoridae or Syrphidae flies were the most abundant visitors to M. micrantha flowers. Overall flower visits decreased (P < 0.05) as sweet potato increased. Thus the mechanism by which sweet potato suppressed sexual reproduction in M. micrantha was essentially two-fold: causing a delay in flowering phenology and reducing pollinator visits. The number, biomass, length, set rate, germination rate, and 1000-grain dry weight of M. micrantha seeds were suppressed (P < 0.05) by sweet potato competition. With proportional increases in sweet potato, sexual and asexual seedling populations of M. micrantha were significantly reduced (P < 0.05). The mortality of both seedling types increased (P < 0.05) with proportional increases in sweet potato. CONCLUSIONS: These results suggest that sweet potato significantly suppresses the reproductive ability of the invasive species M. micrantha, and is a promising alternative to traditional biological control and other methods of control. Planting sweet potato in conjunction with other control methods could provide a comprehensive strategy for managing M. micrantha. The scenario of controlling M. micrantha by utilizing a crop with a similar growth form may provide a useful model for similar management strategies in other systems.


Assuntos
Ipomoea batatas/fisiologia , Mikania/fisiologia , Animais , Abelhas/fisiologia , Dípteros/fisiologia , Ipomoea batatas/crescimento & desenvolvimento , Mikania/crescimento & desenvolvimento , Reprodução
10.
BMC Ecol ; 15: 1, 2015 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-25626963

RESUMO

BACKGROUND: There are a variety of ways of increasing crop diversity to increase agricultural sustainability and in turn having a positive influence on nearby natural ecosystems. Competitive crops may provide potent management tools against invasive plants. To elucidate the competitive mechanisms between a sweet potato crop (Ipomoea batatas) and an invasive plant, mile-a-minute (Mikania micrantha), field experiments were carried out in Longchuan County of Yunnan Province, Southwest China, utilizing a de Wit replacement series. The trial incorporated seven ratios of sweet potato and mile-a-minute plants in 25 m(2) plots. RESULTS: In monoculture, the total biomass, biomass of adventitious root, leafstalk length, and leaf area of sweet potato were all higher than those of mile-a-minute, and in mixed culture the plant height, branch, leaf, stem node, adventitious root, flowering and biomass of mile-a-minute were suppressed significantly (P < 0.05). The relative yield (RY) of mile-a-minute and sweet potato was less than 1.0 in mixed culture, indicating that intraspecific competition was less than interspecific competition. The competitive balance index of sweet potato demonstrated a higher competitive ability than mile-a-minute. Except pH, other soil nutrient contents of initial soil (CK) were significantly higher than those of seven treatments. The concentrations of soil organic matter, total N, total K, available N, available P, available K, exchange Ca, exchange Mg, available Mn, and available B were significantly greater (P < 0.05) in mile-a-minute monoculture soil than in sweet potato monoculture soil, and were reduced by the competition of sweet potato in the mixture. CONCLUSIONS: Evidently sweet potato has a competitive advantage in terms of plant growth characteristics and greater absorption of soil nutrients. Thus, planting sweet potato is a promising technique for reducing infestations of mile-a-minute, providing weed management benefits and economic returns from harvest of sweet potatoes. This study also shows the potential value of replacement control methods which may apply to other crop-weed systems or invaded natural ecosystems.


Assuntos
Agricultura/métodos , Espécies Introduzidas , Ipomoea batatas/crescimento & desenvolvimento , Mikania/crescimento & desenvolvimento , Solo/química , Biomassa , China , Produtos Agrícolas/crescimento & desenvolvimento , Plantas Daninhas/crescimento & desenvolvimento
11.
Lancet Oncol ; 15(6): 612-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24742740

RESUMO

BACKGROUND: The combination of stent insertion and single high-dose brachytherapy is a feasible and safe palliative treatment regimen in patients with unresectable oesophageal cancer. We aimed to further assess the efficacy of this treatment strategy compared to a conventional covered stent in patients with dysphagia caused by unresectable oesophageal cancer. METHODS: In this multicentre, single-blind, randomised, phase 3 trial, we enrolled patients with unresectable oesophageal cancer from 16 hospitals in China. We included adult patients (aged ≥ 20 years) with progressive dysphagia, unresectable tumours due to extensive lesions, metastases, or poor medical condition, and with clear consciousness, cooperation, and an Eastern Cooperative Oncology Group (ECOG) performance status score of 0-3. Eligible patients were randomly assigned (in 1:1 ratio, no stratification) to receive either a stent loaded with (125)iodine radioactive seeds (irradiation group) or a conventional oesophageal stent (control group). The primary endpoint was overall survival. Survival analyses were done in a modified intention-to-treat group. This study is registered with ClinicalTrials.gov, number NCT01054274. FINDINGS: Between Nov 1, 2009, and Oct 31, 2012, 160 patients were randomly assigned to receive treatment with either an irradiation stent (n=80) or a conventional stent (n=80). During a median follow-up of 138 days (IQR 72-207), 148 stents (73 in the irradiation group and 75 in the control group) were successfully placed into the diseased oesophagus in 148 participants. Median overall survival was 177 days (95% CI 153-201) in the irradiation group versus 147 days (124-170) in the control group (p=0.0046). Major complications and side-effects of the treatment were severe chest pain (17 [23%] of 73 patients in the irradiation group vs 15 [20%] of 75 patents in the control group), fistula formation (six [8%] vs five [7%]), aspiration pneumonia (11 [15%] vs 14 [19%]), haemorrhage (five [7%] vs five [7%]), and recurrent dysphagia (21 [28%] vs 20 [27%]). INTERPRETATION: In patients with unresectable oesophageal cancer, the insertion of an oesophageal stent loaded with (125)iodine seeds prolonged survival when compared with the insertion of a conventional covered self-expandable metallic stent.


Assuntos
Adenocarcinoma/radioterapia , Braquiterapia/métodos , Carcinoma de Células Escamosas/radioterapia , Neoplasias Esofágicas/radioterapia , Stents , Adenocarcinoma/mortalidade , Idoso , Braquiterapia/instrumentação , Carcinoma de Células Escamosas/mortalidade , Neoplasias Esofágicas/mortalidade , Feminino , Humanos , Radioisótopos do Iodo/uso terapêutico , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Método Simples-Cego
12.
Tumour Biol ; 35(2): 1389-95, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24048757

RESUMO

Three polymorphisms of X-ray repair cross-complementing groups 1 (XRCC1) Arg194Trp, Arg280His, and Arg399Gln may be associated with the individual susceptibility to glioma. The aim of this study was to investigate any association between three polymorphisms of the XRCC1 gene at codon 194, 280, and 399 and potential glioma risk. We conducted a hospital-based case-control study in northwest China. A total of 1,772 subjects, including 886 glioma patients and 886 healthy controls, were recruited in this study. The peripheral blood samples were extracted. Polymerase chain reaction-restriction fragment length polymorphism method was used to test genotypes. Glioma patients had a significantly higher frequency of XRCC1 194 TT (odds ratio [OR] = 1.76, 95 % confidence interval [CI] = 1.14, 2.72; P = 0.01) and XRCC1 399 AA genotype (OR = 1.62, 95 % CI = 1.09, 2.40; P = 0.02) than controls. When stratified by the grade of glioma, patients with WHO IV glioma had a significantly higher frequency of XRCC1 194 TT (OR = 1.60, 95 % CI = 1.02, 2.51; P = 0.04) and XRCC1 399 AA genotype (OR = 1.59, 95 % CI = 1.04, 2.42; P = 0.03). When stratified by the histology of glioma, there was no significant difference in the distribution of each genotype. This study suggested that XRCC1 Arg194Trp and Arg399Gln polymorphisms were associated with the risk of glioma.


Assuntos
Neoplasias Encefálicas/genética , Proteínas de Ligação a DNA/genética , Estudos de Associação Genética , Glioma/genética , Neoplasias Encefálicas/patologia , Estudos de Casos e Controles , China , Reparo do DNA/genética , Predisposição Genética para Doença , Glioma/patologia , Humanos , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Proteína 1 Complementadora Cruzada de Reparo de Raio-X
13.
Acta Neurochir (Wien) ; 156(11): 2209-13, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25223746

RESUMO

BACKGROUND: A coordinate system was previously developed to identify landmarks on the skull surface to help locate the transverse-sigmoid sinus junction in order to reduce surgical morbidity in retrosigmoid craniotomy; however, in practice we found that this system has important flaws. OBJECTIVE: To develop and evaluate a novel reference coordinate system to precisely locate the inferomedial point of the transverse-sigmoid sinus junction (IMTS) and evaluate the effect of gender and skull side (left or right). METHODS: Forty-two adult skulls (84 sides) were obtained for analyses. The X-axis was defined by point A (where the upper edge of the zygomatic arch joins with the frontal process of the zygomatic bone) and point B (where the upper edge of the zygomatic arch blends posterosuperiorly into the supramastoid crest). The Y-axis was defined by the line perpendicular to the X-axis and extending across the tip of the mastoid. The x and y coordinates of IMTS (IMTS-x and IMTS-y) were measured in this coordinate system. RESULTS: There were 20 male skulls and 22 female skulls. The mean IMTS-x measurements were significantly higher on the right side compared with the left side in both males and females. For the left skull side, the mean IMTS-y measurements were significantly lower in females compared with males. CONCLUSION: This novel reference coordinate system may be a reliable and practical method for identifying the IMTS during retrosigmoid craniotomy. There are significant differences in location of the axes with regard to gender and skull side.


Assuntos
Pontos de Referência Anatômicos , Processo Mastoide/anatomia & histologia , Crânio/anatomia & histologia , Seios Transversos/anatomia & histologia , Zigoma/anatomia & histologia , Adulto , Cavidades Cranianas/anatomia & histologia , Cavidades Cranianas/cirurgia , Craniotomia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Crânio/cirurgia , Seios Transversos/cirurgia
14.
Sci Rep ; 14(1): 16976, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39043781

RESUMO

The treatment, disposal, and resource utilization of waste mud are challenges for engineering construction. This study investigates the road performance of waste mud-solidified soil and explains how solidifying materials influence the strength and deformation characteristics of waste mud. Unconfined compressive strength tests, consolidated undrained triaxial shear tests, resonant column tests, and consolidation compression tests were conducted to evaluate the solidification effect. The test results show that with an increase in cement content from 5 to 9%, the unconfined compressive strength of the waste mud-solidified soil increased by over 100%, the curing time was extended from 3 to 28 days, and the unconfined compressive strength increased by approximately 70%. However, an increase in initial water content from 40 to 60% reduced the unconfined compressive strength by 50%. With the increase of cement content from 5 to 9%, the cohesion and friction angles increased by approximately 78% and 24%, respectively. The initial shear modulus under dynamic shear increased by approximately 38% and the shear strain corresponding to a damping ratio decay to 70% of the initial shear modulus decreased by nearly 11%. The compression coefficient decreased by approximately 55%. Scanning electron microscopy and X-ray diffraction tests showed that a higher cement content led to the formation of more hydration reaction products, especially an increase in the content of AlPO4, which can effectively fill the pores between soil particles, enhance the bonding between soil particles, and form a skeleton with soil particles to improve compactness. Consequently, the strength of the waste mud-solidified soil increased significantly while its compressibility decreased. This study can provide data support for dynamic characteristics of waste mud solidified soil subgrade.

15.
Environ Sci Pollut Res Int ; 31(7): 10887-10895, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38214859

RESUMO

Dehydration with a plate and frame filter press is a common method for treating dredged silt from rivers and lakes. The silt is often conditioned by the addition of solidifying materials before plate and frame press filtration and, therefore, is subjected to the coupling effect of solidification and consolidation. In this study, consolidation tests of the silt with cement were carried out and compared with the silt after only solidification or only consolidation in terms of moisture content, unconfined compressive strength, and leaching concentration. The test results showed that the moisture content of the silt can be reduced to less than 60% under the coupling action of solidification and consolidation, which was 22% and 4% lower than with solidification only or consolidation only, respectively. The effect of consolidation improved the solidification process; the unconfined compressive strength increased rapidly in the early stage of curing and was 30-150% higher than that of solidified silt. The coupling effects of solidification and consolidation on the leaching concentrations of Ni and Cr in silt were the most significant, and the lowest leaching concentrations were 60% and 90% lower than those of solidified only and consolidated only silt, respectively.


Assuntos
Metais Pesados , Metais Pesados/análise , Força Compressiva , Filtração , Lagos
16.
Front Neurol ; 15: 1376216, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38606277

RESUMO

Objectives: This study aimed to investigate the efficacy of using a newly formulated magnesium-rich artificial cerebrospinal fluid (MACSF) as an alternative to normal saline (NS) for intraoperative irrigation during aneurysm clipping in improving the prognosis of patients with Aneurysmal subarachnoid hemorrhage (aSAH). Methods: Patients with aSAH who underwent intraoperative irrigation with MACSF or NS during the clipping in the First Affiliated Hospital of Xi 'an Jiaotong University from March 2019 to March 2022 were selected as MACSF group and NS group, respectively. The primary prognostic indicators were the incidence of favorable outcomes (mRS 0-2). The secondary outcome measures included cerebral vasospasm (CVS), mortality, total hospital stay, and intensive care unit (ICU) stay. Safety was evaluated based on the occurrence rates of hypermagnesemia, meningitis, and hydrocephalus. Results: Overall, 34 and 37 patients were enrolled in the MACSF and NS groups, respectively. At 90 days after aSAH onset, the proportion of favorable prognosis in the MACSF group was significantly higher than that in the NS group (p = 0.035). The incidence of CVS within 14 days after surgery was significantly lower in the MACSF group than that in the NS group (p = 0.026). The mortality rate in the MACSF group was significantly lower than in the NS group (p = 0.048). The median lengths of hospital stay (p = 0.008) and ICU stay (p = 0.018) were significantly shorter in the MACSF group than in the NS group. No significant differences were observed in safety measures. Conclusion: Using MACSF as an irrigation fluid for aneurysm clipping can significantly improve the 90-day prognosis of patients with aSAH, which may be related to the reduced incidence of CVS. Clinical trial registration: https://www.clinicaltrials.gov, identifier NCT04358445.

17.
J Surg Res ; 185(1): 388-98, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23743186

RESUMO

BACKGROUND: It was previously reported that propofol, an intravenously administered hypnotic and anesthetic agent, protects organs from ischemia-reperfusion (I/R) injury. However, the underlying mechanisms are largely unknown. Glycogen synthase kinase 3ß (GSK-3ß) is known to play an important role in the oxidative stress-induced apoptosis. In this study, we investigated the role of GSK-3ß and mitochondrial permeability transition pore (MPTP) in the protective effects of propofol against hepatic I/R injury. MATERIALS AND METHODS: The left and median hepatic artery and the portal vein branches were blocked by no-damage artery clips to create the model of partial ischemia (70%), and liver lobes were subjected to warm ischemia for 30, 60, 90 min, respectively. Reperfusion of 120 min was then initiated by the removal of clamp. The MPTP opening was assessed by measuring mitochondrial large amplitude swelling and mitochondrial membrane potential. RESULTS: Pretreatment with propofol in conditions of hepatic I/R inhibits the apoptosis of hepatocytes as evidenced by decreased terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells. Importantly, propofol suppressed the mitochondrial GSK-3ß by promoting or preserving its phosphorylation at Ser9, thus restraining the opening of MPTP and preventing the mitochondrial swell and mitochondrial membrane potential collapse. CONCLUSIONS: Propofol protects liver from I/R injury by sustaining the mitochondrial function, which is possibly involved with the modulation of MPTP and GSK-3ß.


Assuntos
Anestésicos Intravenosos/farmacologia , Quinase 3 da Glicogênio Sintase/metabolismo , Fígado/efeitos dos fármacos , Propofol/farmacologia , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/prevenção & controle , Animais , Apoptose/efeitos dos fármacos , Glicogênio Sintase Quinase 3 beta , Fígado/enzimologia , Fígado/patologia , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/enzimologia , Membranas Mitocondriais/efeitos dos fármacos , Membranas Mitocondriais/enzimologia , Estresse Oxidativo/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/patologia
18.
Artigo em Inglês | MEDLINE | ID: mdl-36900964

RESUMO

The essence of post-disaster reconstruction is the restoration and rebirth of the affected areas. The earthquake hitting Jiuzhaigou was the first earthquake that had its epicenter in the World Natural Heritage located in China. Ecological restoration and landscape reconstruction are essential for the sustainable development of tourism. This study uses high-resolution remote sensing images to monitor and evaluate the post-disaster restoration and reconstruction process of the leading lakes in Jiuzhaigou. It was found that the lake water quality, vegetation, and road facilities have undergone moderate reconstruction. However, the restoration and reconstruction still faced severe challenges. The ecological environment's stability and balance are prerequisites for the sustainable development of the World Natural Heritage sites. This paper combines the "Build Back Better" concept that advocates risk reduction, scenic spot restoration, and efficient implementation to ensure Jiuzhaigou's restoration and sustainable development. It comes up with specific measures for the resilience development of Jiuzhaigou from the eight principles of overall planning, structural resilience, disaster prevention and mitigation, landscape facilities, social psychology, management mechanisms, policies and regulations, and monitoring and evaluation to provide a reference for the sustainable development of tourism.


Assuntos
Desastres , Terremotos , Lagos , Desenvolvimento Sustentável , Turismo , China
19.
Int J Infect Dis ; 126: 136-144, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36343866

RESUMO

OBJECTIVES: Rabies is an acute lethal infectious disease caused by a lyssavirus infection. In 2018, the World Health Organization proposed a global strategic plan to end human rabies deaths by 2030. However, systematic studies on the global rabies disease burden and epidemiological trends are scarce. METHODS: We extracted the disease burden and epidemiological data of rabies worldwide in the preceding 30 years from the Global Burden of Disease Study 2019 and performed a comprehensive analysis. RESULTS: In 2019, the incident cases of rabies worldwide were 14,075.51 (95% uncertainty interval: 6124.33-21,618.11), and the number of deaths was 13,743.44 (95% uncertainty interval: 6019.13-17,938.53), both of which were lower than that in 1990. With the improvement of the sociodemographic index, the incident cases, the number of deaths, age-standardized incidence rate, age-standardized incidence death rate, and disability-adjusted life years of rabies all showed downward trends. Adolescents and adults aged <50 years represented the majority of rabies cases worldwide. CONCLUSION: The global disease burden of rabies has declined over the past 30 years. Furthermore, the disease burden of rabies was closely related to the sociodemographic index level.


Assuntos
Carga Global da Doença , Raiva , Adulto , Adolescente , Humanos , Raiva/epidemiologia , Incidência , Saúde Global , Organização Mundial da Saúde , Anos de Vida Ajustados por Qualidade de Vida
20.
Front Plant Sci ; 14: 1070674, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37324697

RESUMO

Introduction: In natural systems, diverse plant communities tend to prevent a single species from dominating. Similarly, management of invasive alien plants may be achieved through various combinations of competing species. Methods: We used a de Wit replacement series to compare different combinations of sweet potato (Ipomoea batatas (L.) Lam), hyacinth bean (Lablab purpureus (L.) Sweet) and mile-a-minute (Mikania micrantha Kunth) through measures of photosynthesis, plant growth, nutrient levels in plant tissue and soil, and competitive ability. Results: Cultured alone sweet potato and hyacinth beans exhibited higher total biomass, leafstalk length, and leaf area than mile-a-minute. In mixed culture, either sweet potato or hyacinth bean or both together significantly suppressed the mile-a-minute parameters, i.e., plant height, branch, leaf, adventitious root, and biomass (P<0.05). Based on a significantly lower than 1.0 relative yield of the three plant species in mixed culture, we showed intraspecific competition to be less than interspecific competition. Calculated indices (relative yield, relative yield total, competitive balance index, and change in contribution) demonstrated a higher competitive ability and higher influence of either crop compared to mile-a-minute. The presence of sweet potato and hyacinth bean, especially with both species in combination, significantly reduced (P<0.05) mile-a-minute's net photosynthetic rate (Pn), antioxidant enzyme activities (superoxide dismutase, peroxidase, catalase, and malondialdehyde), chlorophyll content, and nutrient content (N, P, and K). In soil with mile-a-minute in monoculture soil organic matter, total and available N, total and available K, and available P were significantly greater (P<0.05) than in soil with sweet potato grown in monoculture, but less than in soil with hyacinth bean grown in monoculture soil. Nutrient soil content was comparatively reduced for plant mixtures. Plant height, leaf, biomass, Pn, antioxidant enzyme activities, and plant and soil nutrient contents of sweet potato and hyacinth bean tended to be much greater when grown with two crops compared to in mixture with just sweet potato or hyacinth bean. Discussion: Our results suggest that the competitive abilities of both sweet potato and hyacinth bean were greater than that of mile-a-minute, and also that mile-a-minute suppression was significantly improved via a combination of the two crops compared to either sweet potato or hyacinth bean alone.

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