Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 11 de 11
Filter
Add more filters










Publication year range
1.
J Neurosurg ; 140(2): 377-385, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-37877959

ABSTRACT

OBJECTIVE: The general trend in meningioma treatment is shifting from surgery to active surveillance. However, the natural history of meningioma still needs to be clarified, and a simple, practical method is needed to identify fast-growing tumors. The authors aimed to determine whether diffusion-weighted imaging (DWI) could be a valuable imaging modality for predicting meningioma growth. METHODS: Consecutive asymptomatic patients with a meningioma diagnosed on MRI and followed up at the authors' institution between July 2011 and July 2019 were eligible for inclusion in this retrospective study. Univariable and multivariable Cox regression analyses were used to explore whether the relative apparent diffusion coefficient (rADC) was an independent predictor of meningioma growth. Correlations between tumor growth rate (TGR), tumor volume doubling time (VDT), Ki-67, and rADC were assessed using the Pearson correlation coefficient. The predictive ability of rADC was evaluated using receiver operating characteristic (ROC) curves and validated with internal validation data. RESULTS: Sixty-four patients (47 females, 17 males) with a mean age of 62.2 ± 1.4 years were included in this study. Univariable and multivariable analyses revealed that rADC was an independent predictor of meningioma growth (p < 0.05). ROC curve analysis showed that baseline rADC had good predictive power for growing meningiomas (AUC = 0.88, 95% CI 0.78-0.96), as well as slow- or fast-growing meningiomas (AUC = 0.83, 95% CI 0.59-0.98). Moreover, rADC still had a good ability to discriminate between growing and nongrowing meningiomas in the validation set (AUC = 0.85, 95% CI 0.64-1.00). In the 20 patients with tumor growth, baseline rADC was moderately negatively correlated with TGR (r = -0.50, p = 0.02) and strongly positively correlated with VDT (r = 0.63, p = 0.003). Moreover, Ki-67 was significantly associated with rADC in 8 patients who had undergone surgery (r = -0.75, p = 0.03). CONCLUSIONS: In asymptomatic meningiomas, the lower the rADC at baseline, the faster the TGR and the shorter the VDT. DWI could be a valuable tool in predicting meningioma growth in asymptomatic patients.


Subject(s)
Meningeal Neoplasms , Meningioma , Male , Female , Humans , Middle Aged , Meningioma/diagnostic imaging , Meningioma/pathology , Retrospective Studies , Ki-67 Antigen , Diffusion Magnetic Resonance Imaging/methods , Magnetic Resonance Imaging/methods , Meningeal Neoplasms/diagnostic imaging , Meningeal Neoplasms/pathology
2.
Cancer Imaging ; 23(1): 117, 2023 Dec 05.
Article in English | MEDLINE | ID: mdl-38053183

ABSTRACT

BACKGROUND: The consistency of meningiomas is critical to determine surgical planning and has a significant impact on surgical outcomes. Our aim was to compare mono-exponential, bi-exponential and stretched exponential MR diffusion-weighted imaging in predicting the consistency of meningiomas before surgery. METHODS: Forty-seven consecutive patients with pathologically confirmed meningiomas were prospectively enrolled in this study. Two senior neurosurgeons independently evaluated tumour consistency and classified them into soft and hard groups. A volume of interest was placed on the preoperative MR diffusion images to outline the whole tumour area. Histogram parameters (mean, median, 10th percentile, 90th percentile, kurtosis, skewness) were extracted from 6 different diffusion maps including ADC (DWI), D*, D, f (IVIM), alpha and DDC (SEM). Comparisons between two groups were made using Student's t-Test or Mann-Whitney U test. Parameters with significant differences between the two groups were included for Receiver operating characteristic analysis. The DeLong test was used to compare AUCs. RESULTS: DDC, D* and ADC 10th percentile were significantly lower in hard tumours than in soft tumours (P ≤ 0.05). The alpha 90th percentile was significantly higher in hard tumours than in soft tumours (P < 0.02). For all histogram parameters, the alpha 90th percentile yielded the highest AUC of 0.88, with an accuracy of 85.10%. The D* 10th percentile had a relatively higher AUC value, followed by the DDC and ADC 10th percentile. The alpha 90th percentile had a significantly greater AUC value than the ADC 10th percentile (P ≤ 0.05). The D* 10th percentile had a significantly greater AUC value than the ADC 10th percentile and DDC 10th percentile (P ≤ 0.03). CONCLUSION: Histogram parameters of Alpha and D* may serve as better imaging biomarkers to aid in predicting the consistency of meningioma.


Subject(s)
Meningeal Neoplasms , Meningioma , Humans , Meningioma/diagnostic imaging , Meningioma/pathology , Diffusion Magnetic Resonance Imaging/methods , ROC Curve , Area Under Curve , Meningeal Neoplasms/diagnostic imaging , Meningeal Neoplasms/pathology , Retrospective Studies
3.
Chem Commun (Camb) ; 59(53): 8205-8221, 2023 Jun 29.
Article in English | MEDLINE | ID: mdl-37293866

ABSTRACT

Hydrogen production through alkaline water electrolysis holds great promise as a scalable solution for renewable energy storage and conversion. The development of non-precious metal-based electrocatalysts with low-overpotential for alkaline water electrolysis is essential to decrease the cost of electrolysis devices. Although the Ni-based and Fe-based electrocatalysts have been commercially employed in the cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER), it is imperative to persistently pursue the advancement of highly efficient electrocatalysts with enhanced current density and fast kinetics. This feature article overviews the progress of NiMo HER cathodes and NiFe OER anodes in the traditional alkaline water electrolysis process for hydrogen production, including the detailed mechanisms, preparation strategies, and structure-function relationship. Moreover, recent advances of Ni-based and Fe-based electrodes in the process of novel alkaline water electrolysis, involving small energetic molecule electro-oxidation and redox mediator decoupled water electrolysis, are also discussed for hydrogen production with low cell voltage. Finally, the perspective of these Ni-based and Fe-based electrodes in the mentioned electrolysis processes is proposed.


Subject(s)
Iron , Nickel , Electrolysis , Hydrogen , Oxygen , Water
4.
Sensors (Basel) ; 23(6)2023 Mar 08.
Article in English | MEDLINE | ID: mdl-36991634

ABSTRACT

Few-shot semantic segmentation has attracted much attention because it requires only a few labeled samples to achieve good segmentation performance. However, existing methods still suffer from insufficient contextual information and unsatisfactory edge segmentation results. To overcome these two issues, this paper proposes a multi-scale context enhancement and edge-assisted network (called MCEENet) for few-shot semantic segmentation. First, rich support and query image features were extracted, respectively, using two weight-shared feature extraction networks, each consisting of a ResNet and a Vision Transformer. Subsequently, a multi-scale context enhancement (MCE) module was proposed to fuse the features of ResNet and Vision Transformer, and further mine the contextual information of the image by using cross-scale feature fusion and multi-scale dilated convolutions. Furthermore, we designed an Edge-Assisted Segmentation (EAS) module, which fuses the shallow ResNet features of the query image and the edge features computed by the Sobel operator to assist in the final segmentation task. We experimented on the PASCAL-5i dataset to demonstrate the effectiveness of MCEENet; the results of the 1-shot setting and 5-shot setting on the PASCAL-5i dataset are 63.5% and 64.7%, which surpasses the state-of-the-art results by 1.4% and 0.6%, respectively.

5.
Article in English | MEDLINE | ID: mdl-36767766

ABSTRACT

Agricultural eco-efficiency is an important indicator used to measure agriculture's high-quality and sustainable development. Therefore, this paper uses the EBM-Super-ML method with strong disposability of undesired output to calculate Chinese agricultural eco-efficiency and uses a geographical detector to measure the driving force of the factor. The research conclusions are mainly reflected in three aspects. Firstly, from the perspective of eco-efficiency changes, the overall mean value of agricultural eco-efficiency increased by 3.5%, and the regional heterogeneity is significant, with the fastest growth in the eastern region. Secondly, the results of driving force analysis show that the main driving factors of agricultural eco-efficiency divergence are capital inputs, total carbon emissions, labor inputs, agricultural film residues, fertilizer use, and pesticide residues, with driving forces of 0.43, 0.37, 0.34, 0.31, 0.28, and 0.20, respectively. Finally, from the perspective of eco-efficiency improvement potential, the mean value of output improvement potential is 5%, and the input factor is 7%. Among the non-desired outputs, the reduction rate of agricultural films can reach 40%. Among the input factors, labor input has the highest potential for intensive use, while agricultural machinery has a negative effect. Therefore, strengthening the development of the agricultural service industry is of great significance to improve the utilization rate of mechanical equipment and reduce the undesired output of agriculture.


Subject(s)
Agriculture , Pesticide Residues , Sustainable Development , Efficiency , Economic Development , China
6.
J Colloid Interface Sci ; 638: 629-639, 2023 May 15.
Article in English | MEDLINE | ID: mdl-36774876

ABSTRACT

The zinc-ion battery (ZIB) has been extensively researched as one of the promising electrochemical power sources. However, the problem of Zn-dendrite formation during repeated plating and stripping process seriously hinders the development of ZIBs. Herein, three-dimensional (3D) honeycomb-like porous carbon (HPC) with co-doping of zinc and nitrogen is prepared through confining growth of nanoscale zeolite imidazole framework-8 (ZIF-8) on the well-designed nano-pools walls of HPC followed by pyrolysis at 600 ℃ to obtain the final product ZnN/HPC-600, which exhibits large surface area and abundant zincophilic interfaces, ensuring homogeneous distribution of electronic field and low polarization during cycling process. Importantly, ZnN/HPC-600 facilitates the uniform distribution and migration of Zn2+ in this nano-pools structure, avoiding the growth of dendritic Zn crystal during charging stage. The symmetric and asymmetric cells with Zn/ZnN/HPC-600 anodes are assembled, demonstrating excellent cycling reversibility, good rate performance and long-term stability. Besides, a Zn||MnO2 full cell with Zn/ZnN/HPC-600 anode also exhibits robust cycling stability, fast reaction kinetics and almost 100 % coulombic efficiency. This work offers a novel and efficient carbonaceous nano-pools strategy to realize dendrite-free zinc anode in ZIBs.

7.
Eur Radiol ; 33(1): 258-269, 2023 Jan.
Article in English | MEDLINE | ID: mdl-35953734

ABSTRACT

OBJECTIVE: To investigate the value of histogram analysis of T1 mapping and diffusion-weighted imaging (DWI) in predicting the grade, subtype, and proliferative activity of meningioma. METHODS: This prospective study comprised 69 meningioma patients who underwent preoperative MRI including T1 mapping and DWI. The histogram metrics, including mean, median, maximum, minimum, 10th percentiles (C10), 90th percentiles (C90), kurtosis, skewness, and variance, of T1 and apparent diffusion coefficient (ADC) values were extracted from the whole tumour and peritumoural oedema using FeAture Explorer. The Mann-Whitney U test was used for comparison between low- and high-grade tumours. Receiver operating characteristic (ROC) curve and logistic regression analyses were performed to identify the differential diagnostic performance. The Kruskal-Wallis test was used to further classify meningioma subtypes. Spearman's rank correlation coefficients were calculated to analyse the correlations between histogram parameters and Ki-67 expression. RESULTS: High-grade meningiomas showed significantly higher mean, maximum, C90, and variance of T1 (p = 0.001-0.009), lower minimum, and C10 of ADC (p = 0.013-0.028), compared to low-grade meningiomas. For all histogram parameters, the highest individual distinctive power was T1 C90 with an AUC of 0.805. The best diagnostic accuracy was obtained by combining the T1 C90 and ADC C10 with an AUC of 0.864. The histogram parameters differentiated 4/6 pairs of subtype pairs. Significant correlations were identified between Ki-67 and histogram parameters of T1 (C90, mean) and ADC (C10, kurtosis, variance). CONCLUSION: T1 and ADC histogram parameters may represent an in vivo biomarker for predicting the grade, subtype, and proliferative activity of meningioma. KEY POINTS: • The histogram parameter based on T1 mapping and DWI is useful to preoperatively evaluate the grade, subtype, and proliferative activity of meningioma. • The combination of T1 C90 and ADC C10 showed the best performance for differentiating low- and high-grade meningiomas.


Subject(s)
Meningeal Neoplasms , Meningioma , Humans , Meningioma/diagnostic imaging , Meningioma/pathology , Prospective Studies , Ki-67 Antigen/metabolism , Diffusion Magnetic Resonance Imaging/methods , ROC Curve , Meningeal Neoplasms/diagnostic imaging , Meningeal Neoplasms/pathology , Retrospective Studies
8.
Front Oncol ; 11: 737520, 2021.
Article in English | MEDLINE | ID: mdl-34737953

ABSTRACT

Pathological grading of meningioma is insufficient to predict recurrence after resection and to guide individualized treatment strategies. One hundred and thirty-three patients with meningiomas who underwent total resection were enrolled in this retrospective study. Univariate analyses were conducted to evaluate the association between factors and recurrence. Least absolute shrinkage and selection operator (Lasso) was used to further select variables to build a logistic model. The predictive efficiency of the model and WHO grade was compared by using receiver operating characteristic curve (ROC), decision curve analysis (DCA), and net reclassification improvement (NRI). Patients were given a new risk layer based on a nomogram. The recurrence of meningioma in different groups was observed through the Kaplan-Meier curve. Univariate analysis demonstrated that 11 risk factors were associated with prognosis (P < 0.05). The result of ROC proved that the quantified risk-scoring system (AUC = 0.853) had a higher benefit than pathological grade (AUC = 0.689, P = 0.011). The incidence of recurrence of the high risk cohort (69%) was significantly higher than that of the low risk cohort (9%) by Kaplan-Meier analysis (P < 0.001). And all patients who did not relapse in the high risk group received adjuvant radiotherapy. The novel risk stratification algorithm has a significant value for the recurrence of meningioma and can help in optimizing the individualized design of clinical therapy.

9.
Sci Rep ; 11(1): 7652, 2021 Apr 07.
Article in English | MEDLINE | ID: mdl-33828123

ABSTRACT

We report the effect of chemical pressure on the ferromagnetic ordering of the recently reported n-type diluted magnetic semiconductor Ba(Zn[Formula: see text]Co[Formula: see text])[Formula: see text]As[Formula: see text] which has a maximum [Formula: see text] [Formula: see text] 45 K. Doping Sb into As-site and Sr into Ba-site induces negative and positive chemical pressure, respectively. While conserving the tetragonal crystal structure and n-type carriers, the unit cell volume shrink by [Formula: see text] 0.3[Formula: see text] with 15[Formula: see text] Sr doping, but drastically increase the ferromagnetic transition temperature by 18[Formula: see text] to 53 K. Our experiment unequivocally demonstrate that the parameters of Zn(Co)As[Formula: see text] tetrahedra play a vital role in the formation of ferromagnetic ordering in the Ba(Zn,Co)[Formula: see text]As[Formula: see text] DMS.

10.
Medicine (Baltimore) ; 98(44): e17561, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31689761

ABSTRACT

BACKGROUND: Persistent and intractable hiccups bring serious inconvenience to patients' work and daily life, and impair their quality of life. Relevant studies showed that acupuncture therapy might be effective in treating persistent and intractable hiccups. However, there is no consistent conclusion so far. The aim of our research is to investigate the safeties and effectiveness of acupuncture in treating patients with persistent and intractable hiccups. METHODS: We will search randomized controlled trials (RCTs) using acupuncture therapy to treat persistent and intractable hiccups in the following 6 English electronic databases and 3 Chinese electronic databases: MEDLINE, EMBASE, the Cochrane Library, Web of Science, PsycINFO, Allied and Alternative Medicine (AMED), Chinese National Knowledge Infrastructure (CNKI), Chinese Scientific Journals Database (VIP) and Wanfang data. The cure rate and the total effective rate will be considered as the primary outcomes. Complete cessation within a given period post-treatment of hiccups, changes in frequency or intensity of hiccups, concomitant symptom score, and adverse events will be considered as secondary outcomes. We will use Endnote software 9.1 for studies selection, Review Manager software 5.3, and STATA 13.0 software for analysis and synthesis. RESULTS: we will synthesize current studies to evaluate the the safeties and effectiveness of acupuncture for persistent and intractable hiccups. CONCLUSION: Our study will provide evidence of acupuncture therapy for persistent and intractable hiccups.


Subject(s)
Acupuncture Therapy/methods , Hiccup/psychology , Hiccup/therapy , Quality of Life , Chronic Disease , Humans , Randomized Controlled Trials as Topic , Research Design , Meta-Analysis as Topic
11.
Sensors (Basel) ; 16(12)2016 Dec 05.
Article in English | MEDLINE | ID: mdl-27929390

ABSTRACT

As the field of high-precision applications based on carriers continues to expand, the development of low-cost, small, modular receivers and their application in diverse scenarios and situations with complex data quality has increased the requirements of carrier-phase data preprocessing. A new geometry-based cycle slip detection and repair method based on Global Position System (GPS) + BeiDou Navigation Satellite System (BDS) is proposed. The method uses a Time-differenced Carrier Phase (TDCP) model, which eliminates the Inner-System Bias (ISB) between GPS and BDS, and it is conducive to the effective combination of GPS and BDS. It avoids the interference of the noise of the pseudo-range with cycle slip detection, while the cycle slips are preserved as integers. This method does not limit the receiver frequency number, and it is applicable to single-frequency data. The process is divided into two steps to detect and repair cycle slip. The first step is cycle slip detection, using the Improved Local Analysis Method (ILAM) to find satellites that have cycle slips; The second step is to repair the cycle slips, including estimating the float solution of changes in ambiguities at the satellites that have cycle slips with the least squares method and the integer solution of the cycle slips by rounding. In the process of rounding, in addition to the success probability, a decimal test is carried out to validate the result. Finally, experiments with filed test data are carried out to prove the effectiveness of this method. The results show that the detectable cycle slips number with GPS + BDS is much greater than that with GPS. The method can also detect the non-integer outliers while fixing the cycle slip. The maximum decimal bias in repair is less than that with GPS. It implies that this method takes full advantages of multi-system.

SELECTION OF CITATIONS
SEARCH DETAIL
...