The environmental and socioeconomic considerations of energy production have become crucial because of the increasingly complex relationship between energy and the environment. This study aims to ...develop possible mechanisms for perspectives on energy policy and the environment by exploring the mediating role of renewable energy patents. Non-radial data envelopment analysis and panel data models are applied using the panel data from 2010 to 2017 from 30 Chinese provinces. The results show an overall improvement in the environmental performance index (EPI) of China's provinces, but the average EPI is still relatively weak, with an average value between 0.44 and 0.52, which is far below the optimal value 1.. Furthermore, the econometric model offers evidence that provincial renewable energy and emission reduction policies positively impact the enhancement of EPI. The findings have several implications for energy and environmental policies.
•We assess energy policy paradox on environmental performance.•We analyze renewable and emission reduction polices on different levels.•We investigate renewable energy patents impact on carbon emissions reduction.
Electromagnetically induced transparency (EIT) is a promising approach to implement quantum memory in quantum communication and quantum computing applications. In this paper, following a brief ...overview of the main approaches to quantum memory, we provide details of the physical principle and theory of quantum memory based specifically on EIT. We discuss the key technologies for implementing quantum memory based on EIT and review important milestones, from the first experimental demonstration to current applications in quantum information systems.
A learning management system (LMS) is a web-based application or software platform computed to facilitate the development, tracking, management, reporting, and delivery of education and training ...programs. Many valuable and dominant factors are working behind the Learning Management System (LMS), but no one can find which factor is most important and valuable for LMS during COVID-19 among the following five alternatives, called Improved Accessibility, Blended Learning, Collaboration and Communications, Assessment and Evaluation, and Administrative Efficiency. For this, first, we derive the techniques of bipolar complex hesitant fuzzy (BCHF) sets, and then we evaluate some flexible operational laws, called Algebraic operational laws and Aczel-Alsina operational laws. Secondly, using the above techniques, we elaborate the technique of BCHF Aczel-Alsina power averaging (BCHFAAPA), BCHF Aczel-Alsina power weighted averaging (BCHFAAPWA), BCHF Aczel-Alsina power geometric (BCHFAAPG), and BCHF Aczel-Alsina power weighted geometric (BCHFAAPWG) operators. Some basic properties are also investigated for each proposed operator. Further, to evaluate the problem concerning LMS, we compute the multi-attribute decision-making (MADM) techniques for invented operators. Finally, we select some prevailing operators and try to compare their ranking results with our proposed results to enhance the worth and capability of the invented theory.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Summary The use of stereotactic body radiotherapy for metastatic spinal tumours is increasing. Serious adverse events for this treatment include vertebral compression fracture (VCF) and radiation ...myelopathy. Although VCF is a fairly low-risk adverse event (approximately 5% risk) after conventional radiotherapy, crude risk estimates for VCF after spinal SBRT range from 11% to 39%. In this Review, we summarise the evidence and predictive factors for VCF induced by spinal SBRT, review the pathophysiology of VCF in the metastatic spine, and discuss strategies used to prevent and manage this potentially disabling complication.
The vast majority of reports mainly focus on the steady-state performance of parameter estimation. Few findings are reported for the instantaneous performance of parameter estimation because the ...instantaneous performance is difficult to quantify by using the design algorithm, for example, in the initial stage of parameter estimation, the error of parameter estimation varies in a specific region on the basis of the user's request. With that in mind, we design an identification algorithm to address the transient performance of the parameter estimations. In this study, the parameter estimation of nonlinear sandwich system is studied by using the predefined constraint technology and high-effective filter. To achieve the above purpose, the estimation error information reflecting the transient performance of parameter estimation is procured using the developed some intermediate variables. Then, a predefined constraint function is used to prescribe the error convergence boundary, in which the convergence rate is lifted. An error equivalent conversion technique is then employed to obtain the transformed error data for establishing an parameter adaptive update law, in which the estimation error convergence and the predefined domain can be achieved. In comparison with the available estimation schemes, the good instantaneous performance is obtained on the basis of the numerical example and practical process results.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Dosimetric data are reported for five cases of radiation-induced myelopathy after stereotactic body radiotherapy (SBRT) to spinal tumors. Analysis per the biologically effective dose (BED) model was ...performed.
Five patients with radiation myelopathy were compared to a subset of 19 patients with no radiation myelopathy post-SBRT. In all patients, the thecal sac was contoured to represent the spinal cord, and doses to the maximum point, 0.1-, 1-, 2-, and 5-cc volumes, were analyzed. The mean normalized 2-Gy-equivalent BEDs (nBEDs), calculated using an alpha/beta value of 2 for late toxicity with units Gy 2/2, were compared using the t test and analysis of variance test.
Radiation myelopathy was observed at the maximum point with doses of 25.6 Gy in two fractions, 30.9 Gy in three fractions, and 14.8, 13.1, and 10.6 Gy in one fraction. Overall, there was a significant interaction between patient subsets and volume based on the nBED (p = 0.0003). Given individual volumes, a significant difference was observed for the mean maximum point nBED (p = 0.01).
The maximum point dose should be respected for spine SBRT. For single-fraction SBRT 10 Gy to a maximum point is safe, and up to five fractions an nBED of 30 to 35 Gy 2/2 to the thecal sac also poses a low risk of radiation myelopathy.
To report the characteristics of prostate motion as tracked by the stereoscopic X-ray images of the implanted fiducials during hypofractionated radiotherapy with CyberKnife.
Twenty-one patients with ...prostate cancer who were treated with CyberKnife between January 2005 and September 2007 were selected for this retrospective study. The CyberKnife uses a stereoscopic X-ray system to obtain the position of the prostate target through the monitoring of implanted gold fiducial markers. If there is a significant deviation, the treatment is paused while the patient is repositioned by moving the couch. The deviations calculated from X-ray images acquired within the time interval between two consecutive couch motions constitute a data set.
Included in the analysis were 427 data sets and 4,439 time stamps of X-ray images. The mean duration for each data set was 697 sec. At 30 sec, a motion >2 mm exists in about 5% of data sets. The percentage is increased to 8%, 11%, and 14% at 60 sec, 90 sec, and 120 sec, respectively. A similar trend exists for other values of prostate motion.
With proper monitoring and intervention during treatment, the prostate shifts observed among patients can be kept within the tracking range of the CyberKnife. On average, a sampling rate of approximately 40 sec between consecutive X-rays is acceptable to ensure submillimeter tracking. However, there is significant movement variation among patients, and a higher sampling rate may be necessary in some patients.
Transducing non-classical states of light from one wavelength to another is required for integrating disparate quantum systems that take advantage of telecommunications-band photons for optical-fibre ...transmission of quantum information and near-visible, stationary systems for manipulation and storage. In addition, transducing a single-photon source at 1.3 µm to visible wavelengths would be integral to linear optical quantum computation because of near-infrared detection challenges. Recently, transduction at single-photon power levels has been accomplished through frequency upconversion, but it has yet to be demonstrated for a true single-photon source. Here, we transduce triggered single photons from a semiconductor quantum dot at 1.3 µm to 710 nm with 21% (75%) total detection (internal conversion) efficiency. We demonstrate that the upconverted signal maintains the quantum character of the original light, yielding a second-order intensity correlation, g(2) (τ), that shows that the optical field is composed of single photons with g(2) (0) = 0.165 < 0.5.
Dose-volume histogram (DVH) results for 9 cases of post spine stereotactic body radiation therapy (SBRT) radiation myelopathy (RM) are reported and compared with a cohort of 66 spine SBRT patients ...without RM.
DVH data were centrally analyzed according to the thecal sac point maximum (Pmax) volume, 0.1- to 1-cc volumes in increments of 0.1 cc, and to the 2 cc volume. 2-Gy biologically equivalent doses (nBED) were calculated using an α/β = 2 Gy (units = Gy(2/2)). For the 2 cohorts, the nBED means and distributions were compared using the t test and Mann-Whitney test, respectively. Significance (P<.05) was defined as concordance of both tests at each specified volume. A logistic regression model was developed to estimate the probability of RM using the dose distribution for a given volume.
Significant differences in both the means and distributions at the Pmax and up to the 0.8-cc volume were observed. Concordant significance was greatest for the Pmax volume. At the Pmax volume the fit of the logistic regression model, summarized by the area under the curve, was 0.87. A risk of RM of 5% or less was observed when limiting the thecal sac Pmax volume doses to 12.4 Gy in a single fraction, 17.0 Gy in 2 fractions, 20.3 Gy in 3 fractions, 23.0 Gy in 4 fractions, and 25.3 Gy in 5 fractions.
We report the first logistic regression model yielding estimates for the probability of human RM specific to SBRT.
Endometrial fibrosis is the histologic appearance of intrauterine adhesion (IUA). Emerging evidences demonstrated umbilical cord mesenchymal stem cell-derived exosomes (UCMSC-exo) could alleviate ...endometrial fibrosis. But the specific mechanism is not clear. In this study, we explored the effect of UCMSC-exo on endometrial fibrosis, and investigated the possible role of miR-140-3p/FOXP1/Smad axis in anti-fibrotic properties of UCMSC-exo. UCMSC-exo were isolated and identified. Transforming growth factor-β (TGF-β) was used to induce human endometrial stromal cell (HESC) fibrosis. Dual luciferase assay was performed to verify the relationship between miR-140-3p and FOXP1. The expressions of fibrotic markers, SIP1, and p-Smad2/p-Smad3 in HESCs stimulated with UCMSC-exo were detected by western blot. In addition, the effects of miR-140-3p mimic, miR-140-3p inhibitor and FOXP1 over-expression on endometrial fibrosis were assessed. The isolated UCMSC-exo had a typical cup-shaped morphology and could be internalized into HESCs. The expressions of fibrotic markers were significantly increased by TGF-β, which was reversed by UCMSC-exo. MiR-140-3p in UCMSC-exo ameliorated TGf-β-induced HESCs fibrosis. FOXP1 was identified as the direct target of miR-140-3p, which could inversely regulate miR-140-3p's function on HESCs fibrosis. Furthermore, we demonstrated that miR-140-3p in UCMSC-exo regulated Smad signal pathway to exert the anti-fibrotic effect in HESCs. The anti-fibrotic effect of UCMSC-derived exosomes against HESC fibrosis was at least partially achieved by miR-140-3p/FOXP1/Smad axis.
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