47 research outputs found
Cellulase Recycling after High-Solids Simultaneous Saccharification and Fermentation of Combined Pretreated Corncob
Despite the advantageous prospect of second-generation bioethanol, its final commercialization must overcome the primary cost impediment due to enzyme assumption. To solve this problem, this work achieves high-concentration ethanol fermentation and multi-round cellulase recycling through process integration. The optimal time and temperature of the re-adsorption process were determined by monitoring the adsorption kinetics of cellulases. Both glucose and cellobiose inhibited cellulase adsorption. After 96 h of ethanol fermentation, 40% of the initial cellulase remained in the broth, from which 62.5% of the cellulase can be recycled and reused in fresh substrate re-adsorption for 90 min. Under optimum conditions, i.e., pH 5.0, dry matter loading of 15 wt%, cellulase loading of 45 FPU/g glucan, two cycles of fermentation and re-adsorption can yield two-fold increased ethanol outputs and reduce enzyme costs by over 50%. The ethanol concentration in each cycle can be achieved at levels greater than 40 g/L
Capital structure of Public–Private Partnership projects:a sustainability perspective
Capital is key to achieve the standardized operation of public–private partnership (PPP) projects. The capital structure of PPP projects stresses the structure of equity and debt funds, which are important for securing life-cycle ample funds and achieving the expected outcomes of projects. By incorporating sustainability into PPP projects, the capital structure not only secures current needs of funds, it also focuses on life-cycle stable operations and achieves economic, social, and environmental benefits. This study first set the equity–debt ratio and equity investment ratio of the private sector as the dependent variables and built a selection model of the capital structure of PPP projects from a sustainability perspective using the benefit, cost, and project conditions as core factors based on multi-objective programming and a discounted cash-flow model. Then, the qualitative analysis could be achieved according to the analysis of critical factors that had not been calculated. Afterwards, a selection process which combined the multi-objective programming model with qualitative analysis was proposed to achieve a comprehensive selection of the capital structure of PPP projects from the sustainability perspective. Finally, the process was applied to a real project to verify its rationality and usability. This study not only enriches the theoretical research of PPP projects and provides a new idea on which to build the capital structure selection model, it also proposes a selection process that can provide scientific references for the selection and optimization of the capital structure of PPP projects in practice
Neural Speaker Diarization Using Memory-Aware Multi-Speaker Embedding with Sequence-to-Sequence Architecture
We propose a novel neural speaker diarization system using memory-aware
multi-speaker embedding with sequence-to-sequence architecture (NSD-MS2S),
which integrates the strengths of memory-aware multi-speaker embedding (MA-MSE)
and sequence-to-sequence (Seq2Seq) architecture, leading to improvement in both
efficiency and performance. Next, we further decrease the memory occupation of
decoding by incorporating input features fusion and then employ a multi-head
attention mechanism to capture features at different levels. NSD-MS2S achieved
a macro diarization error rate (DER) of 15.9% on the CHiME-7 EVAL set, which
signifies a relative improvement of 49% over the official baseline system, and
is the key technique for us to achieve the best performance for the main track
of CHiME-7 DASR Challenge. Additionally, we introduce a deep interactive module
(DIM) in MA-MSE module to better retrieve a cleaner and more discriminative
multi-speaker embedding, enabling the current model to outperform the system we
used in the CHiME-7 DASR Challenge. Our code will be available at
https://github.com/liyunlongaaa/NSD-MS2S.Comment: Submitted to ICASSP 202
Effect of thyroid hormone replacement treatment on cardiac diastolic function in adult patients with subclinical hypothyroidism: a meta-analysis
BackgroundAlthough subclinical hypothyroidism (SCH) is related to abnormalities in left ventricular diastolic function, the use of levothyroxine as a regular treatment remains debatable. This meta-analysis aimed to determine whether thyroid hormone replacement therapy affects cardiac diastolic function in patients with SCH as measured by echocardiography.MethodsThis meta-analysis included a search of the EMBASE, PubMed, Web of Science, and Cochrane Library databases from their inception to May 18, 2023, for studies analyzing cardiac morphology and functional changes in patients with SCH before and after thyroid hormone replacement. The outcome measures were cardiac morphology and diastolic and overall cardiac function, as assessed using ultrasound parameters (including ventricular wall thickness, chamber size, mitral wave flow, tissue Doppler, and speckle tracking). The quality of the studies was assessed using the Newcastle–Ottawa Scale. The standard mean differences (MDs) and 95% confidence intervals (CI) were calculated using fixed- or random-effects models.ResultsSeventeen studies met the inclusion criteria. A total of 568 patients participated and completed the follow-up. All studies specifically stated that serum thyrotropin levels returned to normal by the end of the study period. Compared with baseline levels, no significant morphological changes were observed in the heart. In terms of diastolic function, we discovered that the ratios of E-velocity to A-velocity (E/A) had greatly improved after thyroid hormone replacement therapy, whereas the ratios of the mitral inflow E wave to the tissue Doppler e’ wave (E/e’) had not. Global longitudinal strain (GLS) increased significantly after treatment with levothyroxine.ConclusionIn adult patients with SCH, thyroid hormone supplementation can partially but not completely improve parameters of diastolic function during the observation period. This meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement, an updated guideline for reporting systematic reviews (11) and was registered with INPLASY (INPLASY202320083).Systematic review registrationhttps://inplasy.com/inplasy-2023-2-0083
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
Preparation and electromagnetic properties characterization of reduced graphene oxide/strontium hexaferrite nanocomposites
With the rapid development of electronics and information technology, electronics and electrical equipment have been widely used in our daily lives. The living environment is full of electromagnetic waves of various frequencies and energy. Electromagnetic wave radiation has evolved into a new type of environmental pollution that has been listed by the WHO (World Health Organization) as the fourth largest source of environmental pollution after water, atmosphere, and noise. Studies have shown that when electromagnetic wave radiation is too much, it can cause neurological disorders. And electromagnetic interference will cause the abnormal operation of medical equipment, precision instruments and other equipment, and therefore cause incalculable consequences. Therefore, electromagnetic protection has become a hot issue of concern to the social and scientific circles
Identity Concealment of Brain Images by Masking
In this paper, a novel method of concealment of facial information was proposed to protect the patient’s privacy. It consists with two steps: the construction of a standard brain template and substitution of the template to a new brain image data. Fifteen medical brain images are used to build the standard brain template. Registration and normalization procedures are applied to construct the standard brain templates by using B-Spline registration. Segmentation is used to substitute the original image for the template image and brain extraction. Canny-edge Level set segmentation algorithm is applied to segment a scalp-skull part from a whole brain volume data. New medical brain images are substituted for the standard template to construct the anonymous face models. In order to verify the validity of the anonymous face model, volumes of extracted brains from an original test brain and its anonymous brain were compared. The result shows that the actual brain part from the anonymous brain is exactly same as one which comes from an original medical brain image