161 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
Prevention measures of the infection disease in Belgium and its revelation to COVID-19
Abstract: The outbreak of Coronavirus Disease 2019 (COVID-19) has brought great
challenges to China and even the world public health. Belgium has rich experiences in
the prevention and control of infectious diseases. By searching the related literature
and policy documents, this study reviews the emergency management laws and
regulations, organization framework, funding, emergency system in Belgium and
summarizes the successful experience of Belgian policies and measures for the
prevention and control of epidemic Ebola in 2014.On this basis, the paper puts
forward suggestions for COVID-19: To establish permanent infectious disease risk
assessment team, build a cloud platform for prevention and control of infectious
diseases by using big data and conduct practices regularly for the prevention of the
infectious diseases.
Key words: Belgium, prevention and control of infectious diseases, COVID-1
Glucomannan-mediated facile synthesis of gold nanoparticles for catalytic reduction of 4-nitrophenol
Therapeutic potential of mesenchymal stem cell-derived exosomes in skeletal diseases
Skeletal diseases impose a considerable burden on society. The clinical and tissue-engineering therapies applied to alleviate such diseases frequently result in complications and are inadequately effective. Research has shifted from conventional therapies based on mesenchymal stem cells (MSCs) to exosomes derived from MSCs. Exosomes are natural nanocarriers of endogenous DNA, RNA, proteins, and lipids and have a low immune clearance rate and good barrier penetration and allow targeted delivery of therapeutics. MSC-derived exosomes (MSC-exosomes) have the characteristics of both MSCs and exosomes, and so they can have both immunosuppressive and tissue-regenerative effects. Despite advances in our knowledge of MSC-exosomes, their regulatory mechanisms and functionalities are unclear. Here we review the therapeutic potential of MSC-exosomes for skeletal diseases
Effect of Pulsed Electric Field Treatment on N-Hydroxyacetylneuraminic Acid Content and Eating Quality of Pork
This study investigated how to reduce the content of N-hydroxyacetylneuraminic acid (Neu5Gc) in pork. By using Neu5Gc standard solution, porcine submandibular gland mucin (PSM) solution, meat pieces and minced meat as experimental subjects, and high performance liquid chromatography with fluorescence detection (HPLC-FLD) for quantitative analysis, the effect of pulsed electric field (PEF) treatment (with 50 cycles of electric shock at 1–4 kV/cm) on the content of total and free Neu5Gc and eating quality attributes (pH, color difference and texture quality) in pork was explored. The results showed that the content of free Neu5Gc in Neu5Gc standard solution showed a decreasing trend as PEF intensity increased, and significantly decreased at PEF intensity of 3 and 4 kV/cm (P 0.05). Therefore, PEF can effectively reduce the content of Neu5Gc in pork and the chewiness and elasticity of pork pieces, but it also shows an adverse effect on the pH and color of pork
Spatiotemporal DNA methylome dynamics of the developing mouse fetus
Cytosine DNA methylation is essential for mammalian development but understanding of its spatiotemporal distribution in the developing embryo remains limited. Here, as part of the mouse Encyclopedia of DNA Elements (ENCODE) project, we profiled 168 methylomes from 12 mouse tissues or organs at 9 developmental stages from embryogenesis to adulthood. We identified 1,808,810 genomic regions that showed variations in CG methylation by comparing the methylomes of different tissues or organs from different developmental stages. These DNA elements predominantly lose CG methylation during fetal development, whereas the trend is reversed after birth. During late stages of fetal development, non-CG methylation accumulated within the bodies of key developmental transcription factor genes, coinciding with their transcriptional repression. Integration of genome-wide DNA methylation, histone modification and chromatin accessibility data enabled us to predict 461,141 putative developmental tissue-specific enhancers, the human orthologues of which were enriched for disease-associated genetic variants. These spatiotemporal epigenome maps provide a resource for studies of gene regulation during tissue or organ progression, and a starting point for investigating regulatory elements that are involved in human developmental disorders
Spatiotemporal DNA methylome dynamics of the developing mouse fetus
Cytosine DNA methylation is essential for mammalian development but understanding of its spatiotemporal distribution in the developing embryo remains limited. Here, as part of the mouse Encyclopedia of DNA Elements (ENCODE) project, we profiled 168 methylomes from 12 mouse tissues or organs at 9 developmental stages from embryogenesis to adulthood. We identified 1,808,810 genomic regions that showed variations in CG methylation by comparing the methylomes of different tissues or organs from different developmental stages. These DNA elements predominantly lose CG methylation during fetal development, whereas the trend is reversed after birth. During late stages of fetal development, non-CG methylation accumulated within the bodies of key developmental transcription factor genes, coinciding with their transcriptional repression. Integration of genome-wide DNA methylation, histone modification and chromatin accessibility data enabled us to predict 461,141 putative developmental tissue-specific enhancers, the human orthologues of which were enriched for disease-associated genetic variants. These spatiotemporal epigenome maps provide a resource for studies of gene regulation during tissue or organ progression, and a starting point for investigating regulatory elements that are involved in human developmental disorders
Non-contemporaneous bilateral stem fractures occurring after staged bilateral hip revision using extensively porous-coated cylindrical femoral stems: a case report
Abstract Background Distally fixed cylindrical femoral stems extensively coated with porous materials are widely used in revision and total hip arthroplasty surgeries. Stem fracture is an uncommon complication; few case reports have been published. Case presentation We report the case of a 51-year-old male exhibiting extensively porous-coated cylindrical femoral stems fracture after staged bilateral hip revision. His body mass index was 24.22 kg/m2. The major risk factor was poor proximal bony support; and femoral stems with smaller diameter. Conclusions Certain patients are at high risk of non-contemporaneous, bilateral femoral stem fractures. It remains unclear whether fracture of the contralateral femoral stem is an inevitable fatigue fracture or reflects the increased weight imposed on the contralateral hip after the first revision. We recommend that a strut bone graft be placed to support the proximal bone, and that non-modular tapered femoral stems be employed in such patients
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