High-concentration sugars production from stover is an important perspective technology for the cellulosic ethanol industrialization. Fed-batch process is an effective way to achieve this goal in the fermentation industry. In this study, based on fed-batch process, high-concentration sugars were produced from pretreated corn stover by enzymatic hydrolysis. After being pretreated by the dilute sulphuric acid, the impacts of the ratio of solid raw material to liquid culture, the content of supplementary materials and the refilling time on the saccharification rate were investigated. Results showed that the initial ratio of solid raw material to liquid culture was 20% (W/V) and the initial concentrations of enzymes for xylanase, cellulose and pectinase were 220 U, 6 FPU, and 50 U per gram of substrates, respectively. After 24 hours and 48 hours, 8% pretreated corn stovers were added respectively together with the additions of xylanase (20 U) and cellulose (2 FPU) per gram of substrates. After 72 hours, the final concentration of reducing sugar was increased to 138.5 g/L from 48.5 g/L of the non fed-batch process. The rate of enzyme hydrolysis of the raw material was 62.5% of the thoretical value in the fed-batch process. This study demonstrated that the fed-batch process could significantly improve the concentration of reducing sugar.
Batch Cell Culture Techniques ; methods ; Carbohydrates ; analysis ; Cellulase ; metabolism ; Cellulose ; metabolism ; Endo-1,4-beta Xylanases ; metabolism ; Ethanol ; metabolism ; Fermentation ; Hydrolysis ; Plant Stems ; chemistry ; metabolism ; Zea mays ; chemistry

Objective To investigate human papillomavirus (HPV) genotypes in adult patients with plantar warts,and to explore their relationship with clinical features of adult plantar warts.Methods PCR,gene sequencing and TA-cloning technique were performed to detect HPV types in 221 patients with plantar warts.Meanwhile,clinical data were recorded,including patients' age,disease duration,symptoms and number of warts.Results Of 221 specimens,HPV DNA was detected in 215,with the HPV-positive rate being 97％.Single HPV infections were detected in 206 specimens (96％,206/215),among which,HPV types included HPV-27 (44.7％,92/206),-2 (12.1％,25/206),-57 (7.3％,15/206),-7 (Alpha genus;0.5％,1/206),-65 (Gamma genus;0.5％,1/206),-1 (33.5％,69/206) and-63 (Mu genus;1.5％,3/206).There were no significant differences in age,disease duration,number of warts,incidence of pain and gender among patients with HPV-27,-2 or-57 infections.Compared with patients with HPV-27 infection,patients with HPV-1 infection were more related to age ≤ 30 years,disease duration ≤ 1 year,number of warts ≤ 2 and high incidence of pain.Conclusion HPV-27,-2,-57 and-1 are the main types in adult patients with plantar warts,and HPV types are correlated with clinical features of adult plantar warts.

Objective:To explore the care experience of the main caregivers of children with juvenile onset recurrent respiratory papillomatosis.Methods:From March to November 2021, the main caregivers of 11 children with juvenile onset recurrent respiratory papillomatosis hospitalized in the Otolaryngology Head and Neck Surgery of Beijing Tongren Hospital, Capital Medical University were selected as the study subjects by objective sampling. Guided by the phenomenology method in qualitative research, in-depth interviews were conducted with the study subjects through the semi-structured interview outline. We used the Colaizzi 7-step analysis method to analyze data and extract themes.Results:A total of 5 themes were proposed, namely, excessive psychological stress, heavy economic burden, heavy care burden, adaptation to challenges and role growth, hope for social supports.Conclusions:The main caregivers of children with juvenile onset recurrent respiratory papillomatosis bear all kinds of stress in the process of caring for children, and they have grown up and hope to get social supports. Medical and nursing staff and society should provide great supports and attention to this group, in order to improve the quality of care for children by caregivers.