Chitin is the second most abundant renewable polysaccharide on Earth.The degradation of chitin into soluble and bioactive N-acetyl chitooligosaccharides(NCOSs)and N-acetyl-D-glucosamine(GlcNAc)has emerged as a pivotal...Chitin is the second most abundant renewable polysaccharide on Earth.The degradation of chitin into soluble and bioactive N-acetyl chitooligosaccharides(NCOSs)and N-acetyl-D-glucosamine(GlcNAc)has emerged as a pivotal step in the efficient and sustainable utilization of chitin resources.However,because of its dense structure,high crystallinity,and poor solubility,chitin typically needs pretreatment via chemical,physical,and other methods before enzymatic conversion to enhance the accessibility between substrates and enzyme molecules.Consequently,there has been considerable interest in exploring the direct biological degradation of crystalline chitin as a cost-effective and environment-friendly technology.This review endeavors to present several biological methods for the direct degradation of chitin.We primarily focused on the importance of chitinase containing chitin-binding domain(CBD).Additionally,various modification strategies for increasing the degradation efficiency of crystalline chitin were introduced.Subsequently,the review systematically elucidated critical components of multi-enzyme catalytic systems,highlighting their potential for chitin degradation.Furthermore,the application of microorganisms in the degradation of crystalline chitin was also discussed.The insights in this review contribute to the explorations and investigations of enzymatic and microbial approaches for the direct degradation of crystalline chitin,thereby fostering advancements in biomass conversion.展开更多
目的探讨术前红细胞分布宽度(red cell distribution width,RDW)、乳酸脱氢酶(lactate dehydrogenase,LDH)对结直肠癌肝转移(colorectal liver metastases,CLM)术后患者预后的预测价值。方法回顾性分析2016年1月-2017年10月于解放军总...目的探讨术前红细胞分布宽度(red cell distribution width,RDW)、乳酸脱氢酶(lactate dehydrogenase,LDH)对结直肠癌肝转移(colorectal liver metastases,CLM)术后患者预后的预测价值。方法回顾性分析2016年1月-2017年10月于解放军总医院第一医学中心诊断为同时性结直肠癌肝转移并行同期根治性切除术的患者34例,收集术前1周内的RDW、LDH及其他相关临床、病理等资料,并对患者进行为期两年的随访。根据生存结局,将患者分为生存组(n=12)和死亡组(n=22),通过Cox比例风险模型分析结直肠癌肝转移术后患者预后的独立影响因素。根据ROC曲线计算所得的最佳临界值进一步将CLM患者分为低风险组(n=26)及高风险组(n=8),绘制Kaplan-Meier曲线比较两组患者术后两年的总生存期(overall survival,OS)。结果死亡组患者的RDW(16.22±5.10 vs 12.93±1.04,P=0.036)和LDH(194.23±36.90 vs 166.17±30.79,P=0.032)显著高于生存组,两组性别、年龄、体质量指数、术前血红蛋白、术前中性粒细胞计数、术前淋巴细胞计数、术前血清白蛋白、肿瘤直径、癌胚抗原及CA199均无统计学差异(P>0.05)。多因素分析显示LDH(HR=3.064,95%CI:1.179~7.961,P=0.022)、RDW(HR=2.372,95%CI:1.004~5.600,P=0.049)是影响CLM行同期手术患者预后的独立影响因素。ROC曲线分析显示RDW联合LDH预测CLM的曲线下面积为0.814,高于RDW的0.750(截断值13.7%)和LDH的0.742(截断值185 U/L)。以RDW≥13.7%且LDH≥185 U/L为高风险,其余为低风险进行分组,高风险组与低风险组术后两年的中位生存期分别为8个月(95%CI:2.5~13.5)及16个月(95%CI:9.8~22.2),差异有统计学意义(P=0.032)。结论RDW与LDH联合使用对CLM行同期根治性手术患者的预后具有良好的预测价值。展开更多
基金supported by the National Key Research and Development Program of China(No.2023YFD2401504)the National Natural Science Foundation of China(Nos.U21A20271,32225039)+2 种基金the Key R&D Program of Shandong Province(No.2022TZXD001)the Earmarked Fund for CARS(No.CARS-48)the Qingdao Shinan District Science and Technology Plan Project(No.2022-3-010-SW).
文摘Chitin is the second most abundant renewable polysaccharide on Earth.The degradation of chitin into soluble and bioactive N-acetyl chitooligosaccharides(NCOSs)and N-acetyl-D-glucosamine(GlcNAc)has emerged as a pivotal step in the efficient and sustainable utilization of chitin resources.However,because of its dense structure,high crystallinity,and poor solubility,chitin typically needs pretreatment via chemical,physical,and other methods before enzymatic conversion to enhance the accessibility between substrates and enzyme molecules.Consequently,there has been considerable interest in exploring the direct biological degradation of crystalline chitin as a cost-effective and environment-friendly technology.This review endeavors to present several biological methods for the direct degradation of chitin.We primarily focused on the importance of chitinase containing chitin-binding domain(CBD).Additionally,various modification strategies for increasing the degradation efficiency of crystalline chitin were introduced.Subsequently,the review systematically elucidated critical components of multi-enzyme catalytic systems,highlighting their potential for chitin degradation.Furthermore,the application of microorganisms in the degradation of crystalline chitin was also discussed.The insights in this review contribute to the explorations and investigations of enzymatic and microbial approaches for the direct degradation of crystalline chitin,thereby fostering advancements in biomass conversion.
文摘目的探讨术前红细胞分布宽度(red cell distribution width,RDW)、乳酸脱氢酶(lactate dehydrogenase,LDH)对结直肠癌肝转移(colorectal liver metastases,CLM)术后患者预后的预测价值。方法回顾性分析2016年1月-2017年10月于解放军总医院第一医学中心诊断为同时性结直肠癌肝转移并行同期根治性切除术的患者34例,收集术前1周内的RDW、LDH及其他相关临床、病理等资料,并对患者进行为期两年的随访。根据生存结局,将患者分为生存组(n=12)和死亡组(n=22),通过Cox比例风险模型分析结直肠癌肝转移术后患者预后的独立影响因素。根据ROC曲线计算所得的最佳临界值进一步将CLM患者分为低风险组(n=26)及高风险组(n=8),绘制Kaplan-Meier曲线比较两组患者术后两年的总生存期(overall survival,OS)。结果死亡组患者的RDW(16.22±5.10 vs 12.93±1.04,P=0.036)和LDH(194.23±36.90 vs 166.17±30.79,P=0.032)显著高于生存组,两组性别、年龄、体质量指数、术前血红蛋白、术前中性粒细胞计数、术前淋巴细胞计数、术前血清白蛋白、肿瘤直径、癌胚抗原及CA199均无统计学差异(P>0.05)。多因素分析显示LDH(HR=3.064,95%CI:1.179~7.961,P=0.022)、RDW(HR=2.372,95%CI:1.004~5.600,P=0.049)是影响CLM行同期手术患者预后的独立影响因素。ROC曲线分析显示RDW联合LDH预测CLM的曲线下面积为0.814,高于RDW的0.750(截断值13.7%)和LDH的0.742(截断值185 U/L)。以RDW≥13.7%且LDH≥185 U/L为高风险,其余为低风险进行分组,高风险组与低风险组术后两年的中位生存期分别为8个月(95%CI:2.5~13.5)及16个月(95%CI:9.8~22.2),差异有统计学意义(P=0.032)。结论RDW与LDH联合使用对CLM行同期根治性手术患者的预后具有良好的预测价值。
