Ethanol production of semi-simultaneous saccharification and fermentation from mixture of cotton gin waste and recycled paper sludge

Ethanol production from the steam-exploded mixture of 75% cotton gin waste and 25% recycled paper sludge in various conditions was investigated by semi-simultaneous saccharification and fermentation (SSSF) consisting of a pre-hydrolysis and a simultaneous saccharification and fermentation (SSF). Four cases were studied: 24-h pre-hydrolysis + 48-h SSF (SSSF 24), 12-h pre-hydrolysis + 60-h SSF (SSSF 12), 72-h SSF, and 48-h hydrolysis + 24-h fermentation (SHF). The ethanol concentration, yield, and productivity of SSSF 24 were higher than those of the other operations. A model of SSF was used to simulate the data for four components in SSF. The analysis of the reaction rates of cellobiose, glucose, cell, and ethanol using the model and the parameters from the experiments showed that there was a transition point of the rate-controlling step at which the cell growth control in the initial 2 h was changed to the cellobiose reaction control in later period during ethanol production of SSF from the mixture.     

岩溶槽谷区植被恢复对土壤团聚体有机碳及碳库管理指数的影响

为揭示岩溶槽谷区植被恢复对土壤结构、土壤有机碳积累和碳库管理水平的影响,该研究选取了弃耕地、林地和草地三种土地利用方式,测定0～20 cm土层土壤团聚体组成、土壤有机碳(SOC)、团聚体有机碳以及土壤易氧化有机碳(EOC)含量。结果表明:(1)与弃耕地相比,林地和草地土壤团聚体平均重量直径(MWD)、几何平均重量直径(MGD)和2～5 mm团聚体含量显著增加,林地和草地土壤团聚体组成以2～5 mm为主,弃耕地以0.5～1 mm和0.25 mm为主,表明退耕还林还草能够促进土壤团聚体形成和稳定。(2)土壤团聚体有机碳含量呈现出林地草地弃耕地,随团聚体粒级增加而增加的趋势;林地和草地以2～5 mm团聚体有机碳贡献率最大,弃耕地则以0.25 mm团聚体贡献为主,表明弃耕地转变为林地和草地后,土壤SOC积累主要归功于2～5 mm有机碳含量的增加,以及团聚体由小粒径向大粒径转变。(3)与弃耕地比较,林地和草地土壤SOC、EOC含量和碳库管理指数(CPMI)均显著提高,其中土壤EOC含量和CPMI变化较为明显;土壤EOC可作为土壤碳库早期变化的有效指标,CPMI能够良好地表征植被恢复对土壤SOC和EOC的影响。     

Epstein-Barr viral BNLF2a protein hijacks the tail-anchored protein insertion machinery to block antigen processing by the transport complex TAP

Virus-infected cells are eliminated by cytotoxic T lymphocytes, which recognize viral epitopes displayed on major histocompatibility complex class I molecules at the cell surface. Herpesviruses have evolved sophisticated strategies to escape this immune surveillance. During the lytic phase of EBV infection, the viral factor BNLF2a interferes with antigen processing by preventing peptide loading of major histocompatibility complex class I molecules. Here we reveal details of the inhibition mechanism of this EBV protein. We demonstrate that BNLF2a acts as a tail-anchored protein, exploiting the mammalian Asna-1/WRB (Get3/Get1) machinery for posttranslational insertion into the endoplasmic reticulum membrane, where it subsequently blocks antigen translocation by the transporter associated with antigen processing (TAP). BNLF2a binds directly to the core TAP complex arresting the ATP-binding cassette transporter in a transport-incompetent conformation. The inhibition mechanism of EBV BNLF2a is distinct and mutually exclusive of other viral TAP inhibitors.     

青稞HvBAS1基因的克隆及表达分析

细胞色素P450单加氧酶(CYP450)是参与植物代谢的最大酶家族,其中CYP734A亚家族成员广泛参与植物激素油菜素类固醇(BRs)的失活。该研究以青稞农家品种‘肚里黄’幼苗为实验材料,通过人工合成激素24 表油菜素内酯(24 eBL)和BRs合成抑制剂油菜素唑(BRZ)处理,分析BRs对青藏高原特色作物青稞(Hordeum vulgare L. var. nudum Hook. f.)的影响;采用RT PCR技术从青稞中克隆HvBAS1基因,并运用实时定量PCR检测其表达特征,为深入分析HvBAS1基因的功能奠定研究基础。结果显示：(1)24 eBL能够显著促进青稞幼苗的生长,而BRZ处理后幼苗长势明显减缓。(2)从青稞中成功克隆到2个与拟南芥BRs失活基因BAS1高度同源的CYP734A亚家族基因,即HvBAS1 1和HvBAS1 2;HvBAS1 1开放阅读框全长1 629 bp,编码542个氨基酸;HvBAS1 2长1 689 bp,编码562个氨基酸,二者氨基酸序列相似性为76.42%;亚细胞定位预测结果显示二者均存在于内质网。(3)实时定量PCR检测发现,青稞HvBAS1 1与HvBAS1 2的表达模式完全不同,其中HvBAS1 1在青稞根中的表达量高于叶中,而HvBAS1 2在叶中的表达量高于根,且随着苗龄的增大,HvBAS1 1在根中的表达呈先升高后降低的趋势,HvBAS1 2在叶片中呈先降低后升高的变化趋势;BRZ处理青稞幼苗后,其HvBAS1 1与HvBAS1 2基因的表达较对照均显著下调,且HvBAS1 2下调更为明显。研究表明,HvBAS1 1和HvBAS1 2很可能都参与了青稞内源BRs的失活,但二者的功能存在差异。     

Neferine suppresses osteoclast differentiation through suppressing NF-κB signal pathway but not MAPKs and promote osteogenesis

Osteoporosis is an ageing disease characterized by elevated osteoclastic bone resorption resulting in bone loss, decrease bone strength, and elevated incidence of fractures. Neferine, a natural compound isolated from the traditional Chinese medicine Nelumbo nucifera (Lotus), has been reported exhibit anti-inflammatory, antioxidant, and anticancer properties. However, its effect on bone remains to be determined. Here we showed that Neferine inhibits RANKL-induced osteoclast formation in a dose- and time-dependent manner. Furthermore, Neferine also demonstrated antiresorptive properties by effectively ameliorating the bone resorptive activity of mature osteoclasts. Mechanistically, Neferine suppressed RANKL-induced activation of NF-κB signaling pathway. This in turn hindered the induction and activation of NFATc1 resulting in downregulation of osteoclast marker genes closely related to differentiation, fusion as well as bone resorption. Interestingly, we found Neferine enhanced the differentiation and bone mineralization activity of MC3T3-E1 preosteoblast cells. Finally, mice treated with Neferine was protected against ovariectomy (OVX)-induced bone loss. The Neferine treatment improved bone volume following ovariectomy and also exhibited less TRAP-positive osteoclasts on bone surface. Collectively our data provide promising evidence that Neferine could be a potential therapeutic application for against osteolytic bone conditions such as osteoporosis.     

BMP7 can promote osteogenic differentiation of human periosteal cells in vitro

To study and evaluate BMP7s functions in osteogenic differentiation of human periosteal cells in vitro. Human periosteal cells from adult tibia were collected and cultured as experimental samples. BMP7 was used to induce periosteal cells in the experiment group with common osteogenic medium. The proliferative activity of periosteal cells was detected by CCK-8. The potentials of osteogenic differentiation were demonstrated as follows: (1) realtime-PCR and ELISA to confirm the expression of the OC, ALP and OPN, (2) Colorimetry, ALP staining and Von Kossa staining were performed to identify ALP activity, ALP expression and calcium nodules, respectively. Based on the significant different expression of OC, ALP and OPN, BMP7 ability of osteogenic differentiation can be identified. ALP activity detection, calcium nodules staining and toluidine staining also provide the power evidence to support BMP7 can promote osteogenic differentiation of human periosteal cells in vitro. To human periosteal cells, BMP7 is a good inducer for osteogenic differentiation. Therefore, it's maybe a potential tool for clinical application.     

Application of a reaction model to improve calculation of the sugar recovery standard for sugar analysis

A kinetic model was applied to improve determination of the sugar recovery standard (SRS) for biomass analysis. Three sets of xylose (0.10-1.00 g/L and 0.999-19.995 g/L) and glucose (0.206-1.602 g/L) concentrations were measured by HPLC following reaction of each for 1 h. Then, parameters in a kinetic model were fit to the resulting sugar concentration data, and the model was applied to predict the initial sugar concentrations and the best SRS value (SRS(p)). The initial sugar concentrations predicted by the model agreed with the actual initial sugar concentrations. Although the SRS(e) calculated directly from experimental data oscillated considerably with sugar concentration, the SRS(p) trend was smooth. Statistical analysis of errors and application of the F-test confirmed that application of the model reduced experimental errors in SRS(e). Reference SRS(e) values are reported for the three series of concentrations.     

Establishment and characterization of an immortalized epicardial cell line

Recently, the increasing significance of the epicardium in cardiac development and regeneration is beginning to be recognized. However, because of the small proportion of primary epicardial cells and the limited cell culture time, further research on the mechanism of epicardial cells is hindered. Here, we transfected simian virus 40 Large T (SV40-LT) into primary epicardial cells to establish an immortalized cell line, named EpiSV40. We further demonstrated that EpiSV40 can be easy to culture and has the proliferation, migration and differentiation capacities comparable to primary epicardial cells. EpiSV40 can serve as an ideal in vitro model for epicardial cell research, which will booster the study of the epicardium in cardiac development and heart regeneration.     

Natriuretic peptide receptor a promotes gastric malignancy through angiogenesis process

Gastric cancer (GC) ranks the third among global cancer-related mortality, especially in East Asia. Angiogenesis plays an important role in promoting tumor progression, and clinical trials have demonstrated that anti-angiogenesis therapy is effective in GC management. Natriuretic peptide receptor A (NPRA) functions significantly in promoting GC development and progression. Whether NPRA can promote angiogenesis of GC remains unclear. Tumor samples collection and immunohistochemical experiment showed that the expression of NPRA was positively correlated with the expression of CD31 and vessel density. In vivo and in vitro analysis showed that NPRA could promote GC-associated angiogenesis and tumor metastasis. Results of Co-IP/MS showed that NPRA could prevent HIF-1α from being degraded by binding to HIF-1α. Protection of HIF-1α improved VEGF levels and thus promoted angiogenesis. In summary, NPRA protected HIF-1α from proteolysis by binding to HIF-1α, increased the expression of HIF-1α, and promoted GC angiogenesis. This study has discovered a new mechanism for NPRA to promote gastric cancer development and a new regulatory mechanism for HIF-1α.Subject terms: Gastric cancer, Gastric cancer