Rice straw, a common agricultural waste, is used as a potential feedstock for bioethanol production. Currently, bioethanol is made mostly from the microbial fermentation of starch‐containing raw ...materials. Therefore, genetically engineered starch‐excess rice straw through interference of starch degradation as a potential strategy to enhance bioethanol production was evaluated in this study. Arabidopsis Starch Excess 4 (SEX4) encodes a chloroplast‐localized glucan phosphatase and plays a role in transitory starch degradation. Despite the identification of a SEX4 homolog in rice, OsSEX4, its biological function remains uncertain. Ectopic expression of OsSEX4 complementary DNA complemented the leaf starch‐excess phenotype of the Arabidopsis sex4‐4 mutant. OsSEX4‐knockdown transgenic rice plants were generated using the RNA interference approach. Starch accumulation was higher in OsSEX4‐knockdown suspension‐cultured cells, leaves, and rice straw compared with the wild type, suggesting that OsSEX4 plays an important role in degradation of transitory starch. The OsSEX4‐knockdown rice plants showed normal plant growth and no yield penalty. Starch‐excess OsSEX4‐knockdown rice straw used as feedstock for fermentation resulted in improved bioethanol yield, with a 50% increase in ethanol production in a vertical mass‐flow type bioreactor, compared with that of the wild‐type straw.
To use rice straw for bioethanol production efficiently, starch accumulation in leaves was engineered by interference of starch degradation. Rice OsSEX4 plays a role in transitory starch degradation as Arabidopsis SEX4 (Starch Excess 4) does. OsSEX4‐knockdown transgenic rice plants were generated using a RNA interference approach. The OsSEX4‐knockdown rice plants showed normal plant growth and no yield penalty. Starch‐excess OsSEX4‐knockdown rice straw used as feedstock for fermentation resulted in improved bioethanol yield, with a 50% increase in ethanol production.
The dynamic stability is crucial to successful operation and passenger comfort in zero-flux electric-dynamic suspension (EDS) systems. Usually, the stability problem is studied by a dynamic method ...where equations of motion are solved, with the electromagnetic interaction and the motion of the vehicle coupled in different levels. The dynamic studies provide information on operation strategies such as active or passive damping designs. In this work, the stability of the system is studied from another angle, where the vehicle body and bogie are taken as a whole and the stability is evaluated from the "potential energy surface" of the system. Although the system is not conservative, the difference between path integrals of electromagnetic force along different paths is small. For approximation, the stability is evaluated by taking the path integral as potential energy. Instead of dynamic stabilities, the method reveals the quasi-static stabilities. Instead of a damping strategy, the work is focused on the geometrical design parameters. The study is done with different system design parameters, which reveals that the height of the upper ground coil is one of the most important parameters that affect the lateral-roll coupled stability. The design principle is to have maximum mutual inductance between the on-board and upper ground coils, as well as maximum spatial derivative of the mutual inductance.
Gastric neoplasm is a high‐mortality cancer worldwide. Chemoresistance is the obstacle against gastric cancer treatment. Mitochondrial dysfunction has been observed to promote malignant progression. ...However, the underlying mechanism is still unclear. The mitokine growth differentiation factor 15 (GDF15) is a significant biomarker for mitochondrial disorder and is activated by the integrated stress response (ISR) pathway. The serum level of GDF15 was found to be correlated with the poor prognosis of gastric cancer patients. In this study, we found that high GDF15 protein expression might increase disease recurrence in adjuvant chemotherapy‐treated gastric cancer patients. Moreover, treatment with mitochondrial inhibitors, especially oligomycin (a complex V inhibitor) and salubrinal (an ISR activator), respectively, was found to upregulate GDF15 and enhance cisplatin insensitivity of human gastric cancer cells. Mechanistically, it was found that the activating transcription factor 4‐C/EBP homologous protein pathway has a crucial function in the heightened manifestation of GDF15. In addition, reactive oxygen species‐activated general control nonderepressible 2 mediates the oligomycin‐induced ISR, and upregulates GDF15. The GDF15–glial cell‐derived neurotrophic factor family receptor a‐like–ISR–cystine/glutamate transporter‐enhanced glutathione production was found to be involved in cisplatin resistance. These results suggest that mitochondrial dysfunction might enhance cisplatin insensitivity through GDF15 upregulation, and targeting mitokine GDF15–ISR regulation might be a strategy against cisplatin resistance of gastric cancer.
Gastric cancer is one of the most fatal and treatment‐resistant malignancies. The mitokine Growth Differentiation factor 15 (GDF15) is a marker for gastric cancer progression, as elevated GDF15 expression is associated with poor clinical outcomes for patients receiving cisplatin‐based chemotherapy. Treating human gastric cancer cells with the mitochondrial poisons oligomycin (a complex V inhibitor) and salubrinal (an integrated stress response activator) upregulated GDF15 and enhanced cisplatin resistance. These results suggest that mitochondrial dysfunction might enhance cisplatin insensitivity through GDF15 upregulation, and that targeting this mitokine might be a strategy against cisplatin resistance of gastric cancer.
Polyamide thin-film composite reverse osmosis (RO) membranes usually suffer from fouling problem, which greatly limits the wide application of RO technology. In this study, a novel rigid-flexible ...interpenetrating polyamide RO membrane was fabricated via two step modifications to alleviate the membrane fouling during the RO process. The first step modification was carried out by incorporation a new aliphatic diamine of 1,3-diamino-2-propanol (DAPL) into the aromatic m-phenylenediamine (MPD) aqueous solution to react with trimesoyl chloride (TMC) to form a rigid-flexible interpenetration polyamide (PA) separation layer for enhancing its permeability. Then, the second modification was performed by grafting PVA on the top surface of the DAPL-based PA layer to tailor more hydrophilic, smoother and less negatively charged surface and endowed the modified membrane favorable antifouling property. Under the optimized condition, the permeability flux of the modified RO membrane reached 58.6 L/m2h with an about 58.8% increase than the pristine RO membrane (about 36.9 L/m2h), and the salt rejection was also maintained about 99.6% without any loss. At the same time, the modified RO membrane presented a favorable resistance to the dye foulants of methylene blue (MB) and crystal violet (CV) with flux recovery rate of 76.8% and 84.2% respectively. This study provides a facile and effective way to fabricate a novel antifouling reverse osmosis composite membrane with favorable comprehensive separation performance.
A new kind of rigid-flexible interpenetrating polyamide reverse osmosis membrane was fabricated by the synergistic introduction DAPL and PVA via two step modifications, and it exhibited favorable separation performance, reliable antifouling property and robust stability. Display omitted
•DAPL and PVA were combined to synergistically modify the conventional RO membrane.•DAPL was first introduced to form the rigid-flexible interpenetrating polyamide matrix.•The DAPL-based polyamide separation layer exhibited great enhancement of permeability.•PVAs were further grafted to improve the membrane surface's antifouling property.•The modified RO membrane showed both high flux and favorable antifouling performances.
In this study, a dendritic amphiphilic hyperbranched polyester acyl chloride (HPE-COCl) with abundant terminal acyl chloride groups was proposed to incorporate into the polyamide skin layer via ...interfacial polymerization to adjust the structure and the separation performance of the thin film composite (TFC) nanofiltration (NF) membranes. The modified NF membranes based on HPE-COCl exhibit looser, more hydrophilic and negatively charged surface, thereby endowing TFC membranes with relatively higher water permeability and selectivity of monovalent/divalent salts, heavy metals/common monovalent salts, and dyes/common monovalent salts. Especially, the TFC-H2 membrane containing 0.07% w/v HPE-COCl significantly increases the water flux by 145% compared to the pristine membrane. Furthermore, the corresponding selectivity of Fe3+/Na+ increase about 5.09 times. The hypothesis on the basis of experimental results is that the HPE-COCl with alternating hydrophilic and hydrophobic units is prone to form a plurality of hydrophilic channels based on PEG units and hydrophobic microdomains based on benzoate units, which enhances the water permeation through capillary forces. Moreover, the strong negatively charged surface formed by high-density terminal carboxyl groups in HPE-COCl facilitates the passage of monovalent salts and retains the lager-sized heavy metal salts and dyes, thereby improving the selectivity of membranes. Thus, this work provides a new idea and method for the development of high performance nanofiltration membranes.
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•HPE-COCl was introduced to modify the NF membrane via interfacial polymerization.•The NF membrane shows rougher, more hydrophilic and negatively charged surface.•The resultant NF membrane exhibits improved water flux and separation selectivity.•The selectivity of Fe3+/Na+ of TFC-H2 membrane is increased by about 5.09 times.•The improved properties are due to the dendritic alternate amphiphilic structure.
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•A series of Ag3PO4–GO photocatalysts with different GO content were prepared.•Photocatalytic activity of Ag3PO4–GO to 2,4-DCP increased with GO content increasing.•GO played ...significant role in the enhanced photocatalytic activity and stability.•Degradation pathway of 2,4-DCP and photocatalytic mechanism of Ag3PO4–GO were proposed.
A series of visible-light responsive photocatalysts prepared using Ag3PO4 immobilized with graphene oxide (GO) with varying GO content were obtained by an electrostatically driven method, and 2,4-dichlorophenol (2,4-DCP) was used to evaluate the performance of the photocatalysts. The composites exhibited superior photocatalytic activity and stability compared with pure Ag3PO4. When the content of GO was 5%, the degradation efficiency of 2,4-DCP could reach 98.95%, and 55.91% of the total organic (TOC) content was removed within 60min irradiation. Meanwhile, the efficiency of 91.77% was achieved for 2,4-DCP degradation even after four times of recycling in the photocatalysis/Ag3PO4–GO (5%) system. Reactive species of O2−, OH and h+ were considered as the main participants for oxidizing 2,4-DCP, as confirmed by the free radical capture experiments. And some organic intermediates including 4-chlorophenol (4-CP), hydroquinone (HQ), benzoquinone (BZQ), 2-chlorohydroquinone and hydroxyhydroquinone (HHQ) were detected by comparison with the standard retention times from the high performance liquid chromatography (HPLC). In short, the enhanced photocatalytic property of Ag3PO4–GO was closely related to the strong absorption ability of GO relative to 2,4-DCP, the effective separation of photogenerated electron–hole pairs, and the excellent electron capture capability of GO.
As a pandemic, a most-common pattern resembled organizing pneumonia (OP) has been identified by CT findings in novel coronavirus disease (COVID-19). We aimed to delineate the evolution of CT findings ...and outcome in OP of COVID-19.
106 COVID-19 patients with OP based on CT findings were retrospectively included and categorized into non-severe (mild/common) and severe (severe/critical) groups. CT features including lobar distribution, presence of ground glass opacities (GGO), consolidation, linear opacities and total severity CT score were evaluated at three time intervals from symptom-onset to CT scan (day 0-7, day 8-14, day > 14). Discharge or adverse outcome (admission to ICU or death), and pulmonary sequelae (complete absorption or lesion residuals) on CT after discharge were analyzed based on the CT features at different time interval.
79 (74.5%) patients were non-severe and 103 (97.2%) were discharged at median day 25 (range, day 8-50) after symptom-onset. Of 67 patients with revisit CT at 2-4 weeks after discharge, 20 (29.9%) had complete absorption of lesions at median day 38 (range, day 30-53) after symptom-onset. Significant differences between complete absorption and residuals groups were found in percentages of consolidation (1.5% vs. 13.8%, P = 0.010), number of involved lobe > 3 (40.0% vs. 72.5%, P = 0.030), CT score > 4 (20.0% vs. 65.0%, P = 0.010) at day 8-14.
Most OP cases had good prognosis. Approximately one-third of cases had complete absorption of lesions during 1-2 months after symptom-onset while those with increased frequency of consolidation, number of involved lobe > 3, and CT score > 4 at week 2 after symptom-onset may indicate lesion residuals on CT.
Preoperative 5-fluorouracil- (5-FU-) based chemoradiotherapy is a standard treatment for locally advanced colorectal cancer (CRC). However, the effect of 5-FU-based chemoradiotherapy on CRC is ...limited due to the development of chemoradiation resistance (CRR), and the molecular mechanisms underlying this resistance are yet to be investigated. Recently, circular RNAs (circRNAs), which can function as microRNA sponges, were found to be involved in the development of several cancers. In this study, we focused on clarifying the modulation of the expression profiles of circRNAs in CRR. Microarray analysis identified 71 circRNAs differentially expressed in chemoradiation-resistant CRC cells. Among them, 47 were upregulated and 24 were downregulated by more than twofold. Furthermore, expression modulation of five representative circRNAs was validated by quantitative reverse transcription PCR (qRT-PCR). Moreover, these modulated circRNAs were predicted to interact with 355 miRNAs. Furthermore, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the most modulated circRNAs regulate several cancers and cancer-related pathways, and the possible mechanism underlying CRR was discussed. This is the first report revealing the circRNA modulations in 5-FU chemoradiation-resistant CRC cells by microarray. The study provided a useful database for further understanding CRR and presents potential targets to overcome CRR in CRC.
This study aimed to evaluate the protein expression of glutathione peroxidase 4 (GPX4) in resected non-small cell lung cancer (NSCLC). The clinical relevance and prognostic significance of GPX4 ...expression were analyzed. We reviewed patients with resected NSCLCs at Taipei Veterans General Hospital between September 2002 and January 2018. Available paraffin-embedded specimens were retrieved for immunohistochemistry (IHC) staining to detect GPX4 expression. The cutoff value for defining GPX4 positivity was determined according to the percentage of tumor stained in the microscopic field. The correlation between immune expression, clinicopathologic data, overall survival (OS), and disease-free survival (DFS) were analyzed. A total of 265 NSCLC specimens were retrieved for IHC staining. GPX4 expression positive was in 192 (72.5%) according to a cutoff value of 5%. GPX4 was a significant prognostic factor for OS and DFS on multivariate analysis at both 5% and 25% cutoff values. GPX4 expression was associated with poor OS and DFS, especially in lung adenocarcinoma (p = 0.008, and 0.027, respectively). In conclusions, IHC analysis revealed that GPX4 expression was associated with poor survival outcomes in patients with resected lung adenocarcinoma. Further research is needed to understand the role of GPX4 in tumorigenesis and the underlying mechanism responsible for survival outcomes in patients with resected lung adenocarcinoma.
Glucagon-like peptide 1 (GLP-1) analogs protect a variety of cell types against oxidative damage and vascular and neuronal injury via binding to GLP-1 receptors. This study aimed to investigate the ...effects of the GLP-1 analogs exendin-4 and liraglutide on cerebral blood flow, reactive oxygen species production, expression of oxidative stress-related proteins, cognition, and pelvic sympathetic nerve-mediated bladder contraction after middle cerebral artery occlusion (MCAO) injury in the db/db mouse model of diabetes.
Sixty minutes of MCAO increased blood and brain reactive oxygen species counts in male db/db mice, as revealed by dihydroethidium staining. MCAO also increased nuclear factor-κB and intercellular adhesion molecule-1 expression and decreased cerebral microcirculation. These effects were attenuated by treatment with exendin-4 or liraglutide. MCAO did not affect basal levels of phosphorylated Akt (p-Akt) or endothelial nitric oxide synthase (p-eNOS); however, exendin-4 and liraglutide treatments significantly enhanced p-Akt and p-eNOS levels, indicating activation of the p-Akt/p-eNOS signaling pathway. MCAO-induced motor and cognitive deficits and micturition dysfunction, indicated by reduced pelvic nerve-mediated voiding contractions and increased nonvoiding contractions, were also partially attenuated by exendin-4 treatment.
The above data indicate that treatment with GLP-1 agonists exerts protective effects against oxidative, inflammatory, and apoptotic damage in brain areas that control parasympathetic/pelvic nerve-mediated voiding contractions and cognitive and motor behaviors in a diabetic mouse model.