Due to the limited resources and environmental problems associated with fossil fuels, there is a growing interest in utilizing renewable resources for the production of biofuels through microbial ...fermentation. Isobutanol is a promising biofuel that could potentially replace gasoline. However, its production efficiency is currently limited by the use of naturally isolated microorganisms. These naturally isolated microorganisms often encounter problems such as a limited range of substrates, low tolerance to solvents or inhibitors, feedback inhibition, and an imbalanced redox state. This makes it difficult to improve their production efficiency through traditional process optimization methods. Fortunately, recent advancements in genetic engineering technologies have made it possible to enhance microbial hosts for the increased production of isobutanol from renewable resources. This review provides a summary of the strategies and synthetic biology approaches that have been employed in the past few years to improve naturally isolated or non-natural microbial hosts for the enhanced production of isobutanol by utilizing different renewable resources. Furthermore, it also discusses the challenges that are faced by engineered microbial hosts and presents future perspectives to enhancing isobutanol production.
Key points
• Promising potential of isobutanol to replace gasoline
• Engineering of native and non-native microbial host for isobutanol production
• Challenges and opportunities for enhanced isobutanol production
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
With the changing lifestyle and the acceleration of aging in the Chinese population, the incidence and mortality of colorectal cancer (CRC) have risen in the last decades. On the contrary, the ...incidence and mortality of CRC have continued to decline in the USA since the 1980s, which is mainly attributed to early screening and standardized diagnosis and treatment. Rectal cancer accounts for the largest proportion of CRC in China, and its treatment regimens are complex. At present, surgical treatment is still the most important treatment for rectal cancer. Since the first Chinese guideline for diagnosis and treatment of CRC was issued in 2010, the fourth version has been revised in 2020. These guidelines have greatly promoted the standardization and internationalization of CRC diagnosis and treatment in China. And with the development of comprehensive treatment methods such as neoadjuvant chemoradiotherapy, targeted therapy, and immunotherapy, the post-operative quality of life and prognosis of patients with rectal cancer have improved. We believe that the inflection point of the rising incidence and mortality of rectal cancer will appear in the near future in China. This article reviewed the current status and research progress on surgical therapy of rectal cancer in China.
In this paper, a class of nonlinear systems with sensor faults and uncertainty problem are considered. The proposed control scheme is designed based on backstepping procedure. Additionally, three ...classes of filters are introduced, a serious of
K
-filters and an auxiliary filter are used to deal with the unmeasurable system states, and the command filters are adopted to avoid the “differential explosion” problem in backstepping design. Furthermore, the bound estimation method is adopted to estimate the unknown system parameters, partial loss fault of sensor and the upper bound of unknown nonlinear functions. Meanwhile, the proposed scheme reduces the amount of calculations in the controller design and and plays a certain role in saving network resources. Even when the sensor fails, the proposed scheme can ensure that all the signals in the closed-loop system are uniformly and ultimately bounded. Finally, a single-link robot arm example is simulated to show the feasibility of the proposed scheme.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The α7 subtype of the nicotinic acetylcholine receptor (α7 nAChR: coded by Chrna7) is known to regulate the cholinergic ascending anti-inflammatory pathway. We previously reported that Chrna7 ...knock-out (KO) mice show depression-like behaviors through abnormal composition of gut microbiota and systemic inflammation. Given the role of subdiaphragmatic vagus nerve in gut–microbiota–brain axis, we investigated whether subdiaphragmatic vagotomy (SDV) could affect depression-like behaviors, abnormal composition of gut microbiota, and microbes-derived metabolites in Chrna7 KO mice. SDV blocked depression-like behaviors and reduced expression of synaptic proteins in the medial prefrontal cortex (mPFC) of Chrna7 KO mice. LEfSe (linear discriminant analysis effect size) analysis revealed that the species Lactobacillus sp. BL302, the species Lactobacillus hominis, and the species Lactobacillus reuteri, were identified as potential microbial markers in the KO + SDV group. There were several genus and species altered among the three groups wild-type (WT) + sham group, KO + sham group, KO + SDV group. Furthermore, there were several plasma metabolites altered among the three groups. Moreover, there were correlations between relative abundance of several microbiome and behavioral data (or synaptic proteins). Network analysis showed correlations between relative abundance of several microbiome and plasma metabolites (or behavioral data). These data suggest that Chrna7 KO mice produce depression-like behaviors and reduced expression of synaptic proteins in the mPFC through gut–microbiota–brain axis via subdiaphragmatic vagus nerve.
•Chrna7 KO mice show depression-like behaviors.•Subdiaphragmatic vagotomy (SDV) blocked depression-like behaviors in Chrna7 KO mice.•SDV affected abnormal composition of gut microbiota, and microbes-derived metabolites in Chrna7 KO mice.•Gut–microbiota–brain axis via vagus nerve plays a role in depression.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Fungi decompose woody debris, an important carbon pool in forests. Fungal community structure is expected to vary according to the wood species, habitats and extent of abiotic disturbance, which have ...consequences for carbon cycling in tropical forests. Here we examined the effects of fungal diversity and composition on woody debris decomposition rates and sought potential mechanisms to explain an observed lack of difference in decomposition rates across a disturbance gradient in a tropical montane rainforest in Xishuangbanna, SW China. We measured wood specific gravity (WSG) loss from 280 logs of Litsea cubeba and Castanopsis mekongensis over 3 years and monitored fungal communities from 418 samples using next-generation sequencing after 0, 18 and 36 months field exposure. Wood species and termite presence determined changes in fungal diversity through time. Overall there was a peak in fungal diversity at 18 mo, suggesting an initial period of colonization followed by a period of increasingly competitive interactions leading to decreased diversity. Litsea logs, which had relatively low initial WSG and thinner bark, harbored higher fungal diversity. Shared fungal OTUs between wood species peaked at 18 mo (~50%). However, fungal diversity was not a significant predictor of WSG loss. An effect of habitat on fungal community composition suggests that functional replacement explains the similar decay rates across the disturbance gradient. In addition, the proportions of saprotroph and white-rot fungi increased through time regardless of wood species. Termite presence reduced WSG loss, but the effect was mediated via the abundance of soft rot fungi. Our results suggest that changes in functional traits, rather than fungal species diversity, may better explain variation in WSG loss. Future studies should investigate roles of fungal functional traits and rot types, particularly those of Ascomycete fungi, whose roles in wood decay are still poorly characterized.
•We investigated fungal community dynamics in decomposing wood in a tropical ecosystem.•Fungal communities varied with habitat without changing wood decay rates.•Saprotroph abundance increase through time and positively affected wood decay rates.•Termites, woody species and exposure time mediate wood decay via soft-rot abundance.•Major fungal functional trait dynamics will improve biogeochemical model accuracy.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Classification of clinical symptoms and diagnostic microbiology are essential to effectively employ antimicrobial therapy for lower respiratory tract infections (LRTIs) in a timely manner. Empirical ...antibiotic treatment without microbial identification hinders the selective use of narrow-spectrum antibiotics and effective patient treatment. Thus, the development of rapid and accurate diagnostic procedures that can be readily adopted by the clinic is necessary to minimize non-essential or excessive use of antibiotics and accelerate patient recovery from LRTI-induced damage. We developed and validated a multiplex real-time polymerase chain reaction (mRT-PCR) assay with good analytical performance and high specificity to simultaneously detect four bacterial pathogens causing pneumonia: Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Moraxella catarrhalis. The analytical performance of mRT-PCR against target pathogens was evaluated by the limit of detection (LOD), specificity, and repeatability. Two hundred and ten clinical specimens from pneumonia patients were processed using an automatic nucleic acid extraction system for the "respiratory bacteria four" (RB4) mRT-PCR assay, and the results were directly compared to references from bacterial culture and/or Sanger sequencing. The RB4 mRT-PCR assay detected all target pathogens from sputum specimens with a coefficient of variation ranging from 0.29 to 1.71 and conservative LOD of DNA corresponding to 5 x 10.sup.2 copies/reaction. The concordance of the assay with reference-positive specimens was 100%, and additional bacterial infections were detected from reference-negative specimens. Overall, the RB4 mRT-PCR assay showed a more rapid turnaround time and higher performance that those of reference assays. The RB4 mRT-PCR assay is a high-throughput and reliable tool that assists decision-making assessment and outperforms other standard methods. This tool supports patient management by considerably reducing the inappropriate use of antibiotics.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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•Cytocompatible bacterial ATRP (b-ATRP) was developed.•Bacterial nanohybrids with high viability were obtained with b-ATRP.•The surface electric property of bacterial cells was ...well-controlled by b-ATRP.•Cr(VI) removal rate was improved by 3 times with bacterial nanohybrid.
Surface-initiated activator regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP) has great potential to modify living cell surface with controlled architecture and tailored phenotype. However, it is challenging to engineer the bacterial cells with current SI-ARGET ATRP due to low cellular tolerance to the toxic reagents in polymerization. In this study, a cytocompatible bacterial SI-ARGET ATRP (b-ATRP) strategy was developed for individual nanoencapsulation of living bacterial cell. With step by step optimization of reaction conditions, living nanohybrid with high cell viability (>70%) was achieved with b-ATRP. Furthermore, living Shewanella nanohybrids with controllable surface electric property were fabricated with b-ATRP and applied for aqueous Cr(VI) treatment. Impressively, nanoencapsulation of cells with poly(4-vinylpyridine) improved the Cr(VI) removal rate by 3 times. This work provided a new approach to engineer the living bacterial cell surface and expanded the ATRP applications to prokaryotic cell and bioremediation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The development of highly reversible multielectron reaction per redox center in sodium super ionic conductor-structured cathode materials is desired to improve the energy density of sodium-ion ...batteries. Here, we investigated more than one-electron storage of Na in Na3VCr(PO4)3. Combining a series of advanced characterization techniques such as ex situ 51V solid-state nuclear magnetic resonance, X-ray absorption near-edge structure, and in situ X-ray diffraction, we reveal that V3+/V4+ and V4+/V5+ redox couples in the materials can be accessed, leading to a 1.5-electron reaction. It is also found that a light change on the local electronic and structural states or phase change could be observed after the first cycle, resulting in the fast capacity fade at room temperature. We also showed that the irreversibility of the phase changes could be largely suppressed at low temperature, thus leading to a much improved electrochemical performance.
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IJS, KILJ, NUK, PNG, UL, UM
Psychological stress is an emotion experienced when people are under mental pressure or encounter unexpected problems. Extreme or repetitive stress increases the risk of developing human disease, ...including cardiovascular disease (CVD), immune diseases, mental disorders, and cancer. Several studies have shown an association between psychological stress and cancer growth and metastasis in animal models and case studies of cancer patients. Stress induces the secretion of stress-related mediators, such as catecholamine, cortisol, and oxytocin, via the activation of the hypothalamic-pituitary-adrenocortical (HPA) axis or the sympathetic nervous system (SNS). These stress-related hormones and neurotransmitters adversely affect stress-induced tumor progression and cancer therapy. Catecholamine is the primary factor that influences tumor progression. It can regulate diverse cellular signaling pathways through adrenergic receptors (ADRs), which are expressed by several types of cancer cells. Activated ADRs enhance the proliferation and invasion abilities of cancer cells, alter cell activity in the tumor microenvironment, and regulate the interaction between cancer and its microenvironment to promote tumor progression. Additionally, other stress mediators, such as glucocorticoids and oxytocin, and their cognate receptors are involved in stress-induced cancer growth and metastasis. Here, we will review how each receptor-mediated signal cascade contributes to tumor initiation and progression and discuss how we can use these molecular mechanisms for cancer therapy.
As morphology is a crucial factor that influences the microwave properties of materials, FeCo nanoplates of 100
nm in diameter and 24
nm in thickness were prepared by a chemical method and microwave ...absorption properties of the epoxy resin composite containing 30
vol.% FeCo nanoplates were investigated. The composite exhibits excellent microwave absorption properties (RL
<
−20
dB) in the frequency range of 3.7–10.5
GHz with the absorber thickness of 1.5-3.5
mm. An optimal reflection loss value of −43
dB is obtained at 8.1
GHz with an absorber thickness of 1.8
mm. The result indicates that the FeCo nanoplates could serve as an outstanding microwave absorber in gigahertz range.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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