No abstract

Carbon-based transition-metal oxides are considered as an appropriate anode material candidate for lithium-ion batteries. Herein, a simple and scalable dry production process is developed to produce carbon-encapsulated 3D net-like FeO /C materials. The process is simply associated with the pyrolysis of a solid carbon source, such as filter paper, adsorbed with ferrite nitrate. The carbon derived from filter paper induces a carbothermal reduction to form metallic Fe, the addition of carbon and iron increase the conductivity of this material. As expected, this 3D net-like FeO /C composite delivers an excellent charge capacity of 851.3 mAh g after 50 cycles at 0.2 A g as well as high stability and rate performance of 714.7 mAh g after 300 cycles at 1 A g . Superior performance, harmlessness, low costs, and high yield may greatly stimulate the practical application of the products as anode materials in lithium-ion batteries.

Self-subunit swapping is one of the post-translational maturation of the cobalt-containing nitrile hydratase (Co-NHase) family of enzymes. All of these NHases possess a gene organization of <β-subunit> <α-subunit> , which allows the activator protein to easily form a mediatory complex with the α-subunit of the NHase after translation. Here, we discovered that the incorporation of cobalt into another type of Co-NHase, with a gene organization of <α-subunit> <β-subunit> , was also dependent on self-subunit swapping. We successfully isolated a recombinant NHase activator protein (P14K) of Pseudomonas putida NRRL-18668 by adding a Strep-tag N-terminal to the P14K gene. P14K was found to form a complex [α(StrepP14K)2] with the α-subunit of the NHase. The incorporation of cobalt into the NHase of P. putida was confirmed to be dependent on the α-subunit substitution between the cobalt-containing α(StrepP14K)2 and the cobalt-free NHase. Cobalt was inserted into cobalt-free α(StrepP14K)2 but not into cobalt-free NHase, suggesting that P14K functions not only as a self-subunit swapping chaperone but also as a metallochaperone. In addition, NHase from P. putida was also expressed by a mutant gene that was designed with a <β-subunit> <α-subunit> order. Our findings expand the general features of self-subunit swapping maturation.

Nitrile hydratase (NHase, EC 4.2.1.84) is one type of metalloenzyme participating in the biotransformation of nitriles into amides. Given its catalytic specificity in amide production and eco-friendliness, NHase has overwhelmed its chemical counterpart during the past few decades. However, unclear catalytic mechanism, low thermostablity, and narrow substrate specificity limit the further application of NHase. During the past few years, numerous studies on the theoretical and industrial aspects of NHase have advanced the development of this green catalyst. This review critically focuses on NHase research from recent years, including the natural distribution, gene types, posttranslational modifications, expression, proposed catalytic mechanism, biochemical properties, and potential applications of NHase. The developments of NHase described here are not only useful for further application of NHase, but also beneficial for the development of the fields of biocatalysis and biotransformation.

We report a cooperative catalytic system comprising a Pd complex, XPhos, and the potassium salt of 5-norbornene-2-carboxylic acid that enables the use of epoxides as alkylating reagents in the Catellani reaction, thereby expanding the existing paradigm of this powerful transformation. The potassium salt of inexpensive 5-norbornene-2-carboxylic acid acts as both mediator and base in the process. This mild, chemoselective, scalable, and atom-economical protocol is compatible with a wide variety of readily available functionalized aryl iodides and epoxides, as well as terminating olefins. The resulting products undergo facile oxa-Michael addition to furnish ubiquitous isochroman scaffolds.

No abstract

ObjectivesThe most serious adverse reaction of cisplatin is acute kidney injury (AKI). Cisplatin-induced acute kidney injury (CIA) has no specific preventive measures. This study aims to explore the characteristics and risk factors for CIA in the elderly and to identify potential methods to reduce CIA.Materials and methodsPatients ≥18 years old, with primary tumors, who received initial cisplatin chemotherapy and whose serum creatinine (SCr) values were measured within 2 weeks pre- and postcisplatin treatment and who had complete medical records, were selected from a single center from January 1, 2013 to December 31, 2015. The exclusion criteria included radiotherapy or surgery, recurrent tumors, previous cisplatin treatment, lack of any SCr values before or after cisplatin therapy, and incomplete medical records.ResultsOut of a total of 527 patients, 349 were elderly. Angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEI/ARB) use (9.2%) was more prevalent in the elderly than in younger patients (2.8%, p = 0.007). The dosage of cisplatin treatment was lower in the elderly, but the incidence of CIA (9.46%) was higher in the elderly than in younger patients (3.37%). There were significant differences in the SCr levels, estimated glomerular filtration rate, ACEI/ARB use, and whether a single application of cisplatin was administered, between the elderly AKI group and the non-AKI group. Multivariable analysis showed that administration of a single application of cisplatin (OR 2.853, 95% CI: 1.229, 6.621, p = 0.015) and ACEI/ARB use (OR 3.398, 95% CI: 1.352, 8.545, p = 0.009) were predictive factors for developing CIA in the elderly.ConclusionThe incidence of CIA in the elderly was higher than in younger patients. ACEI/ ARB usage and administration of a single application of cisplatin were independent risk factors for CIA in the elderly.

BackgroundActivators of Nitrile hydratase (NHase) are essential for functional NHase biosynthesis. However, the activator P14K in P. putida is difficult to heterogeneously express, which retards the clarification of the mechanism of P14K involved in the maturation of NHase. Although a strep tag containing P14K (strep-P14K) was over-expressed, its low expression level and low stability affect the further analysis.ResultsWe successfully expressed P14K through genetic modifications according to N-end rule and analyzed the mechanism for its difficult expression. We found that mutation of the second N-terminal amino-acid of the protein from lysine to alanine or truncating the N-terminal 16 amino-acid sequence resulted in successful expression of P14K. Moreover, fusion of a pelB leader and strep tag together (pelB-strep-P14K) at the N-terminus increased P14K expression. In addition, the pelB-strep-P14K was more stable than the strep-P14K.ConclusionsOur results are not only useful for clarification of the role of P14K involved in the NHase maturation, but also helpful for heterologous expression of other difficult expression proteins.