•Synthetic strategies for developing functional CO2-polycarbonates are reviewed.•Strategies to improve the thermal properties of polycarbonates are presented.•Recent applications of CO2-derived ...polycarbonates are highlighted.
Proof of principles studies by Inoue and coworkers in the late 1960s clearly illustrated the poorly controlled coupling of CO2 and epoxides to provide polycarbonates. These early studies utilizing inadequately defined zinc catalysts derived from diethyl zinc and water have led to the development of a variety of catalysts for these processes over the last two decades. Numerous catalyst systems have been shown to be very effective and selective at affording perfectly alternating copolymers, including those with high levels of regio- and stereo-selectivity. The vast majority of the current literature reports upon the synthesis of hydrophobic polycarbonates which lack functionalities. In this review we will summarize the reports which utilize these well-developed metal-catalyzed CO2/epoxides copolymerization processes to prepare high value-added functionalized polymeric materials for a variety of applications.
Ideally, optimal emergency resource allocation would have been vital for effective relief work during the COVID-19 outbreak. However, the suddenness of the epidemic and uncertainty of its spread ...added some difficulties to distributing emergency resources. First, this study introduces triangular fuzzy numbers to describe the uncertainty of supply and demand of emergency resources, and interval numbers to describe the time required for resource transportation under disaster conditions. To minimize the total delivery time and difference in the total satisfaction rate, this study constructs an optimal model for emergency resource distribution under uncertain conditions that considers both efficiency and equity. Subsequently, an improved genetic algorithm (IMGA) is proposed to obtain the optimal decision scheme. Finally, a case study on emergency resource distribution during the COVID-19 pandemic is conducted for model verification. The results demonstrate that the proposed model can improve the efficiency and effect of emergency resource distribution. The model allocates some emergency resources to each demand site during each emergency period, which can help avoid large losses caused by extreme shortages of resources at a certain demand point. The emergency resource allocation scheme considers the transportation time and degree of impact, which is beneficial for enhancing the flexibility of decision-making and practical applicability of distribution operations. A comparative analysis of the algorithms shows that the proposed IMGA is an effective method for managing emergency resource distribution optimization problems because it has higher solving efficiency, better convergence, and stronger stability. These findings can provide decision support for the optimal distribution of large-scale, multiperiod emergency resources during the COVID-19 pandemic.
Zinc‐ion batteries (ZIBs) feature high safety, low cost, environmental‐friendliness, and promising electrochemical performance, and are therefore regarded as a potential technology to be applied in ...large‐scale energy storage devices. However, ZIBs still face some critical challenges and bottlenecks. The electrolyte is an essential component of batteries and its properties affect the mass transport, energy storage mechanisms, reaction kinetics, and side reactions of ZIBs. The adjustment of electrolyte formulas usually has direct and obvious impacts on the overall output and performance. In this review, advanced electrolyte strategies are overviewed for optimizing the compatibility between cathode materials and electrolytes, inhibiting anode corrosion and dendrite growth, extending electrochemical stability windows, enabling wearable applications, and enhancing temperature tolerance. The underlying scientific mechanisms, electrolyte design principles, and recent progress are presented to provide a better understanding and inspiration to readers. In addition, a comprehensive perspective about electrolyte design and engineering for ZIBs is included.
In this review, the basic scientific issues of Zinc‐ion batteries are carefully analyzed and the recent development in extending lifespan, suppressing dendrite formation, inhibiting side reactions, widening electrochemical stability window, and extending useable temperature range via electrolyte design and engineering are discussed. The comparation among different strategies and effect evaluation is provided, as well as the perspectives of future trends.
Rechargeable aqueous Zn‐ion batteries promise high capacity, low cost, high safety, and sustainability for large‐scale energy storage. The Zn metal anode, however, suffers from the dendrite growth ...and side reactions that are mainly due to the absence of an appropriate solid electrolyte interphase (SEI) layer. Herein, the in situ formation of a dense, stable, and highly Zn2+‐conductive SEI layer (hopeite) in aqueous Zn chemistry is demonstrated, by introducing Zn(H2PO4)2 salt into the electrolyte. The hopeite SEI (≈140 nm thickness) enables uniform and rapid Zn‐ion transport kinetics for dendrite‐free Zn deposition, and restrains the side reactions via isolating active Zn from the bulk electrolyte. Under practical testing conditions with an ultrathin Zn anode (10 µm), a low negative/positive capacity ratio (≈2.3), and a lean electrolyte (9 µL mAh−1), the Zn/V2O5 full cell retains 94.4% of its original capacity after 500 cycles. This work provides a simple yet practical solution to high‐performance aqueous battery technology via building in situ SEI layers.
A unique electrolyte design strategy for in situ solid electrolyte interphase (SEI) construction is proposed in aqueous Zn chemistry to stabilize the Zn–electrolyte interface. Apart from the realization of high Zn reversibility and utilization, the exploitation of the robust in situ SEI enables significantly enhanced cyclability of Zn/V2O5 full cells under practical conditions.
Polyethylene terephthalate (PET) is one of the most widely used plastics in the world. Accumulation of the discarded PET in the environment is creating a global environmental problem. Recently, a ...bacterial enzyme named PETase was found to have the novel ability to degrade the highly crystallized PET. However, the enzymatic activity of native PETase is still low limiting its possible use in recycling of PET. In this study, we developed a whole-cell biocatalyst by displaying PETase on the surface of yeast (Pichia pastoris) cell to improve its degradation efficiency. Our data shows that PETase could be functionally displayed on the yeast cell with enhanced pH and thermal stability. The turnover rate of the PETase-displaying yeast whole-cell biocatalyst towards highly crystallized PET dramatically increased about 36-fold compared with that of purified PETase. Furthermore, the whole-cell biocatalyst showed stable turnover rate after seven repeated use and under some chemical/solvent conditions, and its ability to degrade different commercial highly crystallized PET bottles. Our results reveal that PETase-displaying whole-cell biocatalyst affords a promising route for efficient biological recycling of PET.
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•Yeast cell surface display bacterial PETase can degrade different commercial highly crystallized PET.•The turnover rate of the PETase-displaying yeast whole-cell biocatalyst increased about 36-fold.•The whole-cell biocatalyst system is reusable and robust.
Relevant studies focusing on epidemiological of profiles hypertensive disorders of pregnancy from global data that report the cause-specific prevalence and trends of hypertensive disorders of ...pregnancy at global, regional and national levels from 1990 to 2019 by age and sociodemographic index are still limited.
For hypertensive disorders of pregnancy, point prevalence, annual incidence, and years lived with disability numbers and age standardized rates per 100,000 population were compared at regional and national levels by age and sociodemographic index using data from the global Burden of Disease 2019 Study, covering populations from 204 countries and territories. Estimates are reported with uncertainty intervals to exhibit the changing trends during a specific period.
The incidence of hypertensive disorders of pregnancy increased from 16.30 million to 18.08 million globally, with a total increase of 10.92 % from 1990 to 2019. The age-standardized incidence rate decreased, with an estimated annual percent change of -0.68 (95 % confidence interval CI -0.49 to -0.86). The number of deaths due to hypertensive disorders of pregnancy was approximately 27.83 thousand in 2019, representing a 30.05 % decrease from 1990. Based on the incidence and prevalence, the number of deaths and years lived with disability were highest in the group aged 25-29 years, followed by the groups aged 30-34 and 20-24 years, while the lowest estimated incidence rate was observed in the group aged 25-29 years and higher incidence rates were observed in the youngest and oldest groups. Positive associations between incidence rates and the sociodemographic index and human development index were found for all countries and regions in 2019. Age-standardized incidence rates were higher in countries/regions with lower sociodemographic indices and human development indices.
Our study provides a comprehensive overview of the global burden of hypertensive disorders of pregnancy. The death and incidence rates are decreasing in most countries and all regions except for those with low sociodemographic and human development indexes. This difference is mainly due to the increasing attention to prenatal examinations and health education. Further investigations should focus on forecasting the global disease burden of specific hypertensive disorders of pregnancy and modifiable risk factors.
Congenital laryngeal web is a rare disease that can cause stridor, dyspnea, hoarseness, and other symptoms. Children with this disease generally have stridor, weak crying, and hoarseness at birth, ...but these symptoms can also occur during the days, weeks, months, and even years after birth. Respiratory tract infection will obviously aggravate these manifestations, and recovery is slow after symptomatic treatment. Neck CT and laryngoscopy can detect and diagnose this disease. It is important that the disease can be considered and examined in infants with recurrent stridor and persistent hoarseness after birth.
We report a 23-month-old boy who was admitted to hospital due to stridor and hoarseness after birth. Combined with the results of laryngoscopy, he was diagnosed with congenital laryngeal web, and was treated with carbon dioxide (CO
) laser and cryotherapy by bronchoscope. The prognosis was good.
Congenital laryngeal web is a rare but challenging laryngeal lesion. It is very important that the disease can be considered and examined for infants with recurrent stridor and persistent hoarseness after birth. The treatment strategy after diagnosis should be determined according to the classification of laryngeal web and the severity of children's symptoms.
Highlights
History and benefits of zinc ion hybrid capacitors are introduced.
Carbon materials with different dimensions are developed for the cathodes.
Relationship between carbon structures and ...capacitive performances are discussed.
Current collectors and separators are firstly showcased and summarized.
Zinc ion hybrid capacitors (ZIHCs), which integrate the features of the high power of supercapacitors and the high energy of zinc ion batteries, are promising competitors in future electrochemical energy storage applications. Carbon-based materials are deemed the competitive candidates for cathodes of ZIHC due to their cost-effectiveness, high electronic conductivity, chemical inertness, controllable surface states, and tunable pore architectures. In recent years, great research efforts have been devoted to further improving the energy density and cycling stability of ZIHCs. Reasonable modification and optimization of carbon-based materials offer a remedy for these challenges. In this review, the structural design, and electrochemical properties of carbon-based cathode materials with different dimensions, as well as the selection of compatible, robust current collectors and separators for ZIHCs are discussed. The challenges and prospects of ZIHCs are showcased to guide the innovative development of carbon-based cathode materials and the development of novel ZIHCs.
This study examines the association between chief financial officer (CFO) equity incentives and earnings management. Chief executive officer (CEO) equity incentives have been shown to be associated ...with accruals management and the likelihood of beating analyst forecasts (
Bergstresser and Philippon, 2006;
Cheng and Warfield, 2005). Because CFOs’ primary responsibility is financial reporting, CFO equity incentives should play a stronger role than those of the CEO in earnings management. We find that the magnitude of accruals and the likelihood of beating analyst forecasts are more sensitive to CFO equity incentives than to those of the CEO. Our evidence supports the Securities and Exchange Commission's (SEC) new disclosure requirement on CFO compensation.
The global pandemic caused by severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2), named coronavirus disease 2019, has infected more than 8.9 million people worldwide. This calls for urgent ...effective therapeutic measures. RNA‐dependent RNA polymerase (RdRp) activity in viral transcription and replication has been recognized as an attractive target to design novel antiviral strategies. Although SARS‐CoV‐2 shares less genetic similarity with SARS‐CoV (~79%) and Middle East respiratory syndrome coronavirus (~50%), the respective RdRps of the three coronaviruses are highly conserved, suggesting that RdRp is a good broad‐spectrum antiviral target for coronaviruses. In this review, we discuss the antiviral potential of RdRp inhibitors (mainly nucleoside analogs) with an aim to provide a comprehensive account of drug discovery on SARS‐CoV‐2.
Highlights
RNA‐dependent RNA polymerase plays the vital role in SARS‐CoV‐2 viral replication.
The relationship between structure and funcational of RNA polymerase.
Evaluation and development of potential SARS‐CoV‐2 RdRp inhibitors.
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