- Processing of covalent organic frameworks: an ingredient for a material to succeed. [Journal Article]
- CSChem Soc Rev 2019 Jul 16
- Covalent organic frameworks (COFs) are an emerging class of new organic polymers showing tuneable permanent porosity and crystallinity. They are formed, using modular chemistry concepts, by condensat…
Covalent organic frameworks (COFs) are an emerging class of new organic polymers showing tuneable permanent porosity and crystallinity. They are formed, using modular chemistry concepts, by condensation reactions between their molecular precursors based on the formation of dynamic bonds. Despite much effort having been devoted towards the design of the physical and/or chemical properties of these materials by selecting their initial building blocks, the importance of processability for their applications has only recently emerged. This tutorial review article rationalizes the strategies used so far on COF processability leading to the formation of thin-films, membranes, or individual particles with controlled shape and size as well as composite fabrication. We aim to provide a rational perspective of the importance of COF processability towards potential applications of COFs in many different fields which are at the forefront of research in materials science.
- Time Temperature Superposition Evaluation and Modeling for Container Closure System's Seal Performance at Low Temperatures. [Journal Article]
- PJPDA J Pharm Sci Technol 2019 Jul 15
- Container closure integrity (CCI) is essential for parenteral packaging. CCI performance must be maintained throughout the entire time temperature transition cycle of a sealed drug's product lifespan…
Container closure integrity (CCI) is essential for parenteral packaging. CCI performance must be maintained throughout the entire time temperature transition cycle of a sealed drug's product lifespan. Prior publications have lacked systematic considerations for the impact of dynamic temperature transition coupled with time dependent transition on sealing performance associated with the viscoelastic characteristics of rubber stoppers used in container closure system (CCS). This paper demonstrates that sealing performance changes inherently and is fundamentally both time- and temperature- dependent. Our research results display this critical time temperature transition impact on CCS sealing performance by applying compression stress relaxation (CSR) on a rubber stopper for experimental data collection and modeling evaluation. The experimental results agree with modeling evaluation following Maxwell-Wiechert theory and the time temperature superposition based on the Arrhenius and Williams-Landel-Ferry methods. Both testing and modeling data show good consistency, demonstrating that the sealing force inevitably changes over time together with temperature transition because of the viscoelastic nature of the rubber stoppers. Our results show that compression seal force decreases quickly as temperature decreases. The significant loss of rubber stopper sealing force at lower temperature transitions could contribute significant risk to CCI at low storage and transport temperatures. By employing both experimental testing and modeling evaluation, an in-depth understanding of the time- and temperature- dependent nature of rubber stopper sealing force was developed. The nonlinearity of CSR is quantitatively predictable, deriving from the viscoelastic characteristics of the rubber stopper material coupled with the time temperature superposition. Modeling evaluation, with a powerful capability to handle actual testing data, can be employed as a predictive tool to evaluate the time- and temperature- dependent sealing force throughout the entire sealed drug product lifespan. The present study is only applicable before reaching the rubber glass transition temperature Tg - a critical transition phase that can't be skipped/separated from real time temperature transition, and it will further determine the CCS sealing performance while approaching cryogenic temperature. There has been a growing interest in recent years in the assessment of container closure systems for cold storage and shipment. The present work provides a new, integrated methodology framework and some fresh insights to the parenteral packaging industry for practically and proactively considering, designing, setting up, controlling, and managing stopper sealing performance throughout the entire sealed drug product lifespan. Particularly, CCS seal performance at lower temperature needs to be properly addressed, evaluated, calculated, simulated, predicted, tested, and assessed through an integrated system approach for critical data-driven risk management.
- Characterization of thermally sensitive miRNAs reveals a central role of the FoxO signaling pathway in regulating the cellular stress response of an extreme stenotherm, Trematomus bernacchii. [Journal Article]
- MGMar Genomics 2019 Jul 12; :100698
- Despite the lack of an inducible heat shock response (HSR), the Antarctic notothenioid fish, Trematomus bernacchii, has retained a level of physiological plasticity that can at least partially compen…
Despite the lack of an inducible heat shock response (HSR), the Antarctic notothenioid fish, Trematomus bernacchii, has retained a level of physiological plasticity that can at least partially compensate for the effects of acute heat stress. Over the last decade, both physiological and transcriptomic studies have signaled these fish can mitigate the effects of acute heat stress by employing other aspects of the cellular stress response (CSR) that help confer thermotolerance as well as drive homeostatic mechanisms during long-term thermal acclimations. However, the regulatory mechanisms that determine temperature-induced changes in gene expression remain largely unexplored in this species. Therefore, this study utilized next generation sequencing coupled with an in silico approach to explore the regulatory role of microRNAs in governing the transcriptomic level response observed in this Antarctic notothenioid with respect to the CSR. Using RNAseq, we characterized the expression of 125 distinct miRNA orthologues in T. bernacchii gill tissue. Additionally, we identified 12 miRNAs that appear to be thermally responsive based on differential expression (DE) analyses performed between fish acclimated to control (-1.5 °C) and an acute heat stress (+4 °C). We further characterized the functional role of these DE miRNAs using bioinformatics pipelines to identify putative gene targets of the DE miRNAs and subsequent gene set enrichment analyses, which together suggest these miRNAs are involved in regulating diverse aspects of the CSR in T. bernacchii.
- Factors influencing long-term survival rates of implants placed simultaneously with lateral maxillary sinus floor augmentation: A 6- to 20-year retrospective study. [Journal Article]
- COClin Oral Implants Res 2019 Jul 15
- CONCLUSIONS: The survival of implants placed in <3 mm of RBH, even though it showed a lower CSR, could be considered acceptable. Neither sinus membrane perforation nor the presence of voids appeared to affect implant survival as long as supportive maintenance therapy with proper oral hygiene was provided. This article is protected by copyright. All rights reserved.
- Correction: The role of polysulfide dianions and radical anions in the chemical, physical and biological sciences, including sulfur-based batteries. [Published Erratum]
- CSChem Soc Rev 2019 Jul 15
- Correction for 'The role of polysulfide dianions and radical anions in the chemical, physical and biological sciences, including sulfur-based batteries' by Ralf Steudel et al., Chem. Soc. Rev., 2019,…
Correction for 'The role of polysulfide dianions and radical anions in the chemical, physical and biological sciences, including sulfur-based batteries' by Ralf Steudel et al., Chem. Soc. Rev., 2019, 48, 3279-3319.
- 'Pro-tobacco propaganda': a case study of tobacco industry-sponsored elementary schools in China. [Journal Article]
- TCTob Control 2019 Jul 13
- CONCLUSIONS: National tobacco control legislation banning all forms of indirect marketing including CSR is needed in order to protect the health of future generations.
- The association of serotonin reuptake inhibitors and benzodiazepines with ictal central apnea. [Journal Article]
- EBEpilepsy Behav 2019 Jul 10; 98(Pt A):73-79
- CONCLUSIONS: Seizures in patients taking SRIs have lower occurrence of ICA, and patients on chronic treatment with BZDs have shorter ICA and PGES durations. Preventing or shortening ICA duration by using SRIs and/or BZD in patients with epilepsy may play a possible role in SUDEP risk reduction.
- Rapid improvement of muscle weakness post-thymectomy indicates good long-term neurological outcome in patients with ocular myasthenia gravis. [Journal Article]
- EJEur J Neurol 2019 Jul 12
- CONCLUSIONS: Postoperative rapid remission of MG status predicts a higher likelihood of complete remission in patients with oMG. This article is protected by copyright. All rights reserved.
- Catalytic cascade reactions by radical relay. [Journal Article]
- CSChem Soc Rev 2019 Jul 12
- Radical cascade reactions are an attractive tool for the rapid construction of complex molecular architectures. Although a large number of powerful radical cascades have been developed, stoichiometri…
Radical cascade reactions are an attractive tool for the rapid construction of complex molecular architectures. Although a large number of powerful radical cascades have been developed, stoichiometric amounts of reagents and/or additives are often required to mediate these processes. Radical relay strategies, in which radical character is recycled, require only a catalytic amount of reagent and are particularly attractive as they promise cascades that are high in atom economy. This tutorial review highlights recent advances in this rapidly developing area by setting out and dissecting the reaction designs underpinning state-of-the-art processes involving radical relays. Advances in the field of radical relay cascades will open the door to more efficient synthesis with far-reaching benefits for the makers and end-users of complex molecules.
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- Intercalation chemistry of graphite: alkali metal ions and beyond. [Review]
- CSChem Soc Rev 2019 Jul 11
- Reversibly intercalating ions into host materials for electrochemical energy storage is the essence of the working principle of rocking-chair type batteries. The most relevant example is the graphite…
Reversibly intercalating ions into host materials for electrochemical energy storage is the essence of the working principle of rocking-chair type batteries. The most relevant example is the graphite anode for rechargeable Li-ion batteries which has been commercialized in 1991 and still represents the benchmark anode in Li-ion batteries 30 years later. Learning from past lessons on alkali metal intercalation in graphite, recent breakthroughs in sodium and potassium intercalation in graphite have been demonstrated for Na-ion batteries and K-ion batteries. Interestingly, some significant differences proved to exist for the intercalation of Na+ and K+ into graphite compared with the Li+ case. Such different host-guest interactions are unique depending on the host materials and electrolytes, which greatly contribute to a deeper understanding of intercalation-type electrode materials for next generation alkali metal ion batteries. This review summarizes significant advances from both experimental and theoretical calculations with a focus on comparing the intercalation of three alkali metal ions (Li+, Na+, K+) into graphite and aims to clarify the intimate host-guest relationships and the underlying mechanisms. New approaches developed to achieve favorable intercalation coupled with the challenges in this field are also discussed. We also extrapolate alkali metal ion intercalation in graphite to mono-/multi-valent ions in layered electrode materials, which will deepen the understanding of intercalation chemistry and provide guidance to explore new guests and hosts.