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The directed self-assembly (DSA) of block copolymers (BCPs) is a potential patterning technology for sub-7 nm lithography.

Background Remdesivir was considered to be a specific drug for Corona Virus Disease 2019. This systematic review aims to evaluate remdesivir monotherapy and combination therapy related clinical efficacy and risk. Research design and methods PubMed, Embase, SCIE, Cochrane Library, and American Clinical trial Center were searched up to 1 April 2022. We included randomized controlled trials (RCTs) comparing Remdesivir monotherapy with control drugs, or comparing different combination therapy. Results 11 RCTs and 32 observational studies were included in analysis. In the main outcome, remdesivir use reduced mortality in patients with severe COVID-19 and improve recovery in patients. In other clinical outcomes, remdesivir use was associated with improved clinical status. In safety outcomes, remdesivir use did not cause liver or kidney damage. Compared with remdesivir alone, remdesivir combined with other drugs-steroids, favipiravir, and convalescent plasma- had no effect on mortality. In addition, remdesivir combined with tocilizumab may increase mortality. Conclusion Results of the systematic review showed that remdesivir was positive in COVID-19, especially patients with severe COVID-19. The more effective treatment of COVID-19 with other drugs combined with remdesivir is urgent and challenging research. Trial registration number PROSPERO registration number: CRD42022322859.

A multifunctional catalytic nanomaterial (Co-MOF@AuNP@ABEI) composed of cobalt-doped metal-organic frameworks (Co-MOF), gold nanoparticles (AuNP), and N-(4-aminobutyl)-N-(ethylisoluminol) (ABEI) is reported. Co-MOF@AuNP@ABEI exhibits high synergistic and zero-distance catalytic properties, which are beneficial to the improvement of the detection sensitivity of an electrochemiluminescent (ECL) biosensor. After coupling with the ECL system and 3D magnetic walking nanomachine amplification strategy, the Co-MOF@AuNP@ABEI can achieve an ultrasensitive ECL assay of Burkholderia pseudomallei with the limit of detection (LOD) of 60.3 aM, which is 2 and 4 orders of magnitude lower than individual ECL system without the nanomachine (4.97 fM) and individual walking nanomachine (340 fM), and superior to the pathogenic bacteria analyses in the previous report. Moreover, the LOD of the proposed ECL detection system for the determination of B. pseudomallei in serum sample was as low as 9.0 CFU mL

A series of poly(pentadecafluorooctyl methacrylate)-block-polyhydroxystyrene (PPDFMA-b-PHS) block copolymers (BCPs) were synthesized via reversible addition–fragmentation chain-transfer polymerizat...

A series of liquid crystalline block copolymers (LC BCPs), poly(pentadecafluorooctyl methacrylate)-block-poly(6-(4-(4-methoxyphenylazo)phenoxy)hexyl methacrylate) (PPDFMA-b-P6AzOMe), poly(pentadeca...

C-Glycosyltransferases (CGTs) catalyze the formation of C-glycosidic bonds for the biosynthesis of C-glycosides, but the underlying mechanism is unclear. This process improves the solubility and bioavailability of specialized metabolites, which play important roles in plant growth and development and represent rich resources for drug discovery. Here, we performed functional and structural studies of the CGT UGT708C1 from buckwheat (Fagopyrum esculentum). Enzymatic analysis showed that UGT708C1 is capable of utilizing both UDP-galactose and UDP-glucose as sugar donors. Our structural studies of UGT708C1 complexed with UDP-glucose and UDP identified the key roles of Asp382, Gln383, Thr151, and Thr150 in recognizing the sugar moiety of the donor substrate and Phe130, Tyr102, and Phe198 in binding and stabilizing the acceptor. A systematic site-directed mutagenesis study confirmed the important roles of these residues. Further structural analysis combined with molecular dynamics simulations revealed that phloretin binds to the acceptor binding pocket in a bent state with a precise spatial disposition and complementarity. These findings provide insights into a catalytic mechanism for CGTs.

Directed self-assembly (DSA) of thin films of a block copolymer (BCP) is a promising approach for sub-10 nm lithographic patterning. In this paper, a series of poly(2-vinylpyridine)-block-poly(pent...

Early-age carbonation can make a significant difference in the formation of hydration products in cement-based materials and alter the microstructural and mechanical performances. To understand in detail the impacts and their contribution to cement hydration, dry-mix cement pastes were exposed to instant carbonation with 0.04 %, 1%, 3%, 10 %, 20 % CO2 concentrations for 2 h prior to further water curing. By increasing the CO2 concentration, an increment in strength gain of samples at 2 h (right after early carbonation) as well as being prolonged by water curing at 1, 3, 7 days was noticed. This agrees with TGA and XRD results, demonstrating that the increases in CO2 concentration resulted in a higher carbonation reaction and hydration degree. 29Si NMR results also indicate that the higher the CO2 concentration the lower the calcium to silica ratio (Ca/Si); thus, there is a higher degree of polymerization to promote early hydration. It can be concluded that early carbonation of 2 h in particular with a high CO2 concentration can be beneficial for further cement hydration due to the consumption of calcium hydroxide (CH) and nuclei site effect of calcite crystals, resulting in better microstructural properties and mechanical performance.

Burkholderia pseudomallei (B. pseudomallei) can cause melioidosis that is usually fatal. A reliable and rapid detection method is greatly needed for disease surveillance and diagnosis. Herein, an ultrasensitive electrochemiluminescence (ECL) biosensor was constructed for accurate determination of B. pseudomallei coupled with multifunctional Au@Co-MOF@ABEI nanocubes and 3D magnetic walking nanomachine. The synthesized nanocubes could not only immobilize enormous ABEI but exhibit superior peroxidase-like activity to decompose H2O2 to produce plentiful reactive oxygen species (ROSs) that could further react with ABEI, so that the enhanced ECL signals were achieved. Meanwhile, the target-activated walking nanomachine was efficiently driven by Exonuclease III (Exo III) for further improving the sensitivity of the biosensor. As a result, the fabricated ECL biosensor could detect pathogenic gene down to 60.3 aM with a linear range from 100.0 aM to 100.0 pM. Moreover, the biosensing platform successfully achieved the determination of B. pseudomallei down to 9.0 CFU mL−1 in serum samples. This work exhibited an ultrasensitive and specific performance for B. pseudomallei detection, which would become a versatile tool in the early diagnosis and treatment of melioidosis.

The block copolymer (BCP) approach is a promising route for sub-10 nm semiconductor lithography. In this paper, a series of polystyrene-block-poly(pentadecafluorooctyl methacrylate) (PS-b-PPDFMA) copolymers are designed and synthesized by living anionic polymerization. The BCP phase behavior is investigated using small-angle X-ray scattering and transmission electron microscopy. The resulting BCP materials form sub-5 nm features after 1 min of thermal annealing at 80 °C. The Flory–Huggins interaction parameter of PS-b-PPDFMA is very large (0.353 at 150 °C) because of the significant incompatibility between polystyrene and the perfluoroalkyl block. These results qualify PS-b-PPDFMA as a potential material for sub-5 nm patterning applications.

Directed Self-assembly is a chemical assisted patterning technology, which has attracted a great deal of interest due to its potential high resolution and low cost [1]–[4]. Researchers around the world discovered some sub-5 nm resolution DSA materials with high χ value, which normally requires high annealing temperature or long annealing time. As modern semiconductor manufacturing litho process normally requires hot baking time less than 3 min to ensure cost-effective throughput, fast annealing BCPs thus are essential for future DSA patterning technology. Also our group focus on the development of advanced materials for ArF lithography and we are trying to contribute to China own advanced patterning material industry.

In this manuscript, various fluorine-containing BCPs were synthesized by living anionic polymerization or reversible addition−fragmentation chain-transfer (RAFT) polymerization. The resulted BCPs showed high χ value > 0.2. With similar χ value, we observed that PS-typed BCPs formed microdomains of 5 nm within 1 min at 80°C, whereas polymethacrylate-typed ones required 1 h annealing at 160°C. When rigid side chain was incorporated into the polymethacrylate block, the annealing time can be shortened to 5 min at 160°C. However, the poor film formation of the such BCP with rod-like side chain resulted in rough line pattern after the thermal annealing process. The polymethacrylate-typed BCPs generally requires high boiling point solvents for better film formation and better line patterning.

The S-adenosylmethionine carrier (SAMC) is a membrane transport protein located on the inner membrane of mitochondria that catalyzes the import of S-adenosylmethionine (SAM) into the mitochondrial matrix. SAMC mutations can cause a series of mitochondrial defects, including those affecting RNA stability, protein modification, mitochondrial translation and biosynthesis. Here, we describe the expression, purification and oligomerization of SAMC. The SAMC genes from three species were cloned into a eukaryotic expression vector with a GFP tag, and confocal microscopy analysis showed that these SAMCs were localized to mitochondria. A BacMam expression system was used for the expression of D. rerio SAMC with a FLAG tag. A size-exclusion chromatography analysis showed that SAMC may form a hexamer. A negative-staining electron microscopy analysis showed that SAMC formed tiny uniform particles and also confirmed the oligomerization of SAMC.

C-Glycosyltransferases (CGTs) catalyze the formation of C-glycosidic bonds for the biosynthesis of C-glycosides, but the underlying mechanism is unclear. This process improves the solubility and bioavailability of specialized metabolites, which play important roles in plant growth and development and represent rich resources for drug discovery. Here, we performed functional and structural studies of the CGT UGT708C1 from buckwheat (Fagopyrum esculentum). Enzymatic analysis showed that UGT708C1 is capable of utilizing both UDP-galactose and UDP-glucose as sugar donors. Our structural studies of UGT708C1 complexed with UDP-glucose and UDP identified the key roles of Asp382, Gln383, Thr151, and Thr150 in recognizing the sugar moiety of the donor substrate and Phe130, Tyr102, and Phe198 in binding and stabilizing the acceptor. A systematic site-directed mutagenesis study confirmed the important roles of these residues. Further structural analysis combined with molecular dynamics simulations revealed that phloretin binds to the acceptor binding pocket in a bent state with a precise spatial disposition and complementarity. These findings provide insights into a catalytic mechanism for CGTs.

The directed self-assembly (DSA) of block copolymers has attracted a great deal of interest due to its potential applications in sub-10 nm lithography [1–3]. The conventional organic-organic DSA materials such as poly-(styrene-block-methyl methacrylate) (PS-b-PMMA) have been extensively studied [4,5], however, the low etch contrast between two blocks and the difficulty to reduce L 0 limit its application. In this study, we designed and synthesized the novel DSA materials based on PS-b-PMMA. Through the modifying of acrylics part, segment-segment interaction parameter (χ) can be significantly increased, which leads to rapid self-assembly and high etch contrast.

About 6.5 billion tons of discarded plastic and rubber wastes are generated every year globally, and the disposal of these wastes poses a great threat to the environment due to their long period for degradation. Therefore, a direct recycling and reusing of these wastes as green construction material can potentially reduce the environmental burden. Considering plastic and rubber are both synthesized polymer materials containing similar basic elements with distinct structures, this paper aims to comparatively review the functions and impacts of plastic and rubber wastes used as eco-friendly aggregates on the fresh and hardened properties as well as the durability performance in mortar and concrete. The type and source of plastic and rubber wastes used as aggregate, as well as their effects in terms of aggregate size, replacement content, shape and treatment method are highlighted. In general, the presence of plastic aggregate decreases the workability of concrete, while the effect of rubber aggregate is mainly governed by the size and replacement content. Also, the smooth surface and low specific gravity of plastic/rubber aggregate compared to natural aggregate increased the pore structure which reduced the matrix density and mechanical strength. Nevertheless, chemical treatment of rubber aggregate was found to be an efficient and feasible method to compensate the mechanical strength loss of rubber incorporated concrete. Apart from improving ductility of concrete, one of the most promising characteristics of the plastic/rubber aggregate is the low thermal, acoustical and electrical conductivity and therefore these aggregates are excellent options for producing thermal and sound insulating concrete.

In recent years, high-χ block copolymers (BCPs) have been reported to achieve sub-5 nm resolution. These BCPs always require long annealing time at high annealing temperature, which may limit their implementation into semiconductor process. Since hot baking time in conventional semiconductor process is normally less than 3 minutes, how to shorter the thermal annealing time at lower temperature becomes a new topic for the sub-5 nm high-χ BCPs. In this manuscript, various fluoro-containing BCPs are synthesized by living anionic polymerization or atom transfer radical polymerization. The best BCP formed thermal equilibrium sub-5 nm nano domains after mere 1 min annealing at temperature lower than 100 °C, which is the fastest thermal annealing process reported so far. BCPs with various morphology and domain size are obtained by precise control of both the length and the molar ratio of the two blocks. The resulted smallest half-pitch of the BCPs are less than 5 nm in lamella and hexagonal morphologies. Linear and starshaped BCPs containing PMMA and fluoro-block are also synthesized, which also shows best phase separation into ca. 6 nm half-pitch, however, the annealing time is 1 hour at 180 °C.

The directed self-assembly (DSA) of block copolymers has attracted a great deal of interest due to its potential applications in sub-10 nm or sub-5 nm lithography [1-3]. The conventional organic-organic DSA materials such as poly-(styrene-block-methyl methacrylate) (PS-b-PMMA) have been extensively studied [4,5], however, the low etch contrast and the difficulty to reduce L0 limits its application. In this study, we designed and synthesized the novel DSA materials based on PS-b-PMMA. Through the modifying of acrylics part, segment-segment interaction parameter (x) can be significantly increased, which leads to rapid self-assembly and higher resolution.

A series of novel block copolymers, PS-b-PPDMA, were synthesized via anionic polymerization. Small-angle X-ray scattering (SAXS) spectra and Transmission electron microscope (TEM) images indicated lamella or hexagonal structures with a sub-10 nm half-pitch formed under mild thermal annealing condition. The assembly condition is as quick as 5 min or less at 100 °C thermal annealing. The smallest lamellar D spacing is 11.8 nm. These block copolymers show the potential as DSA material with high intrinsic resolution for sub-10 nm and beyond nodes.

In this paper, a direct grid current control strategy for grid-connected voltage source inverters with an LCL-filter is proposed. The direct grid current control is used to mitigate the grid voltage disturbance, then the characteristics of the inverter system with the proposed controller are investigated and compared with those using traditional control strategies. In the proposed control strategy, the use of the virtual resistance based on the capacitance current is able to realize active damping, and zero compensation is brought in to enhance the stability, and the quasi proportional-resonant (QPR) controller under two-phase static coordinate is designed to track the ac reference current. The strategy integrates the QPR controller with harmonic compensator (HC) to restrain the distortion of the grid voltage. Experimental results are provided to verify the new current control strategy.