Regulations currently in force enable to claim that the lead content in perovskite solar cells is low enough to be safe, or no more dangerous, than other electronics also containing lead. However, ...the actual environmental impact of lead from perovskite is unknown. Here we show that the lead from perovskite leaking into the ground can enter plants, and consequently the food cycle, ten times more effectively than other lead contaminants already present as the result of the human activities. We further demonstrate that replacing lead with tin represents an environmentally-safer option. Our data suggest that we need to treat the lead from perovskite with exceptional care. In particular, we point out that the safety level for lead content in perovskite-based needs to be lower than other lead-containing electronics. We encourage replacing lead completely with more inert metals to deliver safe perovskite technologies.
Effective integration and analysis of new high-throughput data, especially gene-expression and proteomic-profiling data, are expected to deliver novel clinical insights and therapeutic options. ...Unfortunately, technical heterogeneity or batch effects (different experiment times, handlers, reagent lots, etc.) have proven challenging. Although batch effect-correction algorithms (BECAs) exist, we know little about effective batch-effect mitigation: even now, new batch effect-associated problems are emerging. These include false effects due to misapplying BECAs and positive bias during model evaluations. Depending on the choice of algorithm and experimental set-up, biological heterogeneity can be mistaken for batch effects and wrongfully removed. Here, we examine these emerging batch effect-associated problems, propose a series of best practices, and discuss some of the challenges that lie ahead.
Background： Nowadays, social media tools such as short message service, Twitter, video, and web-based systems are more and more used in clinical follow-up, making clinical follow-up much more time- ...and cost-effective than ever before. However, as the most popular social media in China, little is known about the utility of smartphone WeChat application in follow-up. In this study, we aimed to investigate the feasibility and superiority of WeChat application in clinical follow-up. Methods： A total of 108 patients diagnosed with head and neck tumor were randomized to WeChat follow-up （WFU） group or telephone follow-up （TFU） group for 6-month follow-up. The follow-ups were delivered by WeChat or telephone at 2 weeks, 1, 2, 3, and 6 months to the patients after being discharged. The study measurements were time consumption for follow-up delivery, total economic cost, lost-to-follow-up rate, and overall satisfaction for the follow-up method. Results： Time consumption in WFU group for each patient （23.36 ± 6.16 min） was significantly shorter than that in TFU group （42.89 ± 7.15 min） （P 〈 0.001 ）; total economic cost in WFU group （RMB 90 Yuan） was much lower than that in TFU group （RMB 196 Yuan）. Lost-to-follow-up rate in the WFU group was 7.02% （4/57） compared with TFU group, 9.80% （5/51 ）, while no significance was observed （95% confidence interval CI： 0.176-2.740; P = 0.732）. The overall satisfaction rate in WFU group was 94.34% （50/53） compared with 80.43% （37/46） in TFU group （95% CI： 0.057-0.067; P = 0.034）. Conclusions： The smartphone WeChat application was found to be a viable option for follow-up in discharged patients with head and neck tumors. WFU was time-effective, cost-effective, and convenient in communication. This doctor-led follow-up model has the potential to establish a good physician-patient relationship by enhancing dynamic communications and providing individual health instructions.
Catenanes are intriguing molecular architectures with unique properties. Herein, we report the cellular synthesis of protein catenanes containing folded structural domains, aided by synergy between ...p53 dimerization and SpyTag/SpyCatcher chemistry. Concatenation of green fluorescent protein (GFP) was shown to increase chemical stability without disrupting the fluorescence properties, and concatenated dihydrofolate reductase (DHFR) exhibited a melting temperature around 4 °C higher and catalytic activity around 27 % higher than the wild‐type DHFR and the cyclic/linear controls. Catenation also confers considerable proteolytic resistance on DHFR. The results suggest that catenation could enhance both the stability and activity of folded proteins, thus making topology engineering an attractive approach for tailoring protein properties without varying their native sequences.
We go together: Cellular synthesis of protein catenanes containing folded structural domains was effectively achieved by using p53 dimerization and SpyTag/SpyCatcher chemistry. Catenation was found to endow the purified proteins of interest (POIs) with several valuable attributes, including enhanced thermal stability, increased proteolytic resistance, and enhanced enzymatic activity.
Electro‐reforming of renewable biomass resources is an alternative technology for sustainable pure H2 production. Herein, we discovered an unconventional cation effect on the concurrent formate and ...H2 production via glycerol electro‐reforming. In stark contrast to the cation effect via forming double layers in cathodic reactions, residual cations at the anode were discovered to interact with the glycerol oxidation intermediates to steer its product selectivity. Through a combination of product analysis, transient kinetics, crown ether trapping experiments, in situ IRRAS and DFT calculations, the aldehyde intermediates were discovered to be stabilized by the Li+ cations to favor the non‐oxidative C−C cleavage for formate production. The maximal formate efficiency could reach 81.3 % under ≈60 mA cm−2 in LiOH. This work emphasizes the significance of engineering the microenvironment at the electrode–electrolyte interface for efficient electrolytic processes.
Glycerol oxidation selectivity can be efficiently steered via cation–intermediate interactions, resulting in highly selective glycerol electro‐reforming into hydrogen and formate. This work emphasizes the significance of engineering the microenvironment at the electrode–electrolyte interface for efficient electrochemical processes.
Purpose To measure the density of the superficial retinal small vessel network (SRSVN), superficial retinal capillary network (SRCN), deep retinal capillary network (DRCN) and choriocapillaris, and ...the size of the foveal avascular zone (FAZ) in the superficial retinal layer in normal eyes. Design Prospective observational cross-sectional study. Methods In healthy Chinese volunteers, the retinal and choroidal vasculature was visualized by split-spectrum amplitude decorrelation angiography associated optical coherence tomography (RTVueXR Avanti device; Optovue Inc., Fremont, CA, USA). Results Among 105 healthy participants (age:35.9±13.8 years) mean FAZ measured 0.35±0.12mm2 , and mean density of SRSVN, SRCN, DRCN and choriocapillaris was 8.54±0.92%, 31.8±2.6%, 45.8±3.3%, 44.4±3.3% and 44.5±2.7%, respectively. In multivariate analysis, higher SRSVN density was associated with younger age ( P =0.001;standardized regression coefficient β:-0.28;), male gender ( P =0.008; β:-0.23), lower SRCN density ( P <0.001; β:-0.40), and larger mean choriocapillaris vessel diameter ( P =0.001;β:0.30). Higher SRCN density was correlated with male gender ( P =0.007; β:-0.19), lower SRSVN density ( P <0.001; β:-0.44), and higher density of the radial peripapillary capillary density ( P =0.004; β:0.20). Higher DRCN density was correlated with younger age ( P <0.001; β:-0.31), female gender ( P =0.002; β:0.22), higher SRCN density ( P <0.001; β:0.38), and higher choriocapillaris density ( P <0.001; β:0.39). Higher choriocapillaris network density in the central region was associated with higher DRCN density ( P <0.001; β:0.43) and lower radial peripapillary capillary density ( P =0.005; β:-0.26). All retinal vascular parameters were not significantly correlated with axial length or subfoveal choroidal thickness. Conclusions The density of the macular vascular networks decreases with older age and is independent of axial length and subfoveal choroidal thickness in healthy individuals.
Chemical topology has emerged as one intriguing feature in protein engineering. Nature demonstrates the elegance and power of protein topology engineering in the unique biofunctions and exceptional ...stabilities of cyclotides and lasso peptides. With entangling protein motifs and genetically encoded peptide–protein chemistry, artificial proteins with complex topologies, including cyclic proteins, star proteins, and protein catenanes, have become accessible. Among them, proteins with mechanical bonds (‘mechanoproteins’) are of special interest, owing to their potential functional benefits such as structure stabilization, quaternary structure control, synergistic multivalency effect, and dynamic mechanical sliding/switching properties. In this review article, we summarize recent progress in the field of protein topology engineering as well as the challenges and opportunities that it holds.
Chemical topology of the protein backbone has become an important dimension in protein engineering for tuning the stability and dynamic properties of proteins.
Natural proteins with nonlinear backbones or nontrivial topologies exist largely in places where exceptional stability is desired.
Mechanoproteins are proteins containing one or more mechanical bonds.
The dynamic nature of mechanical bonds in proteins has been demonstrated in lasso peptides exhibiting thermally switchable properties.
As a powerful toolset, genetically encoded peptide–protein chemistry has facilitated the design and synthesis of artificial proteins with complex topologies including cyclic, branched, tadpole, lasso, rotaxane, and catenane architectures.
Sensing of benzene vapor is a hot spot due to the volatile drastic carcinogen even at trace concentration. However, achieving convenient and rapid detection is still a challenge. As a sort of ...functional porous material, metal‐organic frameworks (MOFs) have been developed as detection sensors by adsorbing benzene vapor and converting it into other signals (fluorescence intensity/wavelength, chemiresistive, weight or color, etc.). Supramolecular interaction between benzene molecules and the host framework, aperture size/shape and structural flexibility are influential factors in the performance of MOF‐based sensors. Therefore, enhancing the host‐guest interactions between the host framework and benzene molecules, or regulating the diffusion rate of benzene molecules by changing the aperture size/shape and flexibility of the host framework to enhance the detection signal are effective strategies for constructing MOF‐based sensors. This concept highlights several types of MOF‐based sensors for the detection of benzene vapor.
The development and challenges of benzene vapor sensors based on metal‐organic frameworks (MOFs), which achieve effective detection by virtue of the singal changes in weight, chemiresistive, fluorescence or color after adsorption.
The outbreak of COVID-19 caused by SARS-CoV-2 has resulted in more than 50 million confirmed cases and over 1 million deaths worldwide as of November 2020. Currently, there are no effective ...antivirals approved by the Food and Drug Administration to contain this pandemic except the antiviral agent remdesivir. In addition, the trimeric spike protein on the viral surface is highly glycosylated and almost 200,000 variants with mutations at more than 1,000 positions in its 1,273 amino acid sequence were reported, posing a major challenge in the development of antibodies and vaccines. It is therefore urgently needed to have alternative and timely treatments for the disease. In this study, we used a cell-based infection assay to screen more than 3,000 agents used in humans and animals, including 2,855 small molecules and 190 traditional herbal medicines, and identified 15 active small molecules in concentrations ranging from 0.1 nM to 50 μM. Two enzymatic assays, along with molecular modeling, were then developed to confirm those targeting the virus 3CL protease and the RNA-dependent RNA polymerase. Several water extracts of herbal medicines were active in the cell-based assay and could be further developed as plant-derived anti-SARS-CoV-2 agents. Some of the active compounds identified in the screen were further tested in vivo, and it was found that mefloquine, nelfinavir, and extracts of
(RF3),
, and
were effective in a challenge study using hamsters as disease model.
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