RESUMO
Here, we report a DNA-compatible reaction for the generation of cyclopropane derivatives using thiolides with α,ß-unsaturated ketones in the absence of transition metal and N2 protection, which is convenient for DNA encoded library (DEL) construction. This approach allows the rapid and efficient production of a series of DEL libraries of potentially biologically active cyclopropanes and spirocyclopropyl oxindole derivatives.
Assuntos
Ciclopropanos , DNA , Clonagem Molecular , CetonasRESUMO
p53 plays a pivotal role in maintaining the genomic stability of mouse embryonic stem cells (mESCs) through transcriptionally activating and repressing target genes. However, how p53 recognizes its repressed targets remains largely unknown. Herein, we demonstrate that Sall4 negatively regulates DNA damage induced apoptosis (DIA) of mESCs through mediating p53 recruitment to enhancers of ESC-associated genes repressed by p53 from promoters of p53-activated genes. Upon DNA damage, Sall4 is transcriptionally repressed by p53 and plays an anti-apoptotic role without altering p53 activation. Moreover, Sall4 is identified as a novel p53-interacting partner. Consistently, Sall4 exerts its anti-apoptotic function in a p53-dependent manner. Intriguingly, Sall4 depletion not only promotes the transcriptional activation of several p53-regulated pro-apoptotic genes but also compromises p53-mediated repression of ESC master transcription factors in response to DNA damage. Mechanistically, Sall4 balances p53-binding affinity between p53-activated and -repressed genes through tethering p53 to ESC enhancers. In light of our study, Sall4 may contribute to tumorigenesis by antagonizing p53-mediated apoptosis.
Assuntos
Proteínas de Ligação a DNA , Células-Tronco Embrionárias Murinas , Fatores de Transcrição , Proteína Supressora de Tumor p53 , Animais , Camundongos , Dano ao DNA/genética , Células-Tronco Embrionárias Murinas/metabolismo , Ligação Proteica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismoRESUMO
Photosynthesis offers a green approach for the recycling of nicotinamide cofactors primarily NADH in bio-redox reactions. Herein, we report an NADH photosynthesis system where the oxidation of biomass derivatives is designed as an electron supply module (ESM) to afford electrons and superoxide dismutase/catalase (SOD/CAT) cascade catalysis is designed as a reactive oxygen species (ROS) elimination module (REM) to inhibit NADH degradation. Glucose as the electron donor guarantees the reaction sustainability accompanied with oxidative products of gluconic acid and formic acid. Meanwhile, enzyme cascades of SOD/CAT greatly eliminate ROS, leading to a ≈2.00-fold elevation of NADH yield (61.1 % vs. 30.7 %). The initial reaction rate and turnover frequency (TOF) increased by 2.50â times and 2.54â times, respectively, compared with those systems without REM. Our study establishes a novel and efficient platform for NADH photosynthesis coupled to biomass-to-chemical conversion.
RESUMO
Enzyme-photocoupled catalytic systems (EPCSs), combining the natural enzyme with a library of semiconductor photocatalysts, may break the constraint of natural evolution, realizing sustainable solar-to-chemical conversion and non-natural reactivity of the enzyme. The overall efficiency of EPCSs strongly relies on the shuttling of energy-carrying molecules, e.g., NAD+/NADH cofactor, between active centers of enzyme and photocatalyst. However, few efforts have been devoted to NAD+/NADH shuttling. Herein, we propose a strategy of constructing a thylakoid membrane-inspired capsule (TMC) with fortified and tunable NAD+/NADH shuttling to boost the enzyme-photocoupled catalytic process. The apparent shuttling number (ASN) of NAD+/NADH for TMC could reach 17.1, â¼8 times as high as that of non-integrated EPCS. Accordingly, our TMC exhibits a turnover frequency (TOF) of 38â¯000 ± 365 h-1 with a solar-to-chemical efficiency (STC) of 0.69 ± 0.12%, â¼6 times higher than that of non-integrated EPCS.
Assuntos
NAD , Semicondutores , Cápsulas , Catálise , NAD/químicaRESUMO
In recent years, vital signals monitoring in sports and health have been considered the research focus in the field of wearable sensing technologies. Typical signals include bioelectrical signals, biophysical signals, and biochemical signals, which have applications in the fields of athletic training, medical diagnosis and prevention, and rehabilitation. In particular, since the COVID-19 pandemic, there has been a dramatic increase in real-time interest in personal health. This has created an urgent need for flexible, wearable, portable, and real-time monitoring sensors to remotely monitor these signals in response to health management. To this end, the paper reviews recent advances in flexible wearable sensors for monitoring vital signals in sports and health. More precisely, emerging wearable devices and systems for health and exercise-related vital signals (e.g., ECG, EEG, EMG, inertia, body movements, heart rate, blood, sweat, and interstitial fluid) are reviewed first. Then, the paper creatively presents multidimensional and multimodal wearable sensors and systems. The paper also summarizes the current challenges and limitations and future directions of wearable sensors for vital typical signal detection. Through the review, the paper finds that these signals can be effectively monitored and used for health management (e.g., disease prediction) thanks to advanced manufacturing, flexible electronics, IoT, and artificial intelligence algorithms; however, wearable sensors and systems with multidimensional and multimodal are more compliant.
Assuntos
COVID-19 , Esportes , Dispositivos Eletrônicos Vestíveis , Humanos , Inteligência Artificial , Pandemias , COVID-19/diagnóstico , Monitorização Fisiológica/métodosRESUMO
The number of spent lithium-ion batteries (LIBs) will increase exponentially in the coming decade with the retirement of electric vehicles (EVs). There is a knowledge gap in assessing the environmental impact of different terminal disposal paths for EV LIBs in China. Here, we take representative lithium iron phosphate (LFP) power batteries as example and carry out a bottom-up life cycle assessment (LCA). The life cycle stages of battery manufacturing, use, second life and battery recycling are considered to conduct a cradle-to-grave environmental impact analysis. To investigate the environmental benefits of end-of-life (EoL) stage for LFP batteries, two EoL management scenarios are considered in this study. The first one combines second life application with battery recycling, and the second recycles the retired batteries directly after EV use. The result shows that the secondary application of retired LFP batteries in energy storage systems (ESSs) can effectively reduce the net environmental impact of LIB life cycle, especially for fossil fuel depletion. When the service life of secondary use is increased from 1 year to 10 years, the environmental benefits of different impact categories will increase by 0.24-4.62 times. For direct recycle scenario, recycling retired LFP batteries can save more than 30% of metal resources. By comparison, we find that recycling lithium nickel manganese cobalt oxide (NCM) batteries has greater environmental benefits than recycling LFP batteries for all impact categories. When considering the environmental benefits at the EoL stage, most life cycle environmental impact is likely to be offset or even show positive benefits if more than 50% of power batteries can be reused in ESSs after retirement.
Assuntos
Fontes de Energia Elétrica , Lítio , China , Meio Ambiente , Íons , ReciclagemRESUMO
OBJECTIVE: To (1) determine agreement between behavioural mapping and accelerometry for measuring mobility levels in an acute medical inpatient setting and to (2) explore and compare the required resources and costs for both methods. DESIGN: Observational cross-sectional study. SETTING: Tertiary referral teaching hospital in Brisbane, Australia. SUBJECTS: Adult patients admitted to two acute medical wards. MAIN MEASURES: Mobility levels were recorded by behavioural mapping, and thigh and chest-worn accelerometers (ActivPAL). The level of agreement between the two methods was evaluated using the Intraclass Correlation Coefficients for each mobility level (i.e. lying, sitting, upright, standing and walking). RESULTS: Nineteen patients (10 male (53%); mean(SD) age of 72(14) years) were included in the agreement analysis. The Intraclass Correlation Coefficients were high for 'lying' (ICC = 0.87), 'sitting' (ICC = 0.84) and 'upright' (ICC = 0.93), indicating good to excellent agreement between the two methods. For these mobility levels, mean differences between the two methods were small (<2%), with large standard deviations (up to 18%). Agreement was poor for 'standing' (ICC = 0.00) and 'walking' (ICC = 0.35). Both methods were labour-intensive, with labour costs of A$1,285/798 (34 hours) for behavioural mapping and A$1,055/655 (28 hours) for accelerometry. No further costs were involved in behavioural mapping, but clinical backfill was required. Accelerometry involved a financial investment for accelerometers (A$11,100/6,894 for 22 ActivPAL devices). CONCLUSION: Agreement between behavioural mapping and accelerometry was good for measuring 'lying', 'sitting' and 'upright', but poor for 'standing' and 'walking' in an acute inpatient setting. Both behavioural mapping and accelerometry were labour-intensive, with high costs for the accelerometry equipment.
Assuntos
Acelerometria , Comportamentos Relacionados com a Saúde , Postura , Postura Sentada , Caminhada , Adulto , Idoso , Idoso de 80 Anos ou mais , Austrália , Estudos Transversais , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos TestesRESUMO
Enzyme catalysis, as a green, efficient process, displays exceptional functionality, adaptivity and sustainability. Multi-enzyme catalysis, which can accomplish the tandem synthesis of valuable materials/chemicals from renewable feedstocks, establishes a bridge between single-enzyme catalysis and whole-cell catalysis. Multi-enzyme catalysis occupies a unique and indispensable position in the realm of biological reactions for energy and environmental applications. Two complementary strategies, i.e., compartmentalization and substrate channeling, have been evolved by living organisms for implementing the complex in vivo multi-enzyme reactions (MERs), which have been applied to construct multi-enzyme catalytic systems (MECSs) with superior catalytic activity and stabilities in practical biocatalysis. This tutorial review aims to present the recent advances and future prospects in this burgeoning research area, stressing the features and applications of the two strategies for constructing MECSs and implementing in vitro MERs. The concluding remarks are presented with a perspective on the construction of MECSs through rational combination of compartmentalization and substrate channeling.
Assuntos
Biocatálise , Enzimas/metabolismo , Biomimética/métodosRESUMO
The synthesis of ultrafine, uniform, well-dispersed functional nanoparticles (NPs) under mild conditions in a controlled manner remains a great challenge. In biological systems, a well-defined biomineralization process is exploited, in which the control over NPs' size, shape and distribution is temporally and spatially regulated by a variety of biomolecules in a confined space. Inspired by this, we embedded proteins into metal-organic frameworks (MOFs) and explored a novel approach to synthesize metallic NPs by taking the synergy of protein-induced biomineralization process and space-confined effect of MOFs. The generation and growth of ultrafine metal NPs (Ag or Au) was induced by the entrapped lysozyme molecules and confined by the ZIF-8 pores. Due to the narrow size distribution and homogeneous spatial distribution of metal NPs, the as-synthesized NPs exhibit remarkably elevated catalytic activity. These findings demonstrate that MOFs can be loaded with specific proteins to selectively deposit inorganic NPs via biomimetic mineralization and these novel kinds of nanohybrid materials may find applications in catalysis, sensing and optics.
RESUMO
Animates receive preferential attentional processing over inanimates because, from an evolutionary perspective, animates are important to human survival. We investigated whether animacy affects visual statistical learning-the detection and extraction of regularities in visual information from our rich, dynamic, and complex environment. Participants completed a selective-attention task, in which regularities were embedded in two visual streams, an attended and an unattended visual stream. The attended visual stream always consisted of line-drawings of non-objects, while the unattended visual stream consisted of line-drawings of either animates or inanimates. Participants then completed a triplet-discrimination task, which assessed their ability to extract regularities from the attended and unattended visual streams. We also assessed participants' awareness of regularities in the visual statistical learning task, and asked if any learning strategies were used. We were specifically interested in whether the animacy status of line-drawings in the unattended visual stream would affect visual statistical learning. There were four key findings. First, selective attention modulates visual statistical learning, with greater visual statistical learning for attended than for unattended information. Second, animacy does not affect visual statistical learning, with no differences found in visual statistical learning performance between the animate and inanimate condition. Third, awareness of regularities was associated with visual statistical learning of attended information. Fourth, participants used strategies (e.g., naming or labelling stimuli) during the visual statistical learning task. Further research is required to understand whether visual statistical learning is one of the adaptive functions that evolved from ancestral environments.
Assuntos
Atenção , Aprendizagem Espacial , HumanosRESUMO
Cobalt-based heterogeneous catalysts have been demonstrated as an effective PMS activator for pollutant degradation. However, the limited active sites on their surface lead to an unsatisfactory catalytic efficiency. Immobilizing the catalysts on the support material can be a promising modification strategy to solve this problem. MXene has been considered as an ideal support material due to its unique morphology and physicochemical properties. Therefore, in this work, the CoS-loaded Ti3 C2 MXene (CoS/Ti3 C2 MXene) catalyst for peroxymonosulfate (PMS) activation was successfully synthesized through a solvothermal method. Under the simulated sunlight irradiation, the CoS/Ti3 C2 MXene+PMS system achieved an impressive efficiency in removing the organic pollutant rhodamine B (97.2 % in 10â min). Among the tested catalysts, 30 %-CoS-TC stood out, exhibited a broad pH tolerance from 5 to 9 and maintained robust degradation performance over cycles. Upon detailed analysis, the degradation mechanism revealed the collaborative action dominated by singlet oxygen, and supplemented by photogenerated holes and superoxide radicals in the process. Notably, the sandwich-like structure of MXene played a pivotal role, not only dispersing the CoS particles evenly on the surface of catalysts, but also providing ample space for the active sites, thus accelerating the PMS activation for the degradation of rhodamine B. Overall, this study developed an innovative MXene-based catalyst for the application of environmental remediation.
RESUMO
For photoelectrochemical NADH regeneration, an electrode-supported "lipid bilayer membrane" photocathode based on a p-Si semiconductor, an electron transport mediator (OBV2+), and a [Rh(Cp*)(bpy)Cl]+ catalyst was constructed by self-assembly. Mechanistic study shows that OBV2+ can enhance the charge transfer between the semiconductor and catalyst, leading to a significant improvement of the NADH photo-regeneration rate.
RESUMO
Semitransparent organic solar cells (ST-OSCs) show great promise for building integrated photovoltaic systems. The balance between power conversion efficiency (PCE) and average visible transmittance (AVT) is a key point of ST-OSCs. We developed a novel semitransparent organic solar cell (ST-OSC) with high PCE and AVT for building integrated renewable energy applications. We used photolithography to fabricate Ag grid bottom electrodes with high figures of merit of 292.46. We also used an optimized active layer of PM6 and Y6, achieving a PCE of 10.65% and an AVT of 22.78% for our ST-OSCs. By adding optical coupling layers of CBP and LiF alternately, we further increased the AVT to 27.61% and the PCE to 10.87%. Importantly, the balance of PCE and AVT can be achieved by the integrated optimization of the active and optical coupling layers, which leads to a significant increase in light utilization efficiency (LUE). These results are of great importance for particle applications of ST-OSCs.
RESUMO
Herein we report a DNA-compatible Biginelli reaction to construct isocytosine scaffolds. This reaction utilizes a one-pot reaction of DNA-conjugated guanidines with aldehydes and methyl cyanoacetates to give isocytosine derivatives, and the method is well compatible with different types of substrates. This is the first report on the synthesis of an isocytosine backbone in the field of DNA-compatible organic synthesis. The successful development of this reaction can widen the chemical space of DELs.
Assuntos
Citosina , DNA , Guanidina , AldeídosRESUMO
The catalytic (CAT) domain is a key region of poly (ADP-ribose) polymerase 1 (PARP1), which has crucial interactions with inhibitors, DNA, and other domains of PARP1. To facilitate the development of potential inhibitors of PARP1, it is of great significance to clarify the differences in structural dynamics and key residues between CAT/inhibitors and DNA/PARP1/inhibitors through structure-based computational design. In this paper, conformational changes in PAPR1 and differences in key residue interactions induced by inhibitors were revealed at the molecular level by comparative molecular dynamics (MD) simulations and energy decomposition. On one hand, PARP1 inhibitors indirectly change some residues of the CAT domain which interact with DNA and other domains. Furthermore, the interaction between ligands and catalytic binding sites can be transferred to the DNA recognition domain of PARP1 by a strong negative correlation movement among multi-domains of PARP1. On the other hand, it is not reliable to use the binding energy of CAT/ligand as a measure of ligand activity, because it may in some cases differs greatly from the that of PARP1/DNA/ligand. For PARP1/DNA/ligand, the stronger the binding stability between the ligand and PARP1, the stronger the binding stability between PARP1 and DNA. The findings of this work can guide further novel inhibitor design and the structural modification of PARP1 through structure-based computational design.
Assuntos
DNA , Poli(ADP-Ribose) Polimerases , Poli(ADP-Ribose) Polimerases/metabolismo , Ligantes , Poli(ADP-Ribose) Polimerase-1/genética , DNA/metabolismo , Sítios de Ligação , Domínio Catalítico , Reparo do DNARESUMO
Environmental deterioration in urbanizing areas increases the risks of sudden death as well as chronic, infectious, and psychological diseases. Quantifying health-related physical environment can assess the health risk of urban residents. This study uses an integrated evaluation method to simulate the health-related physical environment in the four dimensions of acoustic, wind, thermal, and landscape. According to the case study of one university campus in an urbanizing area in China, results show that (1) areas with unqualified equivalent A sound levels are generally the sports area, green square 1 and laboratory areas, and residents who stay in these areas for a long time suffer the risks of hearing loss and mental stress. (2) The windless area ratio of teaching area 1 and dormitory area 4 is larger than 20%, and respiratory health risks increase because these areas relate to relatively wind discomfort. (3) The high-temperature zone ratio of sports area and green square 2 is larger than 50%, and heatstroke risks increase since these areas relate with low thermal comfort. (4) The overall landscape perception level of dormitories and dining areas is lower than that of the teaching area, and it can cause anxiety and irritability. (5) The sports area has the lowest average overall score of the health-related physical environment among all functional areas, followed by laboratory areas. These findings indicate that the proposed model and method can be valuable tools for the pre-evaluation and optimization of urban planning. It can reduce the health risks of residents in urbanizing areas and can benefit residents' health and urban sustainable development.
Assuntos
Meio Ambiente , Vento , China , Temperatura Alta , Humanos , UniversidadesRESUMO
Photo-Fenton process is an advanced oxidation technology, which is used to eliminate organic pollutants in environmental pollution. In this paper, g-C3N4 quantum dots incorporated hierarchical macro-mesoporous CuO-SiO2 (MM SC-QDs) composite was successfully fabricated by a dual-template method combined with polystyrene sphere (PS) crystal and copolymer F127. With the presence of H2O2, MM SC-QDs exhibited excellent degradation performance against the antibiotic pollutant norfloxacin (NOR) under visible-light assisted heterogeneous Fenton process at neutral condition, which was 27 times higher than that of the Bulk CuO-SiO2. Interconnected macropores, together with abundant mesopores effectively expand specific surface area and improve mass transfer. In addition, the g-C3N4 QDs served as the separation center for photogenerated charges, promoting the separation and migration of the charge carriers. Wherein, the long-lived photogenerated electrons were effectively separated and transferred to the surface of CuO-SiO2, which accelerated the reduction rate of Cu2+ to Cu+, enhancing the photo-Fenton-like catalytic activity. This stable, efficient, and environmentally friendly Cu-based heterogeneous photo-Fenton-like catalyst is expected to become an effective implementation in organic pollution removal. Meanwhile, this paper proves that Cu-based materials can activate H2O2 to generate singlet oxygen (1O2) for the degradation of organic pollutants. The transformation mechanism of 1O2 was clarified, which is helpful to better understand the Fenton-like reaction process of Cu-based materials.
Assuntos
Peróxido de Hidrogênio , Norfloxacino , Catálise , Cobre , Dióxido de SilícioRESUMO
Solar-driven photocatalytic regeneration of cofactors, including reduced nicotinamide adenine dinucleotide (NADH), reduced nicotinamide adenine dinucleotide phosphate (NADPH), and reduced flavin adenine dinucleotide (FADH2), could ensure the sustainable energy supply of enzymatic reactions catalyzed by oxidoreductases for the efficient synthesis of chemicals. However, the elevation of cofactor regeneration efficiency is severely hindered by the inefficient utilization of electrons transferred on the surface of photocatalysts. Inspired by the phenomenon of ferredoxin-NADP+ reductase (FNR) anchoring on thylakoid membrane, herein, a homogeneous catalyst of rhodium (Rh) complex, [Cp∗Rh(bpy)H2O]2+, was anchored on polymeric carbon nitride (PCN) mediated by a tannic acid/polyethyleneimine (TA/PEI) adhesive layer, acquiring PCN@TA/PEI-Rh core@shell photocatalyst. Illuminated by visible light, electrons were excited from the PCN core, then transferred through the TA/PEI shell, and finally captured by the surface-anchored Rh for instant utilization during the regeneration of NADH. The TA/PEI-Rh shell could facilitate the electron transfer from the PCN core and, more importantly, achieved ~1.3-fold elevation of electron utilization efficiency compared with PCN. Accordingly, the PCN@TA/PEI-Rh afforded the NADH regeneration efficiency of 37.8% after 20 min reaction under LED light (405 nm) illumination, over 1.5 times higher than PCN with free Rh. Coupling of the NADH regeneration system with formate dehydrogenase achieved continuous production of formate from carbon dioxide (CO2). Our study may provide a generic and effective strategy to elevate the catalytic efficiency of a photocatalyst through intensifying the electron utilization.
RESUMO
The title polymer, [Zn(3)(C(8)H(8)O(5))(2)(C(3)H(3)N(2))(2)(C(3)H(4)N(2))(2)](n), was formed by the reaction of zinc acetate with imidazole and 7-oxabicyclo-[2.2.1]heptane-2,3-dicarboxylic anhydride (norcan-tharidine). One of the two crystallographically unique Zn(II) atoms is four-coordinated by three N atoms of three imidazole ligands, two of which are deprotonated, and by one carboxyl-ate O atom of the demethyl-cantharate anion. The second Zn(II) atom is situated on an inversion centre and is six-coordinated by the bridging O atoms of two symmetry-related demethyl-cantharate anions and by four carboxyl-ate O atoms of the corresponding carboxyl-ate groups. The polymeric crystal structure is additionally stabilized by N-Hâ¯O hydrogen bonding between the imidazole ligands and carboxyl-ate O atoms.
RESUMO
In the crystal structure of the title complex, [Cd(C(8)H(8)O(5))(C(3)H(4)N(2)S)(3)]·2H(2)O, the Cd(II) atom exhibits a slightly distorted octa-hedral CdO(3)N(3) coordination, defined by the bridging O atom of the bicyclo-heptane unit, two O atoms from the carboxyl-ate groups and by three N atoms from three 2-amino-thia-zole ligands. Uncoordinated lattice water mol-ecules are also present in the crystal structure. N-Hâ¯O and O-Hâ¯O hydrogen-bonding inter-actions link the components into a three-dimensional structure.