Site Of Function Research Articles

Autologous versus synthetic bone grafts for the surgical management of tibial plateau fractures: a systematic review and meta-analysis of randomized controlled trials.

AimsOur objective was to conduct a systematic review and meta-analysis, to establish whether differences arise in clinical outcomes between autologous and synthetic bone grafts in the operative management of tibial plateau fractures.MethodsA structured search of MEDLINE, EMBASE, the online archives of Bone & Joint Publishing, and CENTRAL databases from inception until 28 July 2021 was performed. Randomized, controlled, clinical trials that compared autologous and synthetic bone grafts in tibial plateau fractures were included. Preclinical studies, clinical studies in paediatric patients, pathological fractures, fracture nonunion, or chondral defects were excluded. Outcome data were assessed using the Risk of Bias 2 (ROB2) framework and synthesized in random-effect meta-analysis. The Preferred Reported Items for Systematic Review and Meta-Analyses guidance was followed throughout.ResultsSix studies involving 353 fractures were identified from 3,078 records. Following ROB2 assessment, five studies (representing 338 fractures) were appropriate for meta-analysis. Primary outcomes showed non-significant reductions in articular depression at immediate postoperative (mean difference -0.45 mm, p = 0.25, 95%confidence interval (CI) -1.21 to 0.31, I2 = 0%) and long-term (> six months, standard mean difference -0.56, p = 0.09, 95% CI -1.20 to 0.08, I2 = 73%) follow-up in synthetic bone grafts. Secondary outcomes included mechanical alignment, limb functionality, and defect site pain at long-term follow-up, perioperative blood loss, duration of surgery, occurrence of surgical site infections, and secondary surgery. Mean blood loss was lower (90.08 ml, p < 0.001, 95% CI 41.49 to 138.67) and surgery was shorter (16.17 minutes, p = 0.04, 95% CI 0.39 to 31.94) in synthetic treatment groups. All other secondary measures were statistically comparable.ConclusionAll studies reported similar methodologies and patient populations; however, imprecision may have arisen through performance variation. These findings supersede previous literature and indicate that, despite perceived biological advantages, autologous bone grafting does not demonstrate superiority to synthetic grafts. When selecting a void filler, surgeons should consider patient comorbidity, environmental and societal factors in provision, and perioperative and postoperative care provision.Cite this article: Bone Jt Open 2022;3(3):218–228.

Vision and Visuomotor Performance Following Acute Ischemic Stroke.

BackgroundAs measurable sensory and motor deficits are key to the diagnosis of stroke, we investigated the value of objective tablet based vision and visuomotor capacity assessment in acute mild-moderate ischemic stroke (AIS) patients.MethodsSixty AIS patients (65 ± 14 years, 33 males) without pre-existing visual/neurological disorders and acuity better than 6/12 were tested at their bedside during the first week post-stroke and were compared to 40 controls (64 ± 11 years, 15 males). Visual field sensitivity, quantified as mean deviation (dB) and visual acuity (with and without luminance noise), were tested on MRFn (Melbourne Rapid Field-Neural) iPad application. Visuomotor capacity was assessed with the Lee-Ryan Eye-Hand Coordination (EHC) iPad application using a capacitive stylus for iPad held in the preferred hand.Time to trace 3 shapes and displacement errors (deviations of >3.5 mm from the shape) were recorded. Diagnostic capacity was considered with Receiver Operating Characteristics. Vision test outcomes were correlated with National Institutes of Health Stroke Scale (NIHSS) score at the admission.ResultsOf the 60 AIS patients, 58 grasped the iPad stylus in their preferred right hand even though 31 had left hemisphere lesions. Forty-one patients (68%) with better than 6/12 visual acuity (19 right, 19 left hemisphere and 3 multi-territorial lesions) returned significantly abnormal visual fields. The stroke group took significantly longer (AIS: 93.4 ± 60.1 s; Controls: 33.1 ± 11.5 s, p < 0.01) to complete EHC tracing and made larger displacements (AIS: 16,388 ± 36,367 mm; Controls: 2,620 ± 1,359 mm, p < 0.01) although both control and stroke groups made similar numbers of errors. EHC time was not significantly different between participants with R (n = 26, 84.3 ± 55.3 s) and L (n = 31, 101.3 ± 64.7 s) hemisphere lesions. NIHSS scores and EHC measures showed low correlations (Spearman R: −0.15, L: 0.17). ROC analysis of EHC and vision tests found high diagnostic specificity and sensitivity for a fail at EHC time, or visual field, or Acuity-in-noise (sensivity: 93%, specificity: 83%) that shows little relationship to NIHSS scores.ConclusionsEHC time and vision test outcomes provide an easy and rapid bedside measure that complements existing clinical assessments in AIS. The low correlation between visual function, NIHSS scores and lesion site offers an expanded clinical view of changes following stroke.

Structural insights into the substrate-binding site of main protease for the structure-based COVID-19 drug discovery.

An attractive drug target to combat COVID-19 is the main protease (Mpro ) because of its key role in the viral life cycle by processing the polyproteins translated from the viral RNA. Studying the crystal structures of the protease is important to enhance our understanding of its mechanism of action at the atomic-level resolution, and consequently may provide crucial structural insights for structure-based drug discovery. In the current study, we report a comparative structural analysis of the Mpro substrate binding site for both apo and holo forms to identify key interacting residues and conserved water molecules during the ligand-binding process. It is shown that in addition to the catalytic dyad residues (His41 and Cys145), the oxyanion hole residues (Asn142-Ser144) and residues His164-Glu166 form essential parts of the substrate-binding pocket of the protease in the binding process. Furthermore, we address the issue of the substrate-binding pocket flexibility and show that two adjacent loops in the Mpro structures (residues Thr45-Met49 and Arg188-Ala191) with high flexibility can regulate the binding cavity' accessibility for different ligand sizes. Moreover, we discuss in detail the various structural and functional roles of several important conserved and mobile water molecules within and around the binding site in the proper enzymatic function of Mpro . We also present a new docking protocol in the framework of the ensemble docking strategy. The performance of the docking protocol has been evaluated in predicting ligand binding pose and affinity ranking for two popular docking programs; AutoDock4 and AutoDock Vina. Our docking results suggest that the top-ranked poses of the most populated clusters obtained by AutoDock Vina are the most important representative docking runs that show a very good performance in estimating experimental binding poses and affinity ranking.

Exploring the catalytic function and active sites of a novel C-glycosyltransferase from Anemarrhena asphodeloides

Anemarrhena asphodeloides is an immensely popular medicinal herb in China, which contains an abundant of mangiferin. As an important bioactive xanthone C-glycoside, mangiferin possesses a variety of pharmacological activities and is derived from the cyclization reaction of a benzophenone C-glycoside (maclurin). Biosynthetically, C-glycosyltransferases are critical for the formation of benzophenone C-glycosides. However, the benzophenone C-glycosyltransferases from Anemarrhena asphodeloides have not been discovered. Herein, a promiscuous C-glycosyltransferase (AaCGT) was identified from Anemarrhena asphodeloides. It was able to catalyze efficiently mono-C-glycosylation of benzophenone, together with di-C-glycosylation of dihydrochalcone. It also exhibited the weak O-glycosylation or potent S-glycosylation capacities toward 12 other types of flavonoid scaffolds and a simple aromatic compound with –SH group. Homology modeling and mutagenesis experiments revealed that the glycosylation reaction of AaCGT was initiated by the conserved residue H23 as the catalytic base. Three critical residues H356, W359 and D380 were involved in the recognition of sugar donor through hydrogen-bonding interactions. In particular, the double mutant of F94W/L378M led to an unexpected enzymatic conversion of mono-C- to di-C-glycosylation. This study highlights the important value of AaCGT as a potential biocatalyst for efficiently synthesizing high-value C-glycosides.

Avenanthramide C from Oats Protects Pyroptosis through Dependent ROS-Induced Mitochondrial Damage by PI3K Ubiquitination and Phosphorylation in Pediatric Pneumonia.

Oat containing rich β-glucan, polyphenols, flavonoids, saponins, alkaloids, and other substances shows good biological activities. Therefore, the present study aimed to uncover the possible mechanism and therapeutic effect of Avenanthramide C in lessening inflammatory responses in pediatric pneumonia. Pediatric pneumonia was induced by liposaccharide (LPS) for vivo model and vitro model. Macrophage was performed to determine the mechanism and effects of Avenanthramide C in pediatric pneumonia. NLRP3 activity participated in the effects of Avenanthramide C in pediatric pneumonia. Avenanthramide C induced p-PI3K and p-Akt expressions and reduced ubiquitination of PI3K expression in pediatric pneumonia. On the other hand, Avenanthramide C integrated serine at 821 sites of the PI3K protein function. Avenanthramide C reduced ROS (reactive oxygen species)-induced mitochondrial damage by PI3K/AKT function in a model of pediatric pneumonia. Avenanthramide C protects pyroptosis in a model of pediatric pneumonia by PI3K/AKT/Nrf2/ROS signaling. Taken together, our results demonstrated that Avenanthramide C protects pyroptosis through dependent ROS-induced mitochondrial damage by PI3K ubiquitination and phosphorylation in a model of pediatric pneumonia, suggesting its potential use for the treatment of pediatric pneumonia and other inflammatory diseases.

Transcriptional dynamics of the circulating chicken primordial germ cells revealing key genes in cell adhesion and proliferation prior to gonad colonization.

Primordial germ cells (PGCs), precursors to sperms and oocytes, are responsible for the transfer of genetic information to the next generation. The PGCs arise far away from the developing gonad and thus have to migrate across the embryo to reach their site of function. The migration of PGCs from extraembryonic regions to the genital ridges is accomplished through distinct routes among different species. In particular, the birds PGCs utilized the developing circulation system to travel long distance before settling within the gonad. This study screened the transcriptome profile of chicken PGCs isolated from the bloodstream and the genital ridges to identify the cell intrinsic signals that could guide the unique migration path through circulation. We found cell adhesion and extracellular matrix (ECM) associated pathways were highly enriched in the PGCs from blood but not gonads. The platelet-derived growth factor receptors (PDGFRA and PDGFRB) were downregulated during gonad colonization and knockdown of either PDGFRA or PDGFRB inhibit the proliferation of blood PGCs. Furthermore, the migration of blood PGCs was impaired by the suppression of PDGFRA but not PDGFRB. Hence, the chicken PGCs show dynamic transcriptional remodeling during the blood-to-gonad migration and colonization. The free-floating PGCs in the circulation already express genes associated with cell-cell and cell-ECM interactions and therefore prepare for gonadal colonization.

Imaging the immune system redux.

Imaging the immune system redux.

Monitoring of the Condition of Green Plantations in Shevchenkivskyi District of Kharkiv (on The Example of Bittle Chestnut (Aesculus Hippocastanum L.)

In the complex of measures for improving atmospheric air quality in a modern city and reduction of noise pollution, special emphasis is placed on outdoor green spaces, which primarily perform a sanitary and hygienic function, protect residents and urban sites from harmful transport emissions, localization and partially absorb them. Purpose. Monitoring the state of green spaces in the Shevchenkivskyi district of Kharkiv (for example, bitter chestnut (Aesculus Hippocastanum L.) Methods. Analytical and synthetic method, geoinformation (cartographic modeling and processing of remote sensing data), analysis of information sources and methods of field research. Results. Based on the analysis of literature and fund materials and our own field research, information was obtained on the current state of plantings of common bitter chestnut in the Shevchenkivskyi district of Kharkov. A visual assessment of the quality of common bitter chestnut stands was made, in particular, damage to trees was determined. An inventory map of urban plantations of bitter chestnut in the usual Shevchenkivskyi region was developed using GIS technologies. Recommendations have been developed to improve the ecological state of common bitter chestnut plantations within the Shevchenkivskyi district of Kharkiv. Based on the results of this study and taking into account the preliminary work of scientists, it has been proved that the development of an inventory map of urban plantings of common bitter chestnut makes it possible to find out information about the state of the city's green spaces (number, types, age, diseases and damage, etc.). Conclusion. The obtained data on green spaces can determine the priorities for the development of landscape design, an action plan for urban green infrastructure to adapt to climate change. Based on reliable data, you can draw up a quality plan for the development of urban greening.

Magnetically Retrievable Organocatalyst: An Emergent Green Method for The Rapid Formation of Biodynamically Significant Quinolines

AbstractHerein, highly efficient organocatalyst arginine coupled magnetic nanoparticles have been synthesized and aiming to catalyze synthesis of biodynamically significant quinolines. Results indicate that the catalyst is compatible with a wide range of functional groups and generates various quinoline derivatives in good to excellent yields under solvent free condition. Superior activity of the reported catalyst can be combine with the synergistic effect of the following factors: Firstly use of iron oxide nanoparticles as supports provide large surface areas, high surface‐to‐volume ratio, high reactivity and selectivity and lower consumption of energy, Secondly encapsulation of MNPs (Magnetic Nanoparticles) with L‐arginine not only prevent magnetic aggregation but also imparts many desirable properties like high thermal and chemical stability, finely disperse active sites and enhanced activity. Thirdly use of environmentally more benign, non‐toxic and much cheaper L‐arginine amino acid for coating agent need simple handling and storage. Fourthly potential recovery of this catalytic system by an external magnet, reduces waste, labour and cost, thus satisfy the requirements of green chemistry. Moreover such coating also provides sites for functionalization with other organic groups and thereby broaden their applicability in various research areas such as drug delivery, magnetic resonance imaging, biomedicine and especially in the field of heterocatalysis.

Effect of Al2O3 Passive Layer on Stability and Doping of MoS2 Field-Effect Transistor (FET) Biosensors.

Molybdenum disulfide (MoS2) features a band gap of 1.3 eV (indirect) to 1.9 eV (direct). This tunable band gap renders MoS2 a suitable conducting channel for field-effect transistors (FETs). In addition, the highly sensitive surface potential in MoS2 layers allows the feasibility of FET applications in biosensors, where direct immobilization and detection of biological molecules are conducted in wet conditions. In this work, we report, for the first time, the degradation of chemical vapor deposition (CVD) grown MoS2 FET-based sensors in the presence of phosphate buffer and water, which caused false positive response in detection. We conclude the degradation was originated by physical delamination of MoS2 thin films from the SiO2 substrate. The problem was alleviated by coating the sensors with a 30 nm thick aluminum oxide (Al2O3) layer using atomic layer deposition technique (ALD). This passive oxide thin film not only acted as a protecting layer against the device degradation but also induced a strong n-doping onto MoS2, which permitted a facile method of detection in MoS2 FET-based sensors using a low-power mode chemiresistive I-V measurement at zero gate voltage (Vgate = 0 V). Additionally, the oxide layer provided available sites for facile functionalization with bioreceptors. As immunoreaction plays a key role in clinical diagnosis and environmental analysis, our work presented a promising application using such enhanced Al2O3-coated MoS2 chemiresistive biosensors for detection of HIgG with high sensitivity and selectivity. The biosensor was successfully applied to detect HIgG in artificial urine, a complex matrix containing organics and salts.

Design, Synthesis, and Evaluation of Trivalent PROTACs Having a Functionalization Site with Controlled Orientation.

Trivalent PROTACs having a functionalization site with controlled orientation were designed, synthesized, and evaluated. Based on the X-ray structure of BRD protein degrader MZ1 (1) in complex with human VHL and BRD4BD2, we expected that the 1,2-disubstituted ethyl group near the JQ-1 moiety in MZ1 (1) could be replaced by a planar benzene tether as a platform for further functionalization. To test this hypothesis, we first designed six divalent MZ1 derivatives, 2a-c and 3a-c, by combining three variations of substitution patterns on the benzene ring (1,2-, 1,3-, and 1,4-substitution) and two variations in the number of ethylene glycol units (2 or 1). We then tested the synthesized compounds for the BRD4 degradation activity of each. As expected, we found that 1,2D-EG2-MZ1 (2a), an MZ1 derivative with 1,2-disubstituted benzene possessing two ethylene glycol units, had an activity profile similar to that of MZ1 (1). Based on the structure of 2a, we then synthesized and evaluated four isomeric trivalent MZ1 derivatives, 15a-15d, having a tert-butyl ester unit on the benzene ring as a handle for further functionalization. Among the four isomers, 1,2,5T-EG2-MZ1 (15c) retained a level of BRD4 depletion activity similar to that of 2a without inducing a measurable Hook effect, and its BRD4 depletion kinetics was the same as that of MZ1 (1). Other isomers were also shown to retain BRD4 depletion activity. Thus, the trivalent PROTACs we synthesized here may serve as efficient platforms for further applications.

Mitochondrial Dynamics: Pathogenesis and Therapeutic Targets of Vascular Diseases.

Vascular diseases, particularly atherosclerosis, are associated with high morbidity and mortality. Endothelial cell (EC) or vascular smooth muscle cell (VSMC) dysfunction leads to blood vessel abnormalities, which cause a series of vascular diseases. The mitochondria are the core sites of cell energy metabolism and function in blood vessel development and vascular disease pathogenesis. Mitochondrial dynamics, including fusion and fission, affect a variety of physiological or pathological processes. Multiple studies have confirmed the influence of mitochondrial dynamics on vascular diseases. This review discusses the regulatory mechanisms of mitochondrial dynamics, the key proteins that mediate mitochondrial fusion and fission, and their potential effects on ECs and VSMCs. We demonstrated the possibility of mitochondrial dynamics as a potential target for the treatment of vascular diseases.

Vanadium-Catalyzed Terpolymerization of α,ω-Dienes with Ethylene and Cyclic Olefins: Ready Access to Polar-Functionalized Polyolefins

α,ω-Dienes are an important class of monomers due to their utility in the synthesis of cyclopolyolefins and reactive polyolefin intermediates. In this contribution, the terpolymerization of two α,ω-dienes (i.e., 1,5-hexadiene and 1,7-octadiene) with ethylene and various cyclic olefins [i.e., norbornene (NB), 5-ethylidene-2-norbornene (ENB), and dicyclopentadiene (DCPD)] catalyzed by a chelated imido vanadium complex has been examined. The ENB and DCPD diene termonomers provide additional sites for post-polymerization functionalization. Vanadium-catalyzed terpolymerization of the investigated α,ω-dienes yields polyolefins with a high molecular weight (Mw up to 200 × 103 g mol–1), unimodal and narrow molecular weight distribution, subambient glass transition temperatures (−30 < Tg °C < −3), and a proper content of C═C bonds. Comprehensive NMR investigation of the obtained polymers revealed that subtle changes in the α,ω-diene size have important effects on the numerous combinations of insertion paths (ring closure vs ring opening), from which different repeating units with a C═C bond in the side or main polymer chain and cyclic units are installed. Finally, the poly(ethylene-ter-1,5-hexadiene-ter-NB) was subjected to thiol-ene addition using thioglycolic acid, methyl thioglycolate, and N-acetyl-l-cysteine to access polar-functionalized polyolefins with a degree of functionalization and properties dependent on the thiol substitution.

Post-functionalized metal−organic framework for effective and selective removal of Hg(II) in aqueous media

For the serious hazards to human and natural environment caused by the toxic Hg(II), a new MOF-based adsorption material, UiO-66-AHMT, was designed and synthesized by incorporating the 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole molecule into the UiO-66-NH2 matrix and used for the removal of Hg(II) from aqueous media. As expected, UiO-66-AHMT exhibits rapid removal ability toward Hg(II) and maximum uptake capacity of 327.88 mg/g at 298 K and pH = 5, the adsorption capacity is improved significantly compared to the unmodified UiO-66-NH2 and comparable in the excellent UiO-66 based adsorbents reported so far. The adsorption behaviors of UiO-66-AHMT conform well to the pseudo-second-order and Langmuir models, respectively, which indicate that the adsorption process is mainly monolayer chemisorption. Meanwhile, UiO-66-AHMT shows strong selectivity to Hg(II) in the coexistence of varieties of metal ions and outstanding recyclability characteristics. To investigate the adsorption mechanism, the Hg(II) loaded UiO-66-AHMT mainly analyzed by XPS suggests that the nitrogen- and sulfur-containing groups in grafted molecule have the synergistic complexation to Hg(II). Furthermore, the binding strength between different function sites and Hg(II) are quantified and the stable complexation patterns are obtained based on the DFT calculation. These results strongly confirm that UiO-66-AHMT is a potential adsorbent in the practical treatment of wastewater containing Hg(II).

Evidence exclusive labels in cognitive research cause unstable prevalence estimates over time

AbstractBackgroundWhile age specific prevalence of dementia has recently declined in some high‐income countries it is unclear whether or how the milder end of the spectrum, including Mild Cognitive Impairment might also have changed across generations. This is likely to vary according to how cognitive impairment has been defined, including exclusion criteria. Previous findings from the Cognitive Function and Ageing Studies (CFAS) show prevalence of mild impairment has either increased or remained stable depending on the criteria used, while more severe impairment has decreased over time. Whether different subtypes of MCI used in contemporary studies have different time trends are not known.MethodData are from the English sites of the population representative Cognitive Function and Ageing Studies (CFAS). In 1991 7,635 participants were interviewed in CFAS I in Cambridgeshire, Nottingham and Newcastle with 1457 being diagnostically assessed. In the same geographical areas, the CFAS II investigators interviewed 7,796 individuals in 2011. Using consensus criteria, the population was categorised into MCI and ‘other cognitive impairment no dementia’ OCIND. Each cognitive group was further subtyped by the domain of cognition into amnestic (aMCI and aOCIND), non‐amnestic (naMCI and naOCIND) and multi‐domain (mMCI and mOCIND) groups, memory complaints were included as an OCIND subtype. Prevalence estimates for each were calculated using multinomial logistic regression, adjusted for age, sex and education. Results were standardized to the age‐sex specific UK and global population.ResultBetween 1991 and 2011 naMCI declined substantially (10.5% versus 6.3%), mMCI increased very slightly (5.9% versus 6.3%) while aMCI, whilst relatively rare, more than doubled in prevalence (1.2% versus 2.6%). In terms of OCIND, the prevalence of naOCIND has dropped (from 17.6% to 13.9%), aOCIND has increased (3.8% to 4.9%) while mOCIND has more than doubled (from 5.7% to 11.2%).ConclusionBetween 1991 and 2011 naMCI declined substantially (10.5% versus 6.3%), mMCI increased very slightly (5.9% versus 6.3%) while aMCI, whilst relatively rare, more than doubled in prevalence (1.2% versus 2.6%). In terms of OCIND, the prevalence of naOCIND has dropped (from 17.6% to 13.9%), aOCIND has increased (3.8% to 4.9%) while mOCIND has more than doubled (from 5.7% to 11.2%).

An Insight into the Proofreading Functions of Multisubunit DNA-Dependent RNA Polymerases and Their Catalytic Mechanism

Aim: To analyze the active sites of the proofreading (PR) functions in the multisubunit DNA-dependent RNA polymerases (MSU RNAPs) from prokaryotes, chloroplasts and eukaryotes, and propose a plausible unified catalytic mechanism for these enzymes.&#x0D; Study Design: Data collected on these enzymes from bioinformatics, biochemical, site-directed mutagenesis (SDM), X-ray crystallography and cryo-electron microscopy (cryo-EM) were used for the analyses.&#x0D; Methodology: The protein sequence data of MSU RNAPs from prokaryotes, prokaryotic-types (plant chloroplasts) and eukaryotes were obtained from PUBMED and SWISS-PROT databases. The advanced version of Clustal Omega was used for protein sequence analysis. Along with the conserved motifs identified by the bioinformatics analysis, the data already available from biochemical and SDM experiments, and X-ray crystallographic and cryo-EM data on these enzymes are also used to confirm the possible amino acids involved in the active site of the PR function in these MSU RNAPs&#x0D; Results: All the seven types of MSU RNAPs (I-VII) reported from prokaryotes to eukaryotes were analyzed by the multiple sequence alignment (MSA) software, Clustal Omega, to find out conservations among them. The MSA analysis showed many conserved amino acid motifs including small and large peptide regions from the MSU RNAPs of prokaryotes, eukaryotes and plant chloroplasts. Interestingly, the catalytic amino acid and template-binding pairs are highly conserved in all these polymerases, with a few exceptions. Most of them use a basic amino acid (R/K/H) for initiating catalysis and an -YG/FG- pair for template-binding. Some odd type of catalytic amino acids and template-binding pairs are observed in human pathogens, parasites and organisms which cannot ferment sugars. In all the MSU RNAPs, the proposed polymerase catalytic region also possessed three invariant Cs and an invariant H within it. The invariant Cs is shown to bind a zinc atom and proposed to involve in the PR function by excising any misincorporated nucleotide during the transcription process. In the plant-specific MSU RNAPs IV and V, which involve in transcriptional gene silencing in plants, the catalytic and template-binding pairs do not follow the regular distance conservations as observed with other five of the MSU RNAPs. Their polymerase/PR active site regions are similar to RNAP III rather than to RNAP II, as all three make only low molecular weight RNAs.&#x0D; Conclusions: All the known MSU RNAPs possess three invariant Cs and an invariant H embedded within the polymerase active site itself. The three invariant Cs are shown to bind a zinc atom and the invariant H could act as the proton acceptor from a metal-bound water molecule, for initiating excision of the mismatches by a Zn-mediated hydrolysis. Thus, the PR function in MSU RNAPs is integrated within the polymerase active site itself, which is in sharp contrast to the PR functions reported in DNA-dependent DNA polymerases and RNA-dependent RNA polymerases. Therefore, all the seven MSU RNAPs from prokaryotes and eukaryotes are proposed to follow a unified mechanism to excise the mismatches during transcription. The discovery of intrinsic self-correcting RNA transcription mechanism fulfils the missing link in molecular evolution.

Aggregation-Induced Emission-Active Poly(phenyleneethynylene)s for Fluorescence and Raman Dual-Modal Imaging and Drug-Resistant Bacteria Killing.

Poly(phenyleneethynylene) (PPE) is a widely used functional conjugated polymer with applications ranging from organic optoelectronics and fluorescence sensors to optical imaging and theranostics. However, the fluorescence efficiency of PPE in aggregate states is generally not as good as their solution states, which greatly compromises their performance in fluorescence-related applications. Herein, a series of PPE derivatives with typical aggregation-induced emission (AIE) properties is designed and synthesized. In these PPEs, the diethylamino-substituted tetraphenylethene units function as the long-wavelength AIE source and the alkyl side chains serve as the functionalization site. The obtained AIE-active PPEs with large π-conjugation show strong aggregate-state fluorescence, interesting self-assembly behaviors, inherently enhanced alkyne vibrations in the Raman-silent region of cells, and efficient antibacterial activities. The PPE nanoparticles with good cellular uptake capability can clearly and sensitively visualize the tumor region and residual tumors via their fluorescence and Raman signals, respectively, to benefit the precise tumor resection surgery. After post-functionalization, the obtained PPE-based polyelectrolyte can preferentially image bacteria over mammalian cells and possesses efficient photodynamic killing capability against Gram-positive and drug-resistant bacteria. This work provides a feasible design strategy for developing functional conjugated polymers with multimodal imaging capability as well as photodynamic antimicrobial ability.

Insights on Luminescent Micro- and Nanospheres of Infinite Coordination Polymers.

Coordination polymers have been extensively studied in recent years. Some of these materials can exhibit several properties such as permanent porosity, high surface area, thermostability and light emission, as well as open sites for chemical functionalization. Concerning the fact that this kind of compounds are usually solids, the size and morphology of the particles are important parameters when an application is desired. Inside this context, there is a subclass of coordination polymers, named infinite coordination polymers (ICPs), which auto-organize as micro- or nanoparticles with low crystallinity. Specifically, the particles exhibiting spherical shapes and reduced sizes can be better dispersed, enter cells much easier than bulk crystals and be converted to inorganic materials by topotactic transformation. Luminescent ICPs, in particular, can find applications in several areas, such as sensing probes, light-emitting devices and bioimaging. In this review, we present the state-of-the-art of ICP-based spherical particles, including the growth mechanisms, some applications for luminescent ICPs and the challenges to overcome in future commercial usage of these materials.

Elemental 2D Materials: Solution‐Processed Synthesis and Applications in Electrochemical Ammonia Production

AbstractGraphene and related elemental 2D materials have become core materials in nanotechnology and shown great promise for industrially important electrocatalysis reactions. Although excellent progress has been made over the past few years, research into the field of elemental 2D materials beyond graphene is still at an early stage. Importantly, recent research has revealed the promising efficacy of elemental 2D materials as effective nitrogen reduction reaction (NRR) electrocatalysts due to their many excellent properties including high surface activities, acting as active sites for effective functionalization and defect engineering. This review provides a comprehensive account of recent advances in elemental 2D materials with a major focus on the solution‐based synthesis routes and their applications in electrocatalytic NRR for ammonia (NH3) production. After a concise overview of elemental 2D materials, the advantages and challenges of currently available methods for the synthesis of these 2D materials are discussed. Then, the review focuses on the use of these emerging 2D materials in the electrocatalytic reduction of N2 for sustainable (NH3) synthesis. Finally, the challenges still to be addressed, and important perspectives in this attractive field are emphasized.

Structural Magnetic Resonance Imaging Correlated with Motor Function of Upper Extremity in Patients with Chronic Stroke

Abstract Background Ischemic cerebrovascular stroke is defined as an acute neurological dysfunction caused by focal cerebral infarction after decrease in the blood supply of the brain either by stenosis or occlusion leading to gross physical impairment or disability lasting more than 24 hours. Objective To assess correlation between site of infarction and upper extremity ( UE) function in chronic stroke patients. Methodology A cross sectional study with (30) Patients with chronic ischemic stroke ( &amp;gt;3 months) suffering from persistent UE motor function impairment, MRI brain done to assess the site of infarction. UE motor function assessment using the Fugl Meyer Assessment (FMA-UE) Scale. Results The current study found that no significant correlation between the site of infarction and UE motor function. Conclusion We concluded that the site of infarction not correlated with UE motor function in chronic stroke patients.