Posterior open wound healing in immediate implant placement using reactive soft tissue versus absorbable collagen sponge: a retrospective cohort study

The soft and hard tissue healing of open wounds in immediate implant placement are yet to be explored. The aim of this study was to compare the clinical outcomes of open wound healing using reactive soft tissue (RST) and absorbable collagen sponge (ACS). Forty implants placed immediately in posterior sockets were included; autologous RST was used in 20 and ACS substitute was used in 20. Soft tissue healing was primarily assessed through a novel scoring system and the evaluation of gingival recession. The horizontal bone width (HBW) and interproximal marginal bone level (MBL) were measured on radiographs to observe the hard tissue healing. No significant difference in total soft tissue healing score was observed at 2 weeks postoperatively. Notably, the ACS group showed better tissue colour (P = 0.016) but worse fibrous repair (P = 0.043) scores than the RST group. Gingival recession levels were comparable in the two groups, both before tooth extraction and after placement of the restoration. Regarding hard tissue, HBW and MBL changes showed no intergroup differences. Within the limitations of this study, both RST and ACS seemed effective for open wound closure, achieving ideal soft and hard tissue healing in immediate implant placement.

Liquid Metal Encased in Biomimic Polydopamine Armor to Reinforce Photothermal Conversion and Photothermal Stability

Liquid metal (LM) faces numerous obstacles like spontaneous coalescence, prone oxidizability, and deterioration in photothermal conversion, impeding the potential application as photothermal agent. To tackle these issues, several studies have focused on surface engineering strategy. Developing a feasible and efficient surface engineering strategy is crucial to prevent the aggregation and coalescence of LM, while also ensuring exceptional photothermal conversion and biosecurity. In order to achieve these goals in this work, the biomimetic polydopamine (PDA) armor was chosen to encase a typical LM (eutectic gallium-indium-tin alloy) via self-polymerization. Characterization results showed that the PDA encased LM nanoparticle exhibited enhanced photothermal stability, photothermal conversion, and biosecurity, which could be derived from the following factors: (1) The PDA protective shell acted as an "armor", isolating LM from dissolved oxygen and water, inhibiting heating-accelerated oxidation and shape morphing. (2) The exceptional near-infrared absorption of PDA was conducive to the photothermal conversion. (3) The biomimetic characteristic of polydopamine (PDA) was advantageous for improving the biosecurity. Hence, this work presented a new surface engineering strategy to reinforce LM for photothermal conversion application.

Precise arrangement of metal atoms at the interface by a thermal printing strategy

The kinetics and pathway of most catalyzed reactions depend on the existence of interface, which makes the precise construction of highly active single-atom sites at the reaction interface a desirable goal. Herein, we propose a thermal printing strategy that not only arranges metal atoms at the silica and carbon layer interface but also stabilizes them by strong coordination. Just like the typesetting of Chinese characters on paper, this method relies on the controlled migration of movable nanoparticles between two contact substrates and the simultaneous emission of atoms from the nanoparticle surface at high temperatures. Observed by in situ transmission electron microscopy, a single Fe3O4 nanoparticle migrates from the core of a SiO2 sphere to the surface like a droplet at high temperatures, moves along the interface of SiO2 and the coated carbon layer, and releases metal atoms until it disappears completely. These detached atoms are then in situ trapped by nitrogen and sulfur defects in the carbon layer to generate Fe single-atom sites, exhibiting excellent activity for oxygen reduction reaction. Also, sites' densities can be regulated by controlling the size of Fe3O4 nanoparticle between the two surfaces. More importantly, this strategy is applicable to synthesize Mn, Co, Pt, Pd, Au single-atom sites, which provide a general route to arrange single-atom sites at the interface of different supports for various applications.

[Early brain imaging changes and its influence on electrode impedance after implantation of 3.0 T MRI-compatible deep brain stimulation system in Parkinson's disease subthalamic nucleus]

Objective: To analyze the imaging changes of in the early period after subthalamic nucleus (STN) deep brain stimulation (DBS) surgery for Parkinson's disease (PD) and its impact on electrode impedance by the application of 3.0T MRI-compatible devices. Methods: A retrospective analysis was performed for the data of 43 PD patients who underwent 3.0T MRI-compatible STN-DBS surgery from October 2022 to April 2023 at the First Affiliated Hospital of USTC(Anhui Provincial Hospital), including 27 males and 16 females, aged 43-68 (56±5) years. All patients underwent postoperative 3.0T MRI, CT scans,and impedance measurements 1 week postoperatively.Fifteen patients underwent 3.0T MRI and impedance measurements 1 month postoperatively. The differences in impedance of electrode contacts before and after the 3.0T MRI scans were compared. The occurrence of peri-lead cerebral edema (PLE) in patients was analyzed, as well as the differences in PLE detection rates between the two imaging methods, and the differences in the incidence and volume of PLE at different microelectrode recordings, the occurrence and detection of postoperative PLE, and different microelectrode recording (MER) times and different time nodes were compared. The correlation between electrode impedance and the volume of edema around the nucleus was analyzed. Results: All 43 patients successfully underwent surgery, with a total of 86 electrodes implanted. There was no significant difference in electrode impedance values before and after the 3.0T MRI examinations at 1 week and 1 month postoperatively. The PLE detection rate with 3.0T MRI was 95.12%(39/43), which is significantly higher than that of CT imaging 17.07% (7/43)(χ2=50.705, P<0.001). One week after surgery, the incidence and volume of PLE were higher in the multiple MER group compared with the single MER group, but the difference was not statistically significant. The volume of PLE [M(Q1, Q3) 0 (0, 1.211) cm3] at 1 month was significantly smaller than that at 1 week [0.243 (0, 2.914) cm3] (Z=-3.408, P=0.001). The impedance of electrode contacts within 1 month postoperatively showed a trend of initial decrease followed by an increase, which was negatively correlated with SE volume(r=-0.317, P=0.014). Conclusions: The application of 3.0T MRI-compatible DBS devices in the surgical treatment of PD patients improves the accuracy of early postoperative imaging assessment. The electrode impedance is more stable as the edema around the nucleus subsided at 1 month after surgery, which is suitable for the first program control.

[Analysis of complications and learning curve effects related to deep brain stimulation surgery in 822 Parkinson's disesase patients with the same surgeon]

Objective: To analyze the complications related to deep brain stimulation(DBS) surgery in Parkinson's disease(PD) patients and to determine whether there is a learning curve effect in terms of complications. Methods: Retrospective analysis of the DBS surgical data of 822 PD patients performed by the same surgeon at the First Affiliated Hospital of the University of Science and Technology of China (Anhui Provincial Hospital) from December 2012 to December 2022. The complications related to DBS were evaluated and analyzed the complications of every 100 DBS surgery were further analyzed. Results: A total of 822 PD patients, 453 males and 369 females, aged 31-80 years old, were included. The minimum follow-up period after DBS surgery is 6 months. Surgical related complications occurred in 55 patients (6.69%), including 5 patients (0.61%) with slight bleeding around the electrode, 1 patient (0.12%) with cerebral infarction, 4 patients (0.49%) with postoperative epilepsy, 42 patients (5.11%) with postoperative delirium, 2 patients (0.24%) with respiratory distress, and 1 patient (0.12%) with acute cardiac insufficiency. There were 16 cases (1.94%) of hardware related complications in DBS, of which 4 cases (0.48%) had infection, 1 case (0.12%) had a broken angle at the connection between the pulse generator and the extension wire, 8 cases (0.97%) had an excessively tight extension wire, and 3 cases (0.36%) had an IPG bag hematoma. In the infected cases, 2 patients removed IPG and extension wires. There were 7 cases (0.85%) of stimulus related complications, including 4 cases (0.61%) with programmed sensory abnormalities, 1 case (0.12%) with postoperative abnormal movements and dance like movements, and 2 cases (0.24%) with psychiatric symptoms. A comprehensive analysis was conducted on the above complications, among which 8 cases (0.97%) were relatively serious complications. After active treatment, satisfactory results were achieved, and none of them affected the patient's DBS treatment effect and no patients died. For every 100 cases of DBS surgery complications were analyzed, the percentage of complications decreased significantly from 14.50% (58 cases) in the first 400 cases to 4.73% (20 cases) in the last 400 cases (P<0.001). Conclusion: DBS surgery is safe and has an acceptable low incidence of complications. The incidence of complications also decreases with the accumulation of experience, showing a learning curve effect.

Cell-inspired design of cascade catalysis system by 3D spatially separated active sites

Cells possess isolated compartments that spatially confine different enzymes, enabling high-efficiency enzymatic cascade reactions. Herein, we report a cell-inspired design of biomimetic cascade catalysis system by immobilizing Fe single atoms and Au nanoparticles on the inner and outer layers of three-dimensional nanocapsules, respectively. The different metal sites catalyze independently and work synergistically to enable engineered and cascade glucose detection. The biomimetic catalysis system demonstrates ~ 9.8- and 2-fold cascade activity enhancement than conventional mixing and coplanar construction systems, respectively. Furthermore, the biomimetic catalysis system is successfully demonstrated for the colorimetric glucose detection with high catalytic activity and selectivity. Also, the proposed gel-based sensor is integrated with smartphone to enable real-time and visual determination of glucose. More importantly, the gel-based sensor exhibits a high correlation with a commercial glucometer in real samples detection. These findings provide a strategy to design an efficient biomimetic catalysis system for applications in bioassays and nanobiomedicines.

Axonal damage and astrocytosis are biological correlates of grey matter network integrity loss: a cohort study in autosomal dominant Alzheimer disease

Brain development and maturation leads to grey matter networks that can be measured using magnetic resonance imaging. Network integrity is an indicator of information processing capacity which declines in neurodegenerative disorders such as Alzheimer disease (AD). The biological mechanisms causing this loss of network integrity remain unknown. Cerebrospinal fluid (CSF) protein biomarkers are available for studying diverse pathological mechanisms in humans and can provide insight into decline. We investigated the relationships between 10 CSF proteins and network integrity in mutation carriers (N=219) and noncarriers (N=136) of the Dominantly Inherited Alzheimer Network Observational study. Abnormalities in Aβ, Tau, synaptic (SNAP-25, neurogranin) and neuronal calcium-sensor protein (VILIP-1) preceded grey matter network disruptions by several years, while inflammation related (YKL-40) and axonal injury (NfL) abnormalities co-occurred and correlated with network integrity. This suggests that axonal loss and inflammation play a role in structural grey matter network changes.

Key points

Abnormal levels of fluid markers for neuronal damage and inflammatory processes in CSF are associated with grey matter network disruptions.The strongest association was with NfL, suggesting that axonal loss may contribute to disrupted network organization as observed in AD.Tracking biomarker trajectories over the disease course, changes in CSF biomarkers generally precede changes in brain networks by several years.

Solid Migration to Assemble a Flower-like Nanozyme with Highly Dense Single Copper Sites for Specific Phenol Oxidation

Nanozymes with high catalytic stability and sustainability have emerged as powerful competitors to natural enzymes for diverse biocatalytic applications. However, constructing a nanozyme with high specificity is one of their biggest challenges. Herein, we develop a facile solid migration strategy to access a flower-like single copper site nanozyme (Cu SSN) via direct transformation of copper foam activated by 2-methylimidazole. With highly clustered CuN₃ sites whose local structure is similar to that of natural polyphenol oxidase, the Cu SSN exhibits excellent activity and specificity to oxidize phenols without peroxidase-like activity. Furthermore, the Cu SSN shows high sensitivity in the colorimetric detection of epinephrine with a low detection limit of 0.10 μg mL^-1, exceeding that of most previously reported enzyme-mimicking catalysts. This work not only provides a simple method for the large-scale preparation of high-performance nanozymes but also offers an inspiration for the design of highly specific nanozymes by mimicking the synergy among sites in natural enzymes.

[Recombinant Schistosoma japonicum egg ribonuclease SjCP1412 inhibits the activation of LX-2 hepatic stellate cells in vitro]

OBJECTIVE

To investigate the effect of recombinant Schistosoma japonicum egg ribonuclease SjCP1412 (rSjCP1412) on proliferation, cell cycle, apoptosis and activation of human hepatic stellate cells LX-2 in vitro, and explore the underlying mechanisms.

METHODS

The rSjCP1412 protein was expressed in Escherichia coli BL21 by prokaryotic expression, and the highly purified soluble rSjCP1412 protein was prepared by Ni NTA affinity chromatography and urea gradient refolding dialysis. Yeast RNA was digested using 12.5, 25.0, 50.0 µg rSjCP1412 proteins at 37 °C for 2, 3, 4 h, and the enzymatic products were electrophoresed on 1.5% agarose gel to observe the RNAase activity of rSjCP1412 protein. The proliferation of LX-2 cells stimulated by different doses of rSjCP1412 protein for 48 hours was measured using CCK-8 assay, and the apoptosis of LX-2 cells stimulated by different doses of rSjCP1412 protein for 48 hours was detected using the Annexin V-FITC/PI double staining, while the percentage of LX-2 cells at G0/G1, S and G2/M phases of cell cycle following stimulation with different doses of rSjCP1412 protein for 48 h was detected by DAPI staining. The type I collagen, type III collagen and α-smooth muscle actin (α-SMA) mRNA expression was quantified using quantitative florescent real-time PCR (qPCR) assay and Western blotting at transcriptional and translational levels in LX-2 cells following stimulation with different doses of rSjCP1412 protein for 48 h, while soluble egg antigen (SEA) served a positive control and PBS without rSjCP1412 protein as a normal control in the above experiments. The expression of collagen I, α-SMA and Smad4 protein was determined using Western blotting in LX-2 cells following stimulation with rSjCP1412 protein, transforming growth factor-β1 (TGF-β1) alone or in combination, to examine the signaling for the effect of rSjCP1412 protein on LX-2 cells.

RESULTS

The rSjCP1412 protein was successfully expressed and the highly purified soluble rSjCP1412 protein was prepared, which had a RNase activity. Compared with the normal group, the survival rates of LX-2 cells significantly decreased post-treatment with 12.5, 25.0, 50.0 µg/mL rSjCP1412 protein and SEA for 48 h (F = 22.417 and 20.448, both P values < 0.05). The apoptotic rates of LX-2 cells significantly increased post-treatment with 12.5, 25.0, 50.0 µg/mL rSjCP1412 protein for 48 h (F = 11.350, P < 0.05), and treatment with 12.5, 25.0, 50.0 µg/mL rSjCP1412 protein for 48 h resulted in arrest of LX-2 cells in G0/G1 phase (F = 20.710, P < 0.05). Treatment with 12.5, 25.0, 50.0 µg/mL rSjCP1412 protein for 48 h caused a significant reduction in relative expression levels of collagen I (F = 11.340, P < 0.05), collagen III (F = 456.600, P < 0.05) and α-SMA mRNA (F = 23.100, P < 0.05) in LX-2 cells, and both rSjCP1412 protein and SEA treatment caused a significant reduction in collagen I (F = 1 302.000, P < 0.05), α-SMA (F = 49.750, P < 0.05) and Smad4 protein expression (F = 52.420, P < 0.05) in LX-2 cells. In addition, rSjCP1412 protein treatment inhibited collagen I (F = 66.290, P < 0.05), α-SMA (F = 31.300, P < 0.05) and Smad4 protein expression (F = 27.010, P < 0.05) in LX-2 cells activated by TGF-β1.

CONCLUSIONS

rSjCP1412 protein may induce apoptosis of LX-2 cells and inhibit proliferation, cell cycle and activation of LX-2 cells through down-regulating Smad4 signaling molecules.

New macronarian from the Middle Jurassic of Chongqing, China: phylogenetic and biogeographic implications for neosauropod dinosaur evolution

Macronaria is a clade of gigantic body-sized sauropod dinosaurs widely distributed from the Late Jurassic to the Late Cretaceous globally. However, its origin, early diversification, and dispersal are still controversial. Here, we report a new macronarian Yuzhoulong qurenensis gen. et sp. nov. excavated from the Middle Jurassic (Bathonian) Lower Shaximiao Formation. Yuzhoulong qurenensis bears a unique combination of features, such as two accessory fossae that exist on the posterior surface of dorsal diapophyses of anterior dorsal vertebrae. Results of phylogenetic analyses demonstrate it is one of the earliest-diverging macronarians. This new material represents a Middle Jurassic fossil record of macronarian sauropod worldwide and improves the understanding of the early diversity and dispersal of the Neosauropoda. This discovery further supports that sauropods achieved a more rapid and varied morphological diversity and palaeogeographical dispersal in the Middle Jurassic.

A Conformational Variant of p53 (U-p53AZ) as Blood-Based Biomarker for the Prediction of the Onset of Symptomatic Alzheimer's Disease

BACKGROUND

Ongoing research seeks to identify blood-based biomarkers able to predict onset and progression of Alzheimer's disease (AD).

OBJECTIVE

The unfolded conformational variant of p53 (U-p53AZ), previously observed in AD individuals, was evaluated in plasma samples from individuals participating in the Australian Imaging, Biomarkers and Lifestyle (AIBL) cohort for diagnostic and prognostic assessment, validated on a neuropsychological-based diagnosis, over the course of six years.

DESIGN

Retrospective Longitudinal Prognostic biomarker study.

SETTING

Single-center study based on the AIBL cohort.

PARTICIPANTS

482 participants of the AIBL cohort, aged 60-85 years, without uncontrolled diabetes, vascular disease, severe depression or psychiatric illnesses.

MEASUREMENTS

The AlzoSure® Predict test, consisting of immunoprecipitation (IP) followed by liquid chromatography (LC) tandem mass spectrometry (MS/MS), was performed to quantify the AZ 284® peptide as readout of U-p53AZ and compared with an independent neuropsychological diagnosis. The amyloid load via amyloid β-positron emission tomography (Aβ-PET) and supporting clinical information were included where possible.

RESULTS

U-p53AZ diagnostic and prognostic performance was assessed in both time-independent and time-dependent (36, 72 and 90 months following initial sampling) analyses. Prognostic performance of Aβ-PET and survival analyses with different risk factors (gender, Aβ-PET and APOE ε4 allele status) were also performed. U-p53AZ differentiated neuropsychologically graded AD from non-AD samples, and its detection at intermediate/high levels precisely identified present and future symptomatic AD. In both time-independent and time-dependent prognostic analyses U-p53AZ achieved area under the curve (AUC) >98%, significantly higher than Aβ-PET AUCs (between 84% and 93%, P respectively <0.0001 and <0.001). As single factor, U-p53AZ could clearly determine the risk of AD neuropsychological diagnosis over time (low versus intermediate/high U-p53AZ hazard ratio=2.99). Proportional hazards regression analysis identified U-p53AZ levels as a major independent predictor of AD onset.

CONCLUSIONS

These findings support use of U-p53AZ as blood-based biomarker predicting whether individuals would reach neuropsychologically-defined AD within six years prior to AD diagnosis. Integration of U-p53AZ in screening processes could support refined participant stratification for interventional studies.

Facet Engineering of Nanoceria for Enzyme-Mimetic Catalysis

Nanomaterials with natural enzyme-mimicking characteristics have aroused extensive attention in various fields owing to their economical price, ease of large-scale production, and environmental resistance. Previous investigations have demonstrated that composition, size, shape, and surface modification play important roles in the enzymelike activity of nanomaterials; however, a fundamental understanding of the crystal facet effect, which determines surface energy or surface reactivity, has rarely been reported. Herein, fluorite cubic CeO₂ nanocrystals with controllably exposed {111}, {100}, or {110} facets are fabricated as proof-of-concept candidates to study the facet effect on the peroxidase-mimetic activity. Both experiments and theoretical results show that {110}-dominated CeO₂ nanorods (CeO₂ NR) possess the highest peroxidase-mimetic activity due to the richest defects on their surfaces, which are beneficial to capture metal atoms to further enrich their artificial enzymatic functionality for cascade catalysis. For instance, the introduction of atomically dispersed Au on CeO₂ NR surfaces not only enhances the peroxidase activity but also endows the obtained catalyst with glucose oxidase (GO_x)-mimicking activity, which realizes enzyme-free cascade reactions for glucose colorimetric detection. This work not only provides an understanding for crystal facet engineering of nanomaterials to enhance the catalytic activity but also opens up a new way for the design of biomimetic nanomaterials with multiple functions.

Dual confinement of high-loading enzymes within metal-organic frameworks for glucose sensor with enhanced cascade biocatalysis

The intrinsically fragile nature and leakage of the enzymes is a major obstacle for the commercial sensor of a continuous glucose monitoring system. Herein, a dual confinement effect is developed in a three dimensional (3D) nanocage-based zeolite imidazole framework (NC-ZIF), during which the high-loading enzymes can be well encapsulated with unusual bioactivity and stability. The shell of NC-ZIF sets the first confinement to prevent enzymes leakage, and the interior nanocage of NC-ZIF provides second confinement to immobilize enzymes and offers a spacious environment to maintain their conformational freedom. Moreover, the mesoporosity of the formed NC-ZIF can be precisely controlled, which can effectively enhance the mass transport. The resulted GOx/Hemin@NC-ZIF multi-enzymes system could not only realize rapid detection of glucose by colorimetric and electrochemical sensors with high catalytic cascade activity (with an 8.3-fold and 16-fold enhancements in comparison with free enzymes in solution, respectively), but also exhibit long-term stability, excellent selectivity and reusability. More importantly, the based wearable sweatband sensor measurement results showed a high correlation (>0.84, P < 0.001) with the levels measured by commercial glucometer. The reported dual confinement strategy opens up a window to immobilize enzymes with enhanced catalytic efficiency and stability for clinical-grade noninvasive continuous glucose sensor.

Biocompatible Ruthenium Single-Atom Catalyst for Cascade Enzyme-Mimicking Therapy

Rationally constructing single-atom enzymes (SAEs) with superior activity, robust stability, and good biocompatibility is crucial for tumor therapy but still remains a substantial challenge. In this work, we adopt biocompatible carbon dots as the carrier material to load Ru single atoms, achieving Ru SAEs with superior multiple enzyme-like activity and stability. Ru SAEs behave as oxidase, peroxidase, and glutathione oxidase mimics to synchronously catalyze the generation of reactive oxygen species (ROS) and the depletion of glutathione, thus amplifying the ROS damage and finally causing the death of cancer cells. Notably, Ru SAEs exhibit excellent peroxidase-like activity with a specific activity of 7.5 U/mg, which surpasses most of the reported SAEs and is 20 times higher than that of Ru/C. Theoretical results reveal that the electrons of the Ru 4d orbital in Ru SAEs are transferred to O atoms in H₂O₂ and then efficiently activate H₂O₂ to produce ^•OH. Our work may provide some inspiration for the design of SAEs for cancer therapy.

Tailoring Unsymmetrical-Coordinated Atomic Site in Oxide-Supported Pt Catalysts for Enhanced Surface Activity and Stability

The catalytic properties of supported metal heterostructures critically depend on the design of metal sites. Although it is well-known that the supports can influence the catalytic activities of metals, precisely regulating the metal-support interactions to achieve highly active and durable catalysts still remain challenging. Here, the authors develop a support effect in the oxide-supported metal monomers (involving Pt, Cu, and Ni) catalysts by means of engineering nitrogen-assisted nanopocket sites. It is found that the nitrogen-permeating process can induce the reconstitution of vacancy interface, resulting in an unsymmetrical atomic arrangement around the vacancy center. The resultant vacancy framework is more beneficial to stabilize Pt monomers and prevent diffusion, which can be further verified by the density functional theory calculations. The final Pt-N/SnO₂ catalysts exhibit superior activity and stability for HCHO response (26.5 to 15 ppm). This higher activity allows the reaction to proceed at a lower operating temperature (100 °C). Incorporated with wireless intelligent-sensing system, the Pt-N/SnO₂ catalysts can further achieve continuous monitoring of HCHO levels and cloud-based terminal data storage.

Integrating single-cobalt-site and electric field of boron nitride in dechlorination electrocatalysts by bioinspired design

The construction of enzyme-inspired artificial catalysts with enzyme-like active sites and microenvironment remains a great challenge. Herein, we report a single-atomic-site Co catalyst supported by carbon doped boron nitride (BCN) with locally polarized B-N bonds (Co SAs/BCN) to simulate the reductive dehalogenases. Density functional theory analysis suggests that the BCN supports, featured with ionic characteristics, provide additional electric field effect compared with graphitic carbon or N-doped carbon (CN), which could facilitate the adsorption of polarized organochlorides. Consistent with the theoretical results, the Co SAs/BCN catalyst delivers a high activity with nearly complete dechlorination (~98%) at a potential of -0.9 V versus Ag/AgCl for chloramphenicol (CAP), showing that the rate constant (k) contributed by unit mass of metal (k/ratio) is 4 and 19 times more active than those of the Co SAs/CN and state-of-the-art Pd/C catalyst, respectively. We show that Co single atoms coupled with BCN host exhibit high stability and selectivity in CAP dechlorination and suppress the competing hydrogen evolution reaction, endowing the Co SAs/BCN as a candidate for sustainable conversion of organic chloride.

Single Iron Site Nanozyme for Ultrasensitive Glucose Detection

Nanomaterials with enzyme-mimicking characteristics have engaged great awareness in various fields owing to their comparative low cost, high stability, and large-scale preparation. However, the wide application of nanozymes is seriously restricted by the relatively low catalytic activity and poor specificity, primarily because of the inhomogeneous catalytic sites and unclear catalytic mechanisms. Herein, a support-sacrificed strategy is demonstrated to prepare a single iron site nanozyme (Fe SSN) dispersed on the porous N-doped carbon. With well-defined coordination structure and high density of active sites, the Fe SSN performs prominent peroxidase-like activity by efficiently activating H₂ O₂ into hydroxyl radical (•OH) species. Furthermore, the Fe SSN is applied in colorimetric detection of glucose through a multienzyme biocatalytic cascade platform. Moreover, a low-cost integrated agarose-based hydrogel colorimetric biosensor is designed and successfully achieves the visualization evaluation and quantitative detection of glucose. This work expands the application of single-site catalysts in the fields of nanozyme-based biosensors and personal biomedical diagnosis.

3M™ Petrifilm™ Staph Express Count Plate Method for the Enumeration of Staphylococcus aureus in Selected Dairy Foods: Collaborative Study

The 3M™ Petrifilm™ Staph Express Count plate method was compared with AOAC Official Method 975.55 for the enumeration of Staphylococcus aureus in selected foods. Five foods—ice cream, raw milk, yogurt, whey powder, and cheese—were analyzed for S. aureus by 12 collaborating laboratories. For each food tested, the collaborators received 8 blind test samples consisting of a control sample, a low inoculation level, a medium inoculation level, and a medium inoculation level with background flora, each in duplicate. The mean log10 counts for the methods were comparable for all 5 foods. The repeatability and reproducibility variances of the 24 h Petrifilm Staph Express Count plate method were similar to those of the 72 h standard method.

P4363The predictive capacity of two- and three-dimensional echocardiography detected right ventricular strain in disease severity of pre-capillary pulmonary hypertension

Background

Pulmonary hypertension (PH) patients have poor prognosis due to progressive right ventricular (RV) dysfunction. As a low-cost and non-invasive tool, echocardiography is by far the most widely used technique to investigate the RV structure and function in PH patients. Recent studies showed that RV longitudinal strain (RVLS) measured by two- or three-dimensional echocardiography (2DE, 3DE) was correlated with RV function parameters and have the potential to predict the prognosis of PH patients. However, few studies have compared the value of 2DE- and 3DE- RVLS to predict disease severity of pre-capillary PH patients. Therefore, our study aims to compare the capacity of RVLS assessed by 3DE and 2DE in predicting disease severity of pre-capillary PH patients.

Methods

We consecutively enrolled 57 patients (18 males and 39 females, 35±13 years) with pre-capillary PH diagnosed by right heart catheterization in our center. Standard transthoracic echocardiography was performed in all participants. 2DE- RVLS were obtained from speckle-tracking analyses using GE EchoPAC version 201; while 3DE- RVLS were analyzed by TomTec 4D RV-Function 2.0. On the basis of the risk assessment strategy of 2015 ESC Guidelines for the diagnosis and treatment of pulmonary hypertension, all the participants were classified into low risk or intermediate-high risk groups. Linear regression analyses were performed to evaluate the correlations between RVLS and peak oxygen consumption (PVO2). In addition, receive operating characteristic curves (ROC) were used to compare the predictive values of 2DE- and 3DE-RVLS and identify the optimal cut points for the detection of low risk based on the risk assessment strategy of 2015 ESC Guidelines.

Results

Linear regression analyses showed a significant correlation between PVO2 and 2DE- RVLS (r=−0.484, P<0.001), while a relatively weaker correlation was observed between PVO2 and 3DE- RVLS (r=−0.299, P=0.024). ROC curve showed 2DE-RVEF had a better capacity to classify pre-capillary PH patients into low or intermediate-high risk groups (2DE- vs 3DE-: AUC=0.78, P=0.003 vs AUC=0.69, P=0.044). Optimal cut-offs found 2DE-RVEF <−13.85% had a 73.3% sensibility and 75.0% specificity to predict low risk.

Conclusions

Both two- and three-dimensional echocardiography detected RVLS had the potential to evaluate disease severity of pre-capillary PH patients, but the former may have a better predictive capacity.

Broadband, polarization insensitive low-scattering metasurface based on lossy Pancharatnam-Berry phase particles

In this paper, a novel composite metasurface (MS) with diffuse scattering and absorbing characteristics is proposed to reduce the radar cross section (RCS) of a metal target in a broad band. The combination of absorption and diffusion is realized based on lossy Pancharatnam-Berry (PB) phase particles. The units are arranged according to a coding sequence which is obtained by an optimization algorithm based on simulated annealing algorithm. Simulation results show that the MS obtained based on the optimized coding sequence is insensitive to polarization. Due to the combination of absorption and diffusion, the MS has good performance in both monostatic and bistatic scenarios. Finally, the proposed MS is fabricated and measured, and the experimental results are in good agreement with simulation results. A 10 dB backward reflection reduction can be achieved from 21GHz to 38GHz and a 15 dB backward reflection reduction can be achieved from 22GHz to 35GHz under normal incidence. Furthermore, the MS has good performance under large angle (<45°) incidence.

Unraveling the enzyme-like activity of heterogeneous single atom catalyst

Herein, we report a heterogeneous single iron atom catalyst exhibiting excellent peroxidase, oxidase and catalase enzyme-like activities (defined as single atom enzymes, SAEs), exceeding those of Fe₃O₄ nanozymes by a factor of 40.

Risk factors for intraoperative pressure injuries in patients undergoing digestive surgery: A retrospective study

AIM AND OBJECTIVE

To investigate the incidence of intraoperative blanchable erythema and pressure injuries in patients undergoing digestive surgery and to explore potential risk factors.

BACKGROUND

Pressure injuries pose significant economic and healthcare burden to patients and are used as one of the key indicators of nursing in the operation room with high incidence.

DESIGN

A retrospective observational study.

METHODS

Basic information and the results of 3S intraoperative risk assessment scale of pressure injury were obtained from the information system. And the patients with intraoperative blanchable erythema or pressure injuries were followed up for 72 hr by the information system. The clinical data were collected to analyse risk factors for intraoperative blanchable erythema and pressure injuries by univariate analysis and logistic regression analysis. STROBE checklist for cohort studies was applied in the preparation of the paper.

RESULTS

Of 5,136 surgical cases, 134 (2.61%) had blanchable erythema, 37 (0.72%) had intraoperative pressure injuries, and 8 (0.16%) had pressure injuries at 72-hr follow-up. Preoperative skin under compression, preoperative physical activity, surgical position and extra intraoperative pressure were considered independent risk factors for intraoperative pressure injuries.

CONCLUSION

The incidence of pressure injuries in our study was lower than those reported in the previous studies. Accessing preoperative skin under compression, preoperative physical activity, surgical position and extra intraoperative pressure was considered to be significant for preventing pressure injuries.

RELEVANCE TO CLINICAL PRACTICE

The findings suggest that preoperative skin under compression, preoperative physical activity, surgical position and extra intraoperative pressure are associated with intraoperative pressure injuries in patients undergoing digestive surgery.

Detection of Bisphenol A Using DNA-Functionalized Graphene Field Effect Transistors Integrated in Microfluidic Systems

Bisphenol A (BPA) detection has attracted much attention recently for its importance to food safety and environment. The DNA-functionalized solution-gated graphene transistors are integrated in microfluidic systems and used for recycling detections of BPA for the first time. In the presence of BPA, both single- and double-stranded DNA molecules are detached and released from the graphene surface in aqueous solutions, leading to the change of device electrical performance. The channel currents of the devices change monotonically with the concentration of BPA. Moreover, the devices modified with double-stranded DNA are more sensitive to BPA and show the detection limit down to 10 ng/mL. The highly sensitive label-free BPA sensors are expected to be used for convenient BPA detections in many applications.

Clinical utility of fibrin-related biomarkers in human acute pancreatitis

AIM

To investigate whether the four fibrin-related markers (FRMs) fibrin monomer (FM), D-dimer (D-D), fibrinogen (FIB), and fibrin degradation products (FDP) reflect the extent of coagulation activation in vivo and to assess the predictive value of the FRMs in determining persistent organ failure (POF) and pancreatic necrosis (PN) in acute pancreatitis (AP) patients.

METHODS

One hundred and fifty-two AP patients were included in this prospective observational study. The final outcome was disease severity assessed by presence of POF and PN. The levels of the four FRMs were measured on days 1, 2, 3, and 7 after admission. ROC curves were used to compare the sensitivity, specificity, PPV, and NPV of FM, D-D, and FDP in predicting POF and PN with those of regular biochemical markers C-reaction protein (CRP) and lactate dehydrogenase (LDH).

RESULTS

Of the 152 patients included, 32 had POF and 44 had PN. There was no significant difference in serum FM levels between AP with POF and AP without POF at the first week after admission. Patients with PN had significantly higher FM than those without PN on day 1 (P = 0.043), day 2 (P = 0.008), day 3 (P = 0.001), and day 7 (P = 0.002) after admission. D-D was significantly higher in patients with POF than in those without on day 1 (P = 0.001), day 2 (P = 0.004), day 3 (P = 0.000), and day 7 (P = 0.002). Patients with PN had significantly higher D-D on day 1 (P = 0.023), day 2 (P = 0.045), day 3 (P = 0.000), and day 7 (P = 0.000) after admission. FDP was significantly higher in patients with POF than in those without on day 1 (P = 0.000), day 2 (P = 0.000), day 3 (P = 0.000), and day 7 (P = 0.000). Patients with PN had signficantly higher FDP on day 2 (P = 0.021), day 3 (P = 0.000), and day 7 (P = 0.000) after admission. FIB did not differ significantly between AP patients with POF and those without, or between AP patients with PN and those without. ROC analysis revealed that D-D (AUC = 0.693) and FDP (AUC = 0.711) were superior to CRP (AUC = 0.615) and LDH (AUC = 0.672) in predicting POF on day 1 of hospital admission, and D-D (AUC = 0.832) and FDP (AUC = 0.814) were superior than LDH (AUC = 0.639) and CRP (AUC = 0.706) in predicting PN on day 3 of hospital admission.

CONCLUSION

Plasma FRMs in AP patients increase significantly on the first week after admission. FDP and D-D correlate with disease severity of AP and can be considered as a potentially useful tool for the early diagnosis of AP with POF and PN.

Highly sensitive solution-gated graphene transistor based sensor for continuous and real-time detection of free chlorine

The concentration of free chlorine used for sterilizing drinking water, recreational water, and food processing water is critical for monitoring potential environmental and human health risks, and should be strictly controlled. Here, we report a highly efficient solution-gated graphene transistor (SGGT) device, for the detection of free chlorine in a real-time and convenient manner with excellent selectivity and high sensitivity. The detection mechanism of the SGGT with Au gate electrode is attributed to two combined effects: the reduction of the free chlorine on Au gate electrode; and the direct oxidization of graphene by the free chlorine in solution. The SGGT device shows a linear response range of free chlorine from 1 μM to 100 μM, with detection limit as low as 100 nM, far beyond the sensitivity required for practical applications. Finally, we also demonstrate the performance of the SGGT for determination of free chlorine in local tap water samples. The results presented herein have important implications in the development of portable and disposable devices based on SGGT sensing platform for the simple, real-time, and selective determination of free chlorine.

Minimizing the Sample Sizes of Clinical Trials on Preclinical and Early Symptomatic Stage of Alzheimer Disease

BACKGROUND

Clinical trials of investigational drugs for Alzheimer disease (AD) increasingly focus on the prodromal (symptomatic) stage of the illness and now its preclinical (asymptomatic) stage. Sensitive and specific cognitive and functional endpoints are needed to track subtle cognitive and functional changes in the early and preclinical stages to minimize sample sizes in these trials.

OBJECTIVES

To identify informative items in a standard clinical assessment protocol and a psychometric battery that are predictive of onset of dementia symptom.

DESIGN

Longitudinal retrospective study.

SETTING

Washington University (WU) Knight Alzheimer Disease Research Center (ADRC).

PARTICIPANTS

A total of 735 individuals at least 65 years old and cognitively normal at baseline from a longitudinal clinical cohort at the WU Knight ADRC.

MEASUREMENTS

The annual clinical assessment included a wide spectrum of functional and cognitive domains; a comprehensive psychometric battery was completed about 2 weeks after the clinical evaluation. Psychometricians are blinded to the results of the clinical evaluation and to the prior performance of the participants on the psychometric tests.

RESULTS

The mean age at baseline of the 735 participants was 74.30 and 62.31% were female. 240 individuals developed prodromal dementia symptoms (consistent with mild cognitive impairment due to AD and with very mild AD dementia) during longitudinal follow-up (mean follow-up=6.79 years). Among a total of 562 items in the clinical and cognitive assessments under analysis, 292 (52%) were identified as informative because their longitudinal changes were predictive of symptomatic onset. When these items were used to form the functional and cognitive composites, the longitudinal rates of changes were free of a learning effect and captured subtle longitudinal progression prior to symptomatic onset. The rates of change were much greater right after the symptomatic onset than those from the functional and cognitive composites formed using non-informative items. Although the sample sizes for prevention trials (prior to symptomatic onset) using the informative items still yield large numbers, the sample sizes for early treatment trial (after symptomatic onset) was much smaller than those derived from all the items or from the non-informative items alone.

CONCLUSIONS

The antecedent longitudinal changes in nearly half of the items in a clinical assessment protocol and a comprehensive cognitive battery did not show statistically significant ability to predict the dementia symptom onset, and hence may be non-informative to track the preclinical functional and cognitive progression of AD. The remaining items, on the other hand, captured some of the preclinical changes prior to the symptom onset, but performed much better right after the symptom onset. Currently ongoing prevention trials on preclinical AD of elderly individuals may need to re-assess the sample sizes and statistical power.

[Progress of clinical correlation research on migraine and glaucoma]

Migraine is a common primary headache disorder. The estimated annual prevalence rate of migraine in China is 9.3%. Migraine is typically involved with a series of ocular symptoms including glaucoma, visual performance tests relevant to glaucoma exhibited correlation between glaucoma and migraine. Even though migraine patients exhibit no glaucoma-related signs during intermissions of migraine attacks, the results of visual function tests (visual field, electrophysiology, ocular imaging) relevant to glaucoma still indicate abnormalities. It is fairly typical that most of the patients may neglect their ocular problems when migraine breaks out. Epidemiological data suggests an increasing prevalence of migraine patients with glaucoma, particularly normal tension glaucoma. This paper reviews and discusses the effect of migraine on the clinical assessment and diagnosis of glaucoma. (Chin J Ophthalmol, 2018, 54: 224-228).

Indistinguishable heralded single photon generation via relative temporal multiplexing of two sources

Generating N single photons simultaneously is a formidable challenge due to the lack of deterministic single photon sources. Recent work [New J. Phys. 19, 063013 (2017] has proposed a relative multiplexing scheme that can enhance the N single photons probability with a minimum of active switching resources. We experimentally demonstrate relative temporal multiplexing on two photon sources with a 90% additional enhancement over the standard temporal multiplexing scheme demonstrated previously. 88 ± 11% visibility of Hong-Ou-Mandel quantum interference verifies the indistinguishability of the heralded single photons after the synchronization. This proof-of-principle demonstration points out the potential significance of the relative multiplexing scheme for large-scale photonic quantum information processing.

Modulator figure of merit for short reach data links

The traditional Mach-Zehnder modulator (MZM) figure of merit (FOM) has been defined as (V_π²)/υ_3dBe, and works effectively for LiNbO₃ long haul modulators. However, for plasma dispersion based electro-optic modulators, or any modulator that has an inherent relationship between its bandwidth, required drive voltage, and optical insertion loss/gain, this FOM is inappropriate. This is particularly true for short reach links with no optical amplification. In the following, we propose a new modulator FOM (M-FOM) based on device metrics that are essential for short-reach links, such as the peak-to-peak drive voltage, modulator rise-fall time, and relative optical modulation amplitude. Link sensitivity measurements from two MZMs that have different bandwidths and optical losses are compared using our M-FOM to demonstrate its utility. Furthermore, we present a novel application protocol of our M-FOM to provide deeper insight into the relative system impact that modulator performance has on data links with no optical amplification, by taking the ratio of M-FOMs from two modulators driven with the same radio frequency drive power.

Highly selective and sensitive sensor based on an organic electrochemical transistor for the detection of ascorbic acid

In this study, an organic electrochemical transistor sensor (OECT) with a molecularly imprinted polymer (MIP)-modified gate electrode was prepared for the detection of ascorbic acid (AA). The combination of the amplification function of an OECT and the selective specificity of MIPs afforded a highly sensitive, selective OECT sensor. Cyclic voltammetry and electrochemical impedance spectroscopy measurements were carried out to monitor the stepwise fabrication of the modified electrodes and the adsorption capacity of the MIP/Au electrodes. Atomic force microscopy was employed for examining the surface morphology of the electrodes. Important detection parameters, pH and detection temperature were optimized. With the change in the relative concentration of AA from 1μM to 100μM, the MIP-OECT sensor exhibited a low detection limit of 10nM (S/N > 3) and a sensitivity of 75.3μA channel current change per decade under optimal conditions. In addition, the MIP-OECT sensor exhibited excellent specific recognition ability to AA, which prevented the interference from other structurally similar compounds (e.g., aspartic acid, glucose, uric acid, glycine, glutathione, H₂O₂), and common metal ions (K⁺, Na⁺, Ca²⁺, Mg²⁺, and Fe²⁺). In addition, a series of vitamin C beverages were analyzed to demonstrate the feasibility of the MIP-OECT sensor. Using the proposed principle, several other sensors with improved performance can be constructed via the modification of organic electrochemical transistors with appropriate MIP films.

Can mean platelet volume play a role in evaluating the severity of acute pancreatitis?

AIM

To investigate serum mean platelet volume (MPV) levels in acute pancreatitis (AP) patients and assess whether MPV effectively predicts the disease severity of AP.

METHODS

We included 117 consecutive patients with AP as the AP group and 34 consecutive patients with colorectal polyps (before endoscopic treatment) as the control group. Complete blood counts, liver function, platelet indices (MPV), coagulation parameters, lactate dehydrogenase (LDH) and C-reactive protein (CRP) were measured on days 1, 2, 3 and 7 after admission. Receiver operating characteristic curves were used to compare the sensitivity and specificity of MPV, white blood cell (WBC), LDH and CRP in predicting AP severity. The Modified Glasgow Prognostic Score (mGPS) and the 2012 revised Atlanta criteria were used to evaluate disease severity in AP.

RESULTS

MPV levels were significantly lower in the AP group than in the control group on day 1 (P = 0.000), day 2 (P = 0.029) and day 3 (P = 0.001) after admission. In addition, MPV values were lower on day 1 after admission than on day 2 (P = 0.012), day 3 (P = 0.000) and day 7 (P = 0.002) in all AP patients. Based on the mGPS, 78 patients (66.7%) were diagnosed with mild and 39 patients (33.3%) with severe AP. There was no significant difference in mean MPV levels between patients diagnosed with mild and severe AP based on the mGPS (P = 0.424). According to the 2012 revised Atlanta criteria, there were 98 patients (83.8%) without persistent organ failure (OF) [non-severe acute pancreatitis (non-SAP) group] and 19 patients (16.2%) with persistent OF (SAP group). MPV levels were significantly lower in the SAP group than in the non-SAP group on day 1 after admission (P = 0.002). On day 1 after admission using a cut-off value of 6.65 fL, the overall accuracy of MPV for predicting SAP according to the 2012 revised Atlanta criteria (AUC = 0.716) had a sensitivity of 91.8% and a specificity of 47.4% and was superior to the accuracy of the traditional markers WBC (AUC = 0.700) and LDH (AUC = 0.697).

CONCLUSION

MPV can be used at no additional cost as a useful, non-invasive biomarker that distinguishes AP with persistent OF from AP without persistent OF on day 1 of hospital admission.

A novel method for non-destructive determination of hair photo-induced damage based on multispectral imaging technology

Extended exposure to sunlight may give rise to chemical and physical damages of human hairs. In this work, we report a novel method for non-destructive quantification of hair photodamage via multispectral imaging (MSI) technology. We show that the multispectral reflectance value in near-infrared region has a strong correlation with hair photodamage. More specifically, the hair segments with longer growing time and the same hair root segment after continuous ultraviolet (UV) irradiation displaying more severe photodamage observed via scanning electron microscopy (SEM) micrographs showed significantly higher multispectral reflectance value. Besides, the multispectral reflectance value of hair segments with different growing time was precisely reproduced by exposing the same hair root segment to specific durations of UV irradiation, suggesting that MSI can be adequately applied to determine the sunlight exposure time of the hair. The loss of cystine content of photodamaged hairs was identified to be the main factor that physiologically contributed to the morphological changes of hair surface fibers and hence the variation of their multispectral reflectance spectra. Considering the environmental information recording nature of hairs, we believe that MSI for non-destructive evaluation of hair photodamage would prove valuable for assessing sunlight exposure time of a subject in the biomedical fields.

Distributed electrode Mach-Zehnder modulator with double-pass phase shifters and integrated inductors

A novel high-speed Mach-Zehnder modulator (MZM) fully integrated into a 90 nm CMOS process is presented. The MZM features 'double-pass' optical phase shifter segments, and the first use of integrated inductors in a 'velocity-matched' distributed-electrode configuration.

Enhancing the heralded single-photon rate from a silicon nanowire by time and wavelength division multiplexing pump pulses

Heralded single photons produced on a silicon chip represent an integrated photon source solution for scalable photonic quantum technologies. The key limitation of such sources is their non-deterministic nature introduced by the stochastic spontaneous four-wave mixing (SFWM) process. Active spatial and temporal multiplexing can improve this by enhancing the single-photon rate without degrading the quantum signal-to-noise ratio. Here, taking advantage of the broad bandwidth of SFWM in a silicon nanowire, we experimentally demonstrate heralded single-photon generation from a silicon nanowire pumped by time and wavelength division multiplexed pulses. We show a 90±5% enhancement on the heralded photon rate at the cost of only 14±2% reduction to the signal-to-noise ratio, close to the performance found using only time division multiplexed pulses. As single-photon events are distributed to multiple wavelength channels, this new scheme overcomes the saturation limit of avalanche single-photon detectors and will improve the ultimate performance of such photon sources.