Nuclear Magnetic Resonance Chemical Shift as a Probe for Single-Molecule Charge Transport

Existing modelling tools, developed to aid the design of efficient molecular wires and to better understand their charge-transport behaviour and mechanism, have limitations in accuracy and computational cost. Further research is required to develop faster and more precise methods that can yield information on how charge transport properties are impacted by changes in the chemical structure of a molecular wire. In this study, we report a clear semilogarithmic correlation between charge transport efficiency and nuclear magnetic resonance chemical shifts in multiple series of molecular wires, also accounting for the presence of chemical substituents. The NMR data was used to inform a simple tight-binding model that accurately captures the experimental single-molecule conductance values, especially useful in this case as more sophisticated density functional theory calculations fail due to inherent limitations. Our study demonstrates the potential of NMR spectroscopy as a valuable tool for characterising, rationalising, and gaining additional insights on the charge transport properties of single-molecule junctions.

The feasibility and safety of laparoscopic inguinal hernia repair as a 24-h day surgery for patients aged 80 years and older: a retrospective cohort study

INTRODUCTION

As the proportion of aging adults increases and inguinal hernia repair becomes increasingly popular as a day surgery, the demand for laparoscopic inguinal hernia repair as a day surgery is increasing among patients aged 80 years and older. Relevant research needs to be completed, so we aimed to evaluate laparoscopic inguinal hernia repair as a 24-h day surgery for this group of patients.

METHODS

In this retrospective cohort study, we utilized propensity score matching to analyze the data of patients who underwent laparoscopic inguinal hernia repair at a day surgery center between January 1, 2019, and March 1, 2022. Patients were divided into ≥ 80 years old and < 80 years old groups. We compared the perioperative laboratory results, perioperative outcomes, and 1-year complications between the two groups.

RESULT

A total of 554 patients were included in the study. After propensity score matching, 292 patients were included in the matched cohort (98 patients in the ≥ 80 years old group and 194 patients in the < 80 years old group). During hospitalization, there were significant differences in ASA classification, Caprini score, length of hospital stays, risk of thrombosis, and delayed discharge rate. No significant difference was found in the incidence of total postoperative complications between the two groups at the 1-year follow-up (HR: 0.96, 95% CI 0.36-2.54, P = 0.96).

CONCLUSION

In our study, LIHR as a 24-h day surgery was safe and effective for patients over 80 years old. However, to reduce the rate of delayed discharge, cautious perioperative evaluation is necessary.

Elective Nodal Irradiation vs. Involved-Field Irradiation for Stage Ⅱ-Ⅳ Cervical Esophageal Squamous Cell Carcinoma Patients Undergoing Definitive Concurrent Chemoradiotherapy: A Retrospective Propensity Study with Eight-Year Survival Outcomes

PURPOSE/OBJECTIVE(S)

Definitive concurrent chemoradiotherapy (dCCRT) is suggested as the standard treatment for cervical esophageal squamous cell carcinoma (CESCC). This retrospective propensity study compared the eight-year survival outcomes and acute treatment toxicities of these patients treated with elective nodal irradiation (ENI) versus involved-field irradiation (IFI).

MATERIALS/METHODS

Patients with stage Ⅱ-Ⅳ CESCC treated with dCCRT in our institution between January 1, 2007 and December 31, 2020 were enrolled in the study. All the patients were restaged according to the American Joint Commission (AJCC) 8th edition criteria. The propensity score matching (PSM) was used to minimize the effects of treatment selection bias and potential confounding factors including sex, age, ECOG score, clinical T stage (cT), clinical N stage (cN), clinical TNM stage (cTNM) and radiation dose between the ENI group and IFI group. Survival and the prognostic factors were evaluated.

RESULTS

The 131 eligible patients underwent ENI (60 patients, 45.8%) or IFI (71 patients, 54.2%). The median follow-up time was 95.3 months (range, 28.0-186.2 months) for all the patients. The median OS, 1-, 3-, 5-, and 8-year OS rates were 44.4 months, 87.8%, 55.5%, 39.0%, and 28.3%, respectively. After PSM, there were 49 patients in each group. The median OS, 1-, 3-, 5-, and 8-year OS rates for ENI and IFI group were 32.0 months, 83.7%, 48.9%, 38.8% and 32.4% versus 45.2 months, 89.8%, 52.7%, 38.2%, 26.6%, respectively (P = 0.984; HR 0.99, 95% CI 0.61-1.62). Similar locoregional control was obtained in both groups. The tendency of leukocytopenia and neutropenia was higher in ENI than in IFI (59.2% versus 38.8%; P = 0.068 and 30.6% versus 14.3%; P = 0.089) at the end of dCCRT.

CONCLUSION

Cervical esophageal squamous cell carcinoma patients undergoing definitive concurrent chemoradiotherapy has a satisfactory prognosis with organ conservation. The involved-field irradiation might be a better alternative owing to similar overall survival outcomes and local control with less toxicity of myelosuppression.

Gadolinium (III)-Chelated Deformable Mesoporous Organosilica Nanoparticles as Magnetic Resonance Imaging Contrast Agent

Magnetic resonance imaging (MRI) contrast agents, such as Magnevist (Gd-DTPA), are routinely used for detecting tumors at an early stage. However, the rapid clearance by the kidney of Gd-DTPA leads to short blood circulation time, which limits further improvement of the contrast between tumorous and normal tissue. Inspired by the deformability of red blood cells, which improves their blood circulation, this work fabricates a novel MRI contrast agent by incorporating Gd-DTPA into deformable mesoporous organosilica nanoparticles (D-MON). In vivo distribution shows that the novel contrast agent is able to depress rapid clearance by the liver and spleen, and the mean residence time is 20 h longer than Gd-DTPA. Tumor MRI studies demonstrated that the D-MON-based contrast agent is highly enriched in the tumor tissue and achieves prolonged high-contrast imaging. D-MON significantly improves the performance of clinical contrast agent Gd-DTPA, exhibiting good potential in clinical applications.

Enhanced charge transport across molecule-nanoparticle-molecule sandwiches

The electrical properties of large area molecular devices consisting of gold nanoparticles (GNPs) sandwiched between a double layer of alkanedithiol linkers have been examined. These devices have been fabricated by a facile bottom-up assembly in which an alkanedithiol monolayer is first self-assembled on an underlying gold substrate followed by nanoparticle adsorption and then finally assembly of the top alkanedithiol layer. These devices are then sandwiched between the bottom gold substrates and a top eGaIn probe contact and current-voltage (I-V) curves recorded. Devices have been fabricated with 1,5-pentanedithiol, 1,6-hexanedithiol, 1,8-octanedithiol and 1,10-decanedithiol linkers. In all cases the electrical conductance of the double SAM junctions with GNPs is higher than the corresponding and much thinner single alkanedithiol SAM. Competing models for this enhanced conductance are discussed and it is suggested to have a topological origin arising from how the devices assemble or structure during the fabrication, which gives more efficient cross device electron transport pathways without the GNPs producing short circuits.

Printable assemblies of perovskite nanocubes on meter-scale panel

Hierarchical assemblies of functional nanoparticles can have applications exceeding those of individual constituents. Arranging components in a certain order, even at the atomic scale, can result in emergent effects. We demonstrate that printed atomic ordering is achieved in multiscale hierarchical structures, including nanoparticles, superlattices, and macroarrays. The CsPbBr₃ perovskite nanocubes self-assemble into superlattices in ordered arrays controlled across 10 scales. These structures behave as single nanoparticles, with diffraction patterns similar to those of single crystals. The assemblies repeat as two-dimensional planar unit cells, forming crystalline superlattice arrays. The fluorescence intensity of these arrays is 5.2 times higher than those of random aggregate arrays. The multiscale coherent states can be printed on a meter-scale panel as a micropixel light-producing layer of primary-color photon emitters. These hierarchical assemblies can boost the performance of optoelectronic devices and enable the development of high-efficiency, directional quantum light sources.

Influence of Elasticity of Hydrogel Nanoparticles on Their Tumor Delivery

Polymeric nanocarriers have a broad range of clinical applications in recent years, but an inefficient delivery of polymeric nanocarriers to target tissues has always been a challenge. These results show that tuning the elasticity of hydrogel nanoparticles (HNPs) improves their delivery efficiency to tumors. Herein, a microfluidic system is constructed to evaluate cellular uptake of HNPs of different elasticity under flow conditions. It is found that soft HNPs are more efficiently taken up by cells than hard HNPs under flow conditions, owing to the greater adhesion between soft HNPs and cells. Furthermore, in vivo imaging reveals that soft HNPs have a more efficient tumor delivery than hard HNPs, and the greater targeting potential of soft HNPs is associated with both prolonged blood circulation and a high extent of cellular adhesion.

Gold Nanoparticle-Bridge Array to Improve DNA Hybridization Efficiency of SERS Sensors

The interfacial mass transfer rate of a target has a significant impact on the sensing performance. The surface reaction forms a concentration gradient perpendicular to the surface, wherein a slow mass transfer process decreases the interfacial reaction rate. In this work, we self-assembled gold nanoparticles (AuNPs) in the gap of a SiO₂ opal array to form a AuNP-bridge array. The diffusion paths of vertical permeability and a microvortex effect provided by the AuNP-bridge array synergistically improved the target mass transfer efficiency. As a proof of concept, we used DNA hybridization efficiency as a research model, and the surface-enhanced Raman spectroscopy (SERS) signal acted as a readout index. The experimental verification and theoretical simulation show that the AuNP-bridge array exhibited rapid mass transfer and high sensitivity. The DNA hybridization efficiency of the AuNP-bridge array was 15-fold higher than that of the AuNP-planar array. We believe that AuNP-bridge arrays can be potentially applied for screening drug candidates, genetic variations, and disease biomarkers.

A Separation-Sensing Platform Performing Accurate Diagnosis of Jaundice in Complex Biological Tear Fluids

The detection of biomarkers in tears has aroused great interest owing to the advantages of non-invasive and rapid collection. The combination of ultrasensitivity and label-free detection of surface-enhanced Raman spectroscopy (SERS) sensors is expected to achieve real-time diagnosis in home medical care. However, the surface of SERS sensors is susceptible to biofouling and inactivation by biological impurities in tears, resulting in rapid degradation of sensitivity, limiting the commercialization of point-of-care devices. Herein, a binary nanosphere array with dual properties is constructed as a separation-sensing platform for the diagnosis of target molecules in tears. The upper part of the structure is composed of Au nanoparticles (AuNPs) and a sputtering Au layer, which can bind the target molecules that interact with Au and provide high-strength and high-density SERS hotspots. The lower half is an inactive SiO₂ nanosphere array with periodic large pores that allows biological impurities to penetrate the lower part and be separated from the target analyte. Furthermore, this substrate was integrated into homemade tear kits, enabling simultaneous tear collection, pre-separation, and detection. Combined with the Raman spectra of tears and LDA analysis, we successfully identified patients with jaundice in clinics. This platform is expected to provide an opportunity for early disease screening based on biological fluids.

Self-Assembled Supercrystals Enhance the Photothermal Conversion for Solar Evaporation and Water Purification

Photothermal materials can convert renewable solar energy into thermal energy and have great potential for solar water evaporation. Copper sulfide (Cu_{2- x} S) is an easily available and inexpensive plasmonic material with a high photothermal conversion efficiency and can be applied to solar evaporation and water purification. Monodispersed Cu₇ S₄ nanoparticles (NPs) and supercrystalline self-assembled superparticles are obtained via wet chemical synthesis and micelle self-assembly. The photothermal properties of the superstructures are investigated using the finite difference time domain method and laser radiation photothermography. The results show that the electromagnetic field intensity and photothermal efficiency of the self-assembly are significantly higher than those of isolated NPs, which is due to the plasmonic coupling of the NPs. The evaporation efficiency of the superstructure is significantly higher than that of isolated NPs, the metal salt ion and total organic carbon concentrations in the waterbody significantly decrease after evaporation, and the water polluted by high salt and organic dye concentrations is purified. The water quality significantly improves after the lake water from Fuxian Lake in the Yunnan-Guizhou Plateau of China is used for solar evaporation. The color changes from pale yellow to colorless and the ion and total organic carbon contents significantly decrease.

Genome editing efficiency of four Drosophila suzukii endogenous U6 promoters

The invasive spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) has caused serious economic losses to the fruit industry. The conventional control methods have many limitations and genetic engineering technologies such as CRISPR/Cas9-mediated gene drive are promising approaches. In the CRISPR/Cas9 system, the transcriptional regulatory elements play an important role in the activities of gRNA. Thus, in order to improve the genome editing efficiency of the CRISPR/Cas9 system in D. suzukii, we cloned and tested four endogenous U6 promoters to drive mutagenesis of the white gene. Our results showed that all the four promoters could be used with variable efficiency. The promoter DsU6-3 had the highest genome editing efficiency among the four DsU6 promoters. Compared with the DsU6-3 promoter, the DmU6:3 promoter showed lower efficiency to drive mutagenesis in D. suzukii. These findings expand the range of promoters available to express gRNAs in D. suzukii, facilitating the basic and applied research on this important pest.

Spatial Confinement Tunes Cleavage and Re-Formation of C=N Bonds in Fluorescent Molecules

Molecules in confined spaces exhibit unusual behaviors that are not typically observed in bulk systems. Such behavior can provide alternative strategies for exploring new reaction pathways. Cleavage of the C=N bond of Nile red (NR) in solution is an irreversible reaction. Here, we used spatial confinement within a cationic micelle-confined system to convert this reaction to a reversible process. The fluorescence of NR shifted between red and green for nine cycles. The new chemical pathway based on spatial confinement can be attributed to two factors: increasing the local concentration of reactants and reducing the reaction energy barrier. This effect is supported by both experimental evidence and theoretical calculations. The cross-linked silica shell comprising the confinement chamber stabilizes the enclosed molecules. This reduces fluorophore leakage and maintains fluorescence intensity in most environments, including in solution, on paper, and in hydrogel films, and expands practical applications in encrypted information and multi-informational displays.

Differences in hypertension and prehypertension among people living with and without HIV in China: role of HIV infection and antiretroviral therapy

OBJECTIVES

Hypertension is a growing health concern in people living with HIV (PLWH). However, association between HIV infection and hypertension is equivocal.

METHODS

In all, 1472 PLWH and 2944 HIV-negative individuals frequency-matched by age and sex were derived from the baseline survey of Comparative HIV and Aging Research in Taizhou (CHART), China. Prehypertension was defined as systolic blood pressure (BP) of 120-139 mmHg and/or diastolic blood pressure of 80-89 mmHg.

RESULTS

Despite the fact that prevalence of hypertension was overall lower among PLWH than among HIV-negative people (21.1% vs. 29.1%, P < 0.001), it was similar at ages 18-29 (7.6% vs. 8.5%) and 30-44 years (17.1% vs. 18.5%) but significantly lower in PLWH at ages 45-59 (26.1% vs. 40.7%) and 60-75 years (37.1% vs. 57.3%). Prehypertension prevalence was consistently higher in PLWH across all age groups. In the model adjusting for traditional risk factors, HIV infection was associated with hypertension (adjusted odds ratio [aOR] = 1.27, 95% confidence interval: 1.04-1.55) and prehypertension (aOR = 1.77, 95% CI: 1.51-2.08), and attenuated after additional adjustment for abdominal obesity. Age-stratified analysis showed that these associations of HIV with hypertension were observed at ages 18-29 and 30-44 years and associations with prehypertension were observed at ages 18-29, 30-44 and 45-59 years only. Years since HIV diagnosis and stavudine use were the HIV-specific factors independently associated with hypertension or/and prehypertension.

CONCLUSIONS

HIV infection is independently associated with prehypertension and hypertension especially at younger ages, and this risk may increase as treatment becomes prolonged. Our findings reinforce the urgent necessity for active BP screening and control strategies be adopted for PLWH in China.

Apelin-13 regulates angiotensin ii-induced Cx43 downregulation and autophagy via the AMPK/mTOR signaling pathway in HL-1 cells

Atrial fibrillation is associated with atrial remodeling, in which connexin 43 (Cx43) and cell hypertrophy play important roles. In this study, apelin-13, an aliphatic peptide, was used to explore the protective effects of the adenosine monophosphate-activated protein kinase (AMPK)/mTOR signaling pathway on Cx43 expression and autophagy, using murine atrial HL-1 cells. The expression of Cx43, AMPK, B-type natriuretic peptide (BNP) and pathway-related proteins was detected by Western blot analysis. Cellular fluorescence imaging was used to visualize Cx43 distribution and the cytoskeleton. Our results showed that the Cx43 expression was significantly decreased in HL-1 cells treated with angiotensin II but increased in cells additionally treated with apelin-13. Meanwhile, apelin-13 decreased BNP expression and increased AMPK expression. However, the expression of Cx43 and LC3 increased by apelin-13 was inhibited by treatment with compound C, an AMPK inhibitor. In addition, rapamycin, an mTOR inhibitor, promoted the development of autophagy, further inhibited the protective effect on Cx43 expression and increased cell hypertrophy. Thus, apelin-13 enhances Cx43 expression and autophagy via the AMPK/mTOR signaling pathway, and serving as a potential therapeutic target for atrial fibrillation.

Patience is not always a virtue: effects of terrain complexity on the host-seeking behaviour of adult blacklegged ticks, Ixodes scapularis, in the presence of a stationary host

Blacklegged ticks, Ixodes scapularis Say (Acari: Ixodidae), are the primary vectors of Lyme disease in the U.S.A. In this study, adult ticks were observed on public trails exhibiting increasing levels of terrain complexity with a potential host nearby. The goal of this study was to (a) examine the extent to which adult ticks may actively search (vs. sit-and-wait) for a nearby host, (b) determine whether or not ticks could locate the position of the host in natural conditions and (c) determine the role of terrain complexity on the distances ticks travelled in a short period of time (30 min). Results indicate that, when a potential stationary host is within 50 cm, ticks will utilize an active-search strategy. The majority of ticks moved in the direction of the host in natural conditions. Finally, ticks in a less complex terrain were more active and travelled greater horizontal distances than ticks in a more complex terrain. In conclusion, the use of an active-search approach would likely increase the foraging success of ticks, especially in terrains with minimal complexity, near host animals that have stopped to rest or feed, reinforcing that humans should be vigilant about checking for ticks after being outdoors.

A Metal-Organic Framework Nanosheet-Assembled Frame Film with High Permeability and Stability

The engineering of metal-organic frameworks (MOFs) into membranes and films is being investigated, to transform laboratory-synthesized MOFs into industrially viable products for a range of attractive applications. However, rational design and construction of highly permeable MOF thin films, without trade-offs in terms of structural mechanical stability, remains a significant challenge. Herein, a simple, general strategy is reported to prepare thin MOF nanosheet (NS)-assembled frame film via heteroepitaxial growth from metal hydroxide film. As the thin MOF NS-assembled film significantly enhances the permeability of mass though the film, the resultant gold nanoparticle (Au NP)@MOF film exhibits much higher catalytic efficiency than the Au NP@MOF bulk film. Meanwhile, the unique framework of the MOF NS-assembled film resists torsion and collapse, so the composite catalyst exhibits long-term stability.

Long noncoding RNA ABHD11-AS1 predicts the prognosis of pancreatic cancer patients and serves as a promoter by activating the PI3K-AKT pathway

OBJECTIVE

Accumulating evidence showed aberrant expressions of long non-coding RNAs (lncRNAs) strongly correlated to the development of cancers, including pancreatic cancer (PC). Whether lncRNA ABHD11-AS1 (ABHD11-AS1) is involved in PC remains to be elucidated. Thus, we aimed to evaluate the effects of ABHD11-AS1 on PC and the underlying molecular mechanism.

PATIENTS AND METHODS

RT-PCR was used to detect the expression level of ABHD11-AS1 in both PC tissue and cell lines. Then, the correlation of ABHD11-AS1 expression with clinicopathological features and prognosis was studied. Cell proliferation, apoptosis, migration and invasion abilities were detected by MTT, flow cytometry, and transwell assays. We further investigated the effect of abnormal ABHD11-AS1 expression through the PI3K/AKT and EMT pathway by Western blot assays in treated PC cells.

RESULTS

We found that the expression of ABHD11-AS1 was significantly increased in both PC tissues and cell lines. The clinical analysis revealed that a high level of ABHD11-AS1 expression was correlated with distant metastasis, TNM stage, and tumor differentiation. The Kaplan-Meier analysis showed that high ABHD11-AS1 expression levels predicted poorer survival. Moreover, univariate and multivariate analyses confirmed that the expression of ABHD11-AS1 was an independent and significant factor associated with poor overall survival rates. Loss-of-function experiments showed that the knockdown of ABHD11-AS1 suppressed PC cell proliferation, migration, invasion, and EMT in vitro. Mechanistically, the knockdown of ABHD11-AS1 decreased phospho(p) AKT and phospho(p) PI3K expression, but did not affect the AKT and PI3K expression in PC cells CONCLUSIONS: This study suggested that ABHD11-AS1 may potentially function as a valuable prognostic biomarker and a therapeutic target for PC patients.

General Strategy to Optimize Gas Evolution Reaction via Assembled Striped-Pattern Superlattices

Redesigning heterogeneous catalysts so that they can simultaneously integrate the efficiency and durability under reaction environments with respect to gas fuel production, such as hydrogen (H₂), oxygen (O₂), or carbon monoxide (CO), has proven challenging. In this work, we report the successful template-assisted printing-based assembly of platinum (Pt) nanoparticles (NPs) into striped-pattern (SP) superlattices to produce H₂. In comparison to drop-casting flat Pt NPs films, SP superlattices lead to higher mass transference and smaller bubble stretch force, representing a general strategy to improve the efficiency and durability of pre-existed Pt catalysts for the hydrogen evolution reaction (HER), as well as higher current densities than commercial Pt/C, Pt NP films, and many of the other Pt-based or non-Pt-based HER catalysts reported in the literature. The generic nature of template-assisted printing leads to flexibility in the composition, size, and shape of the constituent NPs or molecules, and thus extends such an accelerated technique for producing the oxygen evolution reaction and electrochemical reduction of CO₂ to CO.

Comparing Diagnostic Properties of the FRAIL-NH Scale and 4 Frailty Screening Instruments among Chinese Institutionalized Older Adults

OBJECTIVE

To examine the diagnostic test accuracy (DTA) of the FRAIL-NH and four frailty screening instruments among institutionalized older adults.

DESIGN

Cross-sectional study.

SETTING

Institutionalized setting, Jinan, China.

PARTICIPANTS

A total of 305 older adults (mean age 79.3 ± 8.4 years, 57.0% female) were enrolled from nursing homes.

MEASUREMENTS

Frailty was assessed by the FRAIL-NH, Physical Frailty Phenotype (PFP), FRAIL, Tilburg Frailty Indicator (TFI), and Groningen Frailty Indicator (GFI), respectively. The Comprehensive Geriatric Assessment (CGA) was used as a reference standard of frailty. The receiver operating characteristic (ROC) curve was plotted to examine the DTA of five frailty screening instruments against the CGA. The optimal cut-point was determined by the maximum value of the Youden index (YI, calculated as sensitivity + specificity - 1).

RESULTS

The prevalence of frailty ranged from 25.9% (FRAIL) to 56.4% (GFI). Areas under the curve (AUCs) against the CGA ranged from 0.80 [95% confidence interval (CI) 0.74 - 0.85: FRAIL] to 0.83 (95% CI 0.78 - 0.88: PFP). At their original cut-points, all five frailty screening instruments presented low sensitivity (32.9% - 69.3%) and high specificity (80.0% - 93.8%), as well as high positive predictive values (90.7% - 94.9%) and low negative predictive values (33.2% - 48.1%). At their optimal cut-points, the sensitivity and specificity of the FRAIL-NH, PFP, and FRAIL tended to be balanced, and their correctly classified rates (76.1% - 81.3%) and kappa values (0.465 - 0.523) increased a lot. ROC contrasts showed that all five frailty screening instruments had similarly good diagnostic accuracy (χ2: 0.0003 - 1.38, P > .05).

CONCLUSION

In the institutionalized setting, the specific FRAIL-NH, self-report FRAIL, TFI, and GFI as well as hybrid PFP, show similarly good diagnostic properties in identifying frailty against the CGA.

Oral vaccination with the porcine circovirus type 2 (PCV-2) capsid protein expressed by Lactococcus lactis induces a specific immune response against PCV-2 in mice

AIMS

Porcine circovirus type 2 (PCV2) can cause postweaning, multisystemic wasting syndrome in pigs, which leads to enormous losses in the swine industry worldwide. Here, a genetically engineered Lactococcus strain expressing the main protective antigen of PCV2, the Cap protein, was developed to act against PCV2 infection as an oral vaccine.

METHODS AND RESULTS

Expression of the Cap protein was confirmed via western blot, ELISA and fluorescence microscopy. Over 90% of the recombinant pAMJ399-Cap/MG1363 survived a simulated gastrointestinal transit. It also survived the murine intestinal tract for at least 11 days. Then, the safety and immunogenicity of pAMJ399-Cap/MG1363 in orally immunized mice was evaluated. The levels of the sIgA, IgG and cytokines (IL-4 and IFN-γ) obtained from the mice immunized with pAMJ399-Cap/MG1363 were significantly higher than those in the control groups.

CONCLUSIONS

pAMJ399-Cap/MG1363 can survive in the gastrointestinal transit and effectively induce mucosal, cellular and humoral immune response against PCV2 infection via oral administration.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates the potential of the genetically engineered Lactococcus lactis as a candidate for an oral vaccine against PCV2.

Signal-Off Electrogenerated Chemiluminescence Biosensing Platform Based on the Quenching Effect between Ferrocene and Ru(bpy)32+-Functionalized Metal-Organic Frameworks for the Detection of Methylated RNA

N⁶-methyladenine (m⁶A), one of the most common chemical modifications of eukaryotic RNA, participates in many important biological processes. An effective strategy for the quantitative determination of m⁶A is of great significance. Herein, we used methylated microRNA-21 (miRNA21) as the model target to propose a simple and sensitive electrogenerated chemiluminescence (ECL) biosensing platform to detect a specific m⁶A RNA sequence. This strategy is based on the fact that the anti-m⁶A-antibody can specifically recognize and bind to the m⁶A site in the RNA sequence, resulting in a quenching effect between Ru(bpy)₃²⁺-functionalized metal-organic frameworks and ferrocene. Luminescent metal-organic frameworks (Ru@MOFs) not only act as ECL indicators but also serve as nanoreactors for the relative ECL reactions owing to their porous or multichannel structure, which overcomes the fact that Ru(bpy)₃²⁺ is easily released when used for aqueous-phase detection, thus enhancing the ECL efficiency. Moreover, the ECL method has fewer modification steps and uses only one antibody to recognize the target RNA sequence, which simplifies the operation process and reduces the detection time, presenting a wide linear range (0.001-10 nM) for m⁶A RNA determination with a low detection limit (0.0003 nM). Additionally, this developed strategy was validated for m⁶A RNA detection in human serum. Thus, the ECL biosensing method provides a new method for m⁶A RNA determination that is simple, highly specific, and sensitive.

Effects of Lactococcus lactis MG1363 producing fusion proteins of bovine lactoferricin-lactoferrampin on growth, intestinal morphology and immune function in weaned piglet

AIMS

We developed a strategy for localized delivery of the LFCA (lactoferricinlactoferrampin), which is actively synthesized in situ by Lactococcus lactis (pAMJ399-LFCA/LLMG1363), and explored the possibility of using pAMJ399-LFCA/LLMG1363 as an alternative additive diet to antibiotics.

METHODS AND RESULTS

The antimicrobial activities of the LFCA derived from pAMJ399-LFCA/LLMG1363 were tested in vitro. The results showed that LFCA had an inhibitory effect on Staphylococcus aureus, Escherichia coli and Salmonella enteritidis. Then, the pAMJ399-LFCA/LLMG1363 was used as an additive diet for piglets. Our data demonstrated that oral administration of pAMJ399-LFCA/LLMG1363 significantly improved the average daily gain, feed-to-gain ratio, intestinal mucosal integrity and decreased the serum endotoxin and d-lactic acid levels. The mRNA expression levels of intestinal tight junction proteins (including occludin, Claudin-1 and ZO-1) were significantly upregulated by pAMJ399-LFCA/LLMG1363 administration. The serum immunoglobulin G (IgG) levels, intestinal secretory immunoglobulin A (sIgA) levels, IL-2, IL-10 and TGF-β levels were significantly increased by pAMJ399-LFCA/LLMG1363. Furthermore, our data revealed that oral administration of pAMJ399-LFCA/LLMG1363 significantly increased the number of general Lactobacillus, and decreased the total viable E. coli counts in the ileum and cecum contents.

CONCLUSIONS

We developed a novel pAMJ399-LFCA/LLMG1363 secreting LFCA, which had probiotic effects on the growth performance, intestinal morphology, intestinal barrier function and immunological indices of weaned piglets.

SIGNIFICANCE AND IMPACT OF THE STUDY

pAMJ399-LFCA/LLMG1363, with probiotic effects on the health of weaned piglets, may be a promising feed additive for weaned piglets.

Coordination mode engineering in stacked-nanosheet metal-organic frameworks to enhance catalytic reactivity and structural robustness

Optimising the supported modes of atom or ion dispersal onto substrates, to synchronously integrate high reactivity and robust stability in catalytic conversion, is an important yet challenging area of research. Here, theoretical calculations first show that three-coordinated copper (Cu) sites have higher activity than four-, two- and one-coordinated sites. A site-selective etching method is then introduced to prepare a stacked-nanosheet metal–organic framework (MOF, CASFZU-1)-based catalyst with precisely controlled coordination number sites on its surface. The turnover frequency value of CASFZU-1 with three-coordinated Cu sites, for cycloaddition reaction of CO₂ with epoxides, greatly exceed those of other catalysts reported to date. Five successive catalytic cycles reveal the superior stability of CASFZU-1 in the stacked-nanosheet structure. This study could form a basis for the rational design and construction of highly efficient and robust catalysts in the field of single-atom or ion catalysis.

Engineering the coordination mode of atom or ion onto the substrate remains challenging. Here, guided by theoretical calculation, the authors prepare stacked-nanosheet MOF based catalyst with precisely controlled coordination sites on the surface and enhanced catalytic reactivity and structural robustness.

Ruthenium@N-doped graphite carbon derived from carbon foam for efficient hydrogen evolution reaction

Ru nanoparticles doped in carbon foam were encapsulated in nitrogen-doped graphite carbon materials (Ru-NGC). The resultant Ru-NGC possesses superior hydrogen evolution activity with a small onset potential of 9.5 mV and excellent durability due to the optimized Ru electronic state in nitrogen-doped graphite.

A Metastable Crystalline Phase in Two-Dimensional Metallic Oxide Nanoplates

A simple method was adopted in which ultrathin cerium oxide nanoplates (<1.4 nm) were synthesized to increase the surface atomic content, allowing transformation from a face-centered cubic (fcc) phase to a body-centered tetragonal (bct) phase. Three types of cerium oxide nanoparticles of different thicknesses (1.2 nm ultrathin nanoplates, 2.2 nm nanoplates, and 5.4 nm nanocubes) were examined using transmission electron microscopy and X-ray diffraction. The metastable bct phase was observed only in ultrathin nanoplates. Thermodynamic energy analysis confirmed that the surface energy of the ultrathin nanoplates is the cause of the remarkable stabilization of the metastable bct phase. The mechanism of surface energy regulation can be expanded to other metallic oxides, thus providing a new means for manipulating and stabilizing novel materials under ambient conditions that otherwise would not be recovered.

Superficial-Layer-Enhanced Raman Scattering (SLERS) for Depth Detection of Noncontact Molecules

Although the strength of Raman signals can be increased by many orders of magnitude on noble metal nanoparticles, this enhancement is confined to an extremely short distance from the Raman-active surface. The key to the development of Raman spectroscopy for applications in diagnosis and detection of cancer and inflammatory diseases, and in pharmacology, relies on the capability of detecting analytes that are noninteractive with Raman-active surfaces. Here, a new Raman enhancement system is constructed, superficial-layer-enhanced Raman scattering (SLERS), by covering elongated tetrahexahedral gold nanoparticle arrays with a superficial perovskite (CH₃ NH₃ PbBr₃ ) film. Plasmonic decay is depressed along the vertical direction away from the noble metal surface and the penetration depth is increased in the perovskite media. The vertical penetration of SLERS is verified by the spatial distribution of the analytes via Raman imaging in layer-scanning mode.

[Effect of oral appliance on reproductive system of the male New-Zealand rabbit with obstructive sleep apnea-hypopnea syndrome]

Objective: To observe the effect of the mandible advanced device on the reproductive system of the male New-Zealand rabbit with obstructive sleep apnea-hypopnea syndrome (OSAHS). Methods: Thirty male New-Zealand white rabbits were randomly divided into three groups (with 10 rabbits in each group): sleep apnea-hypopnea syndrome group (group OSAHS), mandible advanced device group (group MAD) and control group. On the basis of the OSAHS animal model, mandible advanced devices were used for group MAD animals. After intervention for 8 weeks (sleeping by dorsal position, 4-6 hours/d), the samples were gained from the animals under general anesthesia and observed under the transmission electron microscope (TEM) and the AX-80 universal microscope. The cauda epididymis was obtained to be observed the number, viability, motility and abnormal rate of spermatozoa. Results: Compared with the control group, the upper airway space, the saturation of blood oxygen, partial pressure of oxygen, pH, the number, viability rate and motility rate of spermatozoa in cauda epididymis of the group OSAHS were significant decreased (all P<0.05), and the partial pressure of carbon dioxide and the rate of teratospermia was significant increased (both P<0.05). But compared with the control group, these indexes mentioned above in the group MAD showed no statistical significance (all P>0.05). TEM and the light microscope showed that the status of spermatogenic cell, seminiferous tubule and spermatogenic epithelium was improved in the group MAD. The correlation analysis showed that the saturation of blood oxygen had a negative correlation with the rate of teratospermia (r=-0.614, P<0.001). Conclusion: The damage of spermatogenic cells and the decrease of the sperm quality caused by OSAHS in New-Zealand rabbits could be improved by the mandible advanced devices.