Multiscale Regulation of Ordered PtCu Intermetallic Electrocatalyst for Highly Durable Oxygen Reduction Reaction

Transforming the Pt-M alloy into an ordered intermetallic is an effective strategy to improve the electrocatalytic activity and stability toward the oxygen reduction reaction (ORR). However, the synthesis of nanosized intermetallics remains challenging. Herein, we report an efficient ORR electrocatalyst, consisting of a monodisperse nanosized PtCu intermetallic on hollow mesoporous carbon spheres (HMCS). As predicted by theoretical calculations, PtCu intermetallics exhibit beneficial electronic structure, with a low theoretical overpotential of 0.33 V and enhanced Cu stability. Resulting from the multiscale modulation of catalyst structure, the O-PtCu/HMCS catalyst delivers a high mass activity of 2.73 A cm-2Pt at 0.9 V and remarkable stability. Identical location transmission electron microscopy (IL-TEM) investigations demonstrate that the rate of carbon corrosion is alleviated on HMCS, which contributes to the long-term durability. This work provides a promising design strategy for an ORR electrocatalyst, and the IL-TEM investigations offer new perspectives for the performance enhancement mechanism.

[Comparison of the microbiota diversity between autogenous and anautogenous Culex pipiens pallens]

OBJECTIVE

To investigate the microbiota composition and diversity between autogenous and anautogenous Culex pipiens pallens, so as to provide insights into unraveling the pathogenesis of autogeny in Cx. pipiens pallens.

METHODS

Autogenous and anautogenous adult Cx. pipiens pallens samples were collected at 25 ℃, and the hypervariable regions of the microbial 16S ribosomal RNA (16S rRNA) gene was sequenced on the Illumina NovaSeq 6000 sequencing platform. The microbiota abundance and diversity were evaluated using the alpha diversity index, and the difference in the microbiota structure was examined using the beta diversity index. The microbiota with significant differences in the abundance between autogenous and anautogenous adult Cx. pipiens pallens samples was identified using the linear discriminant analysis effect size (LEfSe).

RESULTS

The microbiota in autogenous and anautogenous Cx. pipiens pallens samples belonged to 18 phyla, 28 classes, 70 orders, 113 families, and 170 genera, and the dominant phyla included Proteobacteria, Bacteroidetes, and so on. At the genus level, Wolbachia was a common dominant genus, and the relative abundance was (77.6 ± 11.3)% in autogenous Cx. pipiens pallens samples and (47.5 ± 8.5)% in anautogenous mosquito samples, while Faecalibaculum (0.4% ± 0.1%), Dubosiella (0.5% ± 0.0%) and Massilia (0.5% ± 0.1%) were specific species in autogenous Cx. pipiens pallens samples. Alpha diversity analysis showed that higher Chao1 index and ACE index in autogenous Cx. pipiens pallens samples than in anautogenous samples (both P values > 0.05), and lower Shannon index (P > 0.05) and Simpson index (P < 0.05) in autogenous Cx. pipiens pallens samples than in anautogenous samples. LEfSe analysis showed a total of 48 significantly different taxa between autogenous and anautogenous Cx. pipiens pallens samples (all P values < 0.05).

CONCLUSIONS

There is a significant difference in the microbiota diversity between autogenous and anautogenous Cx. pipiens pallens.

Comparative investigation of transport and deposition of nebulized particles in nasal airways following various middle turbinectomy

BACKGROUND

Topical intranasal medication is required following functional endoscopic sinus surgery (FESS). The optimal particle size of transnasal nebulization aimed at the sinonasal cavities is not conclusive. The current study aims to evaluate the effect of particle size and various surgery scope of middle turbinectomy (MT) on post-full FESS drug delivery to the sinonasal cavities.

METHODS

Sinonasal reconstructions were performed from post-full FESS CT scans in 6 chronic rhinosinusitis with nasal polyps (CRSwNP) patients. Four additional models representing alternative surgery scopes of MT were established from each post-FESS reconstruction for simulation data comparison. Airflow and particle deposition of nebulized delivery were simulated via computational fluid dynamics (CFD) and validated through in vitro experiments. The optimal particle sizes reaching a deposition of at least 75% of the maximum in the targeted regions were identified.

RESULTS

The drug deposition rate onto the targeted regions increased following MT, with the greatest deposition following posterior MT (P-MT). Droplets in the range of 18-26 μm reached a deposition of larger than 75% of the maximum onto the targeted regions. Drug delivery rate in the sinonasal cavities varied significantly among individuals and across different types of MT with varying surgical scopes.

CONCLUSIONS

This study is the first to investigate the effect of various surgery scope on drug delivery by transnasal nebulization to the sinonasal cavities. The findings strongly affirm the vast potential of transnasal nebulization as an effective post-FESS treatment option. Moreover, it emphasizes that the drug delivery process via atomizers to the nasal cavity and paranasal sinuses is highly sensitive to the particle size.

[A multicenter prospective study on early identification of refractory Mycoplasma pneumoniae pneumonia in children]

Objective: To explore potential predictors of refractory Mycoplasma pneumoniae pneumonia (RMPP) in early stage. Methods: The prospective multicenter study was conducted in Zhejiang, China from May 1st, 2019 to January 31st, 2020. A total of 1 428 patients with fever >48 hours to <120 hours were studied. Their clinical data and oral pharyngeal swab samples were collected; Mycoplasma pneumoniae DNA in pharyngeal swab specimens was detected. Patients with positive Mycoplasma pneumoniae DNA results underwent a series of tests, including chest X-ray, complete blood count, C-reactive protein, lactate dehydrogenase (LDH), and procalcitonin. According to the occurrence of RMPP, the patients were divided into two groups, RMPP group and general Mycoplasma pneumoniae pneumonia (GMPP) group. Measurement data between the 2 groups were compared using Mann-Whitney U test. Logistic regression analyses were used to examine the associations between clinical data and RMPP. Receiver operating characteristic (ROC) curves were used to analyse the power of the markers for predicting RMPP. Results: A total of 1 428 patients finished the study, with 801 boys and 627 girls, aged 4.3 (2.7, 6.3) years. Mycoplasma pneumoniae DNA was positive in 534 cases (37.4%), of whom 446 cases (83.5%) were diagnosed with Mycoplasma pneumoniae pneumonia, including 251 boys and 195 girls, aged 5.2 (3.3, 6.9) years. Macrolides-resistant variation was positive in 410 cases (91.9%). Fifty-five cases were with RMPP, 391 cases with GMPP. The peak body temperature before the first visit and LDH levels in RMPP patients were higher than that in GMPP patients (39.6 (39.1, 40.0) vs. 39.2 (38.9, 39.7) ℃, 333 (279, 392) vs. 311 (259, 359) U/L, both P<0.05). Logistic regression showed the prediction probability π=exp (-29.7+0.667×Peak body temperature (℃)+0.004×LDH (U/L))/(1+exp (-29.7+0.667×Peak body temperature (℃)+0.004 × LDH (U/L))), the cut-off value to predict RMPP was 0.12, with a consensus of probability forecast of 0.89, sensitivity of 0.89, and specificity of 0.67; and the area under ROC curve was 0.682 (95%CI 0.593-0.771, P<0.01). Conclusion: In MPP patients with fever over 48 to <120 hours, a prediction probability π of RMPP can be calculated based on the peak body temperature and LDH level before the first visit, which can facilitate early identification of RMPP.

Stabilizing Diluted Active Sites of Ultrasmall High-Entropy Intermetallics for Efficient Formic Acid Electrooxidation

The poisoning of undesired intermediates or impurities greatly hinders the catalytic performances of noble metal-based catalysts. Herein, high-entropy intermetallics i-(PtPdIrRu)2FeCu (HEI) are constructed to inhibit the strongly adsorbed carbon monoxide intermediates (CO*) during the formic acid oxidation reaction. As probed by multiple-scaled structural characterizations, HEI nanoparticles are featured with partially negative Pt oxidation states, diluted Pt/Pd/Ir/Ru atomic sites and ultrasmall average size less than 2 nm. Benefiting from the optimized structures, HEI nanoparticles deliver more than 10 times promotion in intrinsic activity than that of pure Pt, and well-enhanced mass activity/durability than that of ternary i-Pt2FeCu intermetallics counterpart. In situ infrared spectroscopy manifests that both bridge and top CO* are favored on pure Pt but limited on HEI. Further theoretical elaboration indicates that HEI displayed a much weaker binding of CO* on Pt sites and sluggish diffusion of CO* among different sites, in contrast to pure Pt that CO* bound more strongly and was easy to diffuse on larger Pt atomic ensembles. This work verifies that HEIs are promising catalysts via integrating the merits of intermetallics and high-entropy alloys.

Low-loaded Ru on hollow SnO2 for enhanced electrocatalytic hydrogen evolution

In response to the challenges of intermediate poisoning and the high cost of noble metal catalysts in the hydrogen evolution reaction (HER), we develop a Ru-doped SnO2 catalyst. This Ru-SnO2 catalyst has the characteristics of low Ru loading and a hollow structure, which endow it with good electrocatalytic activity and stability for the HER.

Intergrating Hollow Multishelled Structure and High Entropy Engineering toward Enhanced Mechano-Electrochemical Properties in Lithium Battery

Hollow multishelled structures (HoMSs) are attracting great interest in lithium-ion batteries as the conversion anodes, owing to their superior buffering effect and mechanical stability. Given the synthetic challenges, especially elemental diffusion barrier in the multimetal combinations, this complex structure design has been realized in low- and medium-entropy compounds so far. It means that poor reaction reversibility and low intrinsic conductivity remain largely unresolved. Here, a hollow multishelled (LiFeZnNiCoMn)3 O4 high entropy oxide (HEO) is developed through integrating molecule and microstructure engineering. As expected, the HoMS design exhibits significant targeting functionality, yielding satisfactory structure and cycling stability. Meanwhile, the abundant oxygen defects and optimized electronic structure of HEO accelerate the lithiation kinetics, while the retention of the parent lattice matrix enables reversible lithium storage, which is validated by rigorous in situ tests and theoretical simulations. Benefiting from these combined properties, such hollow multishelled HEO anode can deliver a specific capacity of 967 mAh g-1 (89% capacity retention) after 500 cycles at 0.5 A g-1 . The synergistic lattice and volume stability showcased in this work holds great promise in guiding the material innovations for the next-generation energy storage devices.

Pd 4d Orbital Overlapping Modulation on Au@Pd Nanowires for Efficient H2O2 Production

Isolating Pd atoms has been shown to be crucial for the design of a Pd-based electrocatalyst toward 2e- oxygen reduction reaction (ORR). However, there are limited studies focusing on the systematic compositional design that leads to an optimal balance between activity and selectivity. Herein, we design a series of Au@Pd core@shell structures to investigate the influence of the Pd 4d orbital overlapping degree on 2e- ORR performance. Density functional theory (DFT) calculations indicate that enhanced H2O2 selectivity and activity are achieved at Pdn clusters with n ≤ 3, and Pd clusters larger than Pd3 should be active for 4e- ORR. However, experimental results show that Au@Pd nanowires (NWs) with Pd4 as the primary structure exhibit the optimal H2O2 performance in an acidic electrolyte with a high mass activity (7.05 A mg-1 at 0.4 V) and H2O2 selectivity (nearly 95%). Thus, we report that Pd4, instead of Pd3, is the upper threshold of Pd cluster size for an ideal 2e- ORR. It results from the oxygen coverage on the catalyst surface during the ORR process, and such an oxygen coverage phenomenon causes electron redistribution and weakened *OOH binding strength on active sites, leading to enhanced activity of Pd4 with only 0.06 V overpotential in acidic media.

[Clinical analysis of allogeneic hematopoietic stem cell transplantation for seven cases of acute myeloid leukemia with BCR::ABL1 fusion]

Objective: To explore the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in acute myeloid leukemia (AML) patients with BCR::ABL1 fusion. Methods: The clinical data of seven AML patients with BCR::ABL1 fusion from November 2012 to January 2022 were retrospectively analyzed, and their survival status was followed up. Results: The median age of patients at the time of diagnosis was 35 years. Four cases (57.1%) were diagnosed with high leukocyte counts. All cases were assayed as BCR::ABL1 positive and accompanied by four types of gene mutations (NPM1, RUNX1, ASXL1, PHF6) . Seven patients received tyrosine kinase inhibitor (TKI) combined with induction chemotherapy and bridged to allo-HSCT, and six patients received maintenance therapy with TKI. Before allo-HSCT, six patients achieved complete remission, and four patients achieved complete molecular remission (CMR) . After allo-HSCT, the three remaining cases also achieved CMR. All patients were in remission post-allo-HSCT. One case died of infection, and the remaining cases survived without relapse. The 3-year cumulative overall survival rate was (80.0±17.9) %. Conclusions: TKI combined with traditional chemotherapy could achieve a high response rate in AML patients with BCR::ABL1 fusion. In addition, allo-HSCT could enhance the molecular response rate. Maintenance therapy post-HSCT with TKI could improve prognosis.

Improving Alkaline Hydrogen Oxidation through Dynamic Lattice Hydrogen Migration in Pd@Pt Core-Shell Electrocatalysts

Tracking the trajectory of hydrogen intermediates during hydrogen electro-catalysis is beneficial for designing synergetic multi-component catalysts with division of chemical labor. Herein, we demonstrate a novel dynamic lattice hydrogen (LH) migration mechanism that leads to two orders of magnitude increase in the alkaline hydrogen oxidation reaction (HOR) activity on Pd@Pt over pure Pd, even ≈31.8 times mass activity enhancement than commercial Pt. Specifically, the polarization-driven electrochemical hydrogenation process from Pd@Pt to PdHx @Pt by incorporating LH allows more surface vacancy Pt sites to increase the surface H coverage. The inverse dehydrogenation process makes PdHx as an H reservoir, providing LH migrates to the surface of Pt and participates in the HOR. Meanwhile, the formation of PdHx induces electronic effect, lowering the energy barrier of rate-determining Volmer step, thus resulting in the HOR kinetics on Pd@Pt being proportional to the LH concentration in the in situ formed PdHx @Pt. Moreover, this dynamic catalysis mechanism would open up the catalysts scope for hydrogen electro-catalysis.

Threshold of 25(OH)D and consequently adjusted parathyroid hormone reference intervals: data mining for relationship between vitamin D and parathyroid hormone

PURPOSE

By recruiting reference population, we aimed to (1): estimate the 25(OH)D threshold that maximally inhibits the PTH, which can be defined as the cutoff value for vitamin D sufficiency; (2) establish the PTH reference interval (RI) in population with sufficient vitamin D.

METHODS

Study data were retrieved from LIS (Laboratory Information Management System) under literature suggested criteria, and outliers were excluded using Tukey fence method. Locally weighted regression (LOESS) and segmented regression (SR) were conducted to estimate the threshold of 25(OH)D. Multivariate linear regression was performed to evaluate the associations between PTH concentration and variables including 25(OH)D, gender, age, estimated glomerular filtration rate (EGFR), body mass index (BMI), albumin-adjusted serum calcium (aCa), serum phosphate(P), serum magnesium(Mg), and blood collection season. Z test was adopted to evaluate whether the reference interval should be stratified by determinants such as age and gender.

RESULTS

A total of 64,979 apparently healthy subjects were recruited in this study, with median (Q1, Q3) 25(OH)D of 45.33 (36.15, 57.50) nmol/L and median (Q1, Q3) PTH of 42.19 (34.24, 52.20) ng/L. The segmented regression determined the 25(OH)D threshold of 55 nmol/L above which PTH would somewhat plateau and of 22 nmol/L below which PTH would rise steeply. Multivariate linear regression suggested that gender, EGFR, and BMI were independently associated with PTH concentrations. The PTH RI was calculated as 22.17-72.72 ng/L for subjects with 25(OH)D ≥ 55 nmol/L with no necessity of stratification according to gender, age, menopausal status nor season.

CONCLUSION

This study reported 25(OH)D thresholds of vitamin D sufficiency at 55 nmol/L and vitamin D deficiency at 22 nmol/L, and consequently established PTH RIs in subjects with sufficient vitamin D for northern China population for the first time.

[Untargeted metabolomics study of dexamethasone-induced congenital cleft palate in New Zealand rabbits]

Objective: To investigate the metabolic disorders in placental tissues of dexamethasone induced cleft palate mode. Methods: Twelve pregnant rabbits were randomly divided into dexamethasone group (experimental group, 8) and saline control group (4), and a certain amount of dexamethasone and saline were administered intramuscularly to the experimental and control groups respectively from embryonic days (ED) 13 to 16, and placental tissue samples were collected on day 21 of gestation. The corresponding profiles of the embryonic placental tissue samples were obtained by liquid chromatography-triple tandem quadrupole(LC-MS), and the metabolites of the embryonic placental tissues were characterized by principal component analysis among the dexamethasone-treated group with cleft palate (D-CP group), the dexamethasone-treated group without cleft palate (D-NCP group) and the control group. Results: There were significant metabolic differences among the D-CP group, D-NCP group and control group, with a total of 133 differential metabolites (VIP>1, P<0.05) involving in important metabolic pathways including vitamin B6 metabolism, lysine metabolism, arginine anabolic metabolism, and galactose metabolism. The four metabolites, vitamin B6, galactose, lysine and urea, differed among the three groups (P<0.05). There were significant differences in vitamin B6 (0.960±0.249, 0.856±0.368, 1.319±0.322), galactose (0.888±0.171, 1.033±0.182, 1.127±0.127), lysine (1.551±0.924, 1.789±1.435, 0.541±0.424) and urea (0.743±0.142, 1.137±0.301, 1.171±0.457, respectively) levels among control group, D-NCP group and D-CP group (F=5.90, P=0.008; F=5.59, P=0.009; F=4.26, P=0.025; F=5.29, P=0.012). Conclusions: The results indicated that dexamethasone induced cleft palate may be highly correlated with metabolic disorders including vitamin B6 metabolism, lysine metabolism, arginine anabolic metabolism and galactose metabolism.

Assessing the chronic hepatitis B adaptive immune response by profiling specific T-cell receptor repertoire

Challenges in assessing hepatitis B virus (HBV)-specific T cell immunity as an immunological biomarker still remain in chronic hepatitis B (CHB), such as the requirement of large quantities of cells. This study aims to conveniently assess HBV-specific T cells immunity in chronic HBV infected patients. We obtained T cell receptor β chains (TCRβs) from public databases and six acute hepatitis B patients to establish an HBV-specific TCRβs dataset. For some TCRs from one AHB patient, their specificities and epitopes were verified. The potential HBV-specific TCRβs from CHB patients were analyzed using GLIPH2 and established dataset. By analyzing two antiviral therapy cohorts including 42 CHB patients, we showed that individuals with better therapy response may depend more on newly emerging potential HBV-specific TCRβs. In a cross-sectional study containing 207 chronic HBV infected patients, the results exhibited that the characteristics of potential HBV-specific clusters were divergent between CHB and hepatocellular carcinoma patients. Our strategy could profile potential HBV-specific TCRβ repertoire using a small blood sample, which will complement traditional methods for assessing the HBV-specific T cell immunity.

A Peptide-Conjugated Probe with Cleavage-Induced Morphological Change for Treatment on Tumor Cell Membrane

Despite the promising advancements of in situ forming nanoassembly for the inhibition of tumor growth and metastasis, the lack of sufficient triggering sites and hardly controlling the forming position restrict their further developments. Herein, a smart transformable peptide-conjugated probe (DMFA) with enzyme cleavage-induced morphological change is designed for treatment on the tumor cell membrane. Specifically, after self-assembling into nanoparticles and anchoring on the cell membrane with sufficient interaction sites rapidly and stably, DMFA will be efficiently cleaved into α-helix forming part (DP) and β-sheet forming part (LFA) by overexpressed matrix metalloproteinase-2. Thus, the promoted Ca²⁺ influx by DP-induced cell membrane breakage and decreased Na⁺ /K⁺ -ATPase activity by LFA-assembled nanofibers wrapping the cells can inhibit PI3K-Akt signaling pathway, leading to the inhibition of tumor cell growth and metastasis. This peptide-conjugated probe undergoes in situ morphological transformation on the cell membrane, exhibiting great potential in tumor therapy.

Pseudo-Pt Monolayer for Robust Hydrogen Oxidation

Heteroepitaxial core-shell structure is conducive to combining the advantages of the epilayer and the substrate, creating a novel multifunctionality for catalysis application. Herein, we report a pseudomorphic-Pt atomic layer (PmPt) epitaxially growing on an IrPd-core matrix (PmPt@IrPd/C) as an efficient and stable catalyst for alkaline hydrogen oxidation reaction that exhibits ∼29.2 times more mass activity enhancement than that of benchmark Pt/C. The PmPt@IrPd/C catalyst also gives rise to ∼25.0 times more enhancement than Pt/C during a 50,000-cycle accelerated stability test. This robust stability originates from the resistance to carbon corrosion owing to the stronger H2O interaction instead of carbon oxide (COx) poison species, and the modulated hydroxyl (OH*) adsorption could inhibit the OH* species from shuffling the surface Pt atoms away from the substrate. Moreover, the anion-exchange membrane fuel cells assembled by PmPt@IrPd/C with an ultralow Pt loading of 0.009 mgPt cm-2 in the anode can deliver a power density of 1.27 W cm-2.

Mesoscale Mass Transport Enhancement on Well-Defined Porous Carbon Platform for Electrochemical H2O2 Synthesis

Two-electron oxygen reduction toward hydrogen peroxide (H₂O₂) offers a promising alternative for H₂O₂ production, but its commercial utilization is still hindered by the difficulty of transferring lab-observed catalyst performance to the practical reactor. Here we report the investigation of the porosity engineering effect on catalytic performance inconsistency through a material platform consisting of a series of hollow mesoporous carbon sphere (HMCS) samples. The performance comparison of HMCS samples in rotating ring-disk electrode and Zn-air battery together with the simulation of diffusion behavior reveals that, in low current density conditions, large surface area is preferred, but the mass transport governs the performance in high current density regions. On account of the favorable porous structure, HMCS-8 nm delivers the most excellent practical performance (166 mW cm^-2) and performs well in the bifunctional Zn-air battery for the wastewater purification (70% RhB degraded after 2 min and 99% after 32 min).

Ethanol-Induced Hydrogen Insertion in Ultrafine IrPdH Boosts pH-Universal Hydrogen Evolution

Engineering Pt-free catalysts for hydrogen evolution reaction (HER) with high activity and stability is of great significance in electrochemical hydrogen production. Herein, in situ chemical H intercalation into ultrafine Pd to activate this otherwise HER-inferior material to form the ultrafine IrPdH hydride as an efficient and stable HER electrocatalyst is proposed. The formation of PdIrH depends on a new hydrogenation strategy via using ethanol as the hydrogen resource. It is demonstrated that H atoms in IrPdH originate from the OH and CH₂  of ethanol, which fills the gap of ethanol as the hydrogen source for the preparation of Pd hydride. Thanks to the incorporation of H/Ir atoms and ultrafine structure, the IrPdH exhibits superior HER activity and stability in the whole pH range. The IrPdH delivers very low overpotentials of 14, 25 and 60 mV at a current density of 10 mA cm^-2 respectively in 0.5 m H₂ SO₄ , 1 m KOH, and 1 m PBS electrolytes, which are much better than those of commercial Pt/C and most reported noble metal electrocatalysts. Theoretical calculations confirm that interstitial hydrogen availably refines the electronic density of Pd and Ir sites, which optimizes the adsorption of *H and leads to the significant enhancement of HER performance.

Electron Tomography Reveals Porosity Degradation Spatially on Individual Pt-Based Nanocatalysts

Probing porosity evolution is essential to understand the degradation mechanism of electrocatalytic activity. However, spatially dependent degradation pathways for porous catalysts remain elusive. Here, we reveal the multiple degradation behaviors of individual PtCu₃ nanocatalysts spatially by three-dimensional (3D) electron tomography. We demonstrate that the surface area-volume ratio (SVR) of cycled porous particles decreases linearly rather than reciprocally with particle size. Additionally, an improved SVR (about 3-fold enhancement) results in increased oxygen reduction reaction (ORR) efficiency at the early stage. However, in the subsequent cycles, the degradation of catalytic activity is due to the excessive growth of pores, the reduction of reaction sites, and the chemical segregation of Cu atoms. The spatial porosity evolution model of nanocatalysts is applicable for a wide range of catalytic reactions, providing a critical insight into the degradation of catalyst activity.

Heart rate variability and meditation: a meta-analysis

Funding Acknowledgements

Type of funding sources: None.

Background

Meditation can induce changes in autonomic balance, which can benefit cardiovascular health. The present meta-analysis evaluated changes in heart rate variability (HRV) in meditators.

Methods

PubMed and Embase were searched for primary prospective studies using the search terms ‘heart rate variability’ and ‘meditation’ until January 18th, 2019. The statistical significance of the difference between subgroups is evaluated by the standardized mean difference (SMD), 95% confidence interval (CI), and P-value. I2 value was used to assess the statistical heterogeneity between the included studies.

Results

Twenty-one studies involving 538 meditators (experienced= 209, beginners= 329) and 334 controls (mean age= 40.61, 35% male) were included. Regarding time-domain indices, no statistically significant differences were observed when assessing HRV between i) meditators versus controls (SMD= -0.17; 95% CI: [-0.50, 0.17]; p= 0.30; I2= 0%), ii) pre- versus post-meditation (SMD= -0.41; 95% CI: [-1.10, 0.28]; p= 0.25; I2= 80%) or iii) at baseline versus during meditation (SMD= -0.40; 95% CI: [-0.94, 0.14]; p= 0.14; I2= 72%). Pertaining to frequency-domain indices, analysis of low frequency (LF), normalized low frequency (LFnu) and high frequency (HF) between i) meditators versus controls, ii) at baseline versus post-meditation and iii) at baseline versus during meditation yet again did not show any variations. Seven studies assessed normalized high frequency (HFnu) at baseline versus during meditation collectively demonstrated a significantly higher HFnu during meditation in beginners with notable heterogeneity (SMD= 1.29; 95% CI: [0.09, 2.49]; p= 0.04; I2= 95). Moreover, LF/HF was evaluated by seven studies at baseline versus during meditation. Both meta-analysis (SMD= 0.76; 95% CI: [-0.17, 1.69]; p= 0.11; I2= 94%) as well as subset analysis of experienced meditators (SMD= -0.46; 95% CI: [-0.88, -0.03]; p= 0.03; I2= 0%) revealed a significantly lower LF/HF at baseline.

Conclusions

Short-term changes in HRV indices were observed during meditation, but there is limited evidence for significant long-term effects.

Kinetically Accelerated Lithium Storage in High-Entropy (LiMgCoNiCuZn)O Enabled By Oxygen Vacancies

High-entropy oxides (HEOs) are gradually becoming a new focus for lithium-ion battery (LIB) anodes due to their vast element space/adjustable electrochemical properties and unique single-phase retention ability. However, the sluggish kinetics upon long cycling limits their further generalization. Here, oxygen vacancies with targeted functionality are introduced into rock salt-type (MgCoNiCuZn)O through a wet-chemical molten salt strategy to accelerate the ion/electron transmission. Both experimental results and theoretical calculations reveal the potential improvement of lithium storage, charge transfer, and diffusion kinetics from HEO surface defects, which ultimately leads to enhanced electrochemical properties. The currently raised strategy offers a modular approach and enlightening insights for defect-induced HEO-based anodes.

3D Spatial Combination of CN Vacancy-Mediated NiFe-PBA with N-Doped Carbon Nanofibers Network Toward Free-Standing Bifunctional Electrode for Zn-Air Batteries

Constructing flexible free-standing electrodes with efficient bifunctional performance is significant for improving the performance of flexible Zinc-air batteries. Herein, a flexible free-standing bifunctional electrode (N2 -NiFe-PBA/NCF/CC-60) is constructed by the 3D spatial combination of CN vacancy-mediated NiFe Prussian Blue Analogue (NiFe-PBA) and N-doped carbon nanofibers (NCF) rooted on carbon cloth (CC). The in situ formed CN vacancies by N2 -plasma activation tune the local coordination environment and electronic structure of Ni-Fe active sites in NiFe-PBA, thus improving the oxygen evolution reaction (OER) catalytic intrinsic activity, and restraining the loss of Fe element during OER process. The combination of NiFe-PBA and NCF presents a 3D interworking network structure, which exhibits a large specific surface and excellent electrical conductivity, thus guaranteeing sufficient, stable, and efficient oxygen reduction reaction (ORR)/OER active sites. Therefore, the N2 -NiFe-PBA/NCF/CC-60 electrode delivers high-efficiency OER activity with a low overpotential (270 mV at 50 mA cm-2 ) and excellent ORR performance with a positive potential of 0.89 V at 5 mA cm-2 . The N2 -NiFe-PBA/NCF/CC-60 based Zn-air batteries display outstanding discharge/charge stability for 2000 cycles. Meanwhile, the corresponding flexible Zn-air batteries with satisfactory mechanical properties exhibit a low voltage gap of 0.52 V at 1.0 mA cm-2 .

Similarity measurements of B cell receptor repertoire in baseline mice showed spectrum convergence of IgM

BACKGROUND

The B cell receptor (BCR) repertoire is highly diverse among individuals. Poor similarity of the spectrum among inbred baseline mice may limit the ability to discriminate true signals from those involving specific experimental factors. The repertoire similarity of the baseline status lacks intensive measurements.

RESULTS

We measured the repertoire similarity of IgH in blood and spleen samples from untreated BALB/c and C57BL/6J mice to investigate the baseline status of the two inbred strains. The antibody pool was stratified by the isotype of IgA, IgG and IgM. Between individuals, the results showed better convergence of CDR3 and clonal lineage profiles in IgM than in IgA and IgG, and better robustness of somatic mutation networks in IgM than in IgA and IgG. It also showed that the CDR3 clonotypes and clonal lineages shared better in the spleen samples than in the blood samples. The animal batch differences were detected in CDR3 evenness, mutated clonotype proportions, and maximal network degrees. A cut-off of 95% identity in the CDR3 nucleotide sequences was suitable for clonal lineage establishment.

CONCLUSIONS

Our findings reveal a natural landscape of BCR repertoire similarities between baseline mice and provide a solid reference for designing studies of mouse BCR repertoires.

Microrods synthesized of MoO3 with corn straw as biological templates and its electrochemical performance in aqueous aluminum-ion battery

ABSTRACT. In this paper, MoO3 microrods were prepared using corn straw as biological template via roasting process The components and crystal characterization of the material were investigated via X-ray diffraction (XRD)，scanning electron microscopy (SEM), and the electrochemistry property and mechanism were studied. The results showed that the MoO3 material synthesized by template method is orthorhombic structures. The MoO3 particles were submicron and micron rods with uniform distribution and a smooth surface. MoO3 microrods had an average diameter that ranged from 1 to 2 μm. The result indicated that the MoO3 as the new negative of aluminum battery delivers a higher discharge capacity of 190 mA·h·g-1 at a scanning rate of 1 mV·s-1, which showing good capacity and cycling performance.                     KEY WORDS: Biological template, Corn straw, Aqueous aluminum-ion battery, MoO3   Bull. Chem. Soc. Ethiop. 2021, 35(3), 669-675. DOI: https://dx.doi.org/10.4314/bcse.v35i3.17

Ruling Out Real-Valued Standard Formalism of Quantum Theory

Standard quantum theory was formulated with complex-valued Schrödinger equations, wave functions, operators, and Hilbert spaces. Previous work attempted to simulate quantum systems using only real numbers by exploiting an enlarged Hilbert space. A fundamental question arises: are the complex numbers really necessary in the standard formalism of quantum theory? To answer this question, a quantum game has been developed to distinguish standard quantum theory from its real-number analog, by revealing a contradiction between a high-fidelity multiqubit quantum experiment and players using only real-number quantum theory. Here, using superconducting qubits, we faithfully realize the quantum game based on deterministic entanglement swapping with a state-of-the-art fidelity of 0.952. Our experimental results violate the real-number bound of 7.66 by 43 standard deviations. Our results disprove the real-number formulation and establish the indispensable role of complex numbers in the standard quantum theory.

IP3R1/GRP75/VDAC1 complex mediated endoplasmic reticulum stress-mitochondrial oxidative stress in diabetic atrial remodeling

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): National Natural Science Foundation of China

Background

Mitochondrial oxidative stress is an important mechanism of atrial remodeling and atrial fibrillation (AF) in the setting of diabetes. Currently, endoplasmic reticulum (ER) stress is regarded as the key link from homeostasis to dysfunction, and is a central feature of metabolic diseases such as type 2 diabetes. However, the molecular mechanisms underlying these processes have not been fully elucidated.

Objective

To explore the potential role of ER stress-mitochondrial oxidative stress in atrial remodeling and AF induction in diabetes.

Methods

 Mouse atrial cardiomyocytes (HL-1 cells) , type 2 diabetic rats and GRP75 conditional knockout mice were used as models systems. These findings were correlated with biomarker findings in human diabetic patients with confirmed atrial fibrillation.

Results

 In the diabetic rat atria, significant ER stress was observed. Treatment with tunicamycin (TM), an ER stress agonist, mass spectrometry (MS) demonstrated many known ER stress and calmodulin proteins, including Heat shock protein family A (Hsp70) member (Hspa) 5 (GRP78) and Hspa9 (GRP75) and in situ proximity ligation assay (PLA) indicated that TM led to increased protein expression of the IP3R1 (inositol 1,4,5-trisphosphate receptors 1)/GRP75 (glucose-regulated protein 75)/VDAC1 (voltage-dependent anion channel 1) complex in HL-1 cells. Silencing of GRP75 using siRNA in HL-1 cells and GRP75 conditional knockout in our mouse model led to impaired calcium transport from the ER to mitochondria, and alleviated mitochondrial oxidative stress and calcium overload. Moreover, GRP75 deficiency attenuates atrial remodeling and AF progression in Myh6-Cre+/Hspa9flox/flox + TM mice.

Conclusions

 The IP3R1/GRP75/VDAC1 complex mediates endoplasmic reticulum stress-mitochondrial oxidative stress plays an important role in diabetic atrial remodeling. Abstract Figure

The dynamics and association of B and T cell receptor repertoires upon antibody response to hepatitis B vaccination in healthy adults

The Hepatitis B (HB) vaccine is efficacious in preventing hepatitis B virus infection. However, the association between antibody response to the HB vaccine and dynamic immune repertoire changes in different cell subsets remains unclear. Nine healthy participants were administered three doses of HB vaccine following the 0, 1, 6 month schedule. Peripheral CD4⁺ T, memory B (MB), naïve B (NB), and plasma cells (PCs) were sorted before vaccination and 7 days following each dose. The complementary determining region 3 of T-cell receptor β (TCRβ) chain and B-cell receptor (BCR) heavy chain (IgG, IgM, IgA) repertoires were analyzed by high-throughput sequencing. All nine participants elicited protective antibody titers to the vaccine at the end of immunization. Compared with the baseline, MB cells showed a significant increase in IgG usage and decreased IgM usage and repertoire diversity at the end of vaccination. TCRβ diversity changes were highly correlated with those of the BCR in MB cells in participants with a faster and robust antibody responses. The percentage of shared clonotypes between NB and MB cells, and MB cells and PCs were much higher than that between NB cells and PCs. The more clonotypes sharing the faster and stronger antibody responses were observed after HB vaccination. These results suggest the integral involvement of MB cells in vaccine immunization. Interaction between CD4⁺ T and MB cells and B cell differentiation may improve antibody response to HB vaccine.

Efficacy and safety of alginate formulations in patients with gastroesophageal reflux disease: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Alginate formulations are increasingly being used for treating gastroesophageal reflux disease (GERD). However, the benefits of alginate versus control or proton pump inhibitors (PPIs) are somewhat unclear. We performed a systematic review and meta-analysis to summarize data from recent randomized controlled trials (RCTs) comparing the efficacy and safety of alginate-based formulation with PPIs or control for the treatment of GERD.

MATERIALS AND METHODS

PubMed, Embase, Scopus, BioMed Central, CENTRAL, and Google scholar databases were searched from 1st January 2000 to 15th June 2020. Primary outcome was a reduction of symptoms while secondary outcomes were adverse events and treatment withdrawals. Ten articles with 11 RCTs were included.

RESULTS

Qualitative analysis of four trials indicated better outcomes with alginates vs. placebo/antacids. Our pooled analysis, however, indicated no statistically significant difference between alginates and placebo/antacids for relief of heartburn, regurgitation, or dyspepsia. Similarly, no difference was seen between a combination of alginate and PPI vs. PPI alone for reduction of heartburn, regurgitation, or dyspepsia symptoms. The risk of adverse events and treatment withdrawal did not differ between the two groups in either comparison. Descriptive analysis of studies comparing alginate vs. PPI indicated no difference between the two drugs.

CONCLUSIONS

Our study indicates that alginates may have greater efficacy than placebo/antacids in improving outcomes of GERD. However, current evidence on the efficacy of alginate-based formulations vs. PPI or the role of added alginates with PPI is questionable, and suggests no difference between the two drugs. The risk of adverse events with alginates is no greater than that of placebo or PPIs.

Turning Waste into Treasure: Regulating the Oxygen Corrosion on Fe Foam for Efficient Electrocatalysis

Iron corrosion causes a great damage to the economy due to the function attenuation of iron-based devices. However, the corrosion products can be used as active materials for some electrocatalytic reactions, such as oxygen evolution reaction (OER). Herein, the oxygen corrosion on Fe foams (FF) to synthesize effective self-supporting electrocatalysts for OER, leading to "turning waste into treasure," is regulated. A dual chloride aqueous system of "NaCl-NiCl₂ " is employed to tailor the structures and OER properties of corrosion layers. The corrosion behaviors identify that Cl^- anions serve as accelerators for oxygen corrosion, while Ni²⁺ cations guarantee the uniform growth of corrosion layers owing to the appeared chemical plating. The synergistic effect of "NaCl-NiCl₂ " generates one of the highest OER activities that only an overpotential of 212 mV is required to achieve 100 mA cm^-2 in 1.0 m KOH solution. The as-prepared catalyst also exhibits excellent durability over 168 h (one week) at 100 mA cm^-2 and promising application for overall water splitting. Specially, a large self-supporting electrode (9 × 10 cm² ) is successfully synthesized via this cost-effective and easily scale-up approach. By combining with corrosion science, this work provides a significant stepping stone in exploring high-performance OER electrocatalysts.

Facile self-template fabrication of hierarchical nickel-cobalt phosphide hollow nanoflowers with enhanced hydrogen generation performance

Developing facile methods to construct hierarchical-structured transition metal phosphides is beneficial for achieving high-efficiency hydrogen evolution catalysts. Herein, a self-template strategy of hydrothermal treatment of solid Ni-Co glycerate nanospheres followed by phosphorization is delivered to synthesize hierarchical NiCoP hollow nanoflowers with ultrathin nanosheet assembly. The microstructure of NiCoP can be availably tailored by adjusting the hydrothermal treatment temperature through affecting the hydrolysis process of Ni-Co glycerate nanospheres and the occurred Kirkendall effect. Benefitting from the promoted exposure of active sites and affluent mass diffusion routes, the HER performance of the NiCoP hollow nanoflowers has been obviously enhanced in contrast with the solid NiCoP nanospheres. The fabricated NiCoP hollow nanoflowers yield the current density of 10 mA cm^-2 at small overpotentials of 95 and 127 mV in 0.5 mol L^-1 H₂SO₄ and 1.0 mol L^-1 KOH solution, respectively. Moreover, the two-electrode alkaline cell assembled with the NiCoP and Ir/C catalysts exhibits sustainable stability for overall water splitting. The work provides a simple but efficient method to regulate the microstructure of transition metal phosphides, which is helpful for achieving high-performance hydrogen evolution catalysts based on solid-state metal alkoxides.

Optimizing PtFe intermetallics for oxygen reduction reaction: from DFT screening to in situ XAFS characterization

Rational designing of catalysts to promote the sluggish kinetics of the cathode oxygen reduction reaction in proton exchange membrane fuel cells is still challenging, yet of crucial importance to its commercial application. In this work, on the basis of theoretical DFT calculations which suggest that order structured fct-phased PtFe (O-PtFe) with an atomic Pt shell exhibits superior electrocatalytic performance towards the ORR, the desired structure was prepared by using a scalable impregnation-reduction method. The as-prepared O-PtFe delivered enhanced activity (0.68 A mg^-1_Pt) and stability (73% activity retention after 10 000 potential cycles) compared with the corresponding disordered PtFe alloy (D-PtFe) and Pt. To confirm the excellent durability, in situ X-ray absorption fine structure spectroscopy was conducted to probe the local and electronic structure changes of O-PtFe during 10 000 cycle accelerated durability testing. We hope that this facile synthesis method and the in situ XAFS experiment could be readily adapted to other catalyst systems, facilitating the screening of highly efficient ORR catalysts for fuel cell application.

Hierarchical Bimetallic Ni-Co-P Microflowers with Ultrathin Nanosheet Arrays for Efficient Hydrogen Evolution Reaction over All pH Values

Designing efficient nonprecious catalysts with pH-universal hydrogen evolution reaction (HER) performance is of importance for boosting water splitting. Herein, a self-template strategy based on Ni-Co-glycerates is developed to prepare bimetallic Ni-Co-P microflowers with ultrathin nanosheet arrays. The highly porous core-shell structure gives rise to affluent mass transfer channels and availably prevents the aggregation of nanosheets, while the ultrathin nanosheets are favorable for producing abundant active sites. Besides, the produced CoP/NiCoP heterostructure in the bimetallic Ni-Co-P catalyst has excellent HER performance in a wide pH range. The as-prepared catalyst shows low potentials of 90, 157, and 121 mV to deliver a current density of 10 mA cm^-2 in 0.5 M H₂SO₄, 0.5 M PBS, and 1 M KOH solution, respectively. Meanwhile, negligible overpotential decay is achieved in the polarization curves after a long-term stability determination. This work supplies a promising strategy for developing pH-universal HER electrocatalysts based on solid-state metal alkoxides.

P5438Cardiac abnormalities after induction of endoplasmic reticulum stress are associated with mitochondrial dysfunction and connexin43 expression

Background

The endoplasmic reticulum (ER) is responsible for protein synthesis and calcium storage. ER stress, reflected by protein unfolding and calcium handling abnormalities, has been studied as a pathogenetic factor in cardiovascular diseases.

Purpose

The aim of this study is to examine the effects of ER stress on mechanical and electrophysiological functions in the heart and explore the underlying molecular mechanisms.

Methods

A total of 30 rats were randomly divided into control, ER stress induction (tunicamycin) and ER stress inhibition (4-phenylbutyric acid, 4-PBA) groups.

Results

ER stress induction led to significantly systolic and diastolic dysfunction as reflected by maximal increasing/decreasing rate of left intraventricular pressure (±dp/dt), LV peak systolic pressure, LV development pressure and LV end-diastolic pressure. Epicardial electrical mapping performed in vivo revealed reduced conduction velocity, increased conduction heterogeneity and spontaneous ventricular tachycardia. Masson's trichrome staining revealed marked fibrosis in the myocardial interstitium and sub-pericardium and thickened epicardium. Western blot analysis revealed increased pro-fibrotic factor TGF-β1, decreased mitochondrial biogenesis protein PGC-1a, decreased mitochondrial fusion protein MFN2. These changes were associated with decreased mitochondrial membrane potential (MMP) and connexin 43 translocation to mitochondria. These abnormalities can be partially prevented by the ER stress inhibitor 4-PBA.

Conclusions

Our study shows that ER stress induction can produce cardiac electrical and mechanism dysfunction as well as structural remodeling. Mitochondrial function alterations are contributed by CX43 transposition to mitochondria. These abnormalities can be partially prevented by the ER stress inhibitor 4-PBA.

Acknowledgement/Funding

National Natural Science Foundation of China (No. 81570298 to T.L.)

P1890Pioglitazone inhibits diabetes-induced atrial mitochondrial oxidative stress and improves mitochondrial biogenesis, dynamics and function through the PGC-1 signaling pathway

Background

Oxidative stress contributes to adverse atrial remodeling in diabetes mellitus. This can be prevented by the PPAR-γ agonist pioglitazone through its anti-oxidant and anti-inflammatory effects.

Purpose

In this study, the molecular mechanisms underlying these effects were investigated.

Methods

Rabbits were randomly divided into control (C), diabetic (DM), and pioglitazone-treated DM (Pio) groups. Echocardiographic, hemodynamic, electrophysiological, intracellular Ca2+ properties were measured. Serum PPAR-γ levels, serum and tissue oxidative stress and inflammatory markers, mitochondrial morphology, reactive oxygen species (ROS) production rate, respiratory function, and mitochondrial membrane potential (MMP) levels were measured. Protein expression of pro-fibrotic marker transforming growth factor β1 (TGF-β1), and the mitochondrial proteins (PGC-1α, fission and fusion-related proteins) were measured.

Results

Compared with controls, the DM group demonstrated larger left atrial diameter and fibrosis area associated with a higher incidence of inducible AF. Lower serum PPAR-γ level was associated with lower PGC-1α, higher NF-κB and higher TGF-β1 expression. Mn-SOD protein was not different but lower mitochondrial fission- and fusion-related proteins were detected. Mitochondrial swelling, higher mitochondrial ROS, lower respiratory control rate, lower MMP and higher intracellular Ca2+ transients were observed. In the Pio group, reversal of structural remodeling and lower inducible AF incidence were associated with higher PPAR-γ and PGC-1α. NF-κB and TGF-β1 were lower and biogenesis, fission and fusion-related protein were higher. Mitochondrial structure and function, and intracellular Ca2+ transients were improved. In HL-1 cell line, transfected with PGC-1α siRNA blunted the effect of pioglitazone on Mn-SOD protein expression and MMP collapse in H2O2-treated cells.

Conclusion

Diabetes mellitus induces adverse atrial structural and electrophysiological remodeling, abnormal Ca2+ handling and mitochondrial damage and dysfunction. Pioglitazone prevented these abnormalities through the PPAR-γ/PGC-1α pathway.

Acknowledgement/Funding

National Natural Science Foundation of China (No 81570298, 81270245, 30900618 to T.L.)

P2838The impact of anesthesia depth on catheter ablation for atrial fibrillation: a systematic review and meta-analysis of observational studies

Objectives

This meta-analysis and systematic review seeks to compare both characteristic parameters and procedural outcomes of catheter ablation in patients under GA/deep sedation and mild/moderate sedation.

Background

Catheter ablation has become a widely applied intervention for treating symptomatic AF and arrhythmias that are refractory to medical therapy. It can be conducted through from mild sedation to general anesthesia.

Methods

PubMed and Embase were searched up to July 2018 for randomized controlled trials, cohort and observational studies that assessed the outcomes of catheter ablation under GA/deep sedation or mild/moderate sedation. 12 studies were included in this meta-analysis after screening with the inclusion and exclusion criteria. Heterogeneity between studies and publication bias was evaluated by I2 index and Egger's regression, respectively.

Results

Our meta-analysis found catheter AF ablation with GA/deep sedation to be associated with reduced risk of recurrence (RR: 0.79, 95% CI: 0.56 to 1.13, P=0.20) and complications (RR: 0.95, 95% CI: 0.64 to 1.42, P=0.82), though statistically insignificant. In terms of procedural parameters, there was non-significant difference between the two groups when both procedural time (SMD: −0.13, 95% CI: −0.90 to 0.63, P=0.74) and fluoroscopy time (SMD: −0.41, 95% CI: −1.40 to 0.58, P=0.41) were considered. Multivariate meta-regression demonstrated hypertension as an independent moderating factor for complication risk.

Complications Comparison

Conclusion

Apart from an increased likelihood of procedural success, ablation by GA/deep sedation was found to be non-significantly different from the mild/moderate sedation approach in both procedural parameters and outcome measures.

Golden Palladium Zinc Ordered Intermetallics as Oxygen Reduction Electrocatalysts

Exploring Pt-free electrocatalysts with high activity and long durability for the oxygen reduction reaction (ORR) has been long pursued by the renewable energy materials community. In this work, we have designed an ordered intermetallic PdZn/C (O-PdZn) with a several atomic-layer Pd shell, which achieved a 3-fold enhancement in ORR mass activities (MA) in alkaline media, relative to Pd/C and Pt/C. Further Au incorporation in O-PdZn/C (Au-O-PdZn/C) yielded a catalyst with superior durability with less than 10% loss in MA after 30000 potential cycles. These effects have attributed to the rationally designed ordered structure and stabilizing effect of Au atoms. Aberration-corrected scanning transmission electron microscopy and synchrotron-based X-ray fluorescence spectroscopy were employed to show that Au not only galvanically replaced Pd and Zn on the surface but also penetrated through the PdZn lattice and distributed uniformly within the particles. Au-O-PdZn/C was also tested as an effective oxygen cathode in broad applications in rechargeable Li-air and Zn-air batteries.

Acute Cellular Rejection and Infection Rates in Alemtuzumab vs Traditional Induction Therapy Agents for Lung and Heart Transplantation: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Heart and lung transplantation is a high-risk procedure requiring intensive immunosuppressive therapy for preventing organ rejection. Alemtuzumab, a CD52-specific monoclonal antibody, is increasingly used for induction therapy compared with conventional agents. However, there has been no systematic review comparing its efficacy with traditional therapeutic drugs.

METHODS

PubMed and EMBASE were searched to October 1, 2017, for articles on alemtuzumab in cardiothoracic transplant surgery. Of the 433 studies retrieved, 8 were included in the final meta-analysis.

RESULTS

In lung transplantation, alemtuzumab use was associated with lower odds of acute cellular rejection compared with antithymocyte globulin (odds ratio [OR], 0.21; 95% CI, 0.11-0.40; P < .001), lower acute rejection rates (OR, 0.12; 95% CI, 0.03-0.55; P < .01), and infection rates (OR, 0.69; 95% CI, 0.35-1.36; P = .33) when compared with basiliximab. Multivariate meta-regression analysis found that mean age, male sex, single lung transplant, double lung transplant, cytomegalovirus or Epstein-Barr virus status, idiopathic pulmonary fibrosis, cystic fibrosis, and mean ischemic time did not significantly influence acute rejection outcomes. For heart transplantation, alemtuzumab use was associated with lower acute rejection rates when compared with tacrolimus (OR, 0.44; 95% CI, 0.30-0.66; P < .001).

CONCLUSIONS

Alemtuzumab use was associated with lower rejection rates when compared with conventional induction therapy agents (antithymocyte globulin, basiliximab, and tacrolimus) in heart and lung transplantation. However, this was based on observational studies. Randomized controlled trials are needed to verify its clinical use.

Bimetallic Nanoparticle Oxidation in Three Dimensions by Chemically Sensitive Electron Tomography and in Situ Transmission Electron Microscopy

The formation of hollow-structured oxide nanoparticles is primarily governed by the Kirkendall effect. However, the degree of complexity of the oxidation process multiplies in the bimetallic system because of the incorporation of more than one element. Spatially dependent oxidation kinetics controls the final morphology of the hollow nanoparticles, and the process is highly dependent on the elemental composition. Currently, a theoretical framework that can predict how different metal elements result in different oxide morphologies remains elusive. In this work, utilizing a combination of state-of-the-art in situ environmental transmission electron microscopy and three-dimensional (3D) chemically sensitive electron tomography, we provide an in situ and 3D investigation of the oxidation mechanism of the Ni-Fe nanoparticles. The direct measurements allow us to correlate the 3D elemental segregation in the particles with the oxidation morphologies, that is, single-cavity or dual-cavity hollow structure, and multicavity porous structures. Our findings in conjunction with theoretical calculations show that metal concentration, diffusivity, and particle size are important parameters that dictate the mechanical and phase stabilities of the hollow oxide shell, which in turn determine its barrier properties and the final hollow oxide morphology. It sheds light on how to use multielemental oxidation to control morphology in nanomaterials and demonstrates the power of 3D chemical imaging.

Review of the role of leptin in the regulation of male reproductive function

Since discovered in 1994, leptin has been thought to be a pleiotropic hormone that regulates food intake, controls energy balance in the body and influences multiple tissues in the body. Leptin plays an important mediating role in the regulation of neuroendocrine and can transmit the nutritional status signals to the reproductive-related central nervous system. Many studies have shown that leptin may play an important role in the control of reproductive function. Leptin can act on all levels of the hypothalamus-pituitary-gonadal (HPG) axis and may have local effects on the function of testis and spermatogenesis. Leptin is critical for puberty initiation and can also modulate testosterone synthesis by downregulating cAMP-dependent activation of steroidogenic genes expressions. Leptin is found to be higher in infertile men than in normal subjects. Yet, the exact role of leptin in the regulation of male reproductive function remains incomplete. The purpose of this review was to summarise the recent research about the biological effects of leptin on male reproductive system. In-depth study of leptin in reproductive system will help to reveal the pathogenesis of infertility and provide new treatment ideas for human assisted reproductive technology.

Inhibition of hepatitis B virus replication via HBV DNA cleavage by Cas9 from Staphylococcus aureus

Chronic hepatitis B virus (HBV) infection is difficult to cure due to the presence of covalently closed circular DNA (cccDNA). Accumulating evidence indicates that the CRISPR/Cas9 system effectively disrupts HBV genome, including cccDNA, in vitro and in vivo. However, efficient delivery of CRISPR/Cas9 system to the liver or hepatocytes using an adeno-associated virus (AAV) vector remains challenging due to the large size of Cas9 from Streptococcus pyogenes (Sp). The recently identified Cas9 protein from Staphylococcus aureus (Sa) is smaller than SpCas9 and thus is able to be packaged into the AAV vector. To examine the efficacy of SaCas9 system on HBV genome destruction, we designed 5 guide RNAs (gRNAs) that targeted different HBV genotypes, 3 of which were shown to be effective. The SaCas9 system significantly reduced HBV antigen expression, as well as pgRNA and cccDNA levels, in Huh7, HepG2.2.15 and HepAD38 cells. The dual expression of gRNAs/SaCas9 in these cell lines resulted in more efficient HBV genome cleavage. In the mouse model, hydrodynamic injection of gRNA/SaCas9 plasmids resulted in significantly lower levels of HBV protein expression. We also delivered the SaCas9 system into mice with persistent HBV replication using an AAV vector. Both the AAV vector and the mRNA of Cas9 could be detected in the C3H mouse liver cells. Decreased hepatitis B surface antigen (HBsAg), HBV DNA and pgRNA levels were observed when a higher titer of AAV was injected, although this decrease was not significantly different from the control. In summary, the SaCas9 system accurately and efficiently targeted the HBV genome and inhibited HBV replication both in vitro and in vivo. The system was delivered by an AAV vector and maybe used as a novel therapeutic strategy against chronic HBV infection.

Dynamic Perturbations of CD4 and CD8 T Cell Receptor Repertoires in Chronic Hepatitis B Patients upon Oral Antiviral Therapy

Long-term treatment with nucleos(t)ide analogs (NUCs) can improve the antiviral T cell response in chronic hepatitis B (CHB) patients. Whether and to what extent the T cell response is improved by NUCs in the early stage leading to hepatitis B e antigen (HBeAg) seroconversion remain to be clarified. A total of 22 CHB patients undergoing 2-year telbivudine-based therapy were enrolled, including 10 exhibiting a complete response (CR) and 12 exhibiting a non-complete response (NCR) according to HBeAg seroconversion at week 52. Peripheral CD4⁺ and CD8⁺ T cells were sorted at baseline, weeks 12, and 24. The T cell receptor β chain (TCRβ) complementarity-determining region 3 was analyzed by unbiased high-throughput sequencing. Compared with NCR group, patients in CR group had a much lower percentage of persistent clonotypes (P < 0.001) but remarkably higher percentages of new and expanded clonotypes (P < 0.05) between any two time points for both CD4 and CD8 subsets. The CD4 T cells exhibited a stronger response than CD8 population in the patients. The number of new and expanded clonotypes was inversely associated with the decline of viral antigen. In conclusion, NUC-based therapy induces a broad and vigorous T cell response with rapid decline of antigenemia during the early stage of treatment. A broad T cell expansion is crucial for HBeAg seroconversion. Our findings suggest that the potent suppression of hepatitis B virus replication by NUC monotherapy complemented with additional immunomodulatory strategies may increase the likelihood of a functional cure for CHB in the future.