An unenhanced 3D-FLAIR sequence using long repetition time and constant flip angle to image endolymphatic hydrops.

OBJECTIVES: To evaluate a three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) sequence using a long repetition time (TR) and constant flip angle (CFA) in differentiating between perilymph and endolymph in a phantom study, and unenhanced endolymphatic hydrops (EH) imaging in a patient study. METHODS: Three solutions in similar ion and protein concentrations with endolymph, perilymph, and cerebrospinal fluid were prepared for variable flip angle (VFA) 3D-FLAIR (TR 10,000 ms) and CFA (120°) 3D-FLAIR using different TR (10,000, 16,000, and 20,000 ms). Fifty-two patients with probable or definite Meniere's disease received unenhanced CFA (120°) 3D-FLAIR using a long TR (20,000 ms) and 4-h-delay enhanced CFA (120°) 3D-FLAIR (TR 16,000 ms). Image quality, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of them were compared. Agreement in the evaluation of the EH degree between them was analyzed. RESULTS: In the phantom study, CNRs between perilymphatic and endolymphatic samples of VFA 3D-FLAIR (TR 10,000 ms) and CFA 3D-FLAIR (TR 10,000, 16,000, and 20,000 ms) were 6.66 ± 1.30, 17.90 ± 2.76, 23.87 ± 3.09, and 28.22 ± 3.15 (p < 0.001). In patient study, average score (3.65 ± 0.48 vs. 4.19 ± 0.40), SNR (34.56 ± 9.80 vs. 51.40 ± 11.27), and CNR (30.66 ± 10.55 vs. 45.08 ± 12.27) of unenhanced 3D-FLAIR were lower than enhanced 3D-FLAIR (p < 0.001). Evaluations of the two sequences showed excellent agreement in the cochlear and vestibule (Kappa value: 0.898 and 0.909). CONCLUSIONS: The CFA 3D-FLAIR sequence using a long TR could be used in unenhanced EH imaging with high accuracy. CLINICAL RELEVANCE STATEMENT: Unenhanced imaging of endolymphatic hydrops is valuable in the diagnosis and follow-up of patients, especially those who cannot receive contrast-enhanced MRI. KEY POINTS: Ion and protein concentration differences can be utilized in differentiating endolymph and perilymph on MRI. Endolymphatic and perilymphatic samples could be differentiated in vitro on this 3D-FLAIR sequence. This unenhanced 3D-FLAIR sequence is in excellent agreement with the enhanced constant flip angle 3D-FLAIR sequence.

NIR-Triggered On-Demand Nitric Oxide Release for Enhanced Synergistic Phototherapy of Hypoxic Tumor.

Hypoxia of tumor microenvironments is a major factor restricting tumor treatment, which causes progression and metastasis of tumor. The hypoxic tumor microenvironment not only makes the traditional treatment method, such as chemotherapy, ineffective but also hinders the O2-dependent treatments, such as photodynamic therapy (PDT). Recently, stimuli-responsive nitric oxide (NO) donors have attracted extensive research interest in hypoxic tumor treatment because the NO release process is O2-independent. Besides, NO can distribute more uniformly than drug molecules and more widely than the PDT-generated active species due to its strong diffusion ability (200 µm in cells) and long lifetime (2 s in cells). Encouraged by these advantages, a near infrared light-triggered NO release polymeric nanoplatform (P1-CapNO NPs) was constructed by a thermally sensitive NO release unit, a photothermal unit, and a hydrophilic polyethylene glycol unit. P1-CapNO NPs possess strong absorption in the NIR region (the wavelength of maximal absorption peak was 790 nm with a molar absorption coefficient of 2.4 × 105 M-1 cm-1), great photothermal conversion efficiency (23.8%), and NO release ability (the released NO concentration can reach 1.3 µM) under 808 nm laser irradiation. Owing to these advantages, the great synergistic antitumor effect can be achieved in vitro and in vivo even under the hypoxic environment. The synergistic therapeutic strategy in this work could bypass the obstacles caused by hypoxia in tumor treatment and provide a reference for building a NO-involved therapeutic platform.

A Tetradentate Ligand Enables Iron-Catalyzed Asymmetric Hydrogenation of Ketones in a CO- or Isocyanide-Free Fashion.

We herein reported the design and synthesis of a ferrocene-based tetradentate ligand that is featured with modular synthesis and rigid skeleton. Its iron(II) complex facilitates asymmetric direct hydrogenation of ketones without the participation of extra strong-field ligand such as CO and isocyanide. Hydride donor lithium aluminum hydride (LAH) converted non-reactive Fe(II) species to reactive Fe(II) hydride species. With this catalyst, various chiral alcohols including the intermediate for montelukast could be prepared with satisfactory yields and enantioinduction.

High relaxivity Gd3+-based organic nanoparticles for efficient magnetic resonance angiography.

Contrast-enhanced MR angiography (MRA) is a critical technique for vascular imaging. Nevertheless, the efficacy of MRA is often limited by the low rate of relaxation, short blood-circulation time, and metal ion-released potential long-term toxicity of clinical available Gd-based contrast agents. In this work, we report a facile and efficient strategy to achieve Gd-chelated organic nanoparticles with high relaxivity for T1-weighted MRA imaging. The Gd-chelated PEG-TCPP nanoparticles (GPT NPs) have been engineered composite structured consisting of Gd-chelated TCPP and PEG. The spherical structure of TCPP offers more chemical sites for Gd3+ coordination to improve the relaxivity and avoid leakage of the Gd3+ ions. The synthesized GPT NPs exhibit a high relaxation rate of 35.76 mM- 1 s- 1 at 3.0 T, which is higher than the rates for most reported MR contrast agents. Therefore, GPT NPs can be used for MRA with much stronger vascular signals, longer circulation time, and high-resolution arterial vascular visualization than those using clinical MR contrast agents at the same dose. This work may make the T1 MRI contrast agents for high-resolution angiography possible and offer a new candidate for preclinical and clinical applications of MR vascular imaging and vascular disease diagnosis.

Overcoming Tumor Hypoxia through Multiple Pathways Using an All-in-One Polymeric Therapeutic Agent to Enhance Synergistic Cancer Photo/Chemotherapy Effects.

Hypoxia is a significant characteristic of tumors, which causes aggressive tumor growth and strong therapy resistance. Inspired by the improved therapeutic efficacy of synergistic treatment, herein, an all-in-one polymeric therapeutic agent was developed, which could overcome tumor hypoxia through multiple pathways. Multiple therapeutic agents were incorporated into the polymer, including the singlet oxygen (1O2) carrier unit to store cytotoxic reactive oxygen species, the photosensitized and photothermal unit to trigger the capture and release of 1O2, and the hypoxia-responsive prodrug unit to maintain a long-term tumor inhibition. In addition, the hydrophilic polyethylene glycol unit was also introduced to improve water-solubility and biocompatibility. Importantly, this study achieved the capture and controllable release of 1O2 just by regulating the power of an 808 nm laser for the first time, which is more convenient and flexible than previous works. As expected, the as-prepared copolymer displayed reduced oxygen dependence, accompanied with promising synergistic anti-tumor and anti-recurrence efficacies under hypoxic in vitro and in vivo environments. Consequently, this synergistic anti-hypoxia strategy may open up new avenues in the design of all-in-one therapeutic platforms for promoting the development of accurate, efficient, and long-acting treatment in clinical studies.

Yolk-shell structured Au nanorods@mesoporous silica for gas bubble driven drug release upon near-infrared light irradiation.

Drug release systems co-encapusulated with ammonium bicarbonate (ABC) could facilitate drug release upon acidic or thermal stimulations to improve therapeutic effect. However, it is not easy to control drug release rate, owing to relative stable temperature and acidic condition in living body. Besides, the additional loaded ABC reduces drug loading capacity. Herein, a near-infrared light triggered rapid drug release system with high loading capacity was developed by loading ABC and doxorubicin into yolk-shell structured Au nanorods@mesoporous silica. Gas bubbles were generated from the thermolysis of ABC utilizing photothermal effect of Au nanorods to extrude drug molecules. The mesoporous silica shell was finally destroyed along with growing bubbles, resulting in burst drug release. The photothermal therapeutic effect of Au nanorods also contributed in tumor treatment. The excellent therapeutic effect was demonstrated in cancer cells and tumor-bearing mice, which provides a new reference to achieve controllable rapid drug release in cancer medicine.

Rational Design of Near-Infrared-Absorbing Pt(II)-Chelated Azadipyrromethene Dyes as a New Generation of Photosensitizers for Synergistic Phototherapy.

Pt(II) photosensitizers are emerging as novel Pt anticancer agents for cancer photodynamic therapy (PDT) to avoid uncontrollable toxicity of cisplatin. However, the application of Pt(II) photosensitizers is limited by tumor hypoxia and the poor penetration depth of excitation light. To overcome these drawbacks, exploiting the next generation of Pt anticancer agents is of urgent need. According to theoretical calculations, novel near-infrared (NIR)-absorbing Pt(II)-chelated azadipyrromethene dyes (PtDP-X, where X = N, C, and S) were designed. Importantly, spin-orbit coupling of the Pt atom could promote the intersystem crossing of a singlet-to-triplet transition for converting oxygen to singlet oxygen (1O2), and the azadipyrromethene skeleton could provide a strong photothermal effect. As expected, PtDP-X exhibited intense NIR absorption and synergistic PDT and photothermal effects with low dark cytotoxicity. Furthermore, water-soluble and biocompatible PtDP-N nanoparticles (PtDP-N NPs) were prepared that achieved effective tumor cell elimination with low side effects under 730 nm light irradiation in vitro and in vivo. This pioneering work could push the exploitation of NIR-absorbing metal-chelated azadipyrromethene dyes, so as to promote the positive evolution of phototherapy agents.

High-Resolution Diffusion-Weighted Imaging Improves the Diagnostic Accuracy of Dynamic Contrast-Enhanced Sinonasal Magnetic Resonance Imaging.

OBJECT: The aim of the study was to evaluate the incremental value of high-resolution diffusion-weighted imaging and apparent diffusion coefficient (ADC) mapping compared with that of dynamic contrast-enhanced (DCE) sinonasal magnetic resonance imaging (MRI) in the characterization of benign versus malignant sinonasal tumors at 3.0T. MATERIALS AND METHODS: Ninety-eight patients (61 females, 37 males; mean age, 48 years) with sinonasal lesions who underwent high-resolution DW-MRI and DCE-MRI were included in this study. The lesions were divided into malignant and benign groups on the basis of pathological examination. In total, 58 malignant tumors and 40 benign tumors were evaluated. Apparent diffusion coefficients were acquired with 0 and 1000 s/mm b values. Semiquantitative parameters (time-signal intensity curve [TIC] type, time of peak enhancement within the first 2 minutes [Tpeak], peak percentage enhancement within the first 2 minutes [PEpeak], the last time point percentage enhancement [PElast], and the washout percentage-enhancement difference [PEwashout]) were derived from DCE-MRI. The DCE-MRI parameters and ADCs were included in multivariate models to predict a diagnosis of a benign versus malignant lesion. RESULTS: The accuracy using semiquantitative DCE-MRI parameters alone was 70.4% (0.693 area under the ROC curve, 57.5% sensitivity, 79.3% specificity). Adding absolute ADCs to dynamic contrast-enhanced MR data showed the higher diagnostic accuracy of 85.7% (0.873 area under the ROC curve, 85.0% sensitivity, 86.2% specificity). Moreover, the absolute ADCs differed significantly between the benign (mean [SD] ADC, 1.211 [0.32] × 10 mm/s) and malignant (mean [SD] ADC, 0.702 [0.28] × 10 mm/s) sinonasal tumors (P < 0.001). In addition, a significant difference was found between the ADC values of malignant and benign lesions in washout enhancement TICs (t = 7.039, P < 0.001). CONCLUSIONS: High-resolution DWI with ADC mapping significantly improved the diagnostic accuracy of dynamic contrast-enhanced sinonasal MRI at 3.0T. In addition, ADC values could distinguish benign lesions from malignant tumors in washout enhancement TICs.

Binder-Free Three-Dimensional Porous Graphene Cathodes via Self-Assembly for High-Capacity Lithium-Oxygen Batteries.

The porous architectures of oxygen cathodes are highly desired for high-capacity lithium-oxygen batteries (LOBs) to support cathodic catalysts and provide accommodation for discharge products. However, controllable porosity is still a challenge for laminated cathodes with cathode materials and binders, since polymer binders usually shield the active sites of catalysts and block the pores of cathodes. In addition, polymer binders such as poly(vinylidene fluoride) (PVDF) are not stable under the nucleophilic attack of intermediate product superoxide radicals in the oxygen electrochemical environment. The parasitic reactions and blocking effect of binders deteriorate and then quickly shut down the operation of LOBs. Herein, the present work proposes a binder-free three-dimensional (3D) porous graphene (PG) cathode for LOBs, which is prepared by the self-assembly and the chemical reduction of GO with triblock copolymer soft templates (Pluronic F127). The interconnected mesoporous architecture of resultant 3D PG cathodes achieved an ultrahigh capacity of 10,300 mAh g-1 for LOBs. Further, the cathodic catalysts ruthenium (Ru) and manganese dioxide (MnO2) were, respectively, loaded onto the inner surface of PG cathodes to lower the polarization and enhance the cycling performance of LOBs. This work provides an effective way to fabricate free-standing 3D porous oxygen cathodes for high-performance LOBs.

Real-world study of hepatic artery infusion chemotherapy combined with anti-PD-1 immunotherapy for hepatocellular carcinoma patients with portal vein tumor thrombus.

Background: Patients with hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) present a poor prognosis. Current systemic therapies offer limited benefits. Hepatic artery infusion chemotherapy (HAIC) is a local regional treatment for advanced HCC, particularly in selected patients such as patients with PVTT or high intrahepatic tumor burden. Objectives: The purpose of this study is to retrospectively evaluate the efficacy and safety of HAIC combined with anti-PD-1 immunotherapy for HCC patients with PVTT, and explore factors related to survival prognosis, providing clues for treatment decisions for HCC patients. Design: This is a single-center retrospective study conducted over 2 years on consecutive PVTT patients receiving HAIC combined anti-PD-1 antibodies. Methods: The primary endpoint was overall survival (OS). Univariate and multivariate analyses were performed to identify prognostic factors affecting OS. Treatment-associated adverse events were evaluated as well. Results: A total of 119 patients were analyzed. The median OS and PFS were 14.9 months and 6.9 months. A total of 31.1% of grade 3-4 adverse events were reported, with elevated transaminase and total bilirubin being the most common. The independent variables correlated with survival include treatment-related alpha-fetoprotein (AFP) response, the presence of extrahepatic organ metastasis, absolute value of platelet (PLT), neutrophil-to-lymphocyte ratio, and combined usage of tyrosine kinase inhibitors (TKIs). Conclusion: In HCC patients with PVTT, combination therapy with HAIC and anti-PD-1 antibodies might be a promising therapy. The efficacy and safety of this combination protocol on patients with HCC complicated by PVTT warrants further investigation prospectively, especially in combination with TKIs.

Prevention of urinary tract infection using a silver alloy hydrogel-coated catheter in critically ill patients: A single-center prospective randomized controlled study.

Background: A new type of silver alloy hydrogel-coated (SAH) catheter has been shown to prevent bacterial adhesion and colonization by generating a microcurrent, and to block the retrograde infection pathway. However, these have only been confirmed in ordinary patients. This study aims to evaluate the effectiveness of a SAH catheter for preventing urinary tract infections in critically ill patients. Methods: This was a prospective single-center, single-blind, randomized, controlled study. A total of 132 patients requiring indwelling catheterization in the intensive care unit (ICU) of the First Affiliated Hospital of the University of Science and Technology of China between October 2022 and February 2023 and who met the study inclusion/exclusion criteria were randomly divided into two groups. Patients in the SAH catheter group received a SAH catheter, while patients in the conventional catheter group received a conventional siliconized latex Foley catheter. The main outcome measure was the incidence of catheter-associated urinary tract infections (CAUTIs). Secondary outcome indicators included urine positivity for white blood cells and positive urine cultures on 3 days, 7 days, 10 days, and 14 days after catheterization, number of viable bacteria in the catheter biofilm on day 14, pathogenic characteristics of positive urine cultures, length of ICU stay, overall hospital stay, ICU mortality, and 28-day mortality. All the data were compared between the two groups. Results: A total of 68 patients in the conventional catheter group and 64 patients in the SAH catheter group were included in the study. On day 7 after catheter placement, the positivity rate for urinary white blood cells was significantly higher in the conventional catheter group than in the SAH catheter group (33.8% vs. 15.6%, P=0.016). On day 10, the rates of positive urine cultures (27.9% vs. 10.9%, P=0.014) and CAUTIs (22.1% vs. 7.8%, P=0.023) were significantly higher in the conventional catheter group than in the SAH catheter group. On day 14, the numbers of viable bacteria isolated from the catheter tip ([3.21±1.91]×106 colony-forming units [cfu]/mL vs. [7.44±2.22]×104 cfu/mL, P <0.001), balloon segment ([7.30±1.99]×107 cfu/mL vs. [3.48±2.38]×105 cfu/mL, P <0.001), and tail section ([6.41±2.07]×105 cfu/mL vs. [8.50±1.46]×103 cfu/mL, P <0.001) were significantly higher in the conventional catheter group than in the SAH catheter group. The most common bacteria in the urine of patients in both groups were Escherichia coli (n=13) and Pseudomonas aeruginosa (n=6), with only one case of Candida in each group. There were no significant differences between the two groups in terms of ICU hospitalization time, total hospitalization time, ICU mortality, and 28-day mortality. Conclusion: SAH catheters can effectively inhibit the formation of catheter-related bacterial biofilms in critically ill patients and reduce the incidence of CAUTIs, compared with conventional siliconized latex Foley catheters; however, regular replacement of the catheter is still necessary.

Cobalt-Catalyzed Enantioselective Hydrogenation of Diaryl Ketones with Ferrocene-Based Secondary Phosphine Oxide Ligands.

A new class of cobalt catalytic system for asymmetric hydrogenation of ketones was herein reported, involving the development of novel ferrocene-based secondary phosphine oxide ligands. An unusual P-O bidentate coordination pattern with cobalt was confirmed by an X-ray diffraction study. The bichelating tetrahedral cobalt(II) complexes afforded high reactivities (up to 99% yield) and good to excellent enantioselectivities (up to 92% ee) in the AH of various ortho-substituted diaryl ketones. In addition, the diferrocenyl cobalt complex was characterized with intriguing UV-vis absorption and electrochemical properties.

Stabilizing the oxide cathode/sulfide solid electrolyte interface via a novel polyaniline coating prepared by ball milling.

The thermodynamic instability of oxide cathode/sulfide solid electrolyte (SSE) interfaces leads to the large resistances of all-solid-state lithium-ion batteries (ASSLIBs). This work proposes a flexible polyaniline (PANI) coating instead of rigid lithium-containing oxides to stabilize the lithium cobalt oxide (LCO)/SSE interface. The PANI coating is prepared by a facile ball milling followed by annealing. Electrochemical tests demonstrated that the elastic PANI layer lowers and maintains the LCO/SSE interface resistance during cycling. Thus, the high capacity retention of 85.5% after 200 cycles was achieved for ASSLIBs with Li5.5PS4.5Cl1.5 electrolytes.

Comparison of an optimized 3D-real IR and a 3D-FLAIR with a constant flip angle in the evaluation of endolymphatic hydrops.

PURPOSE: To evaluate an optimized 3D-real IR sequence with a longer TR (16,000 ms) based on the modulated flip angle technique in refocused imaging with extended echo train (MATRIX) for the endolymphatic hydrops (EH) after intravenous (IV) single-dose gadolinium (Gd) administration, and compare it with a heavily T2-weighted 3D-FLAIR sequence with a constant flip angle. METHOD: The 3D-FLAIR and 3D-real IR sequences were performed in forty patients with definite Meniere's disease (MD) four hours after IV Gd administration. Image qualities of the two sequences were rated and compared. Contrast-to-noise ratios (CNRs) and signal-to-noise ratios (SNRs) of the two sequences were measured for quantitative comparison. EH was graded on the images of the two sequences by two radiologists. RESULTS: Scores and CNRs of the 3D-real IR were significantly higher than those of the 3D-FLAIR (P < 0.05). SNRs of the two sequences were comparable between the two groups. 3D-real IR had a higher inter- and intra-observer reliability for the grading of cochlear and vestibular EH than 3D-FLAIR. Using 3D-real IR sequence, the detection rate of EH of the whole labyrinth was higher than using 3D-FLAIR (86.6 % vs 73.3 %, p = 0.031). In the patients with unilateral MD, SNRs in the affected sides were significantly higher than the unaffected sides (P < 0.05). CONCLUSIONS: The optimized 3D-real IR with a longer TR is a robust sequence with an improved depiction of EH after IV administration of single-dose Gd. Compared with 3D-FLAIR, it may allow a more precise evaluation and grading of EH.

Correlation assessment of NDVI and land use dynamics with water resources for the southern margin of Mu Us Sandy Land, China.

To prevent desertification, countries worldwide have made diversified efforts, and vegetation restoration has been demonstrated to be an effective approach. However, in regard to sandy land with limited water resources, measures such as revegetation may lead to an increased drought risk. Despite confirmed sand utilization achievements, many controversies remain regarding the advantages of desert greening, especially considering water scarcity. Therefore, the long-run and causal relationships between sandy land, water consumption, and vegetation coverage are necessarily explored. Choosing the southern margin of the Mu Us Sandy Land as the study area, this study explored the interactions between sandy land, water consumption, and normalized difference vegetation index (NDVI) of 2000-2018 with the vector autoregression (VAR) model approach. In the study area, various revegetation projects have been implemented, resulting in a notable reduction in the sandy land area. In addition, the NDVI increased from 0.196 in 2000 to 0.371 in 2018, an increase of 89.3%. The results indicated that there exist long-term stable equilibrium and causal relationships existed between water consumption and sandy land and NDVI. NDVI enhancement is relatively the direct factor that causes the increase of water consumption. It could be inferred that the implemented revegetation measures may rely on a large water consumption amount, which may further aggravate water shortages and ecological damage issues. More scientific and stronger effective water resource management measures should be locally implemented to achieve a balance between water resources and revegetation.

Redox chemistry-enabled stepwise surface dual nanoparticle engineering of 2D MXenes for tumor-sensitive T1 and T2 MRI-guided photonic breast-cancer hyperthermia in the NIR-II biowindow.

With the fast advent of two-dimensional (2D) MXenes, several therapeutic paradigms based on 2D MXenes flourish, but a generic strategy for MXene functionalization to achieve theranostic functionalities and desirable performance is still lacking. In this work, we report a facile and efficient stepwise surface-functionalization strategy to achieve distinct tumor microenvironment (TME)-responsive T1 and T2 magnetic resonance (MR) imaging-guided photothermal breast-cancer hyperthermia in the second near-infrared (NIR-II) biowindow. This approach is based on the stepwise growth of superparamagnetic Fe3O4 and paramagnetic MnOx nanocomponents onto the large surface of ultrathin 2D niobium carbide (Nb2C) MXene nanosheets (Fe3O4/MnOx-Nb2C) by making full use of the redox status/chemistry of the 2D MXene surface. Such a surface-nanoparticle engineering strategy endows Fe3O4/MnOx-Nb2C composite nanosheets with a series of properties that include high photothermal-conversion efficiency in the NIR-II biowindow (1064 nm, η 30.9%) for effective photothermal tumor eradication without further reoccurrence. It also allows TME-responsive T1- and T2-weighted MR imaging and high biocompatibility for guaranteeing further potential clinical transformation. This work not only makes the efficient diagnostic T1- and T2-weighted MR imaging-guided photonic hyperthermia of breast cancer possible, but also broadens the biomedical applications of MXene-based nanoplatforms by developing novel surface-engineering strategies to construct 2D Nb2C MXene-based composite multifunctional nanoplatforms.

A conductive framework embedded with cobalt-doped vanadium nitride as an efficient polysulfide adsorber and convertor for advanced lithium-sulfur batteries.

The industrialization and commercialization of Li-S batteries are greatly hindered by several defects such as the sluggish reaction kinetics, polysulfide shuttling and large volume expansion. Herein, we propose a heteroatom doping method to optimize the electronic structure for enhancing the adsorption and catalytic activity of VN that is in situ embedded into a spongy N-doped conductive framework, thus obtaining a Co-VN/NC multifunctional catalyst as an ideal sulfur host. The synthesized composite has both the unique structural advantages and the synergistic effect of cobalt, VN, and nitrogen-doped carbon (NC), which not only improve the polysulfide anchoring of the sulfur cathode but also boost the kinetics of polysulfide conversion. The density functional theory (DFT) calculations revealed that Co doping could enrich the d orbit electrons of VN for elevating the d band center, which improves its interaction with lithium polysulfides (LiPSs) and accelerates the interfacial electron transfer, simultaneously. As a result, the batteries present a high initial discharge capacity of 1521 mA h g-1 at 0.1 C, good rate performance, and excellent cycling performances (∼876 mA h g-1 at 0.5 C after 300 cycles and ∼490 mA h g-1 at 2 C after 1000 cycles, respectively), even with a high areal sulfur loading of 4.83 mg cm-2 (∼4.70 mA h cm-2 at 0.2 C after 100 cycles). This well-designed work provides a good strategy to develop effective polysulfide catalysis and further obtain high-performance host materials for Li-S batteries.

N-acetylcysteine combined with insulin alleviates the oxidative damage of cerebrum via regulating redox homeostasis in type 1 diabetic mellitus canine.

Neurodegenerative diseases are one of the major complications of type 1 diabetes mellitus (T1DM). The effect of insulin monotherapy on controlling blood glucose and neurodegeneration associated with diabetes is unsatisfactory. It is revealed that oxidative stress is a key element in T1DM. Therefore, N-acetylcysteine (NAC) was used together with insulin to investigate the therapeutic effect on neuronal damage in T1DM in this study. A total of 40 beagles were randomly divided into 5 groups (control group, DM group, insulin monotherapy group, NAC combined with insulin group, and NAC monotherapy group) to explore the effects of NAC on alleviating the oxidative damage in cerebrum. Our results showed that the contents of H2O2, 8-OHdg and MDA were apparently increased in DM group, while DNA and lipid oxidative damage was alleviated by the treatment of NAC and insulin. Histopathology revealed the sparse of neurofibrils and vacuolar degeneration in DM group. Additionally, compared with the control group, the mRNA expression levels of HO-1, nqo1, GCLC and GSTM1 were significantly decreased in DM group, while the opposite trend could be shown under NAC combined with insulin treatment. Meanwhile, the tight junction proteins of ZO-1, occludin and Claudin-1 were up-regulated with the treatment of NAC combined with insulin. Additionally, NAC further alleviated oxidative damage by enhancing the activity of GSH, Trx and TrxR and reducing the activity of catalase, GSSG and Grx to maintain redox homeostasis. These results demonstrated that NAC combined with insulin exerted protective effects against T1DM-induced cerebral injury via maintaining cerebral redox homeostasis.

TiN@C nanocages as multifunctional sulfur hosts for superior lithium-sulfur batteries.

The lithium polysulfide (LiPS) shuttle effect and low redox kinetics are the key problems that hinder performance improvement and prevent achieving the commercial requirements for lithium-sulfur batteries (LSBs), and the reasonable construction of sulfur hosts is one effective strategy to relieve the polysulfide shuttle effect and improve redox kinetics. Herein, N-doped carbon nanocages decorated with homogeneously dispersed TiN nanoparticles (TiN@C NCs) as multifunctional sulfur hosts are designed for superior LSBs. Carbon nanocages provide space to mitigate volume expansion and provide additional physical adsorption to trap the LiPSs. Polar TiN nanoparticles not only exhibit the chemisorption capacity for LiPSs, but also catalyze and promote the conversion of long-chain LiPSs to Li2S2/Li2S in the reduction process as well as the decomposition of Li2S in the oxidation reaction, which significantly boosts electron/ion transport and decreases the potential barrier. Therefore, the S/TiN@C NC cathode has an excellent electrochemical capacity of 1485.7 mA h g-1 at 0.1 C. In particular, the cathode demonstrates high capacity reversibility after 500 cycles at 3 C with a retention of about 73.1%, which is equivalent to a slow capacity decay rate of 0.053% per cycle.

A vanadium-based oxide-nitride heterostructure as a multifunctional sulfur host for advanced Li-S batteries.

The commercial application of lithium-sulfur (Li-S) batteries is obstructed by the inherent dissolution/shuttling of lithium polysulfides (LiPSs) in a sluggish redox reaction. Here, a heterophase V2O3-VN yolk-shell nanosphere encapsulated by a nitrogen-doped carbon layer has been designed to address the problems of the short cycle life and rapid capacity decay of Li-S batteries synchronously. The structural merits comprise efficient polysulfide anchoring (V2O3), rapid electron transfer (VN) and a reinforced frame (N-doped carbon). The assembled cathode based on the V2O3-VN@NC sulfur host delivered a high initial capacity of 1352 mA h g-1 at 0.1C with excellent rate performance (797 mA h g-1 at 2C) and favorable cycle stability with a low capacity-decay rate of only 0.038% per cycle over 800 cycles at 1C. Even with a high sulfur loading of 3.95 mg cm-2, an initial capacity of 954 mA h g-1 at 0.2C could be achieved, along with a good capacity retention of 75.1% after 150 cycles. Density functional theory computations demonstrated the crucial role of the V2O3-VN@NC heterostructure in the trapping-diffusion-conversion of polysulfides. This multi-functional cathode is very promising in realizing practically usable Li-S batteries owing to the simple process and the prominent rate and cyclic performances.