Naringenin enhances the efficacy of ferroptosis inducers by attenuating aerobic glycolysis by activating the AMPK-PGC1α signalling axis in liver cancer.

Liver cancer is a heterogeneous disease characterized by poor responses to standard therapies and therefore unfavourable clinical outcomes. Understanding the characteristics of liver cancer and developing novel therapeutic strategies are imperative. Ferroptosis, a type of programmed cell death induced by lipid peroxidation, has emerged as a potential target for treatment. Naringenin, a natural compound that modulates lipid metabolism by targeting AMPK, shows promise in enhancing the efficacy of ferroptosis inducers. In this study, we utilized liver cancer cell lines and xenograft mice to explore the synergistic effects of naringenin in combination with ferroptosis inducers, examining both phenotypic outcomes and molecular mechanisms. Our study results indicate that the use of naringenin at non-toxic doses to hepatocytes can significantly enhance the anticancer effects of ferroptosis inducers (erastin, RSL3, and sorafenib). The combination index method confirmed a synergistic effect between naringenin and ferroptosis inducers. In comparison to naringenin or ferroptosis inducers alone, the combined therapy caused more robust lipid peroxidation and hence more severe ferroptotic damage to cancer cells. The inhibition of aerobic glycolysis mediated by the AMPK-PGC1α signalling axis is the key to naringenin's effect on reducing ferroptosis resistance in liver cancer, and the synergistic cytotoxic effect of naringenin and ferroptosis inducers on cancer cells was reversed after pretreatment with an AMPK inhibitor or a PGC1α inhibitor. Taken together, these findings suggest that naringenin could boost cancer cell sensitivity to ferroptosis inducers, which has potential clinical translational value.

Correlation between hemoglobin and the risk of common malignant tumors: a 1999-2020 retrospective analysis and causal association analysis.

BACKGROUND: The role of hemoglobin (HGB) in common malignant tumors remains unclear. METHODS: A retrospective analysis was conducted to identify the correlation between HGB levels and risk of 15 malignant tumors using 50,085 samples from the National Health and Nutrition Examination Survey. Mendelian Randomization analyses (MRAs) were performed based on genome-wide association study data to assess the causal relationship between HGB levels and these malignant tumors using more than 700,000 samples. The robustness of the MRA results was confirmed through various analytical methods. Fifty-six in-house samples were used to investigate the correlation between HGB levels and the prognosis in prostate cancer (PRCA) using the Kaplan-Meier curve. RESULTS: High HGB levels were associated with a higher risk for patients with cervix cancer, melanoma, and non-melanoma skin cancer (OR > 1.000, p < 0.05). It served as a protective factor for colon cancer, esophagus cancer, stomach cancer, bone cancer, lung cancer, renal cancer, and PRCA (OR < 1.000, p < 0.05). Furthermore, MRAs suggested that elevated HGB levels were correlated with a reduced risk of PRCA (OR = 0.869, p < 0.05), with no significant association observed between this marker and the remaining 14 malignant tumors. No pleiotropy or heterogeneity was found in the ultimate results for MRAs (p-values > 0.05), suggesting the robustness of the results. The results derived from the in-house data revealed a relationship between higher HGB values and a more favorable prognosis in PRCA (p < 0.05). CONCLUSION: High circulating HGB levels may play a protective prognostic role for PRCA and serve as a protective factor against the occurrence of PRCA.

Intraventricular Thrombosis and Pulmonary Embolism Post-Nuss Procedure: A Rare Case of Chronic Bar Displacement in a 16-Year-Old Patient.

This novel report presents the first known case, to our knowledge, of a 16-year-old male patient who experienced intraventricular thrombosis and pulmonary embolism after a Nuss procedure for pectus excavatum, attributed to chronic bar displacement. Two years after the operation, the patient experienced post-exercise cough and hemoptysis, which led to his admission. Imaging revealed pulmonary embolism, thrombosis in the right ventricular outflow tract, and lung infiltrative lesions. We hypothesize that the chronic bar displacement led to its embedment in the right ventricle, resulting in thrombus formation, which subsequently contributed to partial pulmonary embolism. Surgery revealed the bars' intrusion into the right ventricle and lung. This case highlights the risk of severe complications from bar displacement in the Nuss procedure, which necessitates long-term follow-up evaluation, caution against strenuous activities after surgery, and use of thoracoscopic guidance during bar implantation and removal. It underscores the importance of vigilant evaluation for late-stage complications in patients with respiratory distress or thrombosis after a Nuss procedure.

Modulating Thermal Conductivity via Targeted Phonon Excitation.

Thermal conductivity is a critical material property in numerous applications, such as those related to thermoelectric devices and heat dissipation. Effectively modulating thermal conductivity has become a great concern in the field of heat conduction. Here, a quantum modulation strategy is proposed to modulate the thermal conductivity/heat flux by exciting targeted phonons. It shows that the thermal conductivity of graphene can be tailored in the range of 1559 W m-1 K-1 (decreased to 49%) to 4093 W m-1 K-1 (increased to 128%), compared with the intrinsic value of 3189 W m-1 K-1. The effects are also observed for graphene nanoribbons and bulk silicon. The results are obtained through both density functional theory calculations and molecular dynamics simulations. This novel modulation strategy may pave the way for quantum heat conduction.

Health insurance coverage among incident cancer cases from population-based cancer registries in 49 US states, 2010-2019.

Having health insurance coverage is a strong determinant of cancer care access and survival in the United States. The expansion of Medicaid income eligibility under the Affordable Care Act has increased insurance coverage for working-age adults. Using data from the Cancer Incidence in North America (CiNA) in 2010-2019, we identified 6 432 117 incident cancer cases with known insurance status diagnosed at age 18-64 years from population-based registries of 49 states. Considerable variation in Medicaid coverage and uninsured rate exists across states, especially by Medicaid expansion status. Among expansion states, Medicaid coverage increased from 14.1% in 2010 to 19.9% in 2019, while the Medicaid coverage rate remained lower (range = 11.7% - 12.7%) in non-expansion states. The uninsured rate decreased from 4.9% to 2.1% in expansion states, while in non-expansion states, the uninsured rate decreased slightly from 9.5% to 8.1%. In 2019, 111 393 cancer cases (16.9%) had Medicaid coverage at diagnosis (range = 7.6%-37.9% across states), and 48 357 (4.4%) were uninsured (range = 0.5%-13.2%). These estimates suggest that many patients with cancer may face challenges with care access and continuity, especially following the unwinding of COVID-19 pandemic protections for Medicaid coverage. State cancer prevention and control efforts are needed to mitigate cancer care disparities among vulnerable populations.

Enhanced recovery after surgery for percutaneous CT-guided microwave ablation of lung tumors: A single-center retrospective cohort study.

BACKGROUND: The feasibility and safety of enhanced recovery after surgery (ERAS) for percutaneous computed tomography (CT)-guided microwave ablation (MWA) for treating lung nodules remain unclear. METHODS AND MATERIALS: A total of 409 patients with lung tumors treated at the Department of Thoracic Surgery, First Affiliated Hospital of Guangxi Medical University from August 2020 to May 2023 were enrolled. Perioperative data, including baseline characteristics, operation time, postoperative pain score (visual analog scale [VAS]), hospitalization expenses, postoperative complications, total hospital stay, and patient satisfaction, were observed and recorded. RESULTS: No perioperative mortality occurred in either group and complete ablation was achieved in all patients. Patients in the ERAS group had significantly shorter hospital stays (P < 0.001), reduced operation times (P = 0.047), lower hospitalization expenses (P < 0.001), lower VAS scores (P < 0.001), and fewer complications (P = 0.047) compared with the traditional group. CONCLUSIONS: ERAS for percutaneous CT-guided MWA (ERAA) is safe, effective, and feasible for the treatment of lung nodules.

Tumor-targeted gypenoside nanodrug delivery system with double protective layers.

OBJECTIVES: Gypenoside (Gyp) is easily degraded in the gastrointestinal tract, resulting in its low bioavailability. We aimed to develop a tumor-targeted Gyp nanodrug delivery system and to investigate its antitumor effect in vitro. MATERIALS AND METHODS: We used Gyp as the therapeutic drug molecule, mesoporous silica (MSN) and liposome (Lipo) as the drug carrier and protective layers, and aptamer SYL3C as the targeting element to establish a tumor-targeted nanodrug delivery system (i.e., SYL3C-Lipo@Gyp-MSN). The characteristics of SYL3C-Lipo@Gyp-MSN were investigated, and its drug release performance, cell uptake, and antitumor activity in vitro were evaluated. RESULTS: A tumor-targeted Gyp nanodrug delivery system was successfully prepared. The SYL3C-Lipo@Gyp-MSN was spherical or ellipsoidal; had good dispersion, which enabled it to specifically target and kill the liver tumor cell HepG2; and effectively protected the early leakage of Gyp. CONCLUSIONS: We have established a tumor-targeted nanodrug delivery system that can target and kill liver cancer cells and may provide a strategy for preparing new nanodrug-loaded preparations of traditional Chinese medicine.

Novel NARS2 variants in a patient with early-onset status epilepticus: case study and literature review.

BACKGROUND: NARS2 as a member of aminoacyl-tRNA synthetases was necessary to covalently join a specific tRNA to its cognate amino acid. Biallelic variants in NARS2 were reported with disorders such as Leigh syndrome, deafness, epilepsy, and severe myopathy. CASE PRESENTATION: Detailed clinical phenotypes were collected and the NARS2 variants were discovered by whole exome sequencing and verified by Sanger sequencing. Additionally, 3D protein structure visualization was performed by UCSF Chimera. The proband in our study had early-onset status epilepticus with abnormal EEG and MRI results. She also performed global developmental delay (GDD) and myocardial dysfunction. Next-generation sequencing (NGS) and Sanger sequencing revealed compound heterozygous missense variants [NM_024678.6:exon14: c.1352G > A(p.Arg451His); c.707T > C(p.Phe236Ser)] of the NARS2 gene. The proband develops refractory epilepsy with GDD and hyperlactatemia. Unfortunately, she finally died for status seizures two months later. CONCLUSION: We discovered two novel missense variants of NARS2 in a patient with early-onset status epilepticus and myocardial dysfunction. The NGS enables the patient to be clearly diagnosed as combined oxidative phosphorylation deficiency 24 (COXPD24, OMIM:616,239), and our findings expands the spectrum of gene variants in COXPD24.

COVID-19 vaccination, infection, and symptoms among cancer survivors in the United States.

The experiences of cancer survivors with the COVID-19 pandemic in the United States during 2021 and 2022, when vaccinations became widely available, are largely undocumented. Using nationally representative survey data in 2021 and 2022, we found that compared with adults without a cancer history, cancer survivors were more likely to have at least 2 COVID-19 vaccines (2021: 66.6% vs 62.3%, P = .003; 2022: 77.0% vs 72.4%, P < .001) and as likely to have a COVID-19 infection history (2021: 14.1% vs 14.2%, P = .93; 2022: 39.9% vs 39.3%, P = .55) but, once infected, were more likely to develop moderate to severe symptoms (2021: 62.5% vs 54.2%, P = .02; 54.5% vs 61.3%; P = .13). Among cancer survivors, younger age, lower educational attainment, lack of health insurance, and more comorbidities were statistically significantly associated with lower vaccination rates (P < .001). Among infected cancer survivors, being female and younger were associated with higher likelihood of developing moderate to severe symptoms (P < .001). Our findings suggest tailored efforts to prevent and control COVID-19 infections for cancer survivors.

Adjuvant Therapy-Free Strategy for Stage IB to IIIA Non-Small-Cell Lung Cancer Patients After Radical Resection Based on Longitudinal Undetectable Molecular Residual Disease: Prospective, Multicenter, Single-Arm Study (CTONG 2201).

BACKGROUND: The utility of circulating tumor DNA to monitor molecular residual disease (MRD) has been clinically confirmed to predict disease recurrence in non-small cell lung cancer (NSCLC) patients after radical resection. Patients with longitudinal undetectable MRD show a favorable prognosis and might not benefit from adjuvant therapy. PATIENTS AND METHODS: The CTONG 2201 trial is a prospective, multicenter, single-arm study (ClinicalTrials.gov identifier, NCT05457049), designed to evaluate the hypothesis that no adjuvant therapy is needed for patients with longitudinal undetectable MRD. Pathologically confirmed stage IB-IIIA NSCLC patients who have undergone radical resection will be screened. Only patients with 2 consecutive rounds of undetectable MRD will be enrolled (first at days 3-10, second at days 30 ± 7 after surgery), and admitted for imaging and MRD monitoring every 3 months without adjuvant therapy. The primary endpoint is the 2-year disease-free survival rate for those with longitudinal undetectable MRD. The recruitment phase began in August 2022 and 180 patients will be enrolled. CONCLUSIONS: This prospective trial will contribute data to confirm the negative predictive value of MRD on adjuvant therapy for NSCLC patients. CLINICAL TRIAL REGISTRATION: NCT05457049 (CTONG 2201).

Prediction of lymph node metastasis of lung squamous cell carcinoma by machine learning algorithm classifiers.

BACKGROUND: Lymph node metastasis (LNM) is an essential factor affecting the prognosis of patients with lung squamous cell carcinoma (LUSC), as well as a critical consideration for the choice of treatment strategy. Exploring effective methods for predicting LNM in LUSC may benefit clinical decision making. MATERIALS AND METHODS: We used data collected from the Surveillance, Epidemiology, and End Results (SEER) database to develop machine learning algorithm classifiers, including boosted trees (BTs), based on the primary clinical parameters of patients to predict LNM in LUSC. Training on a large-sample training cohort (n = 8,063) allowed for the construction of several concise classifiers for LNM prediction in LUSC, which were then validated using test and in-house cohorts (n = 2,017 and 57, respectively). RESULTS: The six classifiers established in this research enabled distinction between patients with and without LNM. Among these classifiers, the BT classifier was the top performer, with accuracy, F1 scores, precision, recall, sensitivity, and specificity values of 0.654, 0.621, 0.654, 0.592, 0.592, and 0.711, respectively. The precision recall (PR) and receiver operating characteristic (ROC) (with area under the curve = 0.714) curves also supported this result, which was validated by the in-house cohort. Notably, the tumor stage was a critical factor in determining LNM in patients with LUSC. CONCLUSIONS: The use of classifiers, especially the BT classifier, may serve as a useful tool for improving clinical precision and individualized treatment of patients with LUSC.

Enhancing the interfacial thermal conductance of Si/PVDF by strengthening atomic couplings.

Thermal transport across inorganic/organic interfaces attracts interest from both academia and industry due to their wide applications in flexible electronics, etc. Here, the interfacial thermal conductance of inorganic/organic interfaces consisting of silicon and polyvinylidene fluoride is systematically investigated using molecular dynamics simulations. Interestingly, it is demonstrated that a modified silicon surface with hydroxyl groups can drastically enhance the conductance by 698%. These results are elucidated based on interfacial couplings and lattice dynamics insights. This study not only provides feasible strategies to effectively modulate the interfacial thermal conductance of inorganic/organic interfaces but also deepens the understanding of the fundamental physics underlying phonon transport across interfaces.

Changes in cancer diagnoses and stage distribution during the first year of the COVID-19 pandemic in the USA: a cross-sectional nationwide assessment.

BACKGROUND: The emergence of COVID-19 disrupted health care, with consequences for cancer diagnoses and outcomes, especially for early stage diagnoses, which generally have favourable prognoses. We aimed to examine nationwide changes in adult cancer diagnoses and stage distribution during the first year of the COVID-19 pandemic by cancer type and key sociodemographic factors in the USA. METHODS: In this cross-sectional study, adults (aged ≥18 years) newly diagnosed with a first primary malignant cancer between Jan 1, 2018, and Dec 31, 2020, were identified from the US National Cancer Database. We included individuals across 50 US states and the District of Columbia who were treated in hospitals that were Commission on Cancer-accredited during the study period. Individuals whose cancer stage was 0 (except for bladder cancer), occult, or without an applicable American Joint Committee on Cancer staging scheme were excluded. Our primary outcomes were the change in the number and the change in the stage distribution of new cancer diagnoses between 2019 (Jan 1 to Dec 31) and 2020 (Jan 1 to Dec 31). Monthly counts and stage distributions were calculated for all cancers combined and for major cancer types. We also calculated annual change in stage distribution from 2019 to 2020 and adjusted odds ratios (aORs) using multivariable logistic regression, adjusted for age group, sex, race and ethnicity, health insurance status, comorbidity score, US state, zip code-level social deprivation index, and county-level age-adjusted COVID-19 mortality in 2020. Separate models were stratified by sociodemographic and clinical factors. FINDINGS: We identified 2 404 050 adults who were newly diagnosed with cancer during the study period (830 528 in 2018, 849 290 in 2019, and 724 232 in 2020). Mean age was 63·5 years (SD 13·5) and 1 287 049 (53·5%) individuals were women, 1 117 001 (46·5%) were men, and 1 814 082 (75·5%) were non-Hispanic White. The monthly number of new cancer diagnoses (all stages) decreased substantially after the start of the COVID-19 pandemic in March, 2020, although monthly counts returned to near pre-pandemic levels by the end of 2020. The decrease in diagnoses was largest for stage I disease, leading to lower odds of being diagnosed with stage I disease in 2020 than in 2019 (aOR 0·946 [95% CI 0·939-0·952] for stage I vs stage II-IV); whereas, the odds of being diagnosed with stage IV disease were higher in 2020 than in 2019 (1·074 [1·066-1·083] for stage IV vs stage I-III). This pattern was observed in most cancer types and sociodemographic groups, although was most prominent among Hispanic individuals (0·922 [0·899-0·946] for stage I; 1·110 [1·077-1·144] for stage IV), Asian American and Pacific Islander individuals (0·924 [0·892-0·956] for stage I; 1·096 [1·052-1·142] for stage IV), uninsured individuals (0·917 [0·875-0·961] for stage I; 1·102 [1·055-1·152] for stage IV), Medicare-insured adults younger than 65 years (0·909 [0·882-0·937] for stage I; 1·105 [1·068-1·144] for stage IV), and individuals living in the most socioeconomically deprived areas (0·931 [0·917-0·946] for stage I; 1·106 [1·087-1·125] for stage IV). INTERPRETATION: Substantial cancer underdiagnosis and decreases in the proportion of early stage diagnoses occurred during 2020 in the USA, particularly among medically underserved individuals. Monitoring the long-term effects of the pandemic on morbidity, survival, and mortality is warranted. FUNDING: None.

A nosocomial Pseudomonas aeruginosa ST3495 isolated from a wild Burmese python (Python bivittatus) with suppurative pneumonia and bacteremia in Hainan, China.

Pseudomonas aeruginosa is a common infectious agent associated with respiratory diseases in boas and pythons, however, the histopathology, resistance and virulence are yet described for this species. In this study, we investigated a dying Burmese python rescued from tropical rainforest in Hainan. Clinical signs were open-mouthed breathing, abnormal shedding and anorexia. Abundant yellow mucopurulent secretions were observed in highly ectatic segmental bronchi by postmortem. Histopathological lesions included systemic pneumonia, enteritis, nephritis and carditis. P. aeruginosa was the only species isolated from heart blood, kidney, trachea and lung. The phenotype analysis demonstrated that the isolates had strong biofilm, and were sensitive to amikacin, spectinomycin, ciprofloxacin, norfloxacin and polymyxin B, moreover, the LD50 of the most virulent isolate was 2.22×105 cfu/mL in a zebrafish model. Molecular epidemiological analysis revealed that the isolates belonged to sequence type 3495, the common gene patterns were toxA + exoSYT + phzIM + plcHN in virulence and catB + blaTEM + ant (3'')-I+ tetA in resistance. This study highlights that P. aeruginosa should be worth more attention in wildlife conservation and raise the public awareness for the cross infection and cross spread between animals and human.

The rearrangement of actin cytoskeleton in mossy fiber synapses in a model of experimental febrile seizures.

Background: Experimental complex febrile seizures induce a persistent hippocampal hyperexcitability and an enhanced seizure susceptibility in adulthood. The rearrangement of filamentous actin (F-actin) enhances the excitability of hippocampus and contributes to epileptogenesis in epileptic models. However, the remodeling of F-actin after prolonged febrile seizures is to be determined. Methods: Prolonged experimental febrile seizures were induced by hyperthermia on P10 and P14 rat pups. Changes of actin cytoskeleton in hippocampal subregions were examined at P60 and the neuronal cells and pre- /postsynaptic components were labeled. Results: F-actin was increased significantly in the stratum lucidum of CA3 region in both HT + 10D and HT + 14D groups and further comparison between the two groups showed no significant difference. The abundance of ZNT3, the presynaptic marker of mossy fiber (MF)-CA3 synapses, increased significantly whereas the postsynaptic marker PSD95 did not change significantly. Overlapping area of F-actin and ZNT3 showed a significant increase in both HT+ groups. The results of cell counts showed no significant increase or decrease in the number of neurons in each area of hippocampus. Conclusion: F-actin was significantly up-regulated in the stratum lucidum of CA3, corresponding to the increase of the presynaptic marker of MF-CA3 synapses after prolonged febrile seizures, which may enhance the excitatory output from the dentate gyrus to CA3 and contribute to the hippocampal hyperexcitability.

Strong immune responses and protection of PcrV and OprF-I mRNA vaccine candidates against Pseudomonas aeruginosa.

Pseudomonas aeruginosa (PA) is a leading cause of hospital-acquired and ventilator-associated pneumonia. The multidrug-resistance (MDR) rate of PA is increasing making the management of PA a global challenge. Messenger RNA (mRNA) vaccines represent the most promising alternative to conventional vaccines and are widely studied for viral infection and cancer immunotherapy while rarely studied for bacterial infections. In this study, two mRNA vaccines encoding PcrV- the key component of the type III secretion system in Pseudomonas and the fusion protein OprF-I comprising outer membrane proteins OprF and OprI were constructed. The mice were immunized with either one of these mRNA vaccines or with the combination of both. Additionally, mice were vaccinated with PcrV, OprF, or the combination of these two proteins. Immunization with either mRNA-PcrV or mRNA-OprF-I elicited a Th1/Th2 mixed or slighted Th1-biased immune response, conferred broad protection, and reduced bacterial burden and inflammation in burn and systemic infection models. mRNA-PcrV induced significantly stronger antigen-specific humoral and cellular immune responses and higher survival rate compared with the OprF-I after challenging with all the PA strains tested. The combined mRNA vaccine demonstrated the best survival rate. Moreover, the mRNA vaccines showed the superiority over protein vaccines. These results suggest that mRNA-PcrV as well as the mixture of mRNA-PcrV and mRNA-OprF-I are promising vaccine candidates for the prevention of PA infection.

Complete genome sequence analysis of Edwardsiella tarda SC002 from hatchlings of Siamese crocodile.

Edwardsiella tarda is a Gram-negative, facultative anaerobic rod-shaped bacterium and the causative agent of the systemic disease "Edwardsiellosis". It is commonly prevalent in aquatic organisms with subsequent economic loss and hence has attracted increasing attention from researchers. In this study, we investigated the complete genome sequence of a highly virulent isolate Edwardsiella tarda SC002 isolated from hatchlings of the Siamese crocodile. The genome of SC002 consisted of one circular chromosome of length 3,662,469 bp with a 57.29% G+C content and four novel plasmids. A total of 3,734 protein-coding genes, 12 genomic islands (GIs), 7 prophages, 48 interspersed repeat sequences, 248 tandem repeat sequences, a CRISPR component with a total length of 175 bp, and 171 ncRNAs (tRNA = 106, sRNA = 37, and rRNA = 28) were predicted. In addition, the coding genes of assembled genome were successfully annotated against eight general databases (NR = 3,618/3,734, COG = 2,947/3,734, KEGG = 3,485/3,734, SWISS-PROT = 2,787/3,734, GO = 2,648/3,734, Pfam = 2,648/3,734, CAZy = 130/3,734, and TCDB = 637/3,734) and four pathogenicity-related databases (ARDB = 11/3,734, CARD = 142/3,734, PHI = 538/3,734, and VFDB = 315/3,734). Pan-genome and comparative genome analyses of the complete sequenced genomes confirmed their evolutionary relationships. The present study confirmed that E. tarda SC002 is a potential pathogen bearing a bulk amount of antibiotic resistance, virulence, and pathogenic genes and its open pan-genome may enhance its host range in the future.

Osteogenic and long-term antibacterial properties of Sr/Ag-containing TiO2 microporous coating in vitro and in vivo.

Bacterial infection and poor osseointegration are two critical issues that need to be solved for long-term use of titanium implants. As such, Sr/Ag-containing TiO2 microporous coatings were prepared on a Ti alloy surface in the current study via a single-step microarc oxidation technique. The coatings showed both good cytocompatibility in vitro and biosafety in vivo. Sr/Ag incorporation brought no significant change in the surface micromorphology and physicochemical properties, but endowed the coating with strong osteogenic activity and long-term antibacterial capability in vitro. Furthermore, the osteogenic and antibacterial capability of the coating was also confirmed in vivo. In a rat osseointegration model, new bone formation, implant-bone contact, removal torque and bone mineralization were all significantly increased in the M-Sr/Ag group when compared with those in group M, although they were slightly lower than those in group M-Sr. In a periimplantitis model, no rats suffered infection in the M-Sr/Ag group after 3 months of osseointegration and 5 weeks of bacterial inoculation period, when compared to 100% and 75% infection rates in M and M-Sr groups, respectively. In addition, active bone remodeling and many mesenchymal cells were observed in the M-Sr group, suggesting good bone regeneration potential in Sr-containing coatings in the case of controlled periimplantitis. Overall, the Sr/Ag-containing TiO2 microporous coating is valuable for preventing periimplantitis and improving implant reosseointegration, and is therefore promising for long-term and high quality use of titanium implants.

The effect of strontium content on physicochemical and osteogenic property of Sr/Ag-containing TiO2 microporous coatings.

Strontium (Sr) is the most common element introduced into TiO2 coatings to strengthen the osteogenic property of titanium implants. However, the optimal Sr content and its effect on osteogenic and physicochemical properties of the coatings need to be clarified. In the current study, TiO2 microporous coatings with different contents of Sr (9.64-21.25 wt %) and silver (Ag) (0.38-0.75 wt %) were prepared via micro-arc oxidation technique. Sr contents did not change physicochemical properties of the coatings, including surface microstructure, micropore size and distribution, phase composition, roughness and hydrophilicity. Meanwhile, higher Sr contents (18.23-21.25 wt %) improved cytocompatibility, proliferation and alkaline phosphatase (ALP) activity of preosteoblasts, even the coatings underwent 30 days' PBS immersion. Furthermore, higher Sr contents facilitated preosteoblast growth and spreading, which are essential for their proliferation and osteogenic differentiation. Therefore, it is promising to incorporate higher Sr content (18.23-21.25 wt %) within TiO2 microporous coatings to improve their osteogenic capability.

Order of magnitude reduction in Joule heating of single molecular junctions between graphene electrodes.

Maintaining stability of single-molecular junctions (SMJs) in the presence of current flow is a prerequisite for their potential device applications. However, theoretical understanding of nonequilibrium heat transport in current-carrying SMJs is a challenging problem due to the different kinds of nonlinear interactions involved, including electron-vibration and anharmonic vibrational coupling. Here, we overcome this challenge by accelerating Langevin-type current-induced molecular dynamics using machine-learning potential derived from density functional theory. We show that SMJs with graphene electrodes generate an order of magnitude less heating than those with gold electrodes. This is rooted in the better phonon spectral overlap of graphene with molecular vibrations, rendering harmonic phonon heat transport being dominant. In contrast, in a spectrally mismatched junction with gold electrodes, anharmonic coupling becomes important to transport heat away from the molecule to surrounding electrodes. Our work paves the way for studying current-induced heat transport and energy redistribution in realistic SMJs.