A Novel Particle Swarm Optimization With Genetic Operator and Its Application to TSP

To solve some problems of particle swarm optimization, such as the premature convergence and falling into a sub-optimal solution easily, we introduce the probability initialization strategy and genetic operator into the particle swarm optimization algorithm. Based on the hybrid strategies, we propose a improved hybrid particle swarm optimization, namely IHPSO, for solving the traveling salesman problem. In the IHPSO algorithm, the probability strategy is utilized into population initialization. It can save much more computing resources during the iteration procedure of the algorithm. Furthermore, genetic operators, including two kinds of crossover operator and a directional mutation operator, are used for improving the algorithm’s convergence accuracy and population diversity. At last, the proposed method is benchmarked on 9 benchmark problems in TSPLIB and the results are compared with 4 competitors. From the results, it is observed that the proposed approach significantly outperforms others on most the 9 datasets.

Insight into the Contributions of Surface Oxygen Vacancies on the Promoted Photocatalytic Property of Nanoceria

Oxygen vacancies (OVs) have critical effects on the photoelectric characterizations and photocatalytic activity of nanoceria, but the contributions of surface OVs on the promoted photocatalytic properties are not clear yet. In this work, we synthesized ceria nanopolyhedron (P-CeO₂), ceria nanocube (C-CeO₂) and ceria nanorod (R-CeO₂), respectively, and annealed them at 600 °C in air, 30%, 60% or pure H₂. After annealing, the surface OVs concentration of ceria elevates with the rising of H₂ concentration. Photocatalytic activity of annealed ceria is promoted with the increasing of surface OVs, the methylene blue photodegradation ratio with pure hydrogen annealed of P-CeO₂, C-CeO₂ or R-CeO₂ is 93.82%, 85.15% and 90.09%, respectively. Band gap of annealed ceria expands first and then tends to narrow slightly with the rising of surface OVs, while the valence band (VB) and conductive band (CB) of annealed ceria changed slightly. Both of photoluminescence spectra and photocurrent results indicate that the separation efficiency of photoinduced electron-hole pairs is significantly enhanced with the increasing of the surface OVs concentration. The notable weakened recombination of photogenerated carrier is suggested to attribute a momentous contribution on the enhanced photocatalytic activity of ceria which contains surface OVs.

Therapeutic efficacy of zoledronic acid combined with calcitriol in elderly patients receiving total hip arthroplasty or hemiarthroplasty for osteoporotic femoral neck fracture

Zoledronic acid could improve the clinical outcome in elderly patients receiving total hip arthroplasty or hemiarthroplasty for osteoporotic femoral neck fracture in the 1-year prospective study.

INTRODUCTION

To validate the therapeutic efficacy of zoledronic acid (ZOL) in elderly patients with femoral neck fracture who received total hip arthroplasty (THA) or hemiarthroplasty (HA).

METHODS

Included in this study were 95 elderly patients with femoral neck fractures who received THA/HA between August 2015 and June 2018. They were randomized into a ZOL group and a control group. Patients in ZOL group received a yearly single dose of 5 mg ZOL intravenous injection plus 0.5 μg/day calcitriol and 1000 mg/day calcium carbonate 2 days before THA or HA. Patients in the control group were treated with the same dose of calcitriol and calcium carbonate only without ZOL. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. Bone metabolism markers including the total extension of the peptide type I collagen amino end (P1NP) and beta collagen degradation product (β-CTX) were obtained by serum examination. The postoperative functional outcome was assessed using Harris Hip Score (HHS).

RESULTS

During the follow-up period, BMD in the ZOL group was improved and significantly higher than that in the control group at 6 and 12 months post-operation. Bone metabolism markers P1NP and β-CTX in ZOL group remained at a relatively low level as compared with that in the control group at 6 months after treatment. No significant difference in the mean HHS and the excellent/good rate of joint function was observed during the follow-up period between the two groups. The occurrence of adverse events in the ZOL group was significantly higher than that in the control group.

CONCLUSIONS

A single infusion of ZOL shows promise in improving BMD of the healthy side of the femoral neck, lumbar spine, and total hip and decreasing the level of bone markers, which may improve the clinical outcome of patients with osteoporotic femoral neck fractures receiving THA/HA.

Optimal rare-earth (La, Y and Sm) doping conditions and enhanced mechanism for photocatalytic application of ceria nanorods

Morphological tuning or additional cation doping is one of the potential and simple methods to enhance the photocatalytic properties of ceria, in which rare-earth element doped ceria nanorods (CeO₂-RE NRs) are expected to be a promising photocatalyst with high activity. But the optimal doping conditions, including the variety and concentration of RE elements are ambiguous, and the contribution of doped RE ions to the enhancement of photocatalytic activity needs to be further studied. In this work, we doped La, Y and Sm with a wide range of 0%-30% into CeO₂ NRs, and investigated the phase, morphology, band gap, oxygen vacancy concentration, PL spectra and photocatalytic activity variation under different doping conditions. All synthesized CeO₂-RE NRs possessed a good nanorod morphology except the 15 and 30% Y-doped samples. The energy band gaps of the synthesized samples changed slightly; the 10% CeO₂-RE NRs with the narrowest band gaps possessed the higher photocatalytic performance. The most outstanding photocatalyst was found to be the 10% Y-doped CeO₂ NRs with a methylene blue photodegradation ratio of 85.59% and rate constant of 0.0134 min^-1, which is particularly associated with a significant higher oxygen vacancy concentration and obviously lower recombination rate of photogenerated e^-/h⁺ pairs. The doped RE ions and the promotion of oxygen vacancy generation impede the recombination of photogenerated carriers, which is proposed as the main reason to enhance the photocatalytic property of CeO₂.

Peripheral blood T-cell receptor repertoire as a predictor of clinical outcomes in gastrointestinal cancer patients treated with PD-1 inhibitor

BACKGROUND

Identifying valid biomarkers for patient selection impressively promotes the success of anti-PD-1 therapy. However, the unmet need for biomarkers in gastrointestinal (GI) cancers remains significant. We aimed to explore the predictive value of the circulating T-cell receptor (TCR) repertoire for clinical outcomes in GI cancers who received anti-PD-1 therapy.

METHODS

137 pre- and 79 post-treated peripheral blood samples were included. The TCR repertoire was evaluated by sequencing of complementarity-determining region 3 (CDR3) in the TRB gene. The Shannon index was used to measure the diversity of the TCR repertoire, and Morisita's overlap index was used to determine TCR repertoire similarities between pre- and post-treated samples.

RESULTS

Among all enrolled patients, 76 received anti-PD-1 monotherapy and 61 received anti-PD-1 combination therapy. In the anti-PD-1 monotherapy cohort, patients with higher baseline TCR diversity exhibited a significantly higher disease control rate (77.8% vs. 47.2%; hazard ratio [HR] 3.92; 95% confidence interval [CI] 1.14-13.48; P = 0.030) and a longer progression-free survival (PFS) (median: 6.47 months vs. 2.77 months; HR 2.10; 95% CI 1.16-3.79; P = 0.014) and overall survival (OS) (median: NA vs. 8.97 months; HR 3.53; 95% CI 1.49-8.38; P = 0.004) than those with lower diversity. Moreover, patients with a higher TCR repertoire similarity still showed a superior PFS (4.43 months vs. 1.84 months; HR 13.98; 95% CI 4.37-44.68; P < 0.001) and OS (13.40 months vs. 6.12 months; HR 2.93; 95% CI 1.22-7.03; P = 0.016) even in the cohort with lower baseline diversity. However, neither biomarker showed predictive value in the anti-PD-1 combination therapy cohort. Interestingly, the combination of TCR diversity and PD-L1 expression can facilitate patient stratification in a pooled cohort.

CONCLUSION

The circulating TCR repertoire can serve as a predictor of clinical outcomes in anti-PD-1 therapy in GI cancers.