Unraveling a Concerted Proton-Coupled Electron Transfer Pathway in Atomically Precise Gold Nanoclusters.

Metal nanoclusters (MNCs) represent a promising class of materials for catalytic carbon dioxide and proton reduction as well as dihydrogen oxidation. In such reactions, multiple proton-coupled electron transfer (PCET) processes are typically involved, and the current understanding of PCET mechanisms in MNCs has primarily focused on the sequential transfer mode. However, a concerted transfer pathway, i.e., concerted electron-proton transfer (CEPT), despite its potential for a higher catalytic rate and lower reaction barrier, still lacks comprehensive elucidation. Herein, we introduce an experimental paradigm to test the feasibility of the CEPT process in MNCs, by employing Au18(SR)14 (SR denotes thiolate ligand), Au22(SR)18, and Au25(SR)18- as model clusters. Detailed investigations indicate that the photoinduced PCET reactions in the designed system proceed via an CEPT pathway. Furthermore, the rate constants of gold nanoclusters (AuNCs) have been found to be correlated with both the size of the cluster and the flexibility of the Au-S framework. This newly identified PCET behavior in AuNCs is prominently different from that observed in semiconductor quantum dots and plasmonic metal nanoparticles. Our findings are of crucial importance for unveiling the catalytic mechanisms of quantum-confined metal nanomaterials and for the future rational design of more efficient catalysts.

Stereoselective synthetic approach toward ß-trifluoromethyl vinyl ethers and diethers via reaction of (E)-1,2-dichloro-3,3,3-trifluoroprop-1-ene with phenols.

A convenient method for synthesizing ß-trifluoromethyl vinyl ethers and diethers through the base-mediated C-O coupling of (E)-1,2-dichloro-3,3,3-trifluoroprop-1-ene and phenols has been developed. Remarkably, the present process shows perfect regioselective and stereoselective yield of the Z/E isomers for ß-trifluoromethyl vinyl ethers with high efficiency. Additionally, ß-trifluoromethyl vinyl diethers with identical/diverse phenoxy groups were also obtained and the regulation of the product configuration was achieved. These reactions feature transition-metal-free conditions, wide substrate scope, and atom economy.

A colorimetric sensing strategy based on chitosan-stabilized platinum nanoparticles for quick detection of α-glucosidase activity and inhibitor screening.

α-Glucosidase (α-Glu) is implicated in the progression and pathogenesis of type II diabetes (T2D). In this study, we developed a rapid colorimetric technique using platinum nanoparticles stabilized by chitosan (Ch-PtNPs) to detect α-Glu activity and its inhibitor. The Ch-PtNPs facilitate the conversion of 3,3',5,5'-tetramethylbenzidine (TMB) into oxidized TMB (oxTMB) in the presence of dissolved O2. The catalytic hydrolysis of 2-O-α-D-glucopyranosyl-L-ascorbic acid (AA-2G) by α-Glu produces ascorbic acid (AA), which reduces oxTMB to TMB, leading to the fading of the blue color. However, the presence of α-Glu inhibitors (AGIs) hinders the generation of AA, allowing Ch-PtNPs to re-oxidize colorless TMB back to blue oxTMB. This unique phenomenon enables the colorimetric detection of α-Glu activity and AGIs. The linear range for α-Glu was found to be 0.1-1.0 U mL-1 and the detection limit was 0.026 U mL-1. Additionally, the half-maximal inhibition value (IC50) for acarbose, an α-Glu inhibitor, was calculated to be 0.4769 mM. Excitingly, this sensing platform successfully detected α-Glu activity in human serum samples and effectively screened AGIs. These promising findings highlight the potential application of the proposed strategy in clinical diabetes diagnosis and drug discovery.

Predictive Value of Free Triiodothyronine in Patients with Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention.

Background: Homeostasis of thyroid hormones has significant effects on the cardiovascular system. The aim of this study was to investigate the association between free triiodothyronine (FT3) and adverse cardiovascular events in patients with acute coronary syndrome (ACS) who were undergoing percutaneous coronary intervention (PCI). Methods: A total of 1701 patients with ACS undergoing PCI were included in this study. All patients were divided into three groups according to the tertiles of FT3 level: the lowest tertile (FT3 < 4.51 pmol/L), the middle tertile (4.51 pmol/L ≤ FT3 < 4.89 pmol/L) and the highest tertile group (FT3 ≥ 4.89 pmol/L). The primary study endpoint was a composite of major adverse cardiovascular events (MACE), which included all-cause death, ischemic stroke, myocardial infarction, or unplanned repeat revascularization. Results: During a median follow-up period of 927 days, 349 patients had at least one event. Compared with patients with the highest tertile, those with the lowest tertile had a significantly higher incidence of MACE, all-cause death, MI, ischemic stroke and repeat revascularization (all p values < 0.05). In the multivariate Cox regression analysis, the middle tertile had similar risk of MACE (HR = 0.986, 95% CI 0.728-1.336, p = 0.929) as the highest tertile, but the patients with the lowest tertile had a 92.9% higher risk of MACE (HR = 1.929, 95% CI 1.467-2.535, p < 0.001). There was a non-linear relationship between FT3 and MACE and unplanned repeat revascularization (all p values for non-linear association < 0.001). Adding the tertiles of FT3 level into the baseline model yielded a significant improvement in discrimination for predicting MACE ( Δ AUC = 0.013, p = 0.025). Conclusions: A significantly reduced FT3 level was independently associated with a worse prognosis in patients with ACS undergoing PCI.

Stepwise reduction of bone mineral density increases the risk of cage subsidence in oblique lumbar interbody fusion patients biomechanically: an in-silico study.

BACKGROUND: Cage subsidence causes poor prognoses in patients treated by oblique lumbar interbody fusion (OLIF). Deterioration of the biomechanical environment initially triggers cage subsidence, and patients with low bone mineral density (BMD) suffer a higher risk of cage subsidence. However, whether low BMD increases the risk of cage subsidence by deteriorating the local biomechanical environment has not been clearly identified. METHODS: OLIF without additional fixation (stand-alone, S-A) and with different additional fixation devices (AFDs), including anterolateral single rod screws (ALSRs) and bilateral pedicle screws (BPSs) fixation, was simulated in the L4-L5 segment of a well-validated finite element model. The biomechanical effects of different BMDs were investigated by adjusting the material properties of bony structures. Biomechanical indicators related to cage subsidence were computed and recorded under different directional moments. RESULTS: Overall, low BMD triggers stress concentration in surgical segment, the highest equivalent stress can be observed in osteoporosis models under most loading conditions. Compared with the flexion-extension loading condition, this variation tendency was more pronounced under bending and rotation loading conditions. In addition, AFDs obviously reduced the stress concentration on both bony endplates and the OLIF cage, and the maximum stress on ALSRs was evidently higher than that on BPSs under almost all loading conditions. CONCLUSIONS: Stepwise reduction of BMD increases the risk of a poor local biomechanical environment in OLIF patients, and regular anti-osteoporosis therapy should be considered an effective method to biomechanically optimize the prognosis of OLIF patients.

Preoperative systemic immune-inflammation index predicts prognosis of patients with non-metastatic renal cell carcinoma: a propensity score-matched analysis.

BACKGROUND: A novel systemic immune-inflammation index (SII), based on the neutrophils, lymphocytes and platelet counts, is associated with the prognosis of several cancers. The present study evaluates the prognostic significance of SII in non-metastatic renal cell carcinoma (RCC). METHOD: The present study retrospectively reviewed the medical record of patients with non-metastatic RCC who underwent nephrectomy between 2010 and 2013. Receiver operating characteristic (ROC) curve analysis was performed to identify the optimal cut-off value. In addition, the propensity score matching (PSM) was performed with a matching ratio of 1:1. Univariate and multivariate Cox proportional hazards models were used to identify the prognostic factors. The results were reported by hazard ratio (HR) with 95% confidence interval (95% CI). RESULTS: A total of 646 patients were included in the final analysis. High SII group (> 529) was significantly associated with older age (P = 0.014), larger tumor (P < 0.001), higher pathological T stage (P < 0.001), higher tumor grade (P < 0.001) and more tumor necrosis (P < 0.001). Multivariate Cox regression analysis demonstrated that the higher preoperative SII was significantly associated with worse overall survival (OS) (HR = 2.26; 95% CI 1.44-3.54; P < 0.001) and cancer-specific survival (CSS) (HR = 2.17; 95% CI 1.33-3.55; P = 0.002). After PSM, elevated preoperative SII was an independent predictor of poor OS (HR = 1.78; 95% CI 1.1-2.87; P = 0.018) and CSS (HR = 1.8; 95% CI 1.07-3.03; P = 0.027). CONCLUSION: In conclusion, preoperative SII is associated with adverse factors for RCC. Furthermore, higher preoperative SII is an independent predictor of poor OS and CSS in surgically treated patients with non-metastatic RCC. More prospective and large scale studies are warranted to validate our findings.

An Integrated Microarray Analysis Reveals Significant Diagnostic and Prognostic Biomarkers in Pancreatic Cancer.

BACKGROUND Pancreatic cancer (PAC) is a lethal cancer and it is essential to develop accurate diagnostic and prognostic biomarkers for PAC. MATERIAL AND METHODS An integrated microarray analysis of PAC was conducted to identify differentially expressed genes (DEGs) between PAC and non-tumor controls. Expression of DEGs were further confirmed by The Cancer Genome Atlas and the Genotype-Tissue Expression. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis, and protein-protein integration network construction were performed to further research the biological functions of DEGs. Receiver-operating characteristic analysis and survival analysis were used to evaluate the diagnostic and prognostic value of DEGs for PAC. RESULTS Seventeen microarray datasets were downloaded from Gene Expression Omnibus to conduct the integrated microarray analysis. A total of 1136 DEGs (596 upregulated and 540 downregulated DEGs) in PAC tissues compared with non-tumor controls were identified. Pancreatic secretion (Kegg: 04972), insulin signaling pathway (Kegg: 04910), and several cancer-related pathways including pathways in cancer (Kegg: 05200), MAPK signaling pathway (Kegg: 04010), and pancreatic cancer (Kegg: 05212) were enriched for DEGs in PAC. Seven DEGs (AHNAK2, CDH3, IFI27, ITGA2, LAMB3, SLC6A14, and TMPRSS4) were found to have both great diagnostic and prognostic value for PAC. High expression of these 7 DEGs were significantly associated with poor prognosis of patients with PAC. CONCLUSIONS These 7 DEGs might be potential diagnostic and prognostic biomarkers for PAC and help uncovering the mechanism of PAC.

Comparison of Two Numerical Parameters to Assess Detrusor Contractility in Prognosing Short-Term Outcome after Transurethral Resection of the Prostate.

OBJECTIVE: To investigate and compare the influence of two numerical detrusor contractility parameters, the bladder contractility index (BCI) and the maximum Watts factor (WFmax), on transurethral resection of the prostate (TURP) outcome. METHODS: A retrospective study was conducted on 236 patients who had undergone urodynamic assessment preoperatively and TURP for benign prostatic obstruction. They were evaluated by International Prostate Symptom Score (IPSS) and uroflowmetry preoperatively and 3 months postoperatively. Related criteria were established to determine the overall efficacy of TURP. Logistic regression analysis and receiver operating characteristic curves were made to investigate the influence of the BCI and WFmax on TURP efficacy. RESULTS: Among the 236 patients, 195 treatments were effective and 41 ineffective. Multivariate analysis showed that both the BCI (OR 1.038) and the WFmax (OR 1.291) could influence TURP efficacy. For predicting TURP efficacy, the optimal cut-off values of the BCI and WFmax were 98.7 and 10.27 W/m2, respectively. The AUC, sensitivity and specificity of the BCI were 0.722, 78.5% and 61.0%; those of the WFmax were 0.761, 73.9% and 73.2%, with no significant difference (p > 0.05). CONCLUSIONS: To some extent, the BCI and the WFmax can predict TURP efficacy equally well. A discrimination level of 10.27 W/m2 may be a threshold value for detrusor underactivity (DU); as regards the BCI, the current threshold value is appropriate to diagnose DU.

Sarcopenia predicts prognosis of patients with renal cell carcinoma: A systematic review and meta-analysis.

Sarcopenia, a concept reflecting the loss of skeletal muscle mass, was reported to be associated with the prognosis of several tumors. However, the prognostic value of sarcopenia in patients with renal cancer remains unclear. We carried out this meta-analysis and systematic review to evaluate the prognostic value of sarcopenia in patients with renal cell carcinomas. We comprehensively searched PubMed, Embase, and Cochrane Library from inception to December 2018. Hazard ratio (HR) and 95% confidence interval (CI) were pooled together. A total of 5 studies consisting of 771 patients were enrolled in this quantitative analysis, 347 (45.0%) of which had sarcopenia. Patients with sarcopenia had a worse OS compared with those without sarcopenia (HR=1.76; 95%CI, 1.35-2.31; P<0.001). In the subgroup of patients with localized and advanced/metastatic diseases, sarcopenia was also associated with poor OS (HR=1.48, P=0.039; HR=2.14, P<0.001; respectively). With a limited sample size, we did not observe difference of PFS between two groups (HR=1.56, 95% CI, 0.69-3.50, P=0.282). In the present meta-analysis, we observed that patients with sarcopenia had a worse OS compared with those without sarcopenia in RCC. Larger, preferably prospective studies, are needed to confirm and update our findings.

Image quality and diagnostic value of ultra low-voltage, ultra low-contrast coronary CT angiography.

OBJECTIVE: To explore the image quality (IQ) and diagnostic value of 70 kVp turbo high-pitch coronary CT angiography (THP-CCTA) using automated tube voltage selection (ATVS) and 30 mL of low-concentration contrast agent. METHODS: Patients who underwent 70 kVp THP-CCTA using ATVS with 30 mL of contrast agent (group A) were prospectively enrolled, and those who underwent conventional CCTA (100/120 kVp, prospective sequential mode with 65-75 mL of contrast agent) (group B) were retrospectively selected for study. IQ was assessed subjectively on a 5-point scale, and diagnostic value was assessed based on invasive coronary angiography as the gold standard. Heart rate (HR), HR fluctuation (HRF), body mass index (BMI), effective radiation dose (ED), and iodine uptake (IU) were recorded. RESULTS: A total of 796 patients (398/398 in groups A/B) were included. Between-group differences in age, gender, BMI, HR, HRF, and IQ values were not significant. The ED/IU values were 0.3 ± 0.1 mSv/9.0 ± 0.0 g and 5.8 ± 1.8 mSv/22.9 ± 1.0 g in groups A and B, respectively (p < 0.01). The sensitivity, specificity, positive and negative predictive values, and accuracy of THP-CCTA for the diagnosis of ≥ 50% stenosis were 94.8%, 97.5%, 92.0%, 98.4%, and 96.9% respectively. The mean HR and coronary calcium score were independent predictors of diagnostic image quality, and the best cutoff values were 71.5 bpm and 444.1 respectively. CONCLUSION: This third-generation dual-source CT imaging modality, a 70-kVp THP-CCTA system using ATVS with 30 mL of low-concentration contrast agent, produces high-quality images with high diagnostic accuracy for significant stenosis, with ultra low ED and IU. This technique was most promising in individuals with an HR < 71.5 bpm and coronary calcium score < 444.1. KEY POINTS: • Turbo high-pitch CCTA using 70 kVp via automated tube voltage selection and 30 mL of low-concentration contrast agent is feasible. • This protocol provides high diagnostic accuracy for significant coronary stenosis and reduces radiation doses and iodine uptake significantly. • This protocol was most promising in individuals with an HR < 71.5 bpm and coronary calcium score < 444.1.