Ultrafast photooxidation of protein-bound anionic flavin radicals.

The photophysical properties of anionic semireduced flavin radicals are largely unknown despite their importance in numerous biochemical reactions. Here, we studied the photoproducts of these intrinsically unstable species in five different flavoprotein oxidases where they can be stabilized, including the well-characterized glucose oxidase. Using ultrafast absorption and fluorescence spectroscopy, we unexpectedly found that photoexcitation systematically results in the oxidation of protein-bound anionic flavin radicals on a time scale of less than ∼100 fs. The thus generated photoproducts decay back in the remarkably narrow 10- to 20-ps time range. Based on molecular dynamics and quantum mechanics computations, positively charged active-site histidine and arginine residues are proposed to be the electron acceptor candidates. Altogether, we established that, in addition to the commonly known and extensively studied photoreduction of oxidized flavins in flavoproteins, the reverse process (i.e., the photooxidation of anionic flavin radicals) can also occur. We propose that this process may constitute an excited-state deactivation pathway for protein-bound anionic flavin radicals in general. This hitherto undocumented photochemical reaction in flavoproteins further extends the family of flavin photocycles.

Photocycle alteration and increased enzymatic activity in genetically modified photoactivated adenylate cyclase OaPAC.

Photoactivated adenylate cyclases (PACs) are light activated enzymes that combine blue light sensing capacity with the ability to convert ATP to cAMP and pyrophosphate (PPi) in a light-dependent manner. In most of the known PACs blue light regulation is provided by a blue light sensing domain using flavin which undergoes a structural reorganization after blue-light absorption. This minor structural change then is translated toward the C-terminal of the protein, inducing a larger conformational change that results in the ATP conversion to cAMP. As cAMP is a key second messenger in numerous signal transduction pathways regulating various cellular functions, PACs are of great interest in optogenetic studies. The optimal optogenetic device must be "silent" in the dark and highly responsive upon light illumination. PAC from Oscillatoria acuminata is a very good candidate as its basal activity is very small in the dark and the conversion rates increase 20-fold upon light illumination. We studied the effect of replacing D67 to N, in the blue light using flavin domain. This mutation was found to accelerate the primary electron transfer process in the photosensing domain of the protein, as has been predicted. Furthermore, it resulted in a longer lived signaling state, which was formed with a lower quantum yield. Our studies show that the overall effects of the D67N mutation lead to a slightly higher conversion of ATP to cAMP, which points in the direction that by fine tuning the kinetic properties more responsive PACs and optogenetic devices can be generated.

DOMAS: a data management software framework for advanced light sources.

In recent years, China's advanced light sources have entered a period of rapid construction and development. As modern X-ray detectors and data acquisition technologies advance, these facilities are expected to generate massive volumes of data annually, presenting significant challenges in data management and utilization. These challenges encompass data storage, metadata handling, data transfer and user data access. In response, the Data Organization Management Access Software (DOMAS) has been designed as a framework to address these issues. DOMAS encapsulates four fundamental modules of data management software, including metadata catalogue, metadata acquisition, data transfer and data service. For light source facilities, building a data management system only requires parameter configuration and minimal code development within DOMAS. This paper firstly discusses the development of advanced light sources in China and the associated demands and challenges in data management, prompting a reconsideration of data management software framework design. It then outlines the architecture of the framework, detailing its components and functions. Lastly, it highlights the application progress and effectiveness of DOMAS when deployed for the High Energy Photon Source (HEPS) and Beijing Synchrotron Radiation Facility (BSRF).

Photoswitching Behavior of Flavin-Inhibitor Complex in a Nonphotocatalytic Flavoenzyme.

An unprecedented photoswitching phenomenon of flavin-inhibitor complexes in a flavoenzyme was revealed by femtosecond transient absorption spectroscopy. The vast majority of flavoenzymes, including monomeric sarcosine oxidase (MSOX), perform non-light-driven physiological functions. Yet, the participation of flavin cofactors in photoinduced electron transfer reactions is widespread. MSOX catalyzes the oxidative demethylation of sarcosine; methylthioacetate (MTA) is a substrate analog inhibitor that forms a complex with MSOX exhibiting intense absorption bands over the whole visible range due to flavin-MTA charge transfer (CT) interactions. Here, we demonstrate that upon excitation, these CT interactions vanish during a barrierless high quantum yield reaction in ∼300 fs. The initial complex subsequently geminately re-forms in a few nanoseconds near room temperature in a thermally activated way with an activation energy of 28 kJ/mol. We attribute this hitherto undocumented process to a well-defined photoinduced isomerization of MTA in the active site, as corroborated by experiments with the heavier ligand methylselenoacetate. Photoisomerization phenomena involving CT transitions may be further explored in photocatalytic and photoswitching applications of flavoenzymes.

Photochemical and Molecular Dynamics Studies of Halide Binding in Flavoenzyme Glucose Oxidase.

Glucose oxidase (GOX), a characteristic flavoprotein oxidase with widespread industrial applications, binds fluoride (F- ) and chloride (Cl- ). We investigated binding properties of halide inhibitors of GOX through time-resolved spectral characterization of flavin-related photochemical processes and molecular dynamic simulations. Cl- and F- bind differently to the protein active site and have substantial but opposite effects on the population and decay of the flavin excited state. Cl- binds closer to the flavin, whose excited-state decays in <100 fs due to anion-π interactions. Such interactions appear absent in F- binding, which, however, significantly increases the active-site rigidity leading to more homogeneous, picosecond fluorescence decay kinetics. These findings are discussed in relation to the mechanism of halide inhibition of GOX by occupying the accommodation site of catalytic intermediates and increasing the active-site rigidity.

Preoperative prognostic value of alfa-fetoprotein density in patients with hepatocellular carcinoma undergoing radiofrequency ablation.

OBJECTIVES: To examine the prognostic value of preoperative alfa-fetoprotein (AFP) density and other clinical factors in patients undergoing percutaneous radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC). METHODS: From January 2010 to December 2018, a total of 543 patients undergoing RFA for HCC meeting the Milan criteria were included at our institution. AFP density was calculated as absolute AFP pre-ablation divided by the total volume of all HCC lesions. The survival rates according to AFP density were estimated using the Kaplan-Meier method and compared using the log-rank test. Univariate and multivariate Cox proportional-hazards regression analyses were used to assess predictors of overall survival (OS) and progression-free survival (PFS). RESULTS: The Kaplan-Meier 1-, 3-, and 5-year OS rates were 98.8%, 88.5%, and 70.4%, respectively, for the low AFP density group, and 98.3%, 74.9%, and 49.4%, respectively, for the high AFP density group. The corresponding PFS rates were 78.9%, 56.7%, and 40.9% (low AFP density group), and 63.6%, 40.8%, and 27.5% (high AFP density group). High AFP density was associated with significantly reduced PFS and OS (both p < 0.001). Multivariate analysis suggested that AFP density was a predictor of OS and PFS. CONCLUSIONS: Serum AFP density may serve as a promising predictor of survival in patients with HCC undergoing RFA. High AFP density could identify patients who might be prone to recurrence or progression and need close surveillance.

Two novel polyketones from the leaves and twigs of Clerodendrum trichotomum.

Two novel polyketones, along with four known compounds, were isolated from the leaves and twigs of Clerodendrum trichotomum. Their structures were determined to be clerodendruketone A (1), clerodendruketone B (2), ecdysanols E (3), ecdysanols D (4), 5,5'-dimethoxy-7-oxolariciresinol (5), and (-)-(7'S,8S,8'R)-4,4'-dihydroxy-3,3',5,5'-tetramethoxy-7',9-epoxy-lignan-9'-ol-7-one (6) through the methods of NMR, HRESIMS and ECD data analyses. The antioxidant effects against free radical were tested by DPPH assay. The antibacterial activity against Escherichia coli and Staphylococcus aureus were tested by turbidimetry assay. The results demonstrated that compounds 1 and 2 had significative antibacterial activity, and compound 3 had moderate antioxidant activity.

Characterization of Light-Induced, Short-Lived Interacting Radicals in the Active Site of Flavoprotein Ferredoxin-NADP+ Oxidoreductase.

Radicals of flavin adenine dinucleotide (FAD), as well as tyrosine and tryptophan, are widely involved as key reactive intermediates during electron-transfer (ET) reactions in flavoproteins. Due to the high reactivity of these species and their corresponding short lifetime, characterization of these intermediates in functional processes of flavoproteins is usually challenging but can be achieved by ultrafast spectroscopic studies of light-activatable flavoproteins. In ferredoxin-NADP+ oxidoreductase from Bacillus subtilis (BsFNR), fluorescence of the FAD cofactor that very closely interacts with a neighboring tyrosine residue (Tyr50) is strongly quenched. Here we study short-lived photoproducts of this enzyme and its variants, with Tyr50 replaced by tryptophan or glycine. Using time-resolved fluorescence and absorption spectroscopies, we show that, upon the excitation of WT BsFNR, ultrafast ET from Tyr50 to the excited FAD cofactor occurs in ∼260 fs, an order of magnitude faster than the decay by charge recombination, facilitating the characterization of the reaction intermediates in the charge-separated state with respect to other recently studied systems. These studies are corroborated by experiments on the Y50W mutant protein, which yield photoproducts qualitatively similar to those observed in other tryptophan-bearing flavoproteins. By combining the experimental results with molecular dynamics simulations and quantum mechanics calculations, we investigate in detail the effects of protein environment and relaxations on the spectral properties of those radical intermediates and demonstrate that the spectral features of radical anionic FAD are highly sensitive to its environment, and in particular to the dynamics and nature of the counterions formed in the photoproducts. Altogether, comprehensive characterizations are provided for important radical intermediates that are generally involved in functional processes of flavoproteins.

Treatment effect of radiofrequency ablation versus liver transplantation and surgical resection for hepatocellular carcinoma within Milan criteria: a population-based study.

OBJECTIVES: Restricted mean survival time (RMST) has been increasingly used to assess the treatment effect. We aimed to evaluate a treatment effect of radiofrequency ablation (RFA) versus liver transplantation (LT) and surgical resection (SR) for hepatocellular carcinoma (HCC) within Milan criteria by using an adjusted RMST. METHODS: A total of 7,218 HCC patients (RFA, 3,327; LT, 2,332; SR 1,523) within Milan criteria were eligible for this retrospectively study. The RMST using inverse probability of treatment weighting (IPTW) adjustment were applied to estimate the treatment effect between RFA and LT, RFA, and SR groups. RESULTS: The 3-, 5-, and 10-year IPTW-adjusted difference in RMST of OS for LT over RFA were + 4.5, + 12.4, and + 36.3 months, respectively. For SR versus RFA group, the survival benefit was + 2.3, + 6.1, and + 15.8 months at 3, 5, and 10 years, respectively. But the incremental survival benefit of SR over RFA was only half than that of LT over RFA. In the subgroup of solitary tumor ≤ 2 cm, the adjusted RMST of RFA versus SR was comparable with no statistical differences. Beyond that, in comparison with RFA, a notably greater efficacy of LT and SR was consistently across all subgroups with solitary HCC > 2.0 cm, AFP positive or negative, and fibrosis score 0-4 or 5-6. CONCLUSIONS: RMST provides a measure of absolute survival benefit at a specific time point. Using IPTW-adjusted RMST, we showed that the incremental survival benefit of SR over RFA was about half than that of LT over RFA. KEY POINTS: • The restricted mean survival time offers an intuitive, clinically meaningful interpretation to quantify the treatment effect than the hazard ratio. • Liver transplantation and surgical resection provided better overall survival compared to radiofrequency ablation for HCC patients within Milan criteria, but RFA and SR provide equivalent long-term overall survival for solitary HCC ≤ 2 cm. • The incremental survival benefit of surgical resection over radiofrequency ablation was only half than that of liver transplantation over radiofrequency ablation.

Inter-reader agreement of CEUS LI-RADS among radiologists with different levels of experience.

OBJECTIVES: To investigate the inter-reader agreement of contrast-enhanced ultrasound (CEUS) of Liver Imaging Reporting and Data System version 2017 (LI-RADS v2017) categories among radiologists with different levels of experience. MATERIALS AND METHODS: From January 2014 to December 2014, a total of 326 patients at high risk of hepatocellular carcinoma (HCC) who underwent CEUS were included in this retrospective study. All lesions were classified according to LI-RADS v2017 by six radiologists with different levels of experiences: two residents, two fellows, and two specialists. Kappa coefficient was used to assess consistency of LI-RADS categories and major features among radiologists with different levels of experience. The diagnostic performance of HCC was described by accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC). RESULTS: Inter-reader agreement among radiologists of different experience levels was substantial agreement for arterial phase hyperenhancement, washout appearance, and early or late washout. Inter-reader agreement for LI-RADS categories was moderate to substantial. When LR-5 was used as criteria to determinate HCC, the AUC of LI-RADS for HCC was 0.67 for residents, 0.72 for fellows, and 0.78 for specialist radiologists. When compared between residents and specialists, accuracy, sensitivity, and AUC were significantly different (all p < 0.05). However, there were no significant differences in specificity, PPV, and NPV between the two groups. CONCLUSION: CEUS LI-RADS showed good diagnostic consistency among radiologists with different levels of experience, and consistency increased with experience levels. KEY POINTS: • The inter-reader agreement for LI-RADS categories was moderate to substantial agreement (κ, 0.60-0.80). • When compared between residents and specialists, accuracy, sensitivity, and AUC showed significantly different (all p < 0.05). However, there were no significant differences for specificity, PPV, and NPV between these two groups. • Among the radiologists with more than 1 year of experience, there was no significant difference in the diagnostic performance of HCC, suggesting that CEUS LI-RADS is a good standardized categorization system for high-risk patients.

Photochemical processes in flavo-enzymes as a probe for active site dynamics: TrmFO of Thermus thermophilus.

Quenching of flavin fluorescence by electron transfer from neighboring aromatic residues is ubiquitous in flavoproteins. Apart from constituting a functional process in specific light-active systems, time-resolved spectral characterization of the process can more generally be employed as a probe for the active site configuration and dynamics. In the C51A variant of the bacterial RNA-transforming flavoenzyme TrmFO from the bacterium Thermus thermophilus, fluorescence is very short-lived (~ 1 ps), and close-by Tyr343 is known to act as the main quencher, as confirmed here by the very similar dynamics observed in protein variants with modified other potential quenchers, Trp283 and Trp214. When Tyr343 is modified to redox-inactive phenylalanine, slower and highly multiphasic kinetics are observed on the picosecond-nanosecond timescale, reflecting heterogeneous electron donor-acceptor configurations. We demonstrate that Trp214, which is located on a potentially functional flexible loop, contributes to electron donor quenching in this variant. Contrasting with observations in other nucleic acid-transforming enzymes, these kinetics are strikingly temperature-independent. This indicates (a) near-barrierless electron transfer reactions and (b) no exchange between different configurations on the timescale up to at least 2 ns, despite the presumed flexibility of Trp214. Results of extensive molecular dynamics simulations are presented to explain this unexpected finding in terms of slowly exchanging protein configurations.

Percutaneous thermal ablation of hepatic tumors: local control efficacy and risk factors for artificial ascites failure.

OBJECTIVE: To investigate the risk factors affecting the technical failure of artificial ascites (AA) formation and to evaluate the local control efficacy of percutaneous thermal ablation assisted by the AA for hepatic tumors. METHODS: A total of 341 patients with 362 hepatic tumors who underwent thermal ablation assisted by AA were reviewed retrospectively. The technical success of AA, the volume of liquid, and local efficacy after ablation were assessed. Predictive factors for the technical failure of AA formation and local tumor progression (LTP) were analyzed using univariate and multivariate analysis. RESULTS: The technical success rate of AA formation was 81.8% (296/362). The amount of fluid was higher when the tumor was located in the left lobe of the liver than when it was located in the right lobe (median 950 ml versus 700 ml, p < 0.001). Previous hepatic resection (OR: 12.63, 95% CI: 2.93-54.45, p < 0.001), ablation (OR: 6.48, 95% CI: 1.36-30.92, p = 0.019) and upper-abdomen surgery (OR: 11.34, 95% CI: 1.96-65.67, p = 0.007) were the independent risk factors of AA failure. In the AA success group, the complete ablation rate was higher and the LTP rate was lower than that in the AA failure group (98.7 versus 92.4%, p = 0.012; 8.8 versus 21.2%, p = 0.004). Multivariate analysis identified AA failure (p = 0.004), tumor size (>3.0 cm) (p = 0.002) and metastatic liver tumor (p = 0.008) as independent risk factors for LTP. CONCLUSION: History of hepatic resection, ablation and upper abdomen surgery were significant predictive factors affecting the technical failure of AA formation. Successful introduction of AA before thermal ablation can achieve better local tumor control efficacy.

Lesion outline and thermal field distribution of ablative in vitro experiments in myocardia: comparison of radiofrequency and laser ablation.

OBJECTIVES: To explore the lesion outline and thermal field distribution of radiofrequency ablation (RFA) and laser ablation (LA) in myocardial ablation in vitro. MATERIALS AND METHODS: Twenty-four fresh porcine hearts were ablated with RFA or LA in vitro. The radiofrequency electrode or laser fiber and two parallel thermocouple probes were inserted into the myocardium under ultrasound guidance. The output power for RFA was 20 W/s and for LA was 5 W/s, and the total thermal energies were 1200 J, 2400 J, 3600 J, and 4800 J. The range of ablation lesions was measured, and temperature data were recorded simultaneously. RESULTS: All coagulation zones were ellipsoidal with clear boundaries. The center of LA was carbonized more obviously than that of RFA. With the accumulation of thermal energy and the extended time, all the ablation lesions induced by both RFA and LA were enlarged. By comparing the increase in thermal energy between the two groups, both the short-axis diameter and the volume change showed significant differences between the 1200 J and 3600 J groups and between the 2400 J and 4800 J groups (all P < 0.05). Both the short-axis diameter and the volume of the coagulation necrosis zone formed by LA were always larger than those of RFA at the same accumulated thermal energy. The temperatures of the two thermocouple probes increased with each energy increment. At the same accumulated energy, the temperature of LA was much higher than that of RFA at the same point. The initial temperature increase at 0.5 cm of LA was rapid. The temperature reached 43 °C and the accumulated energy reached 1200 J after approximately 4 min. After that the temperature increased at a slower rate to 70  C. For the RFA at the point of 0.5 cm, the initial temperature increased rapidly to 30 °C with the same accumulated energy of 1200 J after only 1 min. In the range of 4800 J of accumulated thermal energy, only the temperature of LA at the point of 0.5 cm exceeded 60 °C when the energy reached approximately 3000 J. CONCLUSIONS: Both RFA and LA were shown to be reliable methods for myocardial ablation. The lesion outline and thermal field distribution of RFA and LA should be considered when performing thermal ablation in the intramyocardial septum during hypertrophic obstructive cardiomyopathy.

Thermal ablation versus hepatic resection for the treatment of liver metastases from gastrointestinal stromal tumors: a retrospective study.

Objective: The study aimed to compare effectiveness and safety of thermal ablation and hepatic resection in patients with liver metastases of gastrointestinal stromal tumors (GISTs).Method: A total of 55 patients (27 in the ablation group and 28 in the surgery group) with liver metastases were included. Overall survival (OS) and progression-free survival (PFS) were assessed with Kaplan-Meier's survival estimate curves. Univariate and multivariate regression analyses were carried out to identify potential prognostic factors.Results: The median OS was 102.0 months in the ablation group and 117.0 months in the surgery group (p = .875). The 1-, 3- and 5-year OS rates were 100%, 88.9% and 74.1% in the ablation group and 92.8%, 82.1% and 78.6% in the surgery group, respectively. The 1-, 3- and 5-year PFS rates were 48.1%, 25.9% and 18.5% in the ablation group and 67.8%, 64.3% and 64.3% in the surgery group, respectively. Multivariate analysis showed that preoperative tyrosine kinase inhibitor (TKI) treatment (progressive disease, PD) (HR, 13.985; 95% CI, 1.791-109.187; p = .012) was the only significant independent prognostic factor for OS. Tumor number (HR, 1.318; 95% CI, 1.021-1.702; p = .034) was identified as an independent predictor for PFS in multivariate analysis. There were fewer postoperative complications (18.5% vs. 78.6%, p = .001) and shorter lengths of hospital stay (8.0 vs. 16.5 days, p = .001) in the ablation group.Conclusion: Compared with resection, thermal ablation offered comparable OS for liver metastases of GISTs. Furthermore, thermal ablation had the advantages of fewer complications and shorter lengths of hospital stay.

Application of contrast-enhanced ultrasonography for large cell neuroendocrine carcinoma in the urinary bladder: a case report.

BACKGROUND: Large cell neuroendocrine carcinoma (LCNEC) of the urinary bladder is an uncommon malignant bladder tumor, and the overall prognosis is poor. Contrast-enhanced ultrasound (CEUS) provides a new effective modality for tumor detection and diagnosis. CASE PRESENTATION: A 30-year-old man complained of repeated painless gross haematuria for half a month. Conventional ultrasound demonstrated a hypoechoic solitary lesion with hyperechoic margins measuring 3.4 × 3.1 cm in the anterior wall of the bladder. Superb microvascular imaging (SMI) showed a strong flow signal in the mass. CEUS revealed that the lesion was characterized by hyper-enhancement in the early phase and hypo-enhancement in the late phase. The entire bladder wall was disrupted by homogeneous hyper-enhanced tumor tissue on CEUS. Time-intensity curves (TICs) showed a rapid wash-in with a high maximum signal intensity (SI) and quick wash-out. Finally, partial cystectomy was performed and the pathological examination confirmed the diagnosis of LCNEC with invasion into the whole layer of the bladder wall. CONCLUSION: This case suggested that CEUS was a valuable imaging method to detect and diagnose LCNEC in the bladder, and that CEUS can provide information related to the depth of wall invasion and the microvasculature.

Multiparametric ultrasomics of significant liver fibrosis: A machine learning-based analysis.

OBJECTIVE: To assess significant liver fibrosis by multiparametric ultrasomics data using machine learning. MATERIALS AND METHODS: This prospective study consisted of 144 patients with chronic hepatitis B. Ultrasomics-high-throughput quantitative data from ultrasound imaging of liver fibrosis-were generated using conventional radiomics, original radiofrequency (ORF) and contrast-enhanced micro-flow (CEMF) features. Three categories of features were explored using pairwise correlation and hierarchical clustering. Features were selected using diagnostic tests for fibrosis, activity and steatosis stage, with the histopathological results as the reference. The fibrosis staging performance of ultrasomics models with combinations of the selected features was evaluated with machine-learning algorithms by calculating the area under the receiver-operator characteristic curve (AUC). RESULTS: ORF and CEMF features had better predictive power than conventional radiomics for liver fibrosis stage (both p < 0.01). CEMF features exhibited the highest diagnostic value for activity stage (both p < 0.05), and ORF had the best diagnostic value for steatosis stage (both p < 0.01). The machine-learning classifiers of adaptive boosting, random forest and support vector machine were found to be optimal algorithms with better (all mean AUCs = 0.85) and more stable performance (coefficient of variation = 0.01-0.02) for fibrosis staging than decision tree, logistic regression and neural network (mean AUC = 0.61-0.72, CV = 0.07-0.08). The multiparametric ultrasomics model achieved much better performance (mean AUC values of 0.78-0.85) than the features from a single modality in discriminating significant fibrosis (≥ F2). CONCLUSION: Machine-learning-based analysis of multiparametric ultrasomics can help improve the discrimination of significant fibrosis compared with mono or dual modalities. KEY POINTS: • Multiparametric ultrasomics has achieved much better performance in the discrimination of significant fibrosis (≥ F2) than the single modality of conventional radiomics, original radiofrequency and contrast-enhanced micro-flow. • Adaptive boosting, random forest and support vector machine are the optimal algorithms for machine learning.

Size-Dependent Relaxation Processes of Photoexcited [ n]Cycloparaphenylenes ( n = 5-12): Significant Contribution of Internal Conversion in Smaller Rings.

[ n]Cycloparaphenylenes ([ n]CPPs; n, number of phenyl rings) have gained considerable attention because they exhibit interesting properties owing to their highly strained structure and radially oriented p orbitals. Recently, [ n]CPPs with n ≥ 5 have been synthesized, but the ring-size dependence of the deactivation processes of the excited states has not been explained particularly for smaller [ n]CPPs ( n ≤ 7). In the present study, we characterized the deactivation processes of [ n]CPPs (5 ≤ n ≤ 12) using transient absorption spectroscopy at sub-pico-, sub-nano-, nano-, and microsecond time scales. Although the fluorescence quantum yield increased with the ring size, the longest S1-state lifetime was observed with [8]CPP, and both the decrease and increase of the ring size resulted in the decrease of the lifetime. Characterization of the intersystem crossing and internal conversion processes explained unique ring-size dependence of the deactivation processes of [ n]CPPs, i.e., the enhanced radiation rate of the larger CPP and the fast internal conversion rate of smaller CPP dominate their S1-state lifetimes.

Sorafenib versus hepatic arterial infusion chemotherapy for advanced hepatocellular carcinoma: a systematic review and meta-analysis.

BACKGROUND: The clinical benefits and safety of Sorafenib versus hepatic arterial infusion chemotherapy (HAIC) for advanced hepatocellular carcinoma (HCC) are inconsistent in some studies. This meta-analysis aims to evaluate the effectiveness and safety of Sorafenib versus HAIC for patients with advanced HCC. METHODS: An electronic search was performed from PubMed, Embase, the Cochrane Library and Web of Science to identify comparative studies evaluating Sorafenib versus HAIC for HCC. Objective response rate, disease control rate, overall survival, progression-free survival and adverse events were evaluated using meta-analytical techniques. RESULTS: Fourteen retrospective studies with 1779 patients (Sorafenib = 773, HAIC = 1006) were included in the meta-analysis. HAIC delivered favorable outcomes in objective response rate (odds ratio 0.13; 95%CI, 0.07-0.24) and disease control rate (odds ratio 0.48; 95%CI 0.26-0.87) assessed by the Response Evaluation Criteria in Solid Tumors. The pooled hazard ratio for overall survival at 0.60 (95% CI 0.39-0.91) and the pooled hazard ratio for progression-free survival at 0.69(95% CI 0.51-0.95), further indicates that HAIC was superior to Sorafenib. There was a higher incidence of adverse events, including hypertension (odds ratio 13.07; 95% CI 2.37-71.67), fatigue (odds ratio 6.72; 95% CI 2.14-21.13), dermatological disorders (odds ratio 15.87; 95% CI 5.58-45.16) and gastrointestinal disorders (odds ratio 3.20; 95% CI 2.02-5.07) in patients receiving Sorafenib than in those receiving HAIC. CONCLUSION: HAIC offers a safe and effective alternative to Sorafenib with better tumor response and longer overall survival and progression-free survival, hence HAIC should be recommended for the patients with advanced HCC.

3D-Printed Wearable Personalized Orthodontic Retainers for Sustained Release of Clonidine Hydrochloride.

Orthodontic retainers are wearable customizable medical devices for dental protection or alignment. Here, clonidine hydrochloride (CH)-loaded wearable personalized 3D printed orthodontic retainers were studied for local sustained-release of drugs. CH powders were mixed with PEG 4000, Tween 80, poly(lactic acid), and polycaprolactone. The mixture was hot-melt extruded to form a filament that was 3D printed to a customizable original orthodontic retainer with the fused deposition modeling (FDM) method. The original retainer showed a burst release of CH in the early stage of the dissolution process though a sustained release appeared in the late stage. The in vivo burst release of CH would lead to unexpected side effect. The original retainer was modified by coating with hydrophilic polymers or washing with buffered solutions to obtain the coated or washed retainer. The coated retainer still showed a burst release while the washed retainer showed an optimal sustained release. Many CH microparticles existed on the surface of original retainers according to the scanning electron microscopic image so that the burst release was unavoidable. The hydrophilic polymer coating method did not change the release profile because the polymer was also rapidly dissolved. However, most of the surface CH can be eliminated by washing so that the burst release dissappeared in the washed retainer. Furthermore, the simulated CH concentration-time profiles in the circulation of humans of the washed retainer showed the stable and appropriate drug levels for more than 3 days. Wearable personalized 3D printed drug-loaded orthodontic retainers are a promising drug-device for sustained release of drugs.

Influence of Charge Distribution on Structural Changes of Aromatic Imide Derivatives upon One-Electron Reduction Revealed by Time-Resolved Resonance Raman Spectroscopy during Pulse Radiolysis.

Structural changes of aromatic imides upon one-electron reduction are investigated by time-resolved resonance Raman spectroscopy during pulse radiolysis. Significant downshifts are observed for both the aromatic ring stretching and carbonyl stretching modes, which are related to a reduction of the bond order and increase of the charge density on these moieties. For three aromatic imides, i.e., 1,8-naphthalene imide (1,8-NI), 2,3-naphthalene imide (2,3-NI), and naphthalene diimide (NDI), the extent of structural changes is found to follow the order: 2,3-NI > 1,8-NI > NDI, reflecting the influence of charge distribution on molecular structure. To further investigate this phenomenon, a series of homologous NDI derivatives with a substituted phenyl group at the imide position are studied. The Raman peaks between 1550 and 1600 cm-1, which are assigned to aromatic stretching vibrations of the NDI moieties, are found to be sensitive to the charge distribution: stronger electron-withdrawing substituents result in these peaks shifting to slightly higher wavenumbers. As supported by a spin density analysis, despite the fact that the added charge is mostly localized on the NDI moiety, in the presence of an electron-withdrawing group, the subtle charge is likely to delocalize on the phenyl fragment, alleviating the effect of one-electron reduction on the molecular structure.