Cobalt doped Prussian blue modified hollow polydopamine for enhanced antibacterial therapy.

Give the emergence of drug resistance in bacteria resulting from antibiotic misuse, there is an urgent need for research and application of novel antibacterial approaches. In recent years, nanoparticles (NPs) have garnered significant attention due to their potential to disrupt bacteria cellular structure through loading drugs and special mechanisms, thus rendering them inactive. In this study, the surface of hollow polydopamine (HPDA) NPs was utilized for the growth of Prussian blue (PB), resulting in the formation of HPDA-PB NPs. Incorporation of Co element during the preparation process led to partial doping of PB with Co2+ions. The performance test results demonstrated that the HPDA-PB NPs exhibited superior photothermal conversion efficiency and peroxidase-like activity compared to PB NPs. HPDA-PB NPs have the ability to catalyze the formation of hydroxyl radicals from H2O2in a weakly acidic environment. Due to the tiny PB particles on the surface and the presence of Co2+doping, they have strong broad-spectrum antibacterial properties. Bothin vitroandin vivoevaluations confirm their efficacy against various bacterial strains, particularlyStaphylococcus aureus, and their potential to promote wound healing, making them a promising candidate for advanced wound care and antimicrobial applications.

Unsupervised Clustering-Assisted Method for Consensual Quantitative Analysis of Methanol-Gasoline Blends by Raman Spectroscopy.

Methanol-gasoline blends have emerged as a promising and environmentally friendly bio-fuel option, garnering widespread attention and promotion globally. The methanol content within these blends significantly influences their quality and combustion performance. This study explores the qualitative and qualitative analysis of methanol-gasoline blends using Raman spectroscopy coupled with machine learning methods. Experimentally, methanol-gasoline blends with varying methanol concentrations were artificially configured, commencing with initial market samples. For qualitative analysis, the partial least squares discriminant analysis (PLS-DA) model was employed to classify the categories of blends, demonstrating high prediction performance with an accuracy of nearly 100% classification. For the quantitative analysis, a consensus model was proposed to accurately predict the methanol content. It integrates member models developed on clustered variables, using the unsupervised clustering method of the self-organizing mapping neural network (SOM) to accomplish the regression prediction. The performance of this consensus model was systemically compared to that of the PLS model and uninformative variable elimination (UVE)-PLS model. Results revealed that the unsupervised consensus model outperformed other models in predicting the methanol content across various types of methanol gasoline blends. The correlation coefficients for prediction sets consistently exceeded 0.98. Consequently, Raman spectroscopy emerges as a suitable choice for both qualitative and quantitative analysis of methanol-gasoline blend quality. This study anticipates an increasing role for Raman spectroscopy in analysis of fuel composition.

Hard-Soft Thermoset Alloy with Enhanced Toughness, Impact-Resistance, and Electric Conductivity via Interpenetrated Dynamic Crosslinked Interface.

Polymer alloys (PAs) are mixtures of two or more types of polymers to enhance the properties of polymeric materials. However, thermosets with crosslinked structures are immiscible and cannot be prepared PAs. Herein, two immiscible covalent adaptable networks containing phenoxy carbamate bonds are explored as the typical polymeric materials to prepare the hard-soft thermoset alloy (HSTA) by the interpenetrated dynamic crosslinked interface (IDCI) to enhance the toughness. Specifically, two types of polyurethane covalent adaptable networks with either high stiffness (thermoset) or extensibility (elastomer) are prepared, respectively. The granules of thermoset and elastomer are mixed and hot-pressed to prepare the HSTA. The HSTA shows improved mechanical properties with a toughness of 22.8 MJ m-3 which is 14 times higher than that of hard thermoset. In addition, the HSTA shows excellent impact-resistance property after 1000 punctures. Moreover, the obtained HSTA via addition of carbon nanotubes can significantly decrease the electric resistance over six orders of magnitudes as compared to the blending method, which is due to the distribution of the carbon nanotubes at the interfaces of the two networks.

Yolk-shell shaped Au-Bi2S3heterostructure nanoparticles for controlled drug release and combined tumor therapy.

To fabricate a novel stimuli-responsive system enabling controlled drug release and synergistic therapy, yolk-shell shaped bismuth sulfide modified with Au nanoparticles (Au-Bi2S3) was prepared. The Au-Bi2S3nanomaterial with heterojunction structure exhibited excellent photothermal conversion efficiency and considerable free radicals yield under laser irradiation. The drug delivery capacity was confirmed by co-loading Berberine hydrochloride (BBR) and a phase change material 1-tetradecanol (PCM), which could be responsible for NIR light induced thermal controlled drug release.In vitroinvestigation demonstrated that Au-Bi2S3has cell selectivity, and with the assistance of the properties of Au-Bi2S3, the loaded drug could give full play to their cancer cell inhibition ability. Our work highlights the great potential of this nanoplatform which could deliver and control Berberine hydrochloride release as well as realize the synergistic anti-tumor strategy of photothermal therapy, photodynamic therapy and chemotherapy for tumor therapy.

The Effect of Prior Cancer on Survival of Patients With Thymoma.

BACKGROUND: Thymoma is an uncommon intrathoracic malignant tumor and has a long natural history, with overall survival (OS) in these patients lasting decades. It is uncertain whether the survival of a patient with thymoma is affected by their prior cancer history (PCH). Finding out the impact of PCH on thymoma survival has important implications for both decision-making and research. METHODS: The Surveillance, Epidemiology, and End Results database was queried for patients with thymoma diagnosed between 1975 and 2015. Kaplan-Meier methods and the Cox proportional hazards model were used to analyze OS across a variety of stages, ages, and treatment methods, in patients both with and without PCH. RESULTS: A total of 3604 patients with thymoma were identified, including 507 (14.1%) with a PCH. The 10-year survival rate of patients with a PCH (53.8%) was worse than that of those without a PCH (40.32%; 95% CI, 35.24%-45.33%; P < .0001). However, adjusted analyses showed that the impact of a PCH was heterogenous across ages and treatment methods. In subset analyses, PCH was associated with worse survival among patients who were treated with chemoradiotherapy (HR, 2.80; 95% CI, 1.51-5.20; P = .001) and among those who were ≤ 65 years (HR, 1.33; 95% CI, 1.02-1.73; P = .036). CONCLUSIONS: PCH provides an inferior OS for patients with thymoma. However, it does not worsen the survival in some subgroups, and these patients with thymoma may be eligible for study.

Discovery of Weyl Nodal Lines in a Single-Layer Ferromagnet.

Two-dimensional (2D) materials have attracted great attention and spurred rapid development in both fundamental research and device applications. The search for exotic physical properties, such as magnetic and topological order, in 2D materials could enable the realization of novel quantum devices and is therefore at the forefront of materials science. Here, we report the discovery of twofold degenerate Weyl nodal lines in a 2D ferromagnetic material, a single-layer gadolinium-silver compound, based on combined angle-resolved photoemission spectroscopy measurements and theoretical calculations. These Weyl nodal lines are symmetry protected and thus robust against external perturbations. The coexistence of magnetic and topological order in a 2D material is likely to inform ongoing efforts study the rich physics in 2D topological ferromagnets.

Rational design, synthesis and structure-activity relationship of novel substituted oxazole isoxazole carboxamides as herbicide safener.

A series of novel substituted oxazole isoxazole carboxamides derivatives were designed on the basis of active subunit combination. Forty-four novel compounds were synthesized by an efficient one-pot procedure under microwave irradiation. The bioactivity was evaluated as herbicide safener against the injury of chlorsulfuron. It was found that most of the synthesized compounds displayed remarkable protection against chlorsulfuron via enhanced glutathione content and glutathione S transferase activity. Especially compound I-11 exhibited better bioactivity than the safeners isoxadifen-ethyl and R-28725. Molecular docking simulations suggested that the target compounds could compete with chlorsulfuron in the active site of acetolactate synthase, which could explain the protective effects of safeners. The present work demonstrates that the target compounds containing oxazole isoxazole groups could be considered as potential candidates for developing novel safeners in the future.

Simultaneous identification and analysis of cassane diterpenoids in Caesalpinia minax Hance by high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry.

Cassane diterpenoids were successfully and simultaneously identified in Caesalpinia minax Hance by high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry. A total of 59 peaks were detected, and among them 51 compounds, including 41 furanocassane diterpenoids, 10 furanolactone cassane diterpenoids were simultaneously identified and characterized on the basis of the protonated molecule, retention behavior, and fragments in MS(2) . Ten compounds, including seven novel compounds, were identified or tentatively identified for the first time in C. minax. In a positive ion mode, the fragmentation pathways of cassane diterpenoids were also analyzed for the first time. The relative amounts of the five main diterpenoids (caesalpinin L, caesalpinin F2 , bondcellpin C, caesalpinin E, and ξ-caesalmin) were simultaneously quantified by high-performance liquid chromatography. Results showed that the newly discovered and known components of C. minax can be used to determine the material basis of bioactivity; this method can also be applied to analyze cassane diterpenoids in herbal medicines from the genus Caesalpinia belonging to the family Fabaceae.

Synergistic degradation of Tris (2-Chloroethyl) Phosphate (TCEP) by US/Fenton system: Experimental, DFT calculation and toxicity evaluation.

Organophosphorus esters (OPEs), exemplified by tris (2-chloroethyl) phosphate (TCEP), find extensive application in diverse industries such as construction materials, textiles, chemical manufacturing, and electronics, consequently resulting in an increased concentration of these compounds in industrial wastewater. The fundamental objective of this investigation was to examine the degradation of TCEP through the implementation of US/Fenton oxidation techniques in a solution. The findings revealed that the US/Fenton system effectively facilitated the degradation of TCEP, with the Chan kinetic model precisely elucidating the degradation process. Under optimized reaction conditions, the degradation efficiency of TCEP reached an impressive 93.18%. However, the presence of common co-existing aqueous substrates such as Cl-, HCO3-, H2PO4-, and HA hindered the degradation process. Bursting tests and electron paramagnetic resonance (EPR) studies affirmed ∙OH oxidation as the principal mechanism underlying TCEP degradation. Detailed degradation pathways for TCEP were established through the utilization of density-functional theory (DFT) calculations and GC/MS tests. Moreover, the ecotoxicological evaluation of TCEP and its intermediates was conducted using the Toxicity Estimation Software Tool (T.E.S.T.).

Cold Sintering Mediated Engineering of Polycrystalline SnSe with High Thermoelectric Efficiency.

Despite the attractive thermoelectric properties in single crystals, the fabrication of high-performance polycrystalline SnSe by a cost-effective strategy remains challenging. In this study, we prepare the undoped SnSe ceramic with remarkable thermoelectric efficiency by the combination of a cold sintering process (CSP) and thermal annealing. The high sintering pressure during CSP induces not only highly oriented grains but also a high concentration of lattice dislocations and stacking faults, which leads to large lattice strain that can shorten the phonon relaxation time. Meanwhile, the thermal annealing breaks the highly resistive SnOx layers at grain boundaries, which improves the electrical conductivity and power factor. In addition, the grain growth during annealing further turns the broken SnOx layers into nanoparticles, which further lowers the thermal conductivity by enhanced scattering. As a result, a peak ZT of 1.3 at 890 K and a high average ZT of 0.69 are achieved in the polycrystalline SnSe, suggesting great potential in mid-temperature power generation. This work may pave the way for the mass production of SnSe-based ceramics for thermoelectric devices.

Photocatalytic degradation of organophosphorus flame retardants in aqueous solutions: a review and future prospects.

The widespread use of organophosphorus flame retardants (OPFRs) in industrial and household products increases the risk of their environmental exposure, posing a serious threat to ecosystems and human health. Photocatalytic technology has been widely used in wastewater treatment due to its high efficiency, mild reaction conditions, and robustness. This review summarizes the current status of research on photocatalytic degradation of OPFRs, focusing on the effect of different types of catalysts on the degradation efficiency, the effects of pH, and co-existing inorganic and organic ions. And pH and co-existing inorganic mainly affect the active oxygen and the active surface sites of the catalyst. In addition, toxicological calculations of the intermediates of the degradation pathway using T.E.S.T. and ECOSAR showed that photocatalysis could effectively reduce the toxicity of OPFRs. Development of new photocatalytic materials, in-depth study of the degradation mechanism of different catalysts and flame retardants, and attention to practical applications and toxicity issues can be the development direction of future research.

[Effect of lag screw and support plate through axillary approach for the treatment of Ideberg typeâ ¡scapular pelvis fracture].

OBJECTIVE: To analyze the effect of lag screw and support plate through axillary approach for the treatment of Ideberg typeⅡscapular pelvis fracture. METHODS: From January 2016 to June 2021, 26 patients with Ideberg typeⅡglenoid fractures were treated with trans-axillary lag screw combined with supporting plate, including 15 males and 11 females. The age ranged from 21 to 75 years, with an average of (43.12±6.56) years old. The Constant-Murley Shoulder joint Scale and University of California at Los Angeles (UCLA) score were used to evaluate the function and clinical efficacy of shoulder joint. RESULTS: All patients were followed up, and the duration ranged from 19 to 42 months, with an average of (30.6±10.5) months. One year after surgery, the Constant-Murley score increased from preoperative 34.9±2.5(ranged, from 28 to 47) to 87.2±6.8(ranged, from 70 to 95). The UCLA score improved from preoperative 17.9±1.7(9 to 25) to 33.1±2.3(29 to 35). Seventeen patients got an excellent result, with 7 good, and 2 fair. None of the patients had infection, screw, and plate loosening, fracture, and other complications after surgery. Two patients had different degrees of Chronic pain in the shoulder during the follow-up period. CONCLUSION: The treatment of Ideberg typeⅡscapular glenoid fractures through axillary approach with lag screws and supporting steel plates has the advantages of convenient exposure, direct visual restoration of the normal anatomical shape of the scapular glenoid, selection of suitable positions for screw and steel plate placement, achieving better treatment results, and fewer complications. It is an effective and reliable surgical method.

Global burden of esophageal cancer attributable to smoking: a systematic analysis for the Global Burden of Disease Study 2019.

Background: Epidemiological trends of esophageal cancer attributable to smoking remain unclear. This study aimed to estimate the spatiotemporal trends of the esophageal cancer burden attributable to smoking to assist in global esophageal cancer prevention and smoking cessation. Methods: Data on esophageal cancer attributable to smoking were obtained from the Global Burden of Disease Study 2019. The number and age-standardized rates of esophageal cancer mortality (ASMR) and disability-adjusted life years (ASDR) were analyzed by age, sex, and location. Joinpoint regression analysis was used to analyze the temporal trends of esophageal cancer burden attributable to smoking over 30 years. Results: In 2019, the number of global esophageal cancer deaths and disability-adjusted life years (DALYs) attributable to smoking was approximately 203,000 and 475 million, respectively. The global esophageal cancer deaths and DALYs due to smoking were approximately 1.5-fold increased from 1990 to 2019, but the corresponding ASMR and ASDR had decreased. The heaviest burden occurred in East Asia, Mongolia, and the middle socio-demographic index (SDI) region. The male-to-female ratio was approximately 12.7 in the esophageal cancer deaths and DALYs and was approximately 14.3 in the ASMR and ASDR. The heaviest burden appeared in the 60-74 years age group. The estimated annual percentage change (EAPC) in ASMR was highly negatively associated with ASMR in 1990 (ρ = -0.41, p < 0.001) and SDI in 2019 (ρ = -0.29, p < 0.001). Conclusion: Despite reductions in ASMR and ASDR, the esophageal cancer burden attributable to smoking remains heavy, especially in middle SDI regions. Active tobacco control can reduce esophageal cancer burden.

Ferroptosis-dependent breast cancer cell-derived exosomes inhibit migration and invasion of breast cancer cells by suppressing M2 macrophage polarization.

Aim: Ferroptosis, a novel type of iron-dependent cell death, plays a vital role in breast cancer progression. However, the function of ferroptosis-induced cancer cell-derived exosomes in breast cancer remains unclear. In this study, we attempted to investigate the impact of breast cancer cells-derived exosomes induced by ferroptosis on the polarization of macrophages and the progression of breast cancer. Methods: Erastin was used to induce ferroptosis and breast cancer cell-derived exosomes were identified by transmission electron microscopy. Western blot, quantitative reverse transcription PCR, immunofluorescence, flow cytometry, and ELISA were used to determine the role of exosomes in macrophage polarization. Transwell assays were used to detect breast cancer cell migration, and invasion. Results: Our results showed that erastin promoted ferroptosis in breast cancer cells with increased Fe2+ level and ROS production. Breast cancer cell-derived exosomes induced by ferroptosis were successfully isolated and verified to be internalized by macrophages. In addition, ferroptosis-induced breast cancer cell-derived exosomes (Fe-exo) remarkably diminished M2 marker, Arg-1 expression. The ratio of CD206+ macrophages was significantly decreased after Fe-exo treatment. CD206 protein expression and Arg-1 level were dramatically reduced in M2 macrophages incubated by Fe-exo. Moreover, autophagy PCR array showed that the expression of 84 autophagy-related genes were altered after macrophages were incubated by Fe-exo. Furthermore, macrophages incubated by Fe-exo repressed the migration and invasion of breast cancer cells. Conclusion: Ferroptosis-dependent cancer cell-derived exosomes inhibited M2 polarization of macrophages, which in turn inhibited migration and invasion of breast cancer cells. This study provides novel therapeutic strategies for patients with breast cancer.

Cobalt-doped hollow polydopamine for oxygen generation and GSH consumption enhanced chemo-PTT combined cancer therapy.

Nanotechnology has revolutionized the field of therapeutics by introducing a plethora of nanomaterials capable of enhancing traditional drug efficacy or paving the way for innovative treatment methods. Within this domain, we propose a novel Cobalt-doped hollow polydopamine nanosphere system. This system, incorporating Doxorubicin loading and hyaluronic acid (HA) surface coating (CoHPDA@DOX-HA), is designed for combined tumor therapy. The overarching aim is to diminish the administration dosage, mitigate the cytotoxic side effects of chemotherapy drugs, augment chemosensitivity within neoplastic tissues, and attain superior results in tumor treatment via combined therapeutic strategies. The targeted molecule, hyaluronic acid (HA), amplifies the biocompatibility of CoHPDA@DOX-HA throughout circulation and fosters endocytosis of the nanoparticle system within cancer cells. This nanosphere system possesses pH sensitivity properties, allowing for a meticulous drug release within the acidic microenvironment of tumor cells. Concurrently, Polydopamine (PDA) facilitates proficient photothermal therapy upon exposure to 808 nm laser irradiation. This process further amplifies the Glutathione (GSH) depletion, and when coupled with the oxygen production capabilities of the Cobalt-doped hollow PDA, significantly enhances the chemo-photothermal therapeutic efficiency. Findings from the treatment of tumor-bearing mice substantiate that even at dosages equivalent to a singular DOX administration, the CoHPDA@DOX-HA can provide efficacious synergistic therapy. Therefore, it is anticipated that multifunctional nanomaterials with Photoacoustic Tomography (PAT) imaging capabilities, targeted delivery, and a controlled collaborative therapeutic framework may serve as promising alternatives for accurate diagnostics and efficacious treatment strategies.

Nonlinear Extensional Rheology of Poly(n-alkyl methacrylate) Melts with a Fixed Number of Kuhn Segments and Entanglements per Chain.

Molecular theories for dynamics of entangled polymers are based on both the number of Kuhn segments per entanglement Ne and the number of entanglements per chain N/Ne. Extensive studies have shown that, for polymer chains in the solutions or melts, linear viscoelasticity can be properly normalized, whereas the nonlinear extensional rheological properties cannot be normalized when N/Ne is kept the same. The failure of the latter normalization has been attributed to a difference in Ne. Nevertheless, nonlinear rheological studies are lacking for a suitable model system with fixed Ne and N/Ne. In this study, we identify poly(n-alkyl methacrylate)s with the number of carbons per alkyl group below seven as a model system. We find that the degree of the transient strain hardening during extensional flow strengthens with increasing the size of the alkyl group even when Ne and N/Ne are kept the same, which is attributable to the weaker friction reduction when the main backbones are more separated.

The Simplified Analytical Algorithm to the Time Effect of the Simple-Supported Steel and Concrete Composite Beam.

Based on Rusch's creep constitutive relation, differential equations for the redistribution of shrinkage internal force and creep of the composite beam are derived and solved. The closed solution is cumbersome and is inconvenient to be applied practically. It is hard to solve the accurate solution for coupled differential equations. Therefore, a simplified approach is given. However, it ignores the influence of the redistribution of bending moment of the concrete slab on the axial strain and removes the coupling relationship of differential equations so that it makes the solution become convenient. The comparison of the results calculated by the two approaches shows that their calculated errors are small, within 3%, when the stiffness ratio of the concrete slab and the steel beam are less than 0.185. It also shows that the greater the stiffness of the steel beam, the greater the constraint on the creep of the concrete slab, so is the redistribution of internal force.

The outcome of lung transplantation for end-stage pulmonary diseases with pulmonary hypertension: a single-center experience.

Background: Lung transplantation is a treatment for end-stage lung disease. The optimal transplant strategy for patients with end-stage lung disease complicated by pulmonary hypertension (PH) is controversial. The aim of this study is to review this experience and analyze the outcomes of lung transplantation for PH. Methods: This retrospective study collected data on patients with PH undergoing lung transplantation between March 2016 and December 2019 at a single center in China. The perioperative features and short- and medium-term outcomes between single-lung transplantation (SLT) and double-lung transplantation (DLT) were compared. Kaplan-Meier methods were used to analyze overall survival across a variety of transplantation procedures, age, mean pulmonary artery pressure (mPAP), body mass index (BMI), and indications of transplantation. Results: A total of 63 patients with PH were finally included in the analysis. The mean age, mean BMI, and mPAP were 56.37 years, 19.56 kg/m2, and 35.4 mmHg respectively. The overall 1-, 2-, and 3-year survival was 70%, 63%, and 60%, respectively. Five (7.94%) patients died within 30 days after surgery and nine patients (14.3%) died from infection during the followed-up period. There were no significant differences in the short- and medium-term survival outcomes of SLT and DLT, but postoperative pulmonary function was better in DLT. Patients older than 60 years of age had worse survival (P=0.01). Conclusions: The short- and medium-term survival outcomes between SLT and DLT are similar in selected patients with PH. DLT provides better pulmonary function. Patients older than 60 years are associated with worse survival.

Electronic nature of charge density wave and electron-phonon coupling in kagome superconductor KV3Sb5.

The Kagome superconductors AV3Sb5 (A = K, Rb, Cs) have received enormous attention due to their nontrivial topological electronic structure, anomalous physical properties and superconductivity. Unconventional charge density wave (CDW) has been detected in AV3Sb5. High-precision electronic structure determination is essential to understand its origin. Here we unveil electronic nature of the CDW phase in our high-resolution angle-resolved photoemission measurements on KV3Sb5. We have observed CDW-induced Fermi surface reconstruction and the associated band folding. The CDW-induced band splitting and the associated gap opening have been revealed at the boundary of the pristine and reconstructed Brillouin zones. The Fermi surface- and momentum-dependent CDW gap is measured and the strongly anisotropic CDW gap is observed for all the V-derived Fermi surface. In particular, we have observed signatures of the electron-phonon coupling in KV3Sb5. These results provide key insights in understanding the nature of the CDW state and its interplay with superconductivity in AV3Sb5 superconductors.

Impact of prior cancer history on outcomes in thymoma: a propensity score, population-based study.

BACKGROUND: Prior cancer history is a common exclusion in thymoma trials. However, whether prior cancer impacts the survival of thymoma patients and the outcomes of clinical trials remains uncertain. The aim of this study is to identify the impact of prior cancer on outcomes in thymoma. METHODS: Patients with thymoma diagnosed between 1975 to 2017 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Age, histologic types, and thymoma size were stratified to analyze. Propensity score matching (PSM), Kaplan-Meier methods and Cox proportional hazard models were used to analyze the prognostic effect of prior cancer on overall survival (OS). RESULTS: A total of 3,827 thymoma patients were enrolled, of whom 13.22% had a prior cancer history. The Kaplan-Meier curves showed statistically significantly different survival before (P<0.001) and after PSM (P=0.0003). Subgroup analyses stratified by histologic types and thymoma size showed that thymoma patients with prior cancer had inferior survival. But thymoma patients with prior cancer displayed similar OS among patients older than 65 years (P=0.693). In multivariate analyses, patients with prior cancer displayed inferior OS [hazard ratio (HR) =1.39, 95% confidence interval (CI), 1.18 to 1.63]. CONCLUSIONS: Prior cancer conveys an inferior OS among patients with thymoma. But it does not affect the survival adversely in older patients thus broader inclusion trial criteria may be adopted in thymoma patients with a prior cancer history.