Corrigendum: Study on characteristic of epileptic multi-electroencephalograph base on Hilbert-Huang transform and brain network dynamics

[This corrects the article DOI: 10.3389/fnins.2023.1117340.].

Study on characteristic of epileptic multi-electroencephalograph base on Hilbert-Huang transform and brain network dynamics

Lots of studies have been carried out on characteristic of epileptic Electroencephalograph (EEG). However, traditional EEG characteristic research methods lack exploration of spatial information. To study the characteristics of epileptic EEG signals from the perspective of the whole brain，this paper proposed combination methods of multi-channel characteristics from time-frequency and spatial domains. This paper was from two aspects: Firstly, signals were converted into 2D Hilbert Spectrum (HS) images which reflected the time-frequency characteristics by Hilbert-Huang Transform (HHT). These images were identified by Convolutional Neural Network (CNN) model whose sensitivity was 99.8%, accuracy was 98.7%, specificity was 97.4%, F1-score was 98.7%, and AUC-ROC was 99.9%. Secondly, the multi-channel signals were converted into brain networks which reflected the spatial characteristics by Symbolic Transfer Entropy (STE) among different channels EEG. And the results show that there are different network properties between ictal and interictal phase and the signals during the ictal enter the synchronization state more quickly, which was verified by Kuramoto model. To summarize, our results show that there was different characteristics among channels for the ictal and interictal phase, which can provide effective physical non-invasive indicators for the identification and prediction of epileptic seizures.

Spatiotemporal and global profiling of DNA-protein interactions enables discovery of low-affinity transcription factors

Precise dissection of DNA-protein interactions is essential for elucidating the recognition basis, dynamics and gene regulation mechanism. However, global profiling of weak and dynamic DNA-protein interactions remains a long-standing challenge. Here, we establish the light-induced lysine (K) enabled crosslinking (LIKE-XL) strategy for spatiotemporal and global profiling of DNA-protein interactions. Harnessing unique abilities to capture weak and transient DNA-protein interactions, we demonstrate that LIKE-XL enables the discovery of low-affinity transcription-factor/DNA interactions via sequence-specific DNA baits, determining the binding sites for transcription factors that have been previously unknown. More importantly, we successfully decipher the dynamics of the transcription factor subproteome in response to drug treatment in a time-resolved manner, and find downstream target transcription factors from drug perturbations, providing insight into their dynamic transcriptional networks. The LIKE-XL strategy offers a complementary method to expand the DNA-protein profiling toolbox and map accurate DNA-protein interactomes that were previously inaccessible via non-covalent strategies, for better understanding of protein function in health and disease.

Symmetry-broken Josephson junctions and superconducting diodes in magic-angle twisted bilayer graphene

The coexistence of gate-tunable superconducting, magnetic and topological orders in magic-angle twisted bilayer graphene provides opportunities for the creation of hybrid Josephson junctions. Here we report the fabrication of gate-defined symmetry-broken Josephson junctions in magic-angle twisted bilayer graphene, where the weak link is gate-tuned close to the correlated insulator state with a moiré filling factor of υ = -2. We observe a phase-shifted and asymmetric Fraunhofer pattern with a pronounced magnetic hysteresis. Our theoretical calculations of the junction weak link-with valley polarization and orbital magnetization-explain most of these unconventional features. The effects persist up to the critical temperature of 3.5 K, with magnetic hysteresis observed below 800 mK. We show how the combination of magnetization and its current-induced magnetization switching allows us to realise a programmable zero-field superconducting diode. Our results represent a major advance towards the creation of future superconducting quantum electronic devices.

[Application of augmented reality navigation in laparoscopic and robot-assisted liver surgery]

In recent years, laparoscopic surgery and robotic surgery have been widely used, and various intraoperative image navigation systems have also developed rapidly. However, the liver itself has a complex vessel and duct system, which increase the difficulty of liver surgery. The augmented reality image navigation system combines the three-dimensional reconstructed image of the liver with the real liver anatomy, which presents the specific relationship between the tumor location and the surrounding vessels for the surgeon. Compared with other intraoperative image navigation methods, augmented reality has its unique advantages. This paper provides an overview of current advances in registration technology in augmented reality image navigation system, and focuses on its applications in liver surgery, including laparoscopic surgery and robotic surgery. Finally, the technological problems and difficulties still faced at present are summarized, and future directions worth studying in this field are proposed.

Modular Click Assembly DNA-Encoded Glycoconjugate Libraries with on-DNA Functional Group Transformations

Carbohydrates are an important class of naturally active products and play vital roles in regulating various physiological activities. To meet the demand for carbohydrate-based libraries used for the identification of potential drug candidates for pharmaceutical-related targets, we developed a set of on-DNA protocols to construct the DNA-encoded glycoconjugates, including Seyferth-Gilbert homologation, anomeric azidation, and CuAAC cyclization. These on-DNA chemistries enable the generation and modification of DNA-linked glycosyl compounds with good conversions and broad substrate scope. Finally, three DNA-linked glycoconjugate libraries were successfully generated to demonstrate their applicability and feasibility in library preparation.

PPAR-γ signaling in nonalcoholic fatty liver disease: Pathogenesis and therapeutic targets

Non-alcoholic fatty liver disease (NAFLD), currently the leading cause of global chronic liver disease, has emerged as a major public health problem, more efficient therapeutics of which are thus urgently needed. Peroxisome proliferator-activated receptor γ (PPAR-γ), ligand-activated transcription factors of the nuclear hormone receptor superfamily, is considered a crucial metabolic regulator of hepatic lipid metabolism and inflammation. The role of PPAR-γ in the pathogenesis of NAFLD is gradually being recognized. Here, we outline the involvement of PPAR-γ in the pathogenesis of NAFLD through adipogenesis, insulin resistance, inflammation, oxidative stress, endoplasmic reticulum stress, and fibrosis. In addition, the evidence for PPAR-γ- targeted therapy for NAFLD are summarized. Altogether, PPAR-γ is a promising therapeutic target for NAFLD, and the development of drugs that can balance the beneficial and undesirable effects of PPAR-γ will bring new light to NAFLD patients.

Calcium-peroxide-mediated cascades of oxygen production and glutathione consumption induced efficient photodynamic and photothermal synergistic therapy

Photodynamic therapy (PDT) and photothermal therapy (PTT) are potent approaches to cancer treatment. However, the tumor microenvironment (TME) characterized by severe hypoxia and abundant glutathione (GSH) significantly reduces the effectiveness of PDT. In this study, we developed an oxidative stress amplifier CaO₂/ICG@ZIF-8, which was capable of self-sufficient O₂ delivery and GSH depletion to enhance PDT and PTT synergistic therapy. We utilized ZIF-8 as nanocarriers that when loaded with CaO₂ and indocyanine green (ICG) form CaO₂/ICG@ZIF-8 nanoparticles, which exhibit a uniform particle size distribution and a hydrated particle size of about 215 nm. CaO₂ reacts with water under acidic conditions to produce O₂ so CaO₂/ICG@ZIF-8 has an excellent O₂ supply capacity, which is essential for PDT. Moreover, CaO₂/ICG@ZIF-8 also reacts with GSH to form glutathione disulfides (GSSH), enhancing the therapeutic outcome of PDT by preventing the consumption of local ractive oxygen species. Beyond that, CaO₂/ICG@ZIF-8 can produce strong hyperthermia with a photothermal conversion efficiency of about 44%, which is exceedingly appropriate for PTT. Owing to its augmentation, PTT/PDT mediated by CaO₂/ICG@ZIF-8 demonstrates intense tumor inhibitory effects in both in vitro and in vivo studies. Notably, the Zn and Ca generated by CaO₂/ICG@ZIF-8 degradation are essential elements for the body, so CaO₂/ICG@ZIF-8 shows favorable safety. Altogether, the research provides a promising PDT/PTT synergistic therapeutic strategy for cancer and may show more medical applications in the future.

NPS-Crosslinked Fibrin Gels Load with EMSCs to Repair Peripheral Nerve Injury in Rats

Neural tissue engineering has been introduced as a novel therapeutic strategy for trauma-induced sciatic nerve defects. Here, a neuropeptide S (NPS)-crosslinked fibrin scaffolds (NPS@Fg) loaded with an ectomesenchymal stem cell (EMSC) system to bridge an 8-mm sciatic nerve defect in rats are reported. The Schwann cell-like and neural differentiation of the EMSCs on the engineered fibrin scaffolds are also assessed in vitro. These results show that the NPS@Fg promotes the differentiation of EMSCs into neuronal lineage cells, which may also contribute to the therapeutic outcome of the NPS@Fg+EMSCs strategy. After transplantation NPS@Fg+EMSCs into sciatic nerve defects in rats, nerve recovery is assessed up to 12 weeks postinjury. In vivo experiments show that the combination of NPS crosslinked fibrin scaffolds with EMSCs can significantly accelerate nerve healing and improve morphological repair. In the study, NPS@Fg+EMSCs may represent a new potential strategy for peripheral nerve reconstruction.

Plasma poration: Transdermal electric fields, conduction currents, and reactive species transport

Radical species and electric fields produced by gas plasmas are increasingly used in dermatology. Plasma-poration is the key basis for the efficient plasma skin treatment, which involves the plasma electric field, the directional motion of charged particles, and the transport of reactive particles. However, the enabling mechanisms of the plasma-poration remain unclear and require urgent attention. Here, the plasma-induced electric fields in each skin layer are accurately measured for the first time. The maximum electric field in the stratum corneum is 43 kV/cm, while the electric field in the active epidermis and dermis is about 1.8 kV/cm. This electric field strength is in the range of strength required for electroporation. Different from traditional electroporation treatments, the plasma-poration mainly relies on the effects of strong electric fields and the conductive current. The active power of the plasma-poration up to 18.5 kW/cm3 in the stratum corneum can rapidly change the structure of the skin. At the same time, reactive oxygen and nitrogen species also pass through the stratum corneum and effectively interact with the skin tissue. The plasma-poration does not cause any pain, which is an inevitable side effect of common electroporation.

Fabrication of THz corrugated wakefield structure and its high power test

We present overall process for developing terahertz (THz) corrugated structure and its beam-based measurement results. 0.2-THz corrugated structures were fabricated by die stamping method as the first step demonstration towards GW THz radiation source and GV/m THz wakefield accelerator. 150-[Formula: see text]m thick disks were produced from an OFHC (C10100) foil by stamping. Two types of disks were stacked alternately to form 46 mm structure with [Formula: see text] 170 corrugations. Custom assembly was designed to provide diffusion bonding with a high precision alignment of disks. The compliance of the fabricated structure have been verified through beam-based wakefield measurement at Argonne Wakefield Accelerator Facility. Both measured longitudinal and transverse wakefield showed good agreement with simulated wakefields. Measured peak gradients, 9.4 MV/m/nC for a long single bunch and 35.4 MV/m/nC for a four bunch trains, showed good agreement with the simulation.

Privileged heterocycles for DNA-encoded library design and hit-to-lead optimization

It is well known that heterocyclic compounds play a key role in improving drug activity, target selectivity, physicochemical properties as well as reducing toxicity. In this review, we summarized the representative heterocyclic structures involved in hit compounds which were obtained from DNA-encoded library from 2013 to 2021. In some examples, the state of the art in heterocycle-based DEL synthesis and hit-to-lead optimization are highlighted. We hope that more and more novel heterocycle-based DEL toolboxes and in-depth pharmaceutical research on these lead compounds can be developed to accelerate the discovery of new drugs.

Identification of ovarian endometriotic cysts in cystic lesions of the ovary by amide proton transfer-weighted imaging and R2∗ mapping

AIM

To investigate the value of amide proton transfer weighted (APTw) imaging and R2∗ mapping of cystic fluid in differentiating ovarian endometriotic cysts (OE) from other ovarian cystic (OOC) lesions.

MATERIALS AND METHODS

A total of 42 patients who underwent 3 T pelvic magnetic resonance imaging (MRI) were enrolled. Nineteen lesions were OE and 27 lesions were OOC. The APTw imaging and R2∗ values of the cystic fluid were measured and compared between the two groups using the independent sample t-test or Mann-Whitney U-test. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic efficacy of different parameters. The area under ROC curves (AUCs) was compared using the Delong test. Spearman's correlation analysis was used to assess the correlation between APTw imaging and R2∗ values.

RESULTS

APTw imaging values of OE were lower, while R2∗ values were higher in OE than those in OOC (p=0.001 and < 0.001). The AUCs of APTw imaging and R2∗ values to identify OE from OOC were 0.910 and 0.975. The AUC increased to 0.990 when combining APTw imaging and R2∗ values, yet without a significant difference to the APTw imaging or R2∗ value alone (p=0.229 and 0.082, respectively). APTw imaging values were negatively correlated with R2∗ values (r=-0.522, p<0.001).

CONCLUSION

Both APTw imaging and R2∗ values of OE are significantly different from other ovarian cystic lesions. APTw imaging combined with R2∗ values show excellent diagnostic efficacy to differentiate between OE and OOC.

Endoscopic transcranial transdiaphragmatic approach in a single-stage surgery for giant pituitary adenomas

Background

The treatment for giant pituitary adenomas (GPAs, maximal diameter >4 cm) remains challenging, with remarkable mortality and morbidity, and there is no consensus on the optimal surgical approach. Gross total resection (GTR) for GPAs is difficult to achieve through a single transsphenoidal or transcranial approach. Any residual tumor is at risk for postoperative apoplexy. In this study, we propose a new surgical technique for resecting the GPAs in a sing-stage transcranial surgery.

Methods

A retrospective review of 4 patients with complicated GPAs, who had been treated via an endoscopic transcranial transdiaphragmatic approach in a single-stage surgery after routine transcranial resection, was performed. The following data was analyzed: clinical characteristics, preoperative imaging studies, resection rate, perioperative morbidity and mortality, as well as postoperative outcomes.

Results

All patients had nonfunctioning GPAs and preoperative visual disturbances. In three patients, GTR was achieved, and in one patient, near-total resection (90%-100% of the tumor) was achieved. Three patients attained improved postoperative visual function, while one patient's vision remained unchanged. One patient suffered a deficiency in adrenocorticotropic hormone along with thyroid-stimulating hormone, and one patient developed diabetes insipidus. Notably, none of the patients suffered cerebrospinal fluid leakage. However, one patient developed an epidural hematoma and underwent decompressive craniectomy.

Conclusions

The endoscopic transcranial transdiaphragmatic approach in a single-stage surgery can be efficiently and safely performed for maximal excision of GPAs with extensive suprasellar extension. Furthermore, relative to the conventional combined or staged approaches, this innovative surgical strategy provides neurosurgeons with a clear operative field with reduced invasiveness.

[Yin Chan Quan Shu, the Obstetrics and Gynecology Monograph by Wang Kentang]

Yin Chan Quan Shu (Obstetrics and gynecology monograph) is a monograph on obstetrics and gynecology compiled by Wang Kentang in the Ming Dynasty. It had four volumes and was published in the thirtieth year of Wanli (1602) in the Ming Dynasty after it was edited by Zhang Shoukong and others. It was found that Yin Chan Quan Shu has four versions remaining. They were the version printed by Shu Lin Qiao Shan Tang in the Ming Dynasty, held in the National Library of China and the Cabinet Library of Japanese Official Documents Library; the version revised according to the version of Shu Lin Qiao Shan Tang, held in the Library of Capital Medical University, Tianjin Medical College, Shanghai Branch of the Chinese Medical Association, the Library of Guangzhou University of Chinese Medicine and the Cabinet Library of the National Archives of Japan; the version based on the version of Shu Lin Qiao Shan Tang in the Ming Dynasty, transcribed in the fourth year of Wen Hua (1807), collected in the Cabinet Library of the National Archives of Japan; the version transcribed according to the revised version in the Ming Dynasty, collected in the Shanghai Branch of the Chinese Medical Association. It was found that there was no evidence to support the existence of the so-called "version of Kangxi in the Qing Dynasty". This means almost all versions remaining came from the versions published in the Ming Dynasty. The references of Yin Chan Quan Shu came from Pulse Classic (Mai Jing), Chan Bao, Fu Ren Da Quan Liang Fang and other works with the supplement and development by Wang Kentang.Yin Chan Quan Shu was the main sources and foundation of the Criteria of Syndrome Identification and Treatment in Gynecology (Nv Ke Zheng Zhi Zhun Sheng) by Wang Kentang.

Development and multicenter validation of a novel radiomics-based model for identifying eosinophilic chronic rhinosinusitis with nasal polyps

BACKGROUND

Reliable noninvasive methods are needed to identify endotypes of chronic rhinosinusitis with nasal polyps (CRSwNP) to facilitate personalized therapy. Previous computed tomography (CT) scoring system has limited and inconsistent performance in identifying eosinophilic CRSwNP. We aimed to develop and validate a radiomics-based model to identify eosinophilic CRSwNP.

METHODS

Surgical patients with CRSwNP were recruited from Tongji Hospital and randomly divided into training (n = 232) and internal validation cohort (n = 61). Patients from two additional hospitals served as external validation cohort-1 (n = 84) and cohort-2 (n = 54), respectively. Data were collected from October 2013 to May 2021. Eosinophilic CRSwNP was determined by histological criterion. The least absolute shrinkage and selection operator and the logistic regression (LR) algorithm were used to develop a radiomics model. Univariate and multivariate LR were employed to build models based on CT scores, clinical characteristics, and the combination of radiological and clinical characteristics. Model performance was evaluated by assessing discrimination, calibration, and clinical utility.

RESULTS

The radiomics model based on 10 radiomic features achieved an area under the curve (AUC) of 0.815 in the training cohort, significantly better than the CT score model based on ethmoid-to-maxillary sinus score ratio with an AUC of 0.655. The combination of radiomic features and blood eosinophil count had a further improved performance, achieving an AUC of 0.903. The performance of these models was confirmed in all validation cohorts with satisfying predictive calibration and clinical application value.

CONCLUSIONS

A CT radiomics-based model is promising to identify eosinophilic CRSwNP. This radiomics-based method may provide novel insights in solving other clinical concerns, such as guiding personalized treatment and predicting prognosis in patients with CRSwNP.

Targeting of G-protein coupled receptor 40 alleviates airway hyperresponsiveness through RhoA/ROCK1 signaling pathway in obese asthmatic mice

Obesity increases the severity of airway hyperresponsiveness (AHR) in individuals with asthma, but the mechanism is not well elucidated. G-protein coupled receptor 40 (GPR40) has been found to induce airway smooth muscle contraction after activated by long-chain fatty acids (LC-FFAs), suggesting a close correlation between GPR40 and AHR in obese. In this study, C57BL/6 mice were fed a high-fat diet (HFD) to induce obesity with or without ovalbumin (OVA) sensitization, the regulatory effects of GPR40 on AHR, inflammatory cells infiltration, and the expression of Th1/Th2 cytokines were evaluated by using a small-molecule antagonist of GPR40, DC260126. We found that the free fatty acids (FFAs) level and GPR40 expression were greatly elevated in the pulmonary tissues of obese asthmatic mice. DC260126 greatly reduced methacholine-induced AHR, ameliorated pulmonary pathological changes and decreased inflammatory cell infiltration in the airways in obese asthma. In addition, DC260126 could down-regulate the levels of Th2 cytokines (IL-4, IL-5, and IL-13) and pro-inflammatory cytokines (IL-1β, TNF-α), but elevated Th1 cytokine (IFN-γ) expression. In vitro, DC260126 could remarkedly reduce oleic acid (OA)-induced cell proliferation and migration in HASM cells. Mechanistically, the effects that DC260126 alleviated obese asthma was correlated with the down-regulation of GTP-RhoA and Rho-associated coiled-coil-forming protein kinase 1 (ROCK1). Herein, we proved that targeting of GPR40 with its antagonist helped to mitigate multiple parameters of obese asthma effectively.

An overview: Management of patients with advanced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has constituted a significant health burden worldwide, and patients with advanced HCC, which is stage C as defined by the Barcelona Clinic Liver Cancer staging system, have a poor overall survival of 6-8 months. Studies have indicated the significant survival benefit of treatment based on sorafenib, lenvatinib, or atezolizumab-bevacizumab with reliable safety. In addition, the combination of two or more molecularly targeted therapies (first- plus second-line) has become a hot topic recently and is now being extensively investigated in patients with advanced HCC. In addition, a few biomarkers have been investigated and found to predict drug susceptibility and prognosis, which provides an opportunity to evaluate the clinical benefits of current therapies. In addition, many therapies other than tyrosine kinase inhibitors that might have additional survival benefits when combined with other therapeutic modalities, including immunotherapy, transarterial chemoembolization, radiofrequency ablation, hepatectomy, and chemotherapy, have also been examined. This review provides an overview on the current understanding of disease management and summarizes current challenges with and future perspectives on advanced HCC.

Genetic influences of the effect of circulating inflammatory cytokines on osteoarthritis in humans

OBJECTIVE

The causal relationship between inflammatory cytokines and Osteoarthritis (OA) has not been well investigated. This study investigated the causal role of inflammatory cytokines in the risk of OA and total joint arthroplasty using the Mendelian randomization (MR) method.

METHOD

Single nucleotide polymorphisms (SNPs) robustly associated with inflammatory cytokines were used as instrumental variables. The inverse-variance weighted (IVW) method with false discovery rate (FDR) adjusted P-value (q-value) for multiple comparisons were used as the main MR method to estimate causal effects based on the summary-level data for OA (knee and hip OA, respectively) and total joint arthroplasty (TJA). Sensitivity analyses validated the robustness of the results and ensured the absence of heterogeneity and horizontal pleiotropy.

RESULTS

After FDR adjustment, macrophage colony-stimulating factor (MCSF) and vascular endothelial growth factor (VEGF) were identified as causally associated with knee OA (MCSF, odds ratio [OR]: 1.16, 95% confidence interval [CI]: 1.09-1.23, q = 5.05 × 10^-5; VEGF, OR: 1.09, 95% CI: 1.04-1.15, q = 0.011). We also observed that genetically predicted MCSF and VEGF were positively associated with the risk of TJA, and MCP3 was negatively associated with for the risk of TJA, although the effects seem fairly modest. Sensitivity analysis further excluded the influence of heterogeneity and horizontal pleiotropy.

CONCLUSIONS

Inflammatory cytokines, namely MCSF and VEGF, were causally associated with knee OA, which could enhance our understanding of inflammation in OA pathology.

Non-invasive methods to evaluate liver fibrosis in patients with non-alcoholic fatty liver disease

Non-alcoholic Fatty Liver Disease (NAFLD) is a chronic liver disease that is strongly related to insulin resistance and metabolic syndrome, and it has become the most common liver disorder in developed countries. NAFLD embraces the full pathological process of three conditions: steatosis, non-alcoholic steatohepatitis, and finally, cirrhosis. As NAFLD progresses, symptoms will become increasingly severe as fibrosis develops. Therefore, evaluating the fibrosis stage is crucial for patients with NAFLD. A liver biopsy is currently considered the gold standard for staging fibrosis. However, due to the limitations of liver biopsy, non-invasive alternatives were extensively studied and validated in patients with NAFLD. The advantages of non-invasive methods include their high safety and convenience compared with other invasive approaches. This review introduces the non-invasive methods, summarizes their benefits and limitations, and assesses their diagnostic performance for NAFLD-induced fibrosis.

A prognostic nomogram based on log odds of positive lymph nodes to predict the overall survival in biliary neuroendocrine neoplasms (NENs) patients after surgery

BACKGROUND

The prognosis of biliary neuroendocrine neoplasms (NENs) patients is affected by the status of metastatic lymph nodes. The purpose of this study was to explore the prognostic value of the log odds of positive lymph nodes (LODDS) and develop a novel nomogram to predict the overall survival (OS) in biliary NENs patients.

METHODS

A total of 125 patients with histologically confirmed biliary NENs were selected from the Surveillance, Epidemiology and End Results (SEER) database and further divided into training and validation cohorts. The discrimination and calibration of the nomogram were evaluated using the concordance index (C-index), the area under the time-dependent receiver operating characteristic curve (time-dependent AUC), and calibration plots. The net benefits and clinical utility of the nomogram were quantified and compared with those of the SEER staging system using decision curve analysis (DCA), net reclassification index (NRI), and integrated discrimination improvement (IDI). The risk stratifications of the nomogram and the SEER staging system were compared.

RESULTS

LODDS showed the highest accuracy in predicting OS for biliary NENs. The C-index (0.789 for the training cohort and 0.890 for the validation cohort) and the time-dependent AUC (> 0.7) indicated the satisfactory discriminative ability of the nomogram. The calibration plots showed a high degree of consistency. The DCA, NRI, and IDI indicated that the nomogram performed significantly better than the SEER staging system.

CONCLUSION

A novel LODDS-incorporated nomogram was developed and validated to assist clinicians in evaluating the prognosis of biliary NENs patients.