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3309 citation(s) found for "Do, Alexander".

Origin and Course Cavernous Internal Carotid Artery Branches from the Endoscopic Endonasal Perspective: Cadaveric Study and Analysis Clinical Implications
Alexander, Amiya, Dang, Danielle , Leonel, Luciano, Zeppieri, Marco , Peris‐Celda, Maria , Agosti, Edoardo , Alexander, A. Yohan, Pinheiro‐Neto, Carlos

Mayo Clinic

Operative Neurosurgery | October 22, 2024 | Volume: 28 | Issue: 5 | Pages: 687-696

10.1227/ons.0000000000001392 | PMID 39436095 Get It

BACKGROUND AND OBJECTIVE: Endoscopic endonasal approaches to treat cavernous sinus lesions require detailed knowledge of the origin, course, and anatomic variations of the branches of the cavernous internal carotid artery (cICA) because inadvertent avulsion can cause intraoperative ICA injury. We aim to study the origin and course of the branches of the cICA from an endoscopic endonasal perspective and relate these branches to surgically relevant anatomic references. METHODS: Sixty sides of 30 formalin-fixed specimens were dissected to identify the origin and course of cICA branches, including the inferolateral trunk (ILT), the meningohypophyseal trunk (MHT), anterior and inferior McConnell's capsular arteries (MCAs), and the superolateral trunk (SLT). RESULTS: The ILT and MHT were bilaterally in all specimens, whereas the anterior and inferior MCAs were identified in 28% and 25% of dissected sides, respectively. The SLT was only found in 3% of sides dissected. The MHT was the most proximal branch of the cICA, and its origin was an average of 8.9 mm anterior to the foramen lacerum and 3.8 mm superior to the sellar floor. The ILT was the second most proximal branch of the cICA, which originated 6.4 mm from the MHT on average. The anterior and inferior MCAs were present in 28% and 25% of specimens, respectively. The SLT, when present, was the second most proximal branch of the cICA, which originated at a mean height of 2.7 mm from the sellar floor. Overall, complete ILT and MHT were identified in 68% and 77% of cases, respectively. CONCLUSION: The MHT and ILT are constant branches of the cICA, with the MHT originating from the medial cICA posterior bend 4 mm superior to the sellar floor and 9 mm anterior to the foramen lacerum, whereas the ILT arises from the lateral horizontal cICA, 2.3 mm superior to the sellar floor and 6 mm anterior to the MHT.
Evaluation of Blood–Brain Barrier Disruption Using Low- and High-Molecular-Weight Complexes in a Single Brain Sample in a Rat Traumatic Brain Injury Model: Comparison to an Established Magnetic Resonance Imaging Technique
Zvenigorodsky, Vladislav , Gruenbaum, Benjamin F. , Shelef, Ilan , Horev, Anat , Azab, Abed N., Abu-Rabia, Mammduch, Negev, Shahar, Melamed, Israel , Boyko, Matthew , Boyko, Matthew , Gruenbaum, Benjamin Fredrick , Shelef, Ilan , Oleshko, Anna, Zlotnik, Alexander Anatolievich

Mayo Clinic

International Journal of Molecular Sciences | October 21, 2024 | Volume: 25 | Issue: 20 | Pages: 11241

10.3390/ijms252011241 | PMID 39457023 Get It

Traumatic brain injury (TBI), a major cause of death and disability among young people, leads to significant public health and economic challenges. Despite its frequency, treatment options remain largely unsuitable. However, examination of the blood–brain barrier (BBB) can assist with understanding the mechanisms and dynamics of brain dysfunction, which affects TBI sufferers secondarily to the injury. Here, we present a rat model of TBI focused on two standard BBB assessment markers, high- and low-molecular-weight complexes, in order to understand BBB disruption. In addition, we tested a new technique to evaluate BBB disruption on a single brain set, comparing the new technique with neuroimaging. A total of 100 Sprague–Dawley rats were separated into the following five groups: naive rats (n = 20 rats), control rats with administration (n = 20 rats), and TBI rats (n = 60 rats). Rats were assessed at different time points after the injury to measure BBB disruption using low- and high-molecular-weight complexes. Neurological severity score was evaluated at baseline and at 24 h following TBI. During the neurological exam after TBI, the rats were scanned with magnetic resonance imaging and euthanized for assessment of the BBB permeability. We found that the two markers displayed different examples of BBB disruption in the same set of brain tissues over the period of a week. Our innovative protocol for assessing BBB permeability using high- and low-molecular-weight complexes markers in a single brain set showed appropriate results. Additionally, we determined the lower limit of sensitivity, therefore demonstrating the accuracy of this method.
Rates and predictors of loss to follow-up for sporadic vestibular schwannomas undergoing imaging surveillance
Alexander, Marcus, Sáez-Alegre, Miguel , Celda, María Peris, Neff, Brian A., Carlson, Matthew L. , Driscoll, Colin L. W., Link, Michael J. , Peris Celda, Maria, Driscoll, Colin L., Morshed, Ramin A. , Bauman, Megan M. J. , Gompel, Jamie J. Van

Mayo Clinic

Journal of Neurosurgery | October 19, 2024 | Volume: No volume available | Issue: No issue available | Pages: 1-9

10.3171/2024.6.jns232904 | PMID 39423436 Get It

OBJECTIVE Imaging surveillance with serial MRI, or a "wait-and-scan" approach, is a management option for patients with small or medium-sized vestibular schwannomas (VSs). Prior publications have indicated no distinct quality of life advantage to upfront treatment compared with initial wait-and-scan management. However, imaging surveillance is dependent on patient adherence to follow-up. In this study, the authors aimed to identify rates and predictors of patient loss to follow-up during wait-and-scan management of sporadic VS. METHODS A single-center study was conducted including all patients from 2013 to 2018 who had undergone upfront imaging surveillance of sporadic VS. Patient data were retrospectively obtained from the electronic medical record. Outcomes of interest included loss to follow-up unrelated to death and inconsistent adherence to imaging surveillance recommendations. Logistic regression analyses were conducted to evaluate factors associated with loss to follow-up. RESULTS Over a 6-year study period, 270 patients underwent initial imaging surveillance of a sporadic VS. The median tumor diameter was 8.6 mm (range 1–28.9 mm). At the time of censoring, 106 patients (39.3%) had received treatment, 157 (58.1%) had been advised to continue follow-up, and 7 (2.6%) had died of non–VS-related causes. In total, 73 patients (27.0%) were completely lost to follow-up prior to the first treatment or death. Additionally, 60 patients (22.2%) missed at least 1 MRI follow-up or imaging follow-up was delayed by more than 1 year. Multivariable logistic regression identified an out-of-state residence (OR 3.05, 95% CI 1.58–5.89, p = 0.0009) and a smaller tumor size (unit OR per 1-mm increase in size, OR 0.88, 95% CI 0.83–0.95, p = 0.0006) to be associated with loss to follow-up. Patients living ≥ 350 miles from the hospital or with tumors ≤ 3 mm at the time of initial clinic evaluation were most likely to be lost to follow-up. Only a smaller tumor size was associated with an increased risk of inconsistent imaging follow-up (unit OR per 1-mm increase in size, OR 0.92, 95% CI 0.87–0.98, p = 0.007). CONCLUSIONS Patients undergoing imaging surveillance of VS are at risk for loss to follow-up and inconsistent imaging surveillance. Patients with smaller tumors or those living farther away from the treating institution are at highest risk for being lost to follow-up.
Extracting social support and social isolation information from clinical psychiatry notes: comparing a rule-based natural language processing system and a large language model
Patra, Braja Gopal , Lepow, Lauren , Kumar, Praneet Kasi Reddy Jagadeesh, Vekaria, Veer , Sharma, Mohit , Adekkanattu, Prakash , Fennessy, Brian , Hynes, Gavin, Landi, Isotta , Sánchez-Ruiz, Jorge A. , Ryu, Euijung , Nadkarni, Girish N. , Talati, Ardesheer , Zhang, Yiye , Charney, Alexander W. , Pathak, Jyotishman , Lepow, Lauren A , Sharma, Mohit M , Pathak, Jyotishman , Vekaria, Veer , Patra, Braja G , Sanchez-Ruiz, Jorge A , Biernacka, Joanna M. , Weissman, Myrna M. , Olfson, Mark , Mann, J. John

Mayo Clinic

Journal of the American Medical Informatics Association | October 18, 2024 | Volume: 32 | Issue: 1 | Pages: 218-226

10.1093/jamia/ocae260 | PMID 39423850 Get It

Abstract Objectives Social support (SS) and social isolation (SI) are social determinants of health (SDOH) associated with psychiatric outcomes. In electronic health records (EHRs), individual-level SS/SI is typically documented in narrative clinical notes rather than as structured coded data. Natural language processing (NLP) algorithms can automate the otherwise labor-intensive process of extraction of such information. Materials and Methods Psychiatric encounter notes from Mount Sinai Health System (MSHS, n = 300) and Weill Cornell Medicine (WCM, n = 225) were annotated to create a gold-standard corpus. A rule-based system (RBS) involving lexicons and a large language model (LLM) using FLAN-T5-XL were developed to identify mentions of SS and SI and their subcategories (eg, social network, instrumental support, and loneliness). Results For extracting SS/SI, the RBS obtained higher macroaveraged F1-scores than the LLM at both MSHS (0.89 versus 0.65) and WCM (0.85 versus 0.82). For extracting the subcategories, the RBS also outperformed the LLM at both MSHS (0.90 versus 0.62) and WCM (0.82 versus 0.81). Discussion and Conclusion Unexpectedly, the RBS outperformed the LLMs across all metrics. An intensive review demonstrates that this finding is due to the divergent approach taken by the RBS and LLM. The RBS was designed and refined to follow the same specific rules as the gold-standard annotations. Conversely, the LLM was more inclusive with categorization and conformed to common English-language understanding. Both approaches offer advantages, although additional replication studies are warranted.
The Use of Grayscale Muscle Ultrasound to Indicate Muscle Recovery after Peripheral Nerve Reconstruction
Saffari, Sara , Boon, Andrea J. , Saffari, Seyed Ehsan , Saffari, Seyed Ehsan , Shin, Alexander Y.

Mayo Clinic

Plastic & Reconstructive Surgery | October 17, 2024 | Volume: 155 | Issue: 4 | Pages: 709-719

10.1097/prs.0000000000011811 | PMID 39418075 Get It

Background: This study aimed to validate the use of grayscale muscle ultrasound by measuring echo intensity to longitudinally evaluate functional muscle reinnervation in a rabbit peroneal nerve defect model. Methods: Eighteen New Zealand white rabbits underwent a 30-mm peroneal nerve reconstruction with autografts or decellularized allografts. Ultrasound measurements of tibialis anterior muscles were performed before surgery and at 4, 8, 12, 16, 20, and 24 weeks postoperatively and included cross-sectional muscle area, mean gray value (MGV), and mean gray value normalized for area (MGVA). At 24 weeks, functional motor recovery was evaluated with isometric tetanic force (ITF) and compound muscle action potential (CMAP). MGVA data were compared with ITF and CMAP measurements by calculating the Spearman correlation coefficient. Results: Muscle area (left/right [L/R] ratio) of autografts was superior to allografts at 4, 12, 16, 20, and 24 weeks (P < 0.03 for all comparisons). MGVs of the operated side were significantly higher for autografts at 4, 8, and 12 weeks and at 12, 16, 20, and 24 weeks for allografts (P < 0.01 for all comparisons), compared with their unoperated sides. Similar patterns were seen in both groups for MGVA (operated versus control side). MGVA (L/R) demonstrated a strong correlation with ITF (L/R) for autografts (ρ = −0.7) and allografts (ρ = −0.87), but inconsistent with CMAPs (L/R). Conclusions: Quantitative muscle ultrasound demonstrated a reliable, noninvasive tool for evaluating motor recovery in a rabbit peroneal nerve reconstruction model. Clinical translation could provide valuable insights into muscle health and structural changes following nerve reconstruction.
The current state of digital pathology, molecular diagnostics and biobanking in renal cancer: Kidney Cancer Association Consensus Statement
Leibovich, Bradley C. , George, Daniel J. , Pickering, Lisa , Blackmur, James Peter , Jones, James O. , Laird, Alexander , Warren, Anne Y. , George, Daniel J. , Rosa, Salvatore La , Stewart, Grant D.

Mayo Clinic

Medicom Conference Report Proceedings of the 2024 IKCS: Europe Symposium | October 17, 2024 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.55788/bba1f0bd Get It

A Transfer Learning-Based Framework for Classifying Lymph Node Metastasis in Prostate Cancer Patients
Sarkar, S. , Harwood, Matthew , Silva, Alvin C. , Sarkar, Suryadipto , Harwood, Matthew , Wu, Teresa

Mayo Clinic

Biomedicines | October 15, 2024 | Volume: 12 | Issue: 10 | Pages: 2345

10.3390/biomedicines12102345 | PMID 39457657 Get It

Background: Prostate cancer is the second most common new cancer diagnosis in the United States. It is usually slow-growing, and when it is low-grade and confined to the prostate gland, it can be treated either conservatively (through active surveillance) or with surgery. However, if the cancer has spread beyond the prostate, such as to the lymph nodes, then that indicates a more aggressive cancer, and surgery may not be adequate. Methods: The challenge is that it is often difficult for radiologists reading prostate-specific imaging such as magnetic resonance images (MRIs) to differentiate malignant lymph nodes from non-malignant ones. An emerging field is the development of artificial intelligence (AI) models, including machine learning and deep learning, for medical imaging to assist in diagnostic tasks. Earlier research focused on implementing texture algorithms to extract imaging features used in classification models. More recently, researchers began studying the use of deep learning for both stand-alone feature extraction and end-to-end classification tasks. In order to tackle the challenges inherent in small datasets, this study was designed as a scalable hybrid framework utilizing pre-trained ResNet-18, a deep learning model, to extract features that were subsequently fed into a machine learning classifier to automatically identify malignant lymph nodes in patients with prostate cancer. For comparison, two texture algorithms were implemented, namely the gray-level co-occurrence matrix (GLCM) and Gabor. Results: Using an institutional prostate lymph node dataset (42 positives, 84 negatives), the proposed framework achieved an accuracy of 76.19%, a sensitivity of 79.76%, and a specificity of 69.05%. Using GLCM features, the classification achieved an accuracy of 61.90%, a sensitivity of 74.07%, and a specificity of 42.86%. Using Gabor features, the classification achieved an accuracy of 65.08%, a sensitivity of 73.47%, and a specificity of 52.50%. Conclusions: Our results demonstrate that a hybrid approach, i.e., using a pre-trainined deep learning model for feature extraction, followed by a machine learning classifier, is a viable solution. This hybrid approach is especially useful in medical-imaging-based applications with small datasets.
DICER1 -Related Tumor Predisposition: Identification of At-risk Individuals and Recommended Surveillance Strategies
Schultz, Kris Ann P. , Nelson, Alexander T. , Mallinger, Paige, Harris, Anne K. , Kamihara, Junne , Baldinger, Shari , Chen, Kenneth , Pond, Dinel , Hatton, Jessica N. , Dybvik, Anna, Perrino, Melissa R. , Ami, Tal Ben , Su, Yan , Duan, Cuihai , Watson, David , Field, Amanda L., Carr, Ann G. , Schneider, Dominik T. , Schoettler, Peter , Dehner, Louis P. , Mallinger, Paige H R , Chen, Kenneth S , Dybvik, Anna G , Mitchell, Sarah G , Perrino, Melissa R , Ben-Ami, Tal , Kachanov, Denis , Su, Yan , Duan, Chao , Olson, Damon R , Watson, Dave , Field, Amanda L , Harney, Laura A , Garrity Carr, Ann , Frazier, A Lindsay , Schneider, Dominik T , Wilson, David B , MacFarland, Suzanne P , Schoettler, Peter J , Bauer, Andrew J , Dehner, Louis P , Hill, Dana Ashley , Stewart, Douglas R , Messinger, Yoav H , Harris, Anne K , Olson, Damon R. , Wilson, David B. , Messinger, Yoav H.

Mayo Clinic

Clinical Cancer Research | October 14, 2024 | Volume: 30 | Issue: 24 | Pages: 5681-5692

10.1158/1078-0432.ccr-24-1532 | PMID 39400264 Get It

Abstract Purpose: DICER1-related tumor predisposition increases risk for a spectrum of benign and malignant tumors. In 2018, the International Pleuropulmonary Blastoma (PPB)/DICER1 Registry published guidelines for testing- and imaging-based surveillance of individuals with a known or suspected germline DICER1 pathogenic or likely pathogenic (P/LP) variant. One of the goals of the Registry is to continue to refine these guidelines as additional data become available. Experimental Design: Individuals were enrolled in the International PPB/DICER1 Registry, the International Ovarian and Testicular Stromal Tumor Registry, and/or the NCI Natural History of DICER1 Syndrome study. Results: Review of participant records identified 713 participants with a germline DICER1 P/LP variant from 38 countries. To date, 5 cases of type I and 29 cases of type Ir PPB have been diagnosed by surveillance in enrolled individuals. One hundred and three individuals with a germline P/LP variant developed a primary ovarian Sertoli–Leydig cell tumor at a median age of 14 years (range: 11 months–66 years); 13% were diagnosed before 8 years of age, the current age of onset of pelvic surveillance. Additionally, 4% of Sertoli–Leydig cell tumors were diagnosed before 4 years of age. Conclusions: Ongoing data collection highlights the role of lung surveillance in the early detection of PPB and suggests that imaging-based detection and early resection may decrease the risk of advanced PPB. DICER1-related ovarian tumors were detected before 8 years of age, prompting the Registry to recommend earlier initiation of ovarian surveillance with pelvic ultrasound beginning at the time of detection of a germline DICER1 P/LP variant.
Cardiac troponin elevation and mortality in takotsubo syndrome: New insights from the international takotsubo registry
Stähli, Barbara E. , Schindler, Matthias , Schweiger, Victor , Cammann, Victoria L. , Szawan, Konrad A. , Niederseer, David , Würdinger, Michael , Schönberger, Alexander, Schönberger, Maximilian, Koleva, Iva, Mercier, Julien C., Petkova, Vanya, Mayer, Silvia, Gili, Sebastiano , Franke, Jennifer , Meder, Benjamin , Jaguszewski, Miłosz, Knorr, Maike, Jansen, Thomas , Lewinski, Dirk von , Burgdorf, Christof , Kherad, Behrouz , Tschöpe, Carsten , Sarcon, Annahita, Shinbane, Jerold S., Rajan, Lawrence, Michels, Guido, Pfister, Roman , Jacobshagen, Claudius, Karakas, Mahir , Pott, Alexander , Meyer, Philippe , Roffi, Marco , Wolfrum, Mathias , Fischer, Thomas, Vasankari, Tuija , Dworakowski, Rafał , MacCarthy, Philip , Osswald, Stefan , Galiuto, Leonarda , Chan, Christina , Bridgman, Paul , Beug, Daniel , Gilyarova, Ekaterina, Gilyarov, Mikhail , Akın, İbrahim , Poledníková, Karolína, Massoomi, Michael , Carrilho‐Ferreira, Pedro , Hauck, Christian , Paolini, Carla , Bilato, Claudio , Kobayashi, Yoshio , Ishibashi, Iwao, Himi, Toshiharu, Din, Jehangir , Rihal, Charanjit S. , Liu, Kan , Jörg, Lucas, Rickli, Hans , Böhm, M., Pinto, Fausto J. , Widimský, Petr , Felix, Stephan B. , Rottbauer, Wolfgang , Budnik, Monika , Opolski, Grzegorz , Thiele, Holger, Kong, William, Dalakoti, Mayank , Imori, Yoichi , Liberale, Luca , Münzel, Thomas , Bax, J. J., Ghadri, Jelena R. , Vece, Davide Di , Templin, Christian , Budnik, Monika , Roffi, Marco , Liberale, Luca , Montecucco, Fabrizio , von Lewinski, Dirk , Tschöpe, Carsten , Meyer, Philippe , Bilato, Claudio , Citro, Rodolfo , Vecchione, Carmine , Bossone, Eduardo , Neuhaus, Michael, Noutsias, Michel , D’Ascenzo, Fabrizio, Dichtl, Wolfgang , Cuneo, Alessandro , Köenig, Wolfgang , Banning, Adrian , Cuculi, Florim , Kobza, Richard , Airaksinen, Juhani , Napp, L. Christian , Kaiser, Christoph A. , Delmas, Clément , Lairez, Olivier , Shilova, Alexandra S. , El‐Battrawy, Ibrahim , Toušek, Petr , Winchester, David E. , Gałuszka, Jan , Ukena, Christian , Poglajen, Gregor , Kato, Ken , Al‐Shammari, Ali Saad , Prasad, Abhiram , Rihal, Charanjit S. , Schulze, Paul Christian , Bianco, Matteo , Pestana, Gonçalo , Nguyen, Thanh Ha Tuan , Maier, Lars S. , Braun-Dullaeus, Ruediger Christian , Hasenfuß, Gerd , Pieske, Burkert , Schunkert, Heribert , Thiele, Holger , Bauersachs, Johann , Horowitz, John D. , Mario, Carlo Di , Crea, Filippo , Luescher, T F , Ruschitzka, Frank T.

Mayo Clinic

European Journal of Clinical Investigation | October 14, 2024 | Volume: 54 | Issue: 12 | Pages: No page available

10.1111/eci.14317 | PMID 39397275 Get It

AbstractBackgroundThe clinical relevance of cardiac troponin (cTn) elevation in takotsubo syndrome (TTS) remains uncertain. The present study sought to investigate the role of cardiac troponin (cTn) elevations in mortality prediction of patients with Takotsubo syndrome (TTS).MethodsPatients enrolled in the International Takotsubo (InterTAK) Registry from January 2011 to February 2020 with available data on peak cTn levels were included in the analysis. Peak cTn levels during the index hospitalization were used to define clinically relevant myocardial injury. The threshold at which clinically relevant myocardial injury drives mortality at 1 year was identified using restricted cubic spline analysis.ResultsOut of 2′938 patients, 222 (7.6%) patients died during 1‐year follow‐up. A more than 28.8‐fold increase of cTn above the upper reference limit was identified as threshold for clinically relevant myocardial injury. The presence of clinically relevant myocardial injury was significantly associated with an increased risk of mortality at 5 years (adjusted HR 1.58, 95% CI 1.18–2.12, p =.002). Clinically relevant myocardial injury was related to an increased 5‐year mortality risk in patients with apical TTS (adjusted HR 1.57, 95% CI 1.21–2.03, p =.001), in presence of physical stressors (adjusted HR 1.60, 95% CI 1.22–2.11, p =.001), and in absence of emotional stressors (adjusted HR 1.49, 95% CI, 1.17–1.89, p =.001).ConclusionThis study for the first time determined a troponin threshold for the identification of TTS patients at excess risk of mortality. These findings advance risk stratification in TTS and assist in identifying patients in need for close monitoring and follow‐up.
Multidisciplinary management strategies for recurrent brain metastasis after prior radiotherapy: An overview
Kotecha, Rupesh , Rosa, Alonso La , Brown, Paul D. , Vogelbaum, Michael A. , Navarria, Pierina , Bodensohn, Raphael , Karschnia, Philipp , La Rosa, Alonso , Karschnia, Philipp , Niyazi, Maximilian , Minniti, Giuseppe

Mayo Clinic

Neuro-Oncology | October 11, 2024 | Volume: 27 | Issue: 3 | Pages: 597-615

10.1093/neuonc/noae220 | PMID 39495010 Get It

Abstract As cancer patients with intracranial metastatic disease experience increasingly prolonged survival, the diagnosis and management of recurrent brain metastasis pose significant challenges in clinical practice. Prior to deciding upon a management strategy, it is necessary to ascertain whether patients have recurrent/progressive disease vs adverse radiation effect, classify the recurrence as local or distant in the brain, evaluate the extent of intracranial disease (size, number and location of lesions, and brain metastasis velocity), the status of extracranial disease, and enumerate the interval from the last intracranially directed intervention to disease recurrence. A spectrum of salvage local treatment options includes surgery (resection and laser interstitial thermal therapy [LITT]) with or without adjuvant radiotherapy in the forms of external beam radiotherapy, intraoperative radiotherapy, or brachytherapy. Nonoperative salvage local treatments also range from single fraction and fractionated stereotactic radiosurgery (SRS/FSRS) to whole brain radiation therapy (WBRT). Optimal integration of systemic therapies, preferably with central nervous system (CNS) activity, may also require reinterrogation of brain metastasis tissue to identify actionable molecular alterations specific to intracranial progressive disease. Ultimately, the selection of the appropriate management approach necessitates a sophisticated understanding of patient, tumor, and prior treatment-related factors and is often multimodal; hence, interdisciplinary evaluation for such patients is indispensable.