The #1 Medical Tourism Platform since 2014

Best Robotic spine surgery neurosurgeons: TOP 17 doctors

author
Content meets the Bookimed Editorial Policy and is medically reviewed by
Fahad Mawlood - General practitioner. Winner of 4 scientific awards. Served in Western Asia. Former Team Leader of a medical team supporting Arabic-speaking patients. Now responsible for data processing and medical content accuracy.
image
Ozdogan Selcuk
Neurosurgeon
13 years of experience
Turkey, Istanbul
Estexper Clinic

Ozdogan Selcuk

Neurosurgeon
13 years of experience

Assoc. Prof. Ozdogan, M.D., Ph.D., completed his education at Yeditepe University Health Sciences Institute in the Molecular Medicine Doctorate Program under Prof. Dr. Turgay İsbir, and he also studied at Saint Louis University in Arkansas, USA, with Prof. Dr. M. Gazi Yasargil. He pursued a Clinical Fellowship in Brain and Nerve Surgery at Yeditepe University Hospital, guided by Prof. Dr. Yasargil and Prof. Dr. Uğur Türe. Additionally, he underwent specialization training at Ufuk University Faculty of Medicine, the Faculty of Medicine at Gazi University, and completed his secondary education at İçel Anatolian High School.

Professionally, he has held various positions, including Faculty Member in the Department of Neurosurgery at Haliç University, and Associate Professor at Private Adatip Istanbul Hospital and Biruni University Hospital. He has also served as an Associate Professor at S.B.U. Kartal, Sancaktepe, and Istanbul Training and Research Hospitals, and worked as a Chief Assistant at S.B.U. Gaziosmanpaşa Taksim and Kartal Training and Research Hospitals. His earlier roles include Specialist Doctor at S.B.U. Baltalimanı Bone Diseases Hospital and Mus State Hospital, as well as Clinical Fellow at Yeditepe University Faculty of Medicine Hospital.

Assoc. Prof. Özdoğan is a member of several professional associations, including the Turkish Neurosurgery Association, Turkish Spine Association, and the Turkish Neurosurgery Society’s Neuroanatomy, Neurovascular, and Neurooncology Groups. He is also affiliated with the European Association of Neurosurgical Societies.

Read more
image
Ilhan Elmaci
Neurosurgeon
37 years of experience
5.0
29 reviews
Turkey, Istanbul
Istanbul Florence Nightingale Hospital

Ilhan Elmaci

Neurosurgeon
37 years of experience

accreditations:

The European Association of Neurosurgical Societies
European Skull Base Society

He was born in Niğde which is the city middle part of Anatolia. He studied high school in Adana. He graduated from Ankara University Medical School of Medicine. He started his career at Bakırköy Neurological Sciences Hospital in Zeki Oral MD.’s Clinic in 1987 and finished his Neurosurgery residency in 1993. During this period, he completed his micro neurosurgery education, which was a breakthrough for him, at Zurich University “Professor M. Gazi Yaşargil’s Clinic”.

Between 1993-2003, he worked as a teaching assistant and then as an assistant professor at the Professor Necmettin Pamir’s Clinic, Faculty of Medicine, Marmara University. At the same time, he obtained clinical and surgical gains in the field of neurooncology and vascular neurosurgery at Professor Donlin M. Long and Daniele Rigamonti's Clinic at Johns Hopkins University, USA. In 2003, he received the title of Associate Professor of Neurosurgery.

Between 2004-2010, he worked as Chief of Clinic in Göztepe Training and Research Hospital of Ministry of Health. During this period, he led his clinic to become the only accredited clinic by EANS (The European Association of Neurosurgical Societies) in Turkey, with its educational and care services. During this period, he completed his endoscopic skull base training starting at the University of Pittsburgh.

In 2010, he started to work for Acıbadem University Faculty of Medicine and became a Professor of Neurosurgery. He established the Neurosurgery Department in Medipol University Faculty of Medicine on 2012. He served as a Head of Neurosurgery Department in Memorial Health Group Istanbul Hospitals between 2014-2018. He served Neurosurgery Department of Maslak Hospital of Acıbadem Health Group with his team between 2018- September 2021.

Since 01.10.2021, He have started to work with his team at my private clinic located in Fulya and Ulus Hospital of Liv Health Group.

He served as the founding chairman of ”Skull Base Society” in Turkey. He is also a member of the Executive Committee of the European Skull Base Society (ESBS).

There are more than 110 scientific papers which he hs published in international refereed journals (SCI/SCIEx) and in national refereed journals and 18 scientific articles. He Has more than 250 scientific congress presentations, published books and chapters in books.

Read more
image
Ramazan Sari
Neurosurgeon
20 years of experience
5.0
29 reviews
Turkey, Istanbul
Istanbul Florence Nightingale Hospital

Ramazan Sari

Neurosurgeon
20 years of experience

Education:

Medical Faculty, Trakya University,  

Edirne, Turkey (1994-2000)

Professional Experience:

General Practitioner and Emergency Physician

Bartın (2000-2004)

Specialization:  

Department of Neurosurgery, S.B. Göztepe Training and Research Hospital,  

Istanbul (2004-2010)

Participation in the Accreditation Process by the European Association of Neurosurgical Societies (EANS) during  

Specialization (2004-2010)

Completion of Compulsory Service as Specialist Physician

Tokat State Hospital, Tokat (2010-2012)

Assistant Professor, Department of Neurosurgery

Gaziosmanpaşa University, Tokat (2012-2014)

Contribution to the Establishment of the Department of Neurosurgery at Medipol University  

(2012-2014)

Lecturer

Medipol University, Istanbul (2012-2014)

Specialist Physician

Memorial Istanbul Hospitals, Istanbul (2014-2018)

Lecturer, Faculty of Health Sciences

Eurasia University, Istanbul (2014-2021)

Associate Professor in the field of Neurosurgery (2021- )

Specialist Physician

Acıbadem Maslak Hospital, Istanbul (2018-2021)

Specialist Physician

Liv Hospital Ulus, Istanbul (2021-2023)

2023 –

Istanbul Florence Nightingale Hospital, Istanbul

Skills and Achievements:

Obtained Associate Professorship in the field of Neurosurgery (2021)

Experience in Academic Teaching and Management (2012-2021)

Proficiency in Turkish (Native) and English (Advanced)

Read more
image
Salih Murat Imer
Neurosurgeon
39 years of experience
5.0
29 reviews
Turkey, Istanbul
Istanbul Florence Nightingale Hospital

Salih Murat Imer

Neurosurgeon
39 years of experience

Certificates

1. The Course of Functional and Stereotactic Neurosurgery, 1990, Oulu, Finland.

2. European Course participation that holds by EANS for 5 years cycle (Amsterdam/1988, Rostock/1989, Çeşme/1994, Klagenfurt/1995, Aalborg/1996).

3. "Primary Examination" for European Board was passed in Klagenfurt,1995, Austria.

4."Advanced Training on Functional Disorders with Leksell Gamma Knife", 2004, Marseille, France.

5. "Advanced Training on Vestibular Schwannomas and Skull Base Surgery wiyh Leksell Gamma Knife", 2004, Marseille, France.

6. The certificate for "DISC Nucleoplasty in Cervical and Lumbar Disc Diseases", 2004, Freiburg, Germany.

7. "Neuropathfinder" Train - the - Trainer Meeting, 2009, Wien, Austria.

8. " Neuropathfinder" Train - the - Trainer Meeting, 2011, Athens, Greece.

9. The certificate for "Full- Endoscopic Spine Surgery", 2011, Herne, Germany.

Read more
Choosing Right Doctor and Clinic: Insider Tips
When selecting a doctor or clinic, keep these key points in mind:
Check credentials
Verify certifications from bodies like ISAPS, JCI, etc.
Review success rates
Choose doctors with solid experience in your specific treatment.
Read patient reviews
Browse Bookimed reviews from real patients to learn about their experiences.
Ensure effective communication
Pick clinics that offer language support for a smooth treatment process.
Ask about services
Confirm if they provide accommodation and transfers, and check the costs.
Choosing a clinic abroad can be stressful. At Bookimed, with over 800K patients helped, we understand your concerns. We know how to find trusted doctors, the best price-quality options, and solutions for even complex cases. We’re here to guide you every step of the way.
image
Yan Matsiivskiy
Head of Medical Coordinator Team
image
Associate Professor Burak Orhan Boran
Neurosurgeon
22 years of experience
5.0
2 reviews
Turkey, Istanbul
Medipol Acibadem District Hospital

Associate Professor Burak Orhan Boran

Neurosurgeon
22 years of experience

EDUCATION:

  • Turhan and Mediha Tansel Primary School (1979–1984)
  • Kültür College (1984–1988)
  • Semiha Şakir High School (1988–1991)
  • Marmara University Faculty of Medicine (1991–1997)
  • Marmara University Faculty of Medicine, Neurosurgery Department, Specialist Training (1997–2002)
  • Title of Associate Professor in Neurosurgery (May 31, 2021)

ADDITIONAL TRAINING:

  • "Visiting Physician," University of Southern California, Department of Neurosurgery (1998)
  • "Microsurgery Training," GATA (Gülhane Military Medical Academy), Ankara Education and Research Hospital (2003)

PROFESSIONAL EXPERIENCE:

  • Gülhane Military Medical Academy Haydarpaşa Training and Research Hospital (2002–2003)
  • Dr. Lütfi Kırdar Kartal Training and Research Hospital (2003–2005)
  • Private Avicenna Ataşehir Hospital (2005–2012)
  • Private 29 Mayıs Hospital (2012–2013)
  • Maltepe State Hospital (2013–2018)
  • Kartal Dr. Lütfi Kırdar City Hospital (2018–2020)
  • Private Academic Hospital (2020–2022)
  • Hisar Intercontinental Hospital (2022–2024)
  • Private Medipol Acıbadem Regional Hospital (2024–Present)

ADMINISTRATIVE AND ACADEMIC ROLES:

  • Board Member, Neurosurgical Society (2006–2009)
  • Head of the Emergency Department, Maltepe State Hospital (2014–2016)
  • Deputy Chief Physician, Private Academic Hospital (2020–2021)
  • Advisory Board Member, Beykent University Faculty of Medicine (2018–2024)
  • Faculty Member, Galata University Faculty of Health Sciences (2022–2024)
  • Director, Continuous Education Center, Galata University (2022–2024)

 

 

 

Read more
image
Melih Ucer
Neurosurgeon
17 years of experience
Turkey, Istanbul
Neurosurgery Istanbul

Melih Ucer

Neurosurgeon
17 years of experience
Dr. Melih Ucer is a specialized Brain and Nerve Surgeon with a focus on Spine and Spinal Cord Surgery, Degenerative Spine Surgery, and Minimal Invasive Spine Surgery, among others. His career is marked by international practice in the USA and contributions to numerous scientific publications in the field of neurosurgery. He is also an associate professor as of 2021.Read more

Find out about the best doctors here

20 top ranked Robotic spine surgery doctors in the world are represented on this page. The list includes only verified specialists known for their experience and high success rates.

The ranking is composed according to the Bookimed patient reviews and considers the rating of hospitals where doctors practice.

Top 5 Robotic spine surgery doctors on Bookimed.com:

How to choose the best Robotic spine surgery doctors in the world?

The specialist’s CV contains details about the doctor’s expertise and work experience, education, scientific research, and languages spoken. Compare information on several specialists, read carefully about their experience, success rates, and methods they apply. Make sure the chosen doctor has relevant experience in the treatment of a medical issue you are looking for. Read reviews of patients who had a consultation with the chosen specialist.

Famous Robotic spine surgery doctors have vast experience, continue education constantly, participate in professional associations and have positive feedback from patients treated.

What is the cost of a doctor's consultation?

The price for the consultation on Robotic spine surgery varies between experts and depends on certain factors, such as:

  • the country of practicing
  • the clinical experience and reputation
  • the medical degree and educational background
  • the doctor’s workload
  • medical developments, proprietary techniques used, and awards, if any.

How to make an appointment with a chosen doctor?

To schedule your visit, just submit a request on Bookimed.com. Our coordinator will contact you to discuss the time and details of the appointment, so everything will go smoothly.

We can help to find the right doctors for Robotic spine surgery if you have any difficulties with a choice. Bookimed services are free for patients ♥

Where you go for medical treatment

image
Microscopic Spine Surgery
Orthopedic spine surgeon
17 years of experience
Spain, Barcelona
Hospital Universitari Quiron-Dexeus

Microscopic Spine Surgery

Orthopedic spine surgeon
17 years of experience

During his career, Dr. Covaro has a continuous participation in international meetings and contributed to several articles published in scientific magazines. Dr. Covaro is a member of several professional organizations, including the Spanish Society of Orthopedics, AOspine, GEER and Eurospine.

 

Currently, Dr. Covaro attends his patients at the Institut Universitari Dexeus and the Hospital Universitari de Bellvitge, in Barcelona. To make an appointment with Dr. Augusto Covaro, contact ICATME, Institut Universitari Dexeus


 

Read more
Doctor's visit price on request
Robotic spine surgery $26034.75 - $52069.5
More treatments
image
Ismail Gulsen
Neurosurgeon
19 years of experience
Turkey, Ankara
Lokman Hekim Van Hospital

Ismail Gulsen

Neurosurgeon
19 years of experience

Assoc. Dr. İsmail Gülşen is a distinguished neurosurgeon serving at Lokman Hekim Van Hospital in Turkey. With extensive expertise in advanced brain and spine surgery, he has contributed significantly to the field through innovative techniques and patient-focused care. Dr. Gülşen specializes in diagnosing and treating complex neurological conditions, offering cutting-edge surgical interventions. His commitment to excellence is reflected in his continuous pursuit of medical advancements and personalized treatment strategies. For further details on his qualifications and professional achievements contact lokman hekim health group.

Read more
image
Erkan Kaptanoglu
Neurosurgeon
32 years of experience
Turkey, Istanbul
Estexper Clinic

Erkan Kaptanoglu

Neurosurgeon
32 years of experience

Prof. Erkan Kaptanoğlu, M.D. was born in Balikesir, Turkey in 1966. After completing his primary school, secondary school and high school education in Balikesir, he graduated from Istanbul University, Cerrahpasa Faculty of Medicine in 1990. He completed his internship at Peterborough District Hospital and Lincoln County Hospital in the United Kingdom. After a year of compulsory medical service, he completed his residency, which he had started in 1992, at Ankara Numune Training and Research Hospital in 1997 and became a Neurosurgery Specialist. After being assigned at the same hospital as Chief Resident in the same year, he studied “spinal cord injury and spinal cord regeneration” as a “research fellow” alongside Prof. Charles Tator, M.D., at the University of Toronto Faculty of Medicine in 1998-1999. After returning from Canada in 1999, he was tasked by the Ministry of Health to establish a Field Hospital and to work in cooperation with the Turkish Red Crescent Society at Hakkari, Şemdinli for two months. Following this assignment, he volunteered to work for the 1999 Marmara Earthquake relief effort.

He became an Associate Professor of Neurosurgery in 2004. He earned the title Doctor of Science (Ph.D.) by completing a doctorate program on Advanced Neuroscience between 2000-2005, at Hacettepe University Institute of Medical Sciences. He joined the project for autologous stem cell therapy in human spinal cord injuries with the Departments of Neurosurgery and Hematology at the Ankara University Faculty of Medicine. In 2009, he was appointed as Deputy Chief to the 1st Neurosurgery Clinic at the Ankara Numune Hospital, where he had been working.

At this hospital, in which he worked until 2010, he supervised and attended complex cranial, pediatric, spinal, trauma and vascular neurosurgery operations. He continued his academic research at Ankara University, Department of Anatomy and research laboratories of Ankara University and Hacettepe University for the purpose of developing strategies for complex spinal surgery operations.

With his research on spinal cord injuries and spinal anatomy, he won many awards such as the Acibadem Hospital Medical Research Award, 1st Place in 2000, Turkish Neurosurgical Society Dr. Mahir Tevruz Scientific Research Award, Tübitak and Brain Research Society Wheyt Award in 2001, Turkish Neurosurgical Society Hamit Ziya Gokalp Young Neurosurgeons Research Award, 2nd Place in 2002, Turkish Neurosurgical Society Yildiz Yalcinlar Scientific Research Award in 2004.

In 2010, he went to Cyprus to found the Near East University Faculty of Medicine Hospital with the guidance of Hacettepe University, and was appointed as full Professor. Between 2010-2015, he served as the Founder and Head of Department at the Near East University and Founder and Deputy Chief Physician at the University Training and Research Hospital in TRNC.

In 2000-2001, he served as a member of the editorial board for Türk Nöroşirurji Dergisi and Turkish Neurosurgery journal. Between the years 2001-2006, he served as an assistant editor for Türk Nöroşirurji Dergisi and Turkish Neurosurgery journals. In 2002-2003, he served as the Chairman of the Young Neurosurgeons Committee under the Turkish Neurosurgical Society. He was elected to the Turkish Neurosurgical Society Spinal and Peripheral Nerve Surgery Group Board of Directors to serve between 2003-2009. In 2013, he was again elected as a member to the Turkish Neurosurgical Society Spinal and Peripheral Nerve Surgery Group Board of Directors. In 2015, he became the Chairman of the Turkish Neurosurgical Society Spinal and Peripheral Nerve Surgery Group Board of Directors. In 2018, he was elected as a member to the Board of Turkish Neurosurgery Academy.

In 2015, he was appointed to the Marmara University Faculty of Medicine, Department of Neurosurgery and was elected as the Head of Department. During the same period, he also served as the Director of the Institute of Neuroscience. In 2018, he completed his tenure as the Head of Department. Reaching the end of this tenure in 2019, he retired from his duties as the Director of the Institute of Neuroscience and as a Member of the Faculty of Medicine. During his tenure at Marmara University, he supervised and accompanied surgical operations for complex cases from cranial patients to brain tumors (gliomas, meningiomas and hypophysis adenomas in particular), cerebral hemorrhages, Parkinson’s disease, trauma and vascular neurosurgery. He performed complex spinal surgery operations such as surgeries for spinal deformities (e.g. scoliosis and kyphosis), thoracoscopic spinal surgeries and sacral tumor surgeries. He conducted research and experimental studies on stem cell therapy and regeneration in spinal cord injuries. Between 2019-2020, currently He continues his clinical practice and surgeries along with his local and international academic studies, from his private clinic and Istanbul Brain and Spine Center.

He has attended numerous national and international courses and meetings as an instructor and speaker, was a guest speaker in over 100 events and conferences. He has published 65 international, 35 national scientific articles, edited 7 books, written 52 book chapters. He has served in the organizational committee 5 times in international meetings and 22 times in national meetings.

He is a member of the Turkish Medical Association, Turkish Cypriot Medical Association, Turkish Neurosurgical Society, Turkish Spine Society, EUROSPINE, AO Spine, Turkish Neurosurgery Academy.

Read more
image
Halil Can
Neurosurgeon
29 years of experience
Turkey, Istanbul
Atlas University Medicine Hospital

Halil Can

Neurosurgeon
29 years of experience

2002-2007 Istanbul University Istanbul Faculty of Medicine Department of Brain and Nerve Surgery

1988-1995 Trakya University Faculty of Medicine

 

2015- Atlas University Medicine Hospital

2014-2015 Private Pendik Yüzyıl Hospital Brain and Neurosurgery Clinic

2009-2014 Medicine Hospital Brain and Neurosurgery Clinic

2009-2009 Nisa Hospital Brain and Neurosurgery Clinic

2007-2009 Mardin State Hospital Brain and Neurosurgery Clinic

2002-2007 Istanbul University Istanbul Faculty of Medicine Brain and Neurosurgery

1997-2001 Enez Health Center and Enez State Hospital

 

Cervical, Thoracic and Lumbar Disc Surgery (endoscopic/microsurgery)

Far lateral (non-canal) lumbar disc surgery (lateral microsurgical approach)

Neurovascular surgery

Cerebrovascular diseases (vascular diseases of the brain)

Aneurysms

Arteriovenous malformations

Cavernomas

Neuro-oncological surgery

Brain tumors

Glial tumors

Meningiomas

Pituitary gland tumors

Metastatic brain tumors

Skull base tumors

Pontocerebellar angle tumors

Pineal tumors

Intraventricular tumors

Spinal disease surgery

Cervical, thoracic and lumbar spine fractures

Spine and spinal cord tumors

Scoliosis

Degenerative spine diseases

Peripheral nerve disease surgery

Peripheral nerve tumors

Entrapment neuropathies

Carpal tunnel syndrome

Ulnar groove syndrome

Tarsal tunnel syndrome

Functional neurosurgery and pain surgery

Trigeminal neuralgia

Microvascular decompression

Epilepsy surgery

Spasticity surgery

Epiduroscopic interventions

Hydrocephalus surgeries

Endoscopic 3rd ventriculostomy

VP shunt surgeries

LP shunt surgeries

Developmental anomalies

Meningomyelocele

Tethered cord syndrome

Arachnoid cyst

Craniosynostosis surgeries

Chiari malformation

Head trauma

Subdural hematomas

Intracerebral hematomas

 

Article published in internationally refereed journals

Cansever T, Civelek E, Sencer A, Karasu A, Kiris T, Hepgül K, Can H, Canbolat A: Spinal cavernous malformations: a report of 5 cases. Surg Neurol Jun 69 

Effects of combined and individual use of N-methyl-D aspartate receptor antagonist magnesium sulphate and caspase-9 inhibitor z-LEDH-fmk experimental spinal cord injury. A.Sencer, A.Aydoseli, Y.Aras, M.Osman Akçakaya, C.Gömleksiz, H.Can, A.Canbolat. Turkısh Joumal of Trauma&Emergency Surgery 2013

Aydoseli A, Can H, Aras Y, Sabanci PA, Akcakaya MO, Unal OF. Memantine and Q-VD-OPh Treatments in Experimental Spinal Cord Injury: Combined Inhibition of Necrosis and Apoptosis. Turk Neurosurg. 2016

Can H, Kircelli A, Kavadar G, Civelek E, Cansever T, Aydoseli A, Onal MB, Yilmaz C. Lumbosacral Conjoined Root Anomaly: Anatomical Considerations of Exiting Angles and Root Thickness. Turk Neurosurg. 2017

Kırcelli A, Özel Ö, Can H, Sarı R, Cansever T, Elmacı İ. Is the presence of linear fracture a predictor of delayed posterior fossa epidural hematoma? Ulus Travma Acil Cerrahi Derg. 2016 Jul

Kavadar G, Demircioğlu DT, Can H, Emre TY, Civelek E, Senyigit A. The clinical factors associated with benefit finding of complementary medicine use in patients with back pain: A cross-sectional study with cluster analysis. J Back Musculoskelet Rehabil. 2017

Ozer AF, Suzer T, Can H, Falsafi M, Aydin M, Sasani M, Oktenoglu T. Anatomic Assessment of Variations in Kambin’s Triangle: A Surgical and Cadaver Study. World Neurosurg. 2017 Apr

Can H, Aydoseli A, Gömleksiz C, Göker B, Altunrende ME, Dolgun M, Sencer A. Combined and individual use of pancaspase inhibitor Q-VD-OPh and NMDA receptor antagonist riluzole in experimental spinal cord injury. Ulus Travma Acil Cerrahi Derg. 2017

Gomleksiz C, Erbulut DU, Can H, Kodigudla MK, Kelkar AV, Kasapoglu E, Ozer AF, Goel VK. A new lumbar fixation device alternative to pedicle-based stabilization for lumbar spine: In vitro cadaver investigation. J Spinal Cord Med. 2018 Jul 16:1-8.

Aydoseli A, Özgen U, Akgül T, Orhan EK, Adıyaman AE, Can H, Karadağ C. Subacute Traumatic Ascending Myelopathy in a 28-year-old man: A rare case. World Neurosurg. 2019 Apr 28

 

Article published in national refereed journals

1) Intracranial Hemangioblastomas: Clinical Evaluation of 32 Patients T. Cansever, A. Karasu, K. Hepgül, H. Can, A. Sencer Turkish Neurosurgical Journal 2007, Volume:17 

2) Halil Can, Müge Dolgun, Utku Özgen, Cengiz Gömleksiz, Furkan Diren, Aydın Aydoseli, Yavuz Aras, Altay Sencer. Microsurgical Results in Vestibular Schwannoma Patients; Retrospective Clinical Study. JAREM 2019

3) Furkan Diren , Özcan Gayretli , Halil Can , İlke Ali Gürses , Orhan Barlas. Examination of Pons-Cerebellum Cisterna Anatomy with Endoscopic Retrosigmoid Suboccipital Approach: Cadaver Study. JAREM 2019

Read more
Doctor's visit price on request
Robotic spine surgery $9000 - $11000
More treatments
This page may feature information relating to various medical conditions, treatments, and healthcare services available in different countries. Please be advised that the content is provided for informational purposes only and should not be construed as medical advice or guidance. Please consult with your doctor or a qualified medical professional before starting or changing medical treatment.

Related Articles