The Arab world covers a vast geographic area, comprising many different countries in Asia and Africa. The contemporary world owes much of its progress in all fields of human intellectual activity, including medicine, to Arabic culture, especially the advancements made during the Golden Age of Arabic‐Islamic science (8th to 13th centuries C.E.). The glorious historic background of the Arabic world permits us to identify the debt that humanity owes to the Golden Age of Arabic science and to evaluate the research contributions made by Arab countries to biomedical sciences in our own day.

THE GOLDEN AGE OF ARAB SCIENCE The biomedical sciences of the Arabic‐Islamic world underwent remarkable development during the 8th to 13th centuries C.E., a flowering of knowledge and intellect that later spread throughout Europe and greatly influenced both medical practice and education. The scientific glory of the Arabic nation originated on the Arabian Peninsula in the 7th century C.E., where the preaching of the prophet Mohammed united the Arab tribes and inaugurated the Muslim religion (1). The Islamic state was formed in 622 C.E., when the Prophet moved from Mecca to Medina. Within a century after his death (632 C.E.) a large part of the planet, from southern Europe throughout North Africa to Central Asia and on to India, was controlled by and/or influenced by the new Arabic‐Muslim Empire (1, 2). In 711 C.E., Arab Muslims invaded southern Spain and a center of flourishing civilization (al‐Andalus) was created (1). Another center emerged in Baghdad from the Abbasids, who ruled part of the Islamic world during a historic period later characterized as the “Golden Age” (−750 to 1258 C.E.) (3). Arguably, many of the achievements of the Islamic‐Arabic Golden Age were based on previous initiatives taken by the ancient Egyptians, Hebrews, Persians, Greeks, and Romans (1, 2, 4). Hence, translators were invited to Baghdad, where scientists and researchers studied the past and created the future. The result of their work was impressive progress in all sectors of science. The rulers of Islamic Spain, in an attempt to surpass Baghdad, recruited scholars who made contributions of paramount importance to science, medicine, technology, philosophy, and art.

WHAT LED TO THE GOLDEN AGE? “The Golden Age” was based on several factors (5). Muslims following the guidelines of the Prophet studied and searched for knowledge (1, 5, 6). The Quran is clear: “The scholar's ink is more sacred than the blood of martyrs”, while the Prophet promoted medical research preaching that “For every disease, Allah has given a cure.” (5) Communication became easier because the Muslim Empire united extensive geographic areas. Scholars travelled to teach or share ideas. Furthermore, the Arabic language became a unifying factor (4, 5). Translations from Greek, Latin, and Chinese into Arabic were innumerable, thus removing language barriers for scholars. During the same period, Arabs learned from the Chinese how to produce paper and books became more available (5). Libraries were established in Cairo, Aleppo, Baghdad, and urban centers in Iran, central Asia, and Spain, while bookshops with thousands of titles opened in several cities (4, 5). Finally, The House of Wisdom, an academic institution serving as a university, was established in Baghdad in 1004 C.E. (5).

ISLAMIC MEDICINE During that period, Islamic medicine went through impressive developments, which later influenced medical education and practice in Europe (1, 2). Intense efforts for translation and analysis of the works of Hippocrates, Rufus of Ephesus, Dioscurides, and Galen took place (1, 2). Arab scholars synthesized and further elaborated the knowledge they had gathered from ancient manuscripts, adding their own experience. Numerous Arab pioneers are mentioned in medical history. Among the most famous are: Yuhanna ibn Massuwayh who performed dissections and described allergy (4, 7); Abu Bakr Muhummad ibn Zakariyya ar‐Razi (Rhazes) who differentiated smallpox from measles, described the laryngeal branch of the recurrent nerve, introduced mercurial ointments and hot moist compresses in surgery, investigated psychosomatic reactions, and wrote the famous Al‐Hawi, amedical encyclopedia of 30 volumes (4, 7); Az‐Zahrawi (Abulcasis), known as the father of surgery, who performed tracheotomy and lithotomy, introduced the use of cotton and catgut, and described extra‐uterine pregnancy, cancer of the breast, and the sex‐linked inheritance of hemophilia (4, 7); Ibn Sina (Avicenna) who differentiated meningitis from other neurologic diseases, described anthrax and tuberculosis, introduced urethral drug instillation, stressed the importance of hygiene, and dietetics, and the holistic approach to the patient [his work al‐Qanun fil Tibb (The Canon of Medicine), represented the absolute authority in medicine for 500 years (4, 7)]; Ibn‐Zuhr (Avenzoar) who described pericarditis, mediastinitis, and paralysis of the pharynx, and who pointed out the importance of drugs for body and soul (4, 7); and Ibn‐Nafis who studied and described pulmonary circulation (4, 7). Progress was apparent in all medical fields, including anatomy, surgery, anaesthesia, cardiology, ophthalmology, orthopaedics, bacteriology, urology, obstetrics, neurology, psychiatry (including psychotherapy), hygiene, dietetics, and dentistry (1, 4, 7).

EDUCATION, HOSPITALS, AND SCIENCE In that era, a thorough system of medical education was created in the Arab‐Muslim world (1, 4). Arabic medical studies consisted of initial training in such basic sciences as alchemy, pharmacognosy, anatomy, and physiology, which was followed by clinical training in hospitals, where students performed physical examinations, attended ward rounds, and clinical lectures (1, 2). Upon completion of training, future physicians were required to pass oral and practical exams in order to be licensed. Medicine was not only a profession or science, but also a philosophical attitude based upon religion and culture, obeying codes of ethics characterizing the physician's behavior and obligations to patients, colleagues, and the community (4). At the same time, secular hospitals (Bimaristans), developed all over the Arab world (1). These were well‐organized institutions, run under specific regulations and directed by physicians (1, 2). No sexual, religious, social, or economic discrimination interfered with patients' treatment (1). Detailed medical records were kept (1). These hospitals were adequately equipped, and had both inpatient and outpatient units (1, 2). Small, mobile hospital units were also created to serve distant areas and battle fields (1). The first known hospital was established in Damascus in 706 C.E., while the most important one, located in Baghdad, was established in 982 C.E. (2). Along with progress in medicine, there were remarkable developments in pharmacology (1, 2). In the 9th century C.E., manuscripts of Dioscurides and Galen translated from Greek formed the basis of further understanding. Arab scholars became acquainted with herbs, experimented with anesthetics, developed techniques such as distillation, crystallization, solution, and calcinations (1, 2) and introduced new drugs such as camphor, senna, musk, alum, sandalwood, ambergris, mercury, aloes, and aconite. They also developed syrups and juleps, created flavoring extracts made of rose water, orange or lemon peel, and experimented with poisons and antidotes (1, 2, 4). The most famous manual was The Comprehensive Book on Materia Medica and Foodstuffs, an alphabetical guide to over 1400 simples, written by Ibn al‐Baytar (2). The first pharmacies were established in Baghdad in 754 C.E. In the 12th century C.E., pharmacology was differentiated from medicine and alchemy and became an independent discipline (1). The impact of Arabic pharmacology in Europe was tremendous for centuries. Terms used in everyday pharmacy and chemistry such as drug, alkali, alcohol, elixir, aldehydes, etc., are derived from the Arabic (1). Advances in medical sciences were not an isolated phenomenon. Astonishing progress was made in astronomy, mathematics, chemistry, and other fields of science (1, 6, 8). Prominent astronomers were Ibn Firnas, who constructed a planetarium and reputedly was the first man to fly; Al‐Zarqali, who created a kind of astrolabe for measuring the motion of the stars; Al‐Bitruji, who studied stellar movements; Al‐Fargani, who wrote the Elements on Astronomy; and al‐Sufi, who described the Andromeda galaxy. Mathematics was closely linked to astronomy and almost every mathematician was also an astronomer (8). Arithmetic, algebra, geometry, and trigonometry flourished. Famous geometricians were Al‐Hajjaj ibn Yusuf, who first translated Euclid's Elements; and Muhammad and Hasan Banu Musa, who wrote books on the measurement of the sphere and trisection of angles and who discovered kinematical methods of drawing ellipses (8). Among arithmeticians and algebraists, al‐Khwarazmi was considered the greatest. He obtained data from Greeks and Hindus and transmitted arithmetical and algebraic knowledge, which exerted great influence upon medieval mathematics (8). Finally, trigonometry was developed along with astronomy with important representatives such as Ahmad al‐Nahawandi, Al‐Khwarizmi, Habash al‐Hasib, Yahya ibn abi Mansur, and Sanad ibn Ali (8). In the field of chemistry, Jabir Ibn Haiyan introduced the meaning of experimentation, leading from alchemy to modern chemistry. Additionally, the Golden Age was characterized by technological, architectural, and artistic achievements (Figs. 1 and 2). Methods for irrigation including underground channels, windmills, and waterwheels were some of the Arabic inventions (6, 9), while even today Arab architectural miracles and unique objects of art can be admired in many countries, with many of the best examples in southern Spain. Figure 1 Open in figure viewer Pottery cup depicting a leopard. Fatimid period, Egypt (11th century C.E.). Diameter: 20.4 cm. From the Islamic collection of the Benakis Museum, Athens, Greece (printed with permission). Figure 2 Open in figure viewer Glass cup. Egypt, Syria, or Iraq (9th–10th century C.E.). Height: 10 cm. From the Islamic collection of the Benakis Museum, Athens, Greece (printed with permission). Unfortunately, decline is an historical phenomenon observed in all times and cultures, and the Arabic‐Islamic world was no exception. From the 9th century C.E., several provinces had already started to fall away from Abbasid control and in the next four centuries the political power of the Empire was dispersed among new independent states (6). Around the 12th century C.E., the Abbasid Empire became weak, marking the beginning of the end (1, 9). Turks played a major role. Turkish soldiers, who first reinforced the Empire after 861 C.E., undermined the central authority (6). While the Abbasid Caliphate was disintegrating, the Seljuk Caliphate was beginning in 1057 C.E. By then the Empire had lost unity and power due to religious differences, charges of heresy, and assassinations. Along with the internal pressures, the European Crusades (1097–1291 C.E.) further weakened the Muslim Empire (9). Finally, in 1236, Cordoba fell to Spanish Christians (5) and in 1258, Baghdad fell to Mongols (1, 5).

ARAB SCIENCE TODAY To document the contributions of Arab countries to science today, we performed a bibliometric evaluation of the current biomedical research productivity in Arab countries, updating the relevant literature (10, 11) by analyzing data of the last decade and expanding on the issue with the use of various methods of measuring research output and the inclusion of more Arab countries. Although bibliometric analyses have several limitations, such as the inclusion of only a proportion of journals in indexing databases (12, 13), the results of our study offer useful data about the biomedical research productivity in Arab countries during the last decade. The research productivity of 23 Arab countries was evaluated by three different methods. First, by using the PubMed search engine, we identified the number of biomedical articles in which the first author's address was in one of the Arab countries for the period 1994–2003. We used a methodology similar to other bibliometric studies performed by our group (14). In addition, the total number of articles originating from all Arab countries was calculated and compared with worldwide productivity. This method included the use of the Institute for Scientific Information (ISI) Essential Science Indicators (ESI) database. The ESI database provides science trends and statistical information derived from other ISI databases. At the time of our analysis (April 2005) a total of 4941 journals were included in the ESI database and were categorized into 22 broad scientific fields for the 10‐year period 1995–2004. We focused our search on nine biomedical scientific fields: biology and biochemistry, clinical medicine, immunology, microbiology, molecular biology and genetics, multidisciplinary, neuroscience and behavior, psychiatry / psychology, and pharmacology and toxicology. Data in the ESI database is organized in various ways, including national rankings for research productivity in the above scientific fields. Thus, data pertaining to the total number of publications, total number of citations, as well as to the number of citations per paper for the examined 10‐year period, was collected and evaluated for each of the 23 Arab countries. Some Arab countries did not have data in the ESI rankings because they did not pass the needed cumulative citation count threshold as set by ESI. We also evaluated articles published in the top 50 clinical medicine journals as categorized in the ESI database, sorted on the basis of the number of citations per paper. Then, by making use of the ISI Web of Science “advanced search” tool, we identified articles in these journals in which at least one author had an address in an Arab country. We analyzed data on original articles only, excluding publication types such as letters, editorials, and news items. In order to adjust for confounders that affect research productivity, the average population and gross domestic product (GDP) for each country during the study period were calculated# from data obtained from the online World Bank databases (15). Raw and adjusted indicators for the biomedical research productivity of the Arab world during the last 10 years are shown in Table 1. The last two columns present data adjusted for population size and GDP. Researchers from Saudi Arabia published the largest number of articles. However, when adjustments for population and GDP were made, Kuwait and Jordan, respectively, were the most productive. Looking at the cumulative indices of scientific production of the Arab countries, one may notice that although the population of these countries represented 4.6% of the global population and had 1.4% of the global GDP during the study period, they produced 0.5% of the biomedical research indexed in the PubMed database and 0.1% of the articles published in the top 50 clinical medicine journals. Only 30 articles from those published in the top 50 clinical medicine journals during the period 1994–2004 originated exclusively from Arab countries, whereas in 254 others there was also participation of authors from non‐Arab countries [in 146, authors from the USA; and in 112, authors from Western Europe (there were co‐authors from the USA, Western Europe, and Arab countries in some papers)]. Table 1. Raw and adjusted indicators for biomedical research productivity of Arab countries Population (in millions—average 1994–2003) GDP (in billion USDs—average 1994–2003) PubMed Papers (1994–2003) ESI—Papers (1995–2004) Algeria 29.7 42.8 281 370 Bahrain 0.6 6.6 200 ND Comoros 0.5 0.2 3 ND Djibouti 0.6 0.3 14 ND Egypt 62.2 65.6 5,352 5,532 Eritrea 4.0 0.7 17 ND Iraq 22.5 ND 259 ND Jordan 4.7 7.5 1,293 1,167 Kuwait 2.1 26.6 1,554 2,068 Lebanon 4.2 12.1 1,322 1,364 Libya 5.1 ND 172 ND Mauritania 2.5 1.2 35 ND Morocco 28.0 38.9 2,008 2,281 Oman 2.3 12.2 620 ND Qatar 0.6 ND 168 ND Saudi Arabia 20.0 139.5 5,588 7,461 Somalia 8.4 ND 21 ND Sudan 30.5 8.0 384 421 Syria 14.3 12.6 140 14 Tunisia 9.4 21.9 1,753 1,994 Unit. Arab Emirates 3.0 41.0 1,102 1,368 West Bank and Gaza 2.8 3.3 102 ND Yemen 16.9 3.9 97 ND Total 274.9 444.9 22,485 24,040 % of Global 4.6% 1.4% 0.5% ESI Citations (1995–2004) ESI Fields ISI—Papers in the top 50 clinical medicine journals (1994–2004) Articlesa per million population (average population 1994–2003) Articlesa per billion USD (average GDP 1994–2003) 4,186 4 18 9.5 6.6 ND ND 0 333.3 30.3 ND ND 0 6.0 15.0 ND ND 0 23.3 46.7 26,593 8 66 86.0 81.6 ND ND 2 4.3 24.3 ND ND 2 11.5 ND 3,334 3 9 275.1 172.4 8,596 8 21 740.0 58.4 6,947 6 35 314.8 109.3 ND ND 0 33.7 ND ND ND 1 14.0 29.2 7,179 6 29 71.7 51.6 ND ND 14 269.6 50.8 ND ND 1 280.0 ND 31,229 8 69 279.4 40.1 ND ND 0 2.5 ND 2,967 3 7 12.6 48.0 928 2 4 9.8 11.1 8,606 6 17 186.5 80.0 5,922 6 0 367.3 26.9 ND ND 0 36.4 30.9 ND ND 1 5.7 24.9 106,487 284b 0.1% Most Arab countries located in the African continent produced less research, in absolute or adjusted numbers, than the majority of non‐African Arab countries. Although researchers from Egypt and Morocco published a relatively large number of papers and received a good number of citations compared to researchers from other Arab countries, they ranked lower when the data for research productivity were adjusted for population and GDP. Data regarding the number of articles indexed in PubMed, in which the first author's address was in an Arab country, for the years 1994–2003 are presented in Table 2. As shown, there was a continuous increase in the number of articles originating from Arab countries. In 1994 these articles represented 0.4% of the total articles indexed in PubMed, whereas this figure was 0.6% for 2003. Table 2. Number of articles indexed in PubMed for each Arab country during the years 1994–2003 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 Total Algeria 29 25 13 17 19 26 30 44 32 46 281 Bahrain 13 13 11 16 15 19 26 28 25 34 200 Comoros 0 0 0 0 0 2 0 1 0 0 3 Djibouti 1 0 2 4 2 0 1 1 1 2 14 Egypt 346 375 398 391 451 543 591 723 707 827 5352 Eritrea 1 0 0 0 1 0 4 3 3 5 17 Iraq 21 16 12 16 8 22 43 32 43 46 259 Jordan 64 65 86 88 107 135 161 174 221 192 1293 Kuwait 69 102 105 114 143 188 170 190 231 242 1554 Lebanon 61 47 61 88 124 146 160 215 184 236 1322 Libya 19 22 18 10 16 18 22 18 14 15 172 Mauritania 4 5 2 4 5 4 4 4 3 0 35 Morocco 85 126 140 136 166 203 226 289 333 304 2008 Oman 28 34 33 36 44 59 78 110 85 113 620 Qatar 17 12 15 12 16 11 9 26 21 29 168 Saudi Arabia 444 517 526 510 510 480 627 582 698 694 5588 Somalia 7 5 3 2 1 0 0 0 1 2 21 Sudan 39 38 34 30 38 31 29 42 49 54 384 Syria 3 10 2 7 7 20 21 24 18 28 140 Tunisia 141 105 94 124 94 131 167 264 264 369 1753 United Arab Emirates 70 90 96 111 122 102 114 142 115 140 1102 West Bank and Gaza 1 3 5 5 8 10 12 20 15 23 102 Yemen 4 4 4 6 5 10 14 17 15 18 97 Total (Arab countries) 1467 1614 1660 1727 1902 2160 2509 2949 3078 3419 22,485 World total 382,711 390,587 401,431 398,550 416,746 433,254 473,109 481,014 499,995 528,276 440,5673

ON TO THE FUTURE Biomedical research is important not only because of its direct significance for the health and well being of humans, but also because of the great economic advantages it affords. We are persuaded that the scientific community as well as the public and private funding organizations of Arab countries share the responsibility of increasing the funding for biomedical research and for improving the research infrastructure of each Arab country. Also, increased collaboration between Arab countries and their neighbours will offer a considerable benefit to those involved. Moreover, wealthy nations and regions, such as the USA and Europe, have the responsibility to assist Arab countries in their efforts to increase research productivity. This may be accomplished by incorporating well‐trained Arab scientists in international research networks, and by helping them to stay in their home countries, thus increasing the local research productivity. Arabs have a long history of contribution to science, especially during the Arabic‐Islamic Golden Age. However, political, social and economic problems have hampered scientists in Arab countries, making is difficult to optimize their capacity in research productivity in most scientific fields.

We thank Ioannis A. Bliziotis, M.D. and Evi Papastamataki, R.N. for their help with data collection and analysis and Elpis Mantadakis, M.D. for reviewing the manuscript. M.E.F designed the study, supervised data collection and analysis, and wrote the bibliometric part of the paper. E.A.Z. and G.S. wrote the part of the paper regarding the Islamic Golden Age. M.E.F. is guarantor.