Re-evaluation of the symptoms of Hirayama disease through anatomical perspective

Hirayama disease is a rare disease of the anterior horn motor neuron caused by compression of the cervical spinal cord when the neck is flexed. Cervical myelopathy may accompany the disease. It is characterized by symmetrical or asymmetrical muscle weakness and atrophy of muscles innervated by lower cervical and upper thoracic motor neurons. We recorded two male cases of Hirayama disease between the ages of 15 and 21 based on magnetic resonance imaging (MRI) features obtained from the cervical neutral state and from the flexion position which appeared in the right upper extremity. Loss of strength and atrophy in the right upper extremities was existent in clinical findings of these patients. When MRI was taken in the flexion position, there were dilated veins as hypointense signal void on T2 weighted series in posterior epidural area. The contrast enhancement was seen on these veins. It was observed that the posterior dura was displaced anteriorly and the anterior subarachnoid space was narrow. In cases which show clinical findings such as atrophy and loss of strength, having normal MRI results obtained in the neutral position makes it difficult to diagnose Hirayama Disease. In case of a suspicion of Hirayama disease the diagnosis can be made more easily by MRI taken in the flexion position. These case reports aim to bring Hirayama disease to mind and optimize the management of affected individuals

An ınvestigation of polymorphism of calcium carbonate in the presence of proline

Bu çalışmada, kalsiyum karbonatın polimorfik faz dönüşümü katkı maddesi olarak kullanılan prolin varlığında incelenmiştir. Deneyler 1L kapasiteli çift ceketli kristalizörde, 30 C sıcaklık ve pH 8,5’da yürütülmüştür. 50 ve 100 ppm olmak üzere iki farklı katkı konsantrasyonunda deneyler gerçekleştirilmiştir. Reaktan olarak kalsiyum klorür dihidrat ve sodyum karbonat kullanılmıştır. Deney süresince belirli zaman aralıklarında numuneler alınarak, kristallerin yapısı, fonksiyonel grupları, morfolojisi, tane boyutları ve yüzey yüklerinin değişimi belirlenmiştir. XRD ve FTIR analiz sonuçları, kalsiyum karbonat kristallerinin prolin varlığında kalsit formundan vaterit formuna dönüştüğünü göstermiştir. SEM görüntüleri saf ortamda üretilen kalsit kristallerinin kübik formda olduğunu buna karşın prolin varlığında kristallerin yuvarlak görünümlü vaterit morfolojisine sahip kristallere dönüştüğünü göstermiştir. Ayrıca, prolinin kalsiyum karbonat kristallerinin yüzey alanına ve yüzey yüküne olan etkisi BET analizi ve zeta potansiyeli ölçümleri yapılarak belirlenmiştir. Saf ortamda üretilen kalsit kristallerinin BET yüzey alanı ve zeta potansiyeli değeri sırasıyla 0,7 m2/g ve –8,0 ± 2,1 mV olarak ölçülmüştür. Buna karşın, 100 ppm prolin varlığında kristallerin BET yüzey alanı 3.7 m2/g’a yükselmiş ve prolinin kristallerin yüzeyine fiziksel olarak adsorplanmasından dolayı zeta potansiyel değerleri daha negatif (–24,0 ± 2,6 mV) hale gelmiştir. Sonuç olarak, katkı maddesi olarak kullanılan prolinin kalsiyum karbonatın hem fiziksel hem de morfolojik özelliklerini önemli ölçüde değiştirdiği gösterilmiş ve farklı formlarda kalsiyum karbonat kristallerinin üretilmesine imkân sağlayacağı tespit edilmiştir.In this study, the polymorphic phase transformation of calcium carbonate was analyzed in the presence of proline used as an additive. The experiments were carried out in a 1-litre double-jacketed crystallizer at 30 C and pH 8.5. The experiments were performed at two different concentrations of 50 and 100 ppm. Calcium chloride dihydrate and sodium carbonate were used as the reactants. During the polymorphic transformation process, the samples were withdrawn from the crystallizer at regular time intervals and the structure, functional group, morphology, particle size and surface charges of the calcium carbonate were determined as a function of the time. XRD and FTIR results showed that calcium carbonate crystals transformed from calcite to vaterite structures in the presence of proline. SEM images indicated that the calcium carbonate crystals prepared in pure media was cubic shaped crystals and the morphology transformed into spherical like vaterite crystals in the presence of proline. Moreover, the effects of proline on the surface area and surface charge of calcium carbonate were investigated by BET and zeta potential analysis. BET surface area and zeta potential for calcite crystals prepared in pure media were 0.7 m2/ g and - 8.0 ± 2.1 mV, respectively. By the addition of proline to the crystallization media, BET surface area increased to 3.7 m2/g, and the surface became more negative (- 24.0 ± 2.6 mV)

Clinical features of winter sports injuries: A prospective single center study

Introduction: This study aimed to present the epidemiological and clinical effects of skiing training and use of protective equipment on skiing, sledding and snowboarding injuries. Methods: The patients were evaluated in two groups according to both their skiing experience and use of protective equipment. The characteristics of the patients, such as age, gender, injury area, and injury type were statistically evaluated according to the groups. Results: A total of 191 patients, 68 (35.6%) female and 123 (64.4%) male, were evaluated. There was a significant difference between the patients with and without skiing experience (P=0.001). When the patients were evaluated according to the presence of protective equipment, 25 (59.5%) patients who had no experience did not wear protective equipment, and this rate was statistically significant compared to the experienced group (P=0.001). Concerning the diagnoses of the patients according to injury areas, joint dislocation and soft tissue trauma were mostly detected in the upper extremities, bone fractures in the lower extremities and organ injury in the thorax. Conclusion: Shoulder and wrist traumas were the most common injuries among the patients with previous skiing experience while tibial fractures were mostly seen in those without such experience. Tibia fractures were mostly observed in the patients using protective equipment, and skin incisions in those that did not use protective equipment. Therefore, in winter sports injuries, patients’ skiing experience and protective equipment use should be questioned and more attention should be paid to the above-mentioned injuries

(E)-1-(4-Hydroxyphenyl)-3-(substituted-phenyl)prop-2-en-1-ones: Synthesis, In Vitro Cytotoxic Activity and Molecular Docking Studies

A series of chalcone compounds (2–11) were designed and synthesized to determine their cytotoxic effects. The structures of 2–11 were fully characterized by their physical and spectral data. The in vitro cytotoxic effects of 2–11 were evaluated against human ovarian cancer (A2780), breast cancer (MCF-7) and prostate cancer (PC-3 and LNCaP) cell lines. The activity potentials of compounds were further evaluated through molecular docking studies with AutoDock4 and Vina softwares. All the compounds (except compound 5) showed significant cytotoxic effects at high doses in all cancer cell lines. Among all the compounds studied, one compound i.e. compound 2 demonstrated dose-dependent activity, particularly against A2780/LNCaP cancer cell lines. The most effective compounds 8, 9, 10 and 11 reduced the cell viability of A2780, MCF-7, PC-3 and LNCaP cells by 50–98%, while other compounds 2, 4 and 7 reduced the cell viability of A2780 cells by 70–90% at concentrations of 50 and 100 µM

Functional Disconnection and Compensation in Mild Cognitive Impairment: Evidence from DLPFC Connectivity Using Resting-State fMRI

The known regional abnormality of the dorsolateral prefrontal cortex (DLPFC) and its role in various neural circuits in mild cognitive impairment (MCI) has given prominence to its importance in studies on the disconnection associated with MCI. The purpose of the current study was to examine the DLPFC functional connectivity patterns during rest in MCI patients and the impact of regional grey matter (GM) atrophy on the functional results. Structural and functional MRI data were collected from 14 MCI patients and 14 age, gender-matched healthy controls. We found that both the bilateral DLPFC showed reduced functional connectivity with the inferior parietal lobule (IPL), superior/medial frontal gyrus and sub-cortical regions (e.g., thalamus, putamen) in MCI patients when compared with healthy controls. Moreover, the DLPFC connectivity with the IPL and thalamus significantly correlated with the cognitive performance of patients as measured by mini-mental state examination (MMSE), clock drawing test (CDT), and California verbal learning test (CVLT) scores. When taking GM atrophy as covariates, these results were approximately consistent with those without correction, although there may be a decrease in the statistical power. These results suggest that the DLPFC disconnections may be the substrates of cognitive impairments in MCI patients. In addition, we also found enhanced functional connectivity between the left DLPFC and the right prefrontal cortex in MCI patients. This is consistent with previous findings of MCI-related increased activation during cognitive tasks, and may represent a compensatory mechanism in MCI patients. Together, the present study demonstrated the coexistence of functional disconnection and compensation in MCI patients using DLPFC functional connectivity analysis, and thus might provide insights into biological mechanism of the disease

Effects of different sowing times and production technics on the yield and quality of Salvia hispanica L. under Çukurova conditions.

TEZ11249Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 2018.Kaynakça (s. 81-93) var.xiv, 95 s. : res. (bzs. rnk.), tablo ; 29 cm.Chia olarak bilinen Salvia hispanica L. Lamiaceae familyasına ait tek yıllık bir bitkidir. Bolivya’dan temin edilen Salvia hispanica L. tohumları ile Çukurova koşullarında Tesadüf Blokları Faktöriyel Deneme desenine göre 3 tekrarlamalı olarak kurulan denemede farklı ekim ve dikim zamanları (1 Nisan, 15 Nisan, 30 Nisan, 15 Mayıs) ile farklı üretim şekillerinin (Tohum ile üretim, Fide ile üretim) morfolojik ve kimyasal özelliklere olan etkisi incelenmiştir. Bitki boyu, ana dal sayısı, yan dal sayısı, bitki ağırlığı, başak sayısı, boğum sayısı, başak ağırlığı, tohum ağırlığı, tohum verimi ve protein oranı bakımından en uygun ekim zamanı 1 Nisan olarak saptanmıştır. Hem diğer ekim zamanlarına hem de fide üretim şekline göre daha iyi değerler elde edilmiştir. Ancak, başak uzunluğu, bin tane tohum ağırlığı ve yağ oranı 15 Mayıs tarihindeki tohumla üretim şeklinde diğerlerine göre üstünlük göstermiştir. Çukurova koşullarında Chia bitkisinde ekim zamanı ve üretim şekillerinin ilk kez denendiği bu denemede koşullarımızda yetişmekle birlikte verimlerin yüksek olmadığı bu nedenle ileriki çalışmalarda gün uzunluğuna nötr çeşitlerin denenmesi önerilmektedir.Salvia hispanica L., known as Chia, belonging to Lamiaceae family, is annual plant. Salvia hispanica L. seeds provided from Bolivia were used as plant material. Field trials were arranged in the complete factorial randomized block design with 3 replicates under Çukurova conditions. In the study, different sowing times (1, 15 30 April and 15 May) and (production technics such as seeds or seedlings) were investigated. As a result, plant height, main branch number, secondary branch numbers, plant weight, head numbers, number of nodes, head weight, seed weight, seed yield and protein ratio were higher in sowing time of 1 April and production from seedling. Some other plant characteristics such as spike length, thousand-seed weight and oil ratio were the highest in the sowing time of 15 May and production by seeds. According to the results of present study, which is the first research investigating the effects of sowing times and cultivation techincs under Çukurova, we come to the conclusion that Chia could be cultivated under our conditions, but the obtained yield from the the cultivar used in the study was the lower than world averages, so it can be recommended the day-neutral cultivars must be used in the future studies.Bu çalışma Ç.Ü. Bilimsel Araştırma Projeleri Birimi tarafından desteklenmiştir. Proje No: FYL-2017-8557

Evaluation of caseswith acute viral hepatitis hospitalized bethween 1990-2004 in the clinic of infectious diseases, meram faculty of medicine, Selçuk University

1990-2004 yılları arasında kliniğimizde akut viral hepatit tanısı ile yatan 561 olgu etyolojik, epidemiyolojik, klinik ve laboratuvar özelliklerinin belirlenmesi amacı ile geriye dönük olarak değerlendirildi. Olgular 7-77 yaş arasında olup yaş ortalaması 26.76Ü4.51 idi. Olguların 297'si erkek, 264'ü kadın olup 270'i (%48.2) HAV, 233'ü (%41.5) HBV, 18'i (%3.2) HCV, 3'ü (%0.5) HDV, l'i (%0.2) HEV, 4'ü (%0.7) HAV+HBV koinfeksiyonu, 3'ü (%0.5) diğer (2'si HSV tip 2 ve l'i EBV) ve 29 tanesi (%5.2) etiyolojisi saptanamayan grupta yert aldı. Hepatit A olgularının en sık sonbahar ve kış aylarında ve daha çok öğrencilerde görüldüğü saptandı. Olguların 377 tanesinde (%67.2) bulaşma yolu saptanamadı. En sık görülen yakınmalar halsizlik (%73.8), sanlık (%67), bulantı (%66.1) ve idrar renginde koyulaşma (%56.9) idi. En sık görülen bulgular ise ikter (%85), hepatomegali (%44) ve splenomegali (%8.2) idi. Ortalama AST değeri 1433.38 (106-7963), ortalama ALT değeri 1951.96 ( 218-15596 ), total bilirubin ortalama değeri ise 9.13 (1.3-35) idi.Five hundred sixty one cases hospitalized in our clinic between 1990-2004 were evaluated respect to etiological, epidemiological, clinical and laboratory features retrospectively. The age of cases was between 7-77 (mean: 26.76±14.51). 297 of them were male and 264 were female. 270 of them (48.2%) were HAV infection, 233 (41.5%) HBV, 18 (3.2%) HCV, 3 (0.5%) HDV, 1 (0.2%) HEV, 4 (0.7%) HAV and HBV coinfection, 3 (0,5%) others (2 HSV type 2 and 1 EBV), and etiology could not be determined in 29 (5.2%) of the cases. Hepatitis A cases were seen frequently in autumn and winter and seen more in students. In 377 (67.2%) of the cases any route of transmission could not be determined. The most frequent symptoms were weakness (73.8%), jaundice (67%), nausea (66.1%) and dark urine (56.9%). The most frequent signs were jaundice (85%), hepatomegaly (44%) and splenomegaly (8.2%). Mean AST level was 1433.38 (106-7963), ALT was 1951.96 (218-15596) and total bilirubin was 9.13 (1.3-35)

Evaluation of the distribution of mechanoreceptors and neural body in anatomical structures stabilizing the hip joint using silver impregnation stain

Kalça eklemi sahip olduğu yüksek hareket yeteneği sayesinde ayakta durma, oturma, koşma, çömelme gibi pek çok hareketin gerçekleştirilmesinde önemli rol oynayan bir eklemdir. Kalça ekleminin stabilizasyonunu sağlayan anatomik yapılardaki mekanoreseptör ve nöral yapıların dağılımı, cerrahi girişim planlanan koksartrozlu hastalarda eklem kapsülü üzerindeki uygun cerrahi insizyon yerinin belirlenmesinde oldukça önemlidir. Literatürde bu eklemin stabilizasyonunda görevli olan anatomik yapılar ( ligamentum transversum acetabuli, ligamentum capitis femoris (ligamentum teres), labrum acetabulare, kalça eklem kapsülü) ile ilgili farklı metotlarla boyamalar yapılarak mekanoreseptörlerin ve nöral yapıların dağılımına ilişkin çeşitli çalışma yapılmıştır. Yapılan çalışmalar koksartrozlu hasta kalçada, kalça eklemi stabilizasyonuna katılan bütün anatomik yapıların mekanoreseptör dağılımı hakkında detaylı bilgi verememektedir. Bu çalışma, kalça ekleminin stabilizasyonunu sağlayan anatomik yapıların canlı dokudan alınan örneklerindeki mekanoreseptörlerin ve nöral yapıların dağılımını detaylı olarak ortaya koymayı amaçlamaktadır. Hastaların ameliyatları esnasında çıkartılan ligamentum transversum acetabulare, ligamentum capitis femoris, labrum acetabulare dokusu ve kalça eklem kapsülün'den yapılan örneklemeler gümüş çöktürme yöntemi ile boyanarak bu yapılardaki mekanoreseptör ve nöral yapıların dağılımları incelenmiştir. Bu çalışmada bahsi geçen anatomik yapılar içerisinde koksartroz durumunda mekonoreseptör sayısının ligamentum transversum acetabulide en fazla olduğu, ligamentum tereste koksartroz durumunda mekanoreseptör dağılımında diğer bölgelere göre daha az olduğu, yapılan diğer çalışmalar ile mukayese edildiğinde eklem kapsülündeki mekanoreseptör sayısında ciddi bir azalış olduğu, ligamentum tereste ise mekanoreseptör varlığı tespit edilmiştir. Serbest sinir sonlanmaları en fazla labrumda tespit edilmiş olup, ligamentum tereste istatistiksel olarak anlamlı bir şekilde mekanoreseptör sayısının serbest sinir sonlanmalarna göre daha fazla olduğu gösterilmiştir.Due to its high mobility, hip joint plays a crucial role in executing many movements such as standing, sitting, running, crouching. The distribution of mechanoreceptors and neural structures in anatomical structures that provide stabilization of the hip joint is very important in determining the location of the appropriate surgical incision site on the joint capsule in patients with coxarthroses who are planned for surgery. Various studies have been conducted about the mechanoreceptors and distribution of neural structures in anatomical structures providing stabilization of the joint such as transvers acetabular ligament, ligament of head of femur, acetabular labrum and joint capsule applying different staining methods. They do not provide detailed information about the mechanoreceptor distribution of all anatomic structures participating in stabilization of the hip joint with the patients with coxarthrosis. This study aims to provide detailed results about the distribution of mechanoreceptors and neural structures from living tissue samples of anatomical structures providing stabilization of the hip joint. The transverse acetabular ligament, ligamentum teres, acetabular labrum tissue and samples from joint capsule were collected during the surgery. Each specimen was stained with silver impregnation technique and mechanoreceptors and neural structures in these structures have been examined. In this study, the number of mechanoreceptors in coxarthrosis was the highest in transverse acetabular ligament, mechanoreceptor distribution was lower in ligamentum teres than other regions and significant decrease was found in the number of mechanoreceptor amount in joint capsule when compared to previous studies. Most of the free nerve endings were in labrum and It is shown that the number of mechanoreceptors was significantly higher than free nerve endings in ligamentum teres

Evaluation of the ratio between right and left liver volume and the diameter of the liver vascular structures in living donor liver transplantation

Bu çalışmanın amacı canlı verici karaciğer naklinde, karaciğer greft hacminin gerçeğe yakın tahmin edilebilmesi için daha önce literatürde yer almayan parametrelerin ortaya konulmasıdır. Retrospektif olarak canlı karaciğer verici nakli adayı olan 200 hasta çalışmaya dahil edilmiştir. Çalışmaya dahil edilen hastalara ait, preoperatif dönemde bilgisayarlı tomografi ile çekilen arteriyel, venöz ve portal faz görüntüleri üzerinde vasküler yapıların (vena portae hepatis, vena portae hepatis'in ramus dexter ve sinister'i, arteria hepatica propria, arteria hepatica propria'nın ramus dexter ve sinister'i, v. hepatica dextra, v. hepatica intermedia, v. hepatica sinistra) çapları ve karaciğerin total hacmi, sağ lob hacmi ve sol lob hacmi ölçülmüştür. Çalışmaya dahil edilen hastaların total karaciğer hacmi ortalama 1472,5±278,08 cm3, sağ lob karaciğer hacmi ortalama 931,74 ± 210,96 cm3 olarak, sol lob karaciğer hacmi ortalama 543,90 ± 136,67 cm3 olarak bulunmuştur. RHA değerinde gerçekleşecek 1mm'lik artışın RLV değerinde 80.489 cm3'lük artışa neden olacağı saptandı. RVP değerinde gerçekleşecek 1mm'lik artışın RLV değerinde 27.335 cm3'lük artışa neden olacağı saptanmıştır. RHV değerinde gerçekleşecek 1mm'lik artışın RLV değerinde 17.133 cm3'lük düşüşe neden olacağı saptanmıştır. LHA değerinde gerçekleşecek 1mm'lik artışın LLV değerinde 29.611 cm3'lük artışa neden olacağı saptandı. LVP değerinde gerçekleşecek 1mm'lik artışın LLV değerinde 17.915 cm3'lük artışa neden olacağı saptandı. MHV değerinde gerçekleşecek 1mm'lik artışın LLV değerinde 15.979 cm3'lük düşüşe neden olacağı bulunmuştur. Bu sonuçların, özellikle gelişmiş yazılım destekli BT'lerin bulunmadığı yerlerde, klinisyenlere tahmini karaciğer hacimlerini hesaplama formüllerine ek olarak yardımcı olacağını düşünmekteyiz.This aim of this study is to present parameters that were not previously included in related literature to estimate the liver graft volume in living donor liver transplantation. Retrospectively, 200 patients who were candidates for living liver donor transplantation were included in the study. Arterial, venous and portal phase images of the patients included in the study taken by computed tomography in the preoperative period and were examined for the vascular structures (hepatic portal vein, right and left branches of the hepatic portal vein, proper hepatic artery, left and right branches of the proper hepatic artery, right hepatic vein, intermediate (middle) hepatic vein, left hepatic vein) diameters and total liver volume, moreover right lobe volume and left lobe volume were measured. The mean total liver volume of the patients included in the study was 1472.5±278.08 cm3, the mean right lobe liver volume was 931.74 ± 210.96 cm3, and the mean left lobe liver volume was 543.90 ± 136.67 cm3. We realized that an increase of 1 mm in the RHA value would cause an increase of 80,489 cm3 in the RLV value. It was determined that an increase of 1 mm in the RVP value would cause an increase of 27,335 cm3 in the RLV value. It was determined that a 1 mm increase in RHV value would cause a 17.133 cm3 decrease in RLV value. It was determined that 1 mm increase in LHA value would cause an increase of 29,611 cm3 in LLV value. It was determined that 1 mm increase in LVP value would cause an increase of 17,915 cm3 in LLV value. It was found that 1mm increase in MHV value will cause 15,979 cm3decrease in LLV value. It is thought that our results will help clinicians in addition to formulas to calculate estimated liver volumes, especially where advanced software-assisted CTs are not available

A bibliometric analysis of reverse logistics

Küresel bir dünyada üretim ve pazarlama zincirinde lojistik faaliyetleri, uluslararası bir ağ oluşturularak karmaşık süreçlere göre yapılmaktadır. Lojistik süreçleri artan sürdürülebilirlik gereksinimi ve artan çevresel kirlilik sonucunda; üretilerek kullanılan ürünlerin ve çeşitli malzemelerin geri dönüşümü ile atıkların imhası işlemleriyle birlikte tersine lojistiğe dönüşmüştür. Bu çalışmanın amacı, tersine lojistik ile ilgili olarak 2016-2020 yılları arasında yapılan çalışmaların taranması ve araştırmaların yoğunlaştığı konular, coğrafya ve araştırmacılar belirlenerek tersine lojistikle ilgili literatüre bibliyometrik analiz katkısıyla yapılacak çalışmalara ışık tutarak yol gösterici olabilmektir. Bu amaçla Selçuk Üniversitesi Merkez Kütüphanesinin abone olduğu ve kullanıcıların erişimine sunulan Web of Science (WOS) veri tabanından alınan tersine lojistikle ilgili 182 makale bibliyometrik analiz yöntemi ile incelenmiştir. Araştırmada bibliyometrik analiz yöntemi için geliştirilen VOSviewer adlı paket programı kullanılmıştır. Yapılan analizler sonucunda tersine lojistik alanında yapılan yayınlarda en yüksek atıf sayısının 2019 yılında gerçekleştiği, en sık kullanılan anahtar kelimenin sürdürülebilirlik (sustainability) olduğu belirlenmiştir. Ayrıca en fazla çalışma yapan ülkenin Çin Halk Cumhuriyeti, en fazla atıf puanına sahip olan ülkenin Danimarka olduğu tespit edilmiştir. Analiz bulgularına göre, Kannan Govindan’ın bu alanda en fazla yayın yapan ve atıf alan araştırmacı olduğu sonucuna ulaşılmıştır.Logistics activities in the manufacture and marketing chain in a global world are conducted in line with complex processes by generating an international network. As a result of the increasing environmental pollution and the need for sustainability, logistics processes have turned into reverse logistics with waste disposal and recycling of products and materials. The aim of this study is to screen articles on reverse logistics between 2016 and 2020 and identify the topics, geographies, and researchers they focus on in order to shed light on the topic through bibliometric analysis and contribute to the literature and pave the way for further research. For this purpose, the Web of Science (WOS) database has been scanned. The review yielded 182 articles on reverse logistics, which were analyzed through bibliometric analysis conducted using VOSviewer software package. The results showed that articles on reverse logistics were most cited in 2019 and that the most frequently used keyword was sustainability. Most studies were from the People's Republic of China. Denmark has the highest citation score. According to the analysis results, Kannan Govindan is the researcher who has published the most articles and been cited the most by other researchers