bluuebunny/crossref_metadata_2025 huggingface dataset:
A rare left ventricular cardiac myxoma mimicking fibroma: A case report
Authors: Xia Liang-Yan , Zhu Hong-Ling , Li Rong-Hang , Pan Xiao-Hua , Liu Bo , Xu Jing
Published: April 2022

Background: In most cases, it is not difficult to differentiate common left ventricular (LV) cardiac myxomas from fibromas because they are different disease entities and have different imaging findings. Herein, we present a case of a tumor with histological characteristics of a LV cardiac myxoma even though its imaging and macroscopical views were similar to that of fibroma.Case presentation: A 65-year-old woman was admitted to the hospital with chest tightness and palpitations which persisted for 2 years. Transthoracic echocardiogram (TTE) and transesophageal echocardiography (TEE) revealed a 23 mm × 8 mm, polyp-like-shaped, homogeneous, firm, solitary, mobile and solitary LV mass, which protruded into the left atrium during systole, resulting in mild mitral regurgitation. LV contrast-enhanced echocardiography revealed that there was little contrast agent filling in the LV mass. To further clarify the nature of the mass, non-enhanced and contrast-enhanced coronary computed tomography (CT) angiograms showed a 19 mm × 8 mm relatively homogeneous low density with punctate calcifications mass and no significant enhancement. Thus, we preoperatively diagnosed her condition as a LV fibroma and performed excision of the tumor under cardiopulmonary by-pass by using port-access approach through right mini-thoracotomy. The postoperative pathological diagnosis of the tumor was in fact a LV myxoma.Conclusions: LV cardiac myxomas mimicking fibroma makes diagnosis difficult, and pathology is the gold standard for the diagnosis of myxoma. Complete surgical resection is the first choice to treat LV myxomas.
Probability wave is a real wave, a double helix electrical field carried by the charged elementary particle and the nuclei
Authors: Chen Sennian
Published: April 2022

Steven Weinberg, one of the founders of the Standard Model of Physics, asked years ago [1]: is the wave function of quantum mechanics real, or is it just used by scientists to calculate? We try to find the answer. We study the general solution of the Schrödinger equation mathematically. We will prove that for satisfying the Schrödinger equation, the particle should possess a helical structure of mass density. Then we will prove further that (i) charged elementary particles and atomic nucleus fall into two categories: they have charge or, but different directions of charges helices, like right-handed electron and left-handed electron etc. (ii) Charge (or) distributes double helically on the particle side boundary. It generates and carries a double helix external electric field with the same velocity. (iii) This E-wave will be proved is just the de Broglie wave. (iv) Its function is particle’s state function in quantum mechanics. (v) Charged particle itself and the de Broglie E-wave it carries form a particle-wave hybrid structure. The E -wave exhibits all the possible states and probabilities; as for the particle itself it can take only one basis state randomly, such as at an eigen state in the atom and molecular or at a point on the interference pattern. (vi) The orbital motion of an electron in the lower energy layers of atom and molecule does not radiate EM energy to collapse into the nucleus. (vii) Self-interference of the hybrid structure can better explain the single particle double-slit interference
Effect of mammography screening on long-term survival of breast cancer patients: Results from the National Cancer Screening Program in Korea
Authors: Luu Xuan Quy , Lee Kyeongmin , Jun Jae Kwan , Suh Mina , Jung Kyu-Won , Choi Kui Son
Published: April 2022

BackgroundBreast cancer (BC) is the most commonly diagnosed cancer type globally with the geo-ethnic differences in BC epidemiology. Therefore, many countries have adopted national cancer screening programs to reduce the burden of BC. Currently, the Korean National Cancer Screening Program provides biannual mammography screening for women aged ≥40 years. However, there were limited Asian studies investigating the effect of mammography screening, especially study with the long-term follow-up. Our study investigated the effect of mammography on the long-term survival of BC patients aged 40 years or older according to the screening history and duration since screening. MethodsThe study cohort was organized from three nationwide databases of the Korean National Cancer Screening Program, the Korean Central Cancer Registry, and death certificates. We included 24,387 women diagnosed with invasive cancer or ductal carcinoma in situ in 2008 and 2009 and followed up until December 31, 2019. The Kaplan–Meier analysis and the log-rank test were used to compare the survival of the subgroups. Cox proportional-hazards regression was used to investigate the effect of BC screening on mortality.ResultsOverall, 20,916/24,387 patients (85.8%) were alive at the end of the follow-up period (median: 10.5 years). The long-term survival rate was significantly lower in the never-screened group (80.3%) than in the screened group (88.9%) (P<0.001). The survival rate ranged from only 22.4% in patients with distant stage to 96.4% in DCIS patients. A 35% BC mortality reduction (hazard ratio [HR]=0.65, 95% confidence interval [CI]=0.60–0.70) from screening was observed. Subgroup analysis based on cancer stage showed reductions of 62%, 36%, and 24% for subgroups of localized stage, regional stage, and distant stage, respectively. Women aged 40–49 years received the least benefit from BC screening (HR=0.71, 95% CI=0.62–0.81).ConclusionsMammography screening was effective in reducing the risk of BC-specific death in Asian women across all cancer stages. However, this effect was relatively small among women in their 40s, suggesting that more detailed and specialized screening strategies are needed.
Impact of COVID-19 Pandemic on Singapore’s Aviation Industry
Authors: Rangaswamy Easwaramoorthy , Hoe Winston Hoo Kian , Nawaz Nishad
Published: April 2022

COVID-19, a global pandemic, is proving a significant threat to various sectors globally, including the aviation industry. There has been limited research on the Singapore aviation industry, their responses and preparedness and the impact of COVID-19 during and post-pandemic. With such a gap in the literature, this study aims at understanding the impact that the pandemic has specifically on Singapore’s aviation industry both current and in the future while focusing on the existing mitigation measures. A survey questionnaire was used to collect quantifiable data from airport and non-airport workers to analyse various attributes, such as the perception of mitigation and air travel demand. The results concluded that attitudes towards pandemic and mitigation measures significantly led to better expectations of air travel recovery. It is to be noted that beyond domestic and global attitudes, rebound of international travel essentially relies on borders to be opened and multiple countries’ collaboration and coordination.
Using an Explicit Query and a Topic Model for Scientific Article Recommendation
Authors: smail Boussaadi
Published: April 2022

The search for relevant scientific articles is a crucial step in a scientific research project. However, the considerable number of articles published and uploaded online in digital databases (such as google scholar, semantic scholar, etc.) makes this task tedious and negatively impacts the researcher's productivity. This article proposes a new method of recommending scientific articles, taking advantage of content-based filtering. The challenge is to target the relevant information to meet the researcher's needs regardless of his research's domain. Our recommendation method has based on a semantic exploration using the latent factors. Our goal is to achieve an optimal topic model, which will serve as the basis for the recommendation process. Experiences confirm our performance expectations by showing relevance and objectivity in the results.
Clinical Utility and Correlates of Cerebrospinal Fluid 14-3-3 Protein in the Evaluation of Rapid Progressive Dementia
Authors: Kong Yu , Chen Zhongyun , Liu Li , Chu Min , Cui Yue , Xie Kexin , Zhang Jing , Wu Li-yong
Published: April 2022

Background
The 14-3-3 protein in cerebrospinal fluid (CSF) is a suitable marker for the differential diagnosis of patients with rapidly progressive dementia (RPD) suspected of Creutzfeldt-Jakob disease (CJD). However, the CSF 14-3-3 protein has also been detected in various non-prion-related RPD. Our objective was to investigate the general distribution of RPD with positive 14-3-3 result and to evaluate the association between CSF 14-3-3 protein and the clinical features, auxiliary examination and prognosis in patients with RPD.
Methods
A total of 317 patients with RPD were enrolled in this study and followed-up for at least 2 years. The clinical, auxiliary examination and prognostic data were collected. The CSF 14-3-3 test was performed for all patients, and the distribution of various diseases with a positive 14-3-3 result was analyzed. The patients were divided into the CJD and non-prion RPD groups, and the association of CSF 14-3-3 with clinical features, auxiliary examination and prognosis were tested in both groups.
Results
The 14-3-3 protein test was positive in a broad spectrum of diseases with RPD, and the most frequent diagnosis was CJD, followed by non-prion disorders like autoimmune encephalitis and neurodegenerative disease. In the CJD group, the positive rate was 50.3%, and CSF 14-3-3 protein was associated with shorter survival (p = 0.031), advanced stage (p = 0.018), and visual (p = 0.045) and cerebellar dysfunction (p = 0.025). In the non-prion RPD group, the positive rate was 23.3%, and 14-3-3 protein was more common in the older patients (p = 0.028) and those presenting myoclonus (p = 0.008).
Conclusions
The clinical characteristics of patients with positive 14-3-3 test differed significantly from those with the negative result in both the CJD and non-prion RPD groups. In the non-prion RPD group, CSF 14-3-3 protein was more common in patients with myoclonus.
Twelve Tips on Pursuing a Master of Science Degree for Malaysian Medical Graduates and Their Supervisors
Authors:   Department of Medicine, Faculty of Medicine, Universiti Sultan Zainal Abidin, Terengganu, Malaysia, Yeoh Boon Seng
Published: April 2022

In Malaysia, prolonged unemployment following graduation has resulted in a growing interest among medical graduates in pursuing postgraduate research. This article offers educational resources in the form of 12 tips for medical graduates who plan to pursue a postgraduate science degree and their supervisors. It emphasises the reciprocal mentor–mentee relationship in the academic pursuit of a research project. This article is based on the author's personal experience of enrolment in a Master of Science (MSc) degree immediately upon completing the Doctor of Medicine programme combined with relevant educational theories. The 12 tips are arranged according to study progression from enrolment decision to the implementation of the research project. The author addresses the frequently asked questions of medical graduates. A learner-centred approach to research supervision is advocated. The educational challenges faced by research supervisors are discussed and approaches presented that may inform teaching efficacy to promote the agency of research supervisors. Pursuing a postgraduate research degree is a growing trend among new medical graduates in Malaysia. This article collates available literature and the author’s critical reflection to provide a practical framework that caters to the lack of formal educational resources specific to medical graduates in the MSc programme.
Evaluating Online Learning Strategy and Assessment Methods in the Course of Human Biology for the Preparatory Year Medical Students During COVID-19 Pandemic Lockdown
Authors:   Medical Education Department, Faculty of Medicine, Suez Canal University, Ismailia, Egypt, Elaraby Shimaa E. , Ghoneim Fatma M. ,   Faculty Development Unit, Medical Education Department, Fakeeh College for Medical Sciences, Jeddah, Saudi Arabia, Elsamanoudy Ayman Z. ,   Department of Clinical Biochemistry, Faculty of Medicine, King Abdul-Aziz University, Jeddah, Saudi Arabia,   Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
Published: April 2022

Since the lockdown caused by the COVID-19 crisis, there has been insufficient reporting regarding the evaluation of students’ performance in biology courses in medical schools. This study is designed to evaluate the online learning strategy by examining its effects on preparatory medical students’ performance. The target population included preparatory year medical students (n = 115) at Fakeeh College for Medical Sciences in Saudi Arabia. The human biology course (15 weeks) was taught using two different teaching strategies due to the lockdown and home-schooling decision. The first eight weeks were conducted on campus and the remaining seven weeks were conducted using online interactive lectures and virtual classrooms via Blackboard platform. The latter is the formal platform used by the college for online teaching. Continuous and final assessment results were used to assess student performance and to evaluate the effects of online learning on students’ knowledge and skills. The results of the final examinations demonstrated a significant increase (p < 0.05) in student performance. The mean of the students’ scores increased by 1.28 in the final examinations compared to the midterm examinations for female students (n = 73). Similarly, there was a significant increase in the male students’ scores in the final examinations. The mean increased by 1.24 in the final compared to the midterm examination for male students (n = 42). Online assessment tools are proved to be successful assessment methods and could provide additional non-traditional methods for students’ performance evaluation. Furthermore, with online learning and assessment, students’ performance is enhanced.
Comparative Study of Malaysian Medical Students’ Empathy Scores Between Preclinical and Clinical Training
Authors:   Department of Paediatrics, Quest International University, Perak, Malaysia, Aye Swe Zin , Sein Htwe Htwe ,   Department of Paediatrics, Quest International University, Perak, Malaysia, Nyunt Myat Kalayar ,   Department of Public Health, Newcastle University Medicine Malaysia, Johor, Malaysia, Min Yupa ,   Department of Pathology, Quest International University, Perak, Malaysia
Published: April 2022

This study aims to compare the empathy scores of Malaysian medical students between preclinical and clinical training, and to identify the predictive factors for empathic behaviour. In this cross-sectional study, the medical student version of the Jefferson Scale of Empathy (JSE-S) was distributed to medical students at Quest International University (QIU), Malaysia. The JSE-S scores are analysed using independent t-tests to determine any significant difference between the preclinical and clinical training. We use a one-way ANOVA test to identify the factors influencing medical students’ empathy levels. A total of 85% of the students responded to the questionnaires. The mean JSE-S scores for QIU medical students is 106.2 (M = 106.2, SD = 13.5). Female students have significantly higher empathy scores than males (F(1,240) = 8.32, p = 0.004). The compassionate domain of empathy scores increased significantly with an increase in the year of medical school (F(4,237) = 3.135, p = 0.015). Compared to medical students in preclinical training, clinical students had statistically significant higher empathy scores in compassionate care (t(240) = –2.08, p = 0.039). In general, medical students in QIU exhibited an increasing trend of empathy scores across their training. Interestingly, compared to preclinical students, clinical students had higher affective empathy scores (compassionate care) whereas their cognitive empathy scores remained unchanged. We suggest including courses on cognitive empathy training in the QIU curriculum.
A Novel Blended Learning Module in Family Medicine: An Interventional Study at the Faculty of Medicine, Suez Canal University, Ismailia, Egypt
Authors:   Department of Family Medicine, Faculty of Medicine, Suez Canal University, Ismailia, Egypt, Aboelfotoh Tamis Mohamed , Sayed Ahmed Hazem A. ,   Department of Family Medicine, Faculty of Medicine, Suez Canal University, Ismailia, Egypt, El Dahshan Nahed Amin ,   Department of Family Medicine, Faculty of Medicine, Suez Canal University, Ismailia, Egypt, Diab Mohamed Mohammedy ,   Department of Family Medicine, Faculty of Medicine, Suez Canal University, Ismailia, Egypt, Hosny Somaya ,   Department of Histology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
Published: April 2022

Blended learning (BL) has been reported as an effective method for teaching family medicine to undergraduates in high-income countries; however, studies of its effectiveness are limited in low- and middle-income countries. This study aimed to assess the effectiveness of an innovative BL module in family medicine including knowledge, skills and attitudes (KSA), and e-learning experiences. The grades of the fourth-year medical students at the Faculty of Medicine, Suez Canal University were correlated with the above items. A pre–post interventional study was conducted on a convenience sample of 117 fourth-year students in the educational year 2017–2018. Their KSA were assessed using valid and reliable questionnaires before and after the intervention was implemented. The intervention combined the traditional training in primary healthcare settings with the newly designed asynchronous e-learning module on the Moodle platform. The prepared website consisted of e-sections and an e-forum which was validated by expert staff. A questionnaire about students’ e-learning experiences was used to assess students’ satisfaction. The students’ final fourth-year marks for the family medicine module were correlated with their KSA and e-learning satisfaction. The overall means of students’ KSA were statistically significantly improved post-implementation. The posttest students’ skills were positively correlated with their marks in family medicine (rs = 0.308, p = 0.001). Students valued the e-resources and their relevance to the face-to-face activities. They were satisfied with their e-learning experiences (54.7%). Their e-learning satisfaction was positively correlated with the improvement in their knowledge (rs = 0.20, p = 0.031). BL had positive effects on students’ KSA and their satisfaction with the family medicine module. Combined asynchronous and synchronous e-learning in the COVID-19 era was applied in this study.
Design and validation of the Brand Personality Scale in Tourist Destinations
Authors: Joel Cruz-Tarrillo Jose , Liliana Haro-Zea Karla , Effer Apaza Tarqui Edison , Turpo-Chaparro Josue
Published: April 2022

The new modality caused by COVID-19 has significantly affected tourism, from the decrease in demand and the deterioration of facilities due to lack of budget to the point of becoming unattractive. In response to this, the objective of this research work is to design and validate a scale to measure Brand Personality in Tourist Destinations (BPTD). The results were structured in three phases. In the first phase, an exhaustive search of the bibliography and first version of the instrument were generated. Moreover, a panel of 12 professionals between academics and managers was held, who evaluated the features and content validation by a panel of 7 experts. In the second phase, data collection was carried out with the participation of 998 tourists. In the third phase, exploratory and confirmatory factor analysis was carried out, obtaining a KMO of 0.979 and a p-value of 0.000. The total explained variance of the 21 items grouped in three dimensions represents 87.27%. In the confirmatory analysis, χ2 = 921.57, p = 0.000, RMR = 0.069, GFI = 0.917, AGFI = 0.829, CFI = 0.980, TLI = 0.976, NFI = 0.975, IFI = 0.980 and RMSA = 0.065, with an appropriate internal consistency (performance: α = 0.984; social innovation α = 0.982; honesty α = 0.964). Composite reliability was CR > 0.70 and convergent validity was AVE > 0.5. In conclusion, the values imply an acceptable adjustment, for which the model is adequate, and the scale is valid to be applied in tourism.
A case of mastitis in an allomother mongrel bitch nursing a jaguar cub
Authors: VASIU IOSIF , DĄBROWSKI ROMAN , TODESCU LIVIU , MOCANU EMANUEL MIHAI , BOCHNIARZ MARIOLA , SZCZUBIAŁ MAREK , SAMARDZIJA MARKO , FIŢ NICODIM IOSIF , BRUDAŞCĂ FLORINEL GHEORGHE , TVARIJONAVICIUTE ASTA
Published: April 2022

Allonursing is typical in mammals, especially in the polytocous taxa with large litters. One of the immediate benefits of allonursing is milk evacuation of distended mammary glands, especially in females who lost their offspring, predisposing them to mastitis. Mastitis represents the inflammation of the mammary gland and in carnivores it can affect a section of the gland or the entire mammary tissue (13). Therefore, it is considered an emergency (2, 15) since if left untreated mastitis can suffer local and systemic complications like mammary gangrene, septicemia, or neonatal mortality. This case report presents a mastitis episode in an allomothering mongrel bitch after starting to allonurse a one-day-old jaguar cub and her single puppy. Laboratory assays showed the presence of mild leukocytosis, folded milk C-reactive protein (CRP; 5.1 μg/mL) levels, an alkaline milk pH reaction (pH > 7), increased cell counts, phagocytosis, and presence of Staphylococcus aureus and Enterococcus faecalis in the cultured milk samples.
Drug Utilization Pattern of Antihypertensives in a Private Healthcare Setting in Enugu, Nigeria
Authors: Udem Ngozi Dorathy
Published: April 2022

Hypertension is a public health challenge worldwide. Drug utilization study is a component of medical audit that monitors and evaluates prescribing practices and recommends necessary modifications. This study focused on the drug utilization pattern of antihypertensive drugs. The study was a retrospective study of facility records on drug use among hypertensive patients. It was conducted in a private health care setting facility in Enugu. A total of 1,005 prescriptions were evaluated for drug prescribing patterns. The blood pressure control was evaluated. A combination of two drugs was frequently prescribed (42.3%). Drug prescribing pattern showed that Angiotensin receptor blocker (Losartan) was mostly frequently prescribed (38.94%). Drug utilization of antihypertensive drugs was in agreement with JNC 7&8 recommendations. In the study combination of two or more anti-hypertensive drugs was frequently prescribed. The blood pressure control among the population was greater than 90%.
Determinants of Quality of Tuberculosis Services in Lusaka, Zambia
Authors: Sikateyo Theresa Chansa Chilufya
Published: April 2022

The Zambian government, through the Vision 2030 policy, has prioritized health and is committed to the attainment of ‘equity of access to cost-effective quality health services, as close to the family as possible by providing a continuum of care with particular emphasis on promotional, preventive, curative, and rehabilitation services. This, however, is challenged by the high disease burden of communicable and Non-Communicable Diseases (NCDs) tuberculosis inclusive. This study was conducted to identify and assess determinants of the quality of TB services. The study utilized a cross-sectional design involving a mixed-methods approach consisting of a desk review facility-based survey of patients on TB treatment using quantitative and qualitative data collection techniques. The study covered 352 randomly selected TB patients, 58 conveniently selected TB treatment support persons, 9 purposively selected TB community volunteers, and 6 purposively selected facility-based service providers. The determinants of good quality of TB care include technical performance, access to services, the effectiveness of care, interpersonal relations, the efficiency of service delivery, continuity of service, safety, physical infrastructure, comforts, and choice of service. Results confirm that good health is a function of the quality of healthcare and utilization of healthcare services and service utilization is affected by social demographics of patients such as age, sex, marital status, type of TB treatment support person, inter alia. Patient’s demographic factors determined how the patient view the quality of TB serviced they received.
Adalékok az iskolai testi fenyítéssel kapcsolatos vélekedések előzményeinek 19. századi történetéhez
Authors: Baska Gabriella
Published: April 2022

Kutatásomban egy a „botbüntetésről” szóló 1887-es magyarországi szakmai vita érveit próbálom meg értelmezni a diskurzuselemzés módszerével minél szélesebb jogtörténeti és művelődéstörténeti összefüggésrendszerbe ágyazva. A vita alapján feltételezem, hogy a korszakban lezajló szellemi erjedés az iskolai gyakorlat és a tanítói szerep átalakulásának is alapjául szolgált, azaz a mentalitásváltásnak valamiféle határmezsgyéjén vagyunk, legalábbis egy olyan mezsgyén, ami a társadalom egy részének gondolkodásmódját döntően befolyásolhatta. Ez idő tájt már a laikus közvélemény egy részét is foglalkoztatta az iskolai testi fenyítés kérdése, és kritikusai leginkább a magyar társadalmi élet „elmaradottságával” hozták azt összefüggésbe. Forrásom a Néptanoda című újság, amely a pécsi tanítóegylet kiadásában 1867-től jelent meg hetente és a környező tanítóegyesületek közlönyeként funkcionált. Bár – ahogy látni fogjuk – számszerűen alulmaradtak, mégis voltak a vizsgált vitának olyan résztvevői, akik a botütés végleges eltörlésére voksoltak már 1887-ben is. Ugyan napjaink jogszabályai a testi fenyítés tekintetében egyértelműen tiltó álláspontot képviselnek, teljes egészében sem a napi gyakorlatból, sem a nevelői mentalitásból nem tűnt még el ez a sok vitát kiváltó nevelői módszer. Tanulmányommal az ezzel kapcsolatos korábbi diskurzus érvrendszerének megismeréséhez szeretnék hozzájárulni.
Végzős szakközépiskolás tanulók továbbtanulási szándéka
Authors: Józsa Gabriella
Published: April 2022

A továbbtanulási döntéseket számos társadalmi és egyéni tényező befolyásolja, akár az általános iskola, akár a középiskola utáni továbbtanulásra gondolunk. A magyar iskolarendszerben kitüntetett elágazási pont az általános iskola utáni továbbtanulás, hiszen ez a tanulók egész iskolai pályáját és jövőjét is meghatározhatja. Az Oktatási Hivatal felvételi adatbázisai alapján lényegesen kevesebb diák jelentkezik és nyer felvételt a felsőoktatásba érettségit adó szakképzésből, mint gimnáziumból. Tanulmányunk célja, hogy feltárjuk a végzős szakközépiskolás tanulók felsőoktatási továbbtanulásának és tovább nem tanulásának motívumait. Ennek vizsgálatára saját fejlesztésű kérdőívet készítettünk, melynek segítségével a végzős szakközépiskolások továbbtanulási motivációját, önszelekcióját és családi háttértényezőit vizsgáljuk. A próbamérésben 105 fő végzős szakközépiskolás tanuló vett részt. A papíralapú kérdőívek kitöltésére 2019 őszén került sor. Elemzésünkben többváltozós statisztikai módszereket alkalmaztunk, a továbbtanulás bejóslására pedig logisztikus regressziós modellt állítottunk fel. Eredményeink rámutatnak arra, hogy az általunk vizsgált affektív tényezők szignifikánsan befolyásolják a szakközépiskolások továbbtanulási szándékait.
Tanulószervezeti jellemzők és a pedagógusok tanulása a hazai köznevelési rendszerben
Authors: Lénárd Sándor , Szivák Judit , Tóth-Pjeczka Katalin , Urbán Krisztián , Horváth László
Published: April 2022

A pedagógusok folyamatos szakmai fejlődését (FSZF) nagymértékben tudja támogatni az a szervezet, az a tanuló szakmai közösség, ahol a mindennapi munkájukat végzik. E tanulmány a Models of Teacher Learning című kutatás részeként az FSZF szervezeti szintjét, elsősorban a tanuló szervezeti dimenziók hatását vizsgálja. A pedagógusok tanulását szervezeti kontextusban vizsgáló kutatások szervezeti szerepekhez, légkörhöz, szervezeti tanulási tervek elemzéséhez kapcsolódnak. Ugyanakkor funkcionális szempontból az iskola működése kisebb egységekre tagolódik, strukturálódik, így a két fogalom, szervezet – intézmény szétválik. Kutatásunkban a tanulószervezeti dimenziók hatását vizsgáljuk, azt a célt tűztük ki, hogy megvizsgáljuk egy reprezentatív magyar pedagógusi mintán a Marsick és Watkins (2003) által fejlesztett Tanulószervezeti dimenziók kérdőív érvényességét és megbízhatóságát. Először a tanulószervezeti kérdőív érvényességi és megbízhatósági mutatóit ismertetjük, majd előbb a külső, kontingencia-tényezők mentén elvégzett összefüggésvizsgálatokat, utána pedig a tanulási tevékenységmintázatokkal kapcsolatos elemzéseket és a legfontosabb eredményeket mutatjuk be.
Tanárszakos hallgatók szakmai fejlődését és tanulását meghatározó kontextuális elemek és vizsgálati lehetőségeik
Authors: Rapos Nóra , Tókos Katalin , Eszes Fruzsina , Nagy Krisztina
Published: April 2022

A tanárok és tanárszakos hallgatók tanulásának komplex, humánökológiai szempontú értelmezése az egyén és környezetének (mezo- és makroszint egyaránt) kapcsolatát dinamikus rendszerként írja le. E dinamizmus feltárása elképzelhetetlen az egyes rendszerelemek belső struktúrájának megértése nélkül. Míg a hallgatók tanulásának személyes és makroszintű jellemzői könnyen azonosíthatók, és így jól belátható rendszert alkotnak, addig kihívást jelentő kérdés, hogy miként definiálható az a mezoszintű tanulási tér, amelyben – az egyén (hallgató) szakmai tanulását szociokonstruktivista nézőpontból vizsgálva és a képzéshez kötődő, illetve azon túli tanulásra is fókuszálva – az informális tanulási folyamatok is értelmezhetővé válnak. Tanulmányunkban a képzési programot mint tágan értelmezett adaptív rendszert azonosítottuk elemzési egységként, ami valójában megfelel egy dinamikus, folyamat alapú kurrikulum értelmezésnek, magában foglalva annak szándékolt és a hallgatók által észlelt jellegét is.
Evaluación de impacto del Programa Escuelas de Tiempo Completo en el estado de Tlaxcala
Authors: Carro Olvera Adriana , Lima Gutiérrez José Alfonso
Published: April 2022

En las dos últimas décadas, en diversos países de América Latina los sistemas educativos establecieron como estrategia de mejora la ampliación de la jornada escolar con un enfoque de inclusión y equidad educativa. En el caso de México, con ese propósito se implementó en 2007 el Programa de Escuelas de Tiempo Completo. En ese contexto, el presente artículo evalúa el impacto de este en los centros escolares de educación básica en el estado de Tlaxcala. Mediante una metodología mixta, se calculó el impacto en dos grupos de tratamiento: un grupo de intervención (escuelas del Programa con jornada ampliada) y un grupo de control (escuelas de jornada normal). La metodología cuantitativa consistió en la aplicación de cuestionarios en 110 escuelas, y la cualitativa se desarrolló a través de grupos focales con los beneficiarios. Los resultados indican una mejora en la infraestructura, la alimentación, el equipamiento, la cobertura curricular y el trabajo colaborativo de los docentes, pero, en relación con los niveles de aprendizaje obtenidos de los informes de la prueba PLANEA (Plan Nacional para la Evaluación de los Aprendizajes), los avances son poco significativos.
IMP Dehydrogenase: Structural Aspects of Inhibitor Binding
Authors: Goldstein Barry M. , Colby Thomas D.
Published: April 2022

Inosine monophosphate dehydrogenase (IMPDH, E.C.
1.1.1.205) is recognized as an important target for both antileukemic and immunosuppressive therapy. IMPDH catalyzes the NAD-dependent oxidation of inosine 5' monophosphate (IMP) to xanthosine 5' monophosphate. Several classes of IMPDH inhibitors are now in use or under development. These include agents that bind at either the substrate site (e.g. ribavirin and mizoribine) or at the NAD site. (mycophenolic acid and
thiazole-4-carboxamide adenine dinucleotide). All suffer from some degree of toxicity and/or
susceptibility to metabolic inactivation. The finding that IMPDH exists as two isoforms, one of which (type II) is induced in tumor cells, has led to the search for potentially more effective isoform-specific agents.

Recently, a number of crystal structures of IMPDH have become available. These include structures of the human type II, hamster, Tritrichomonas foetus, Streptococcus pyogenes and Borrelia burgdorferi enzymes. Each structure crystallizes as a tetramer of al P barrels, with the active site located partly at the monomer-monomer interface. The substrate and cofactor bind in a continuous cleft on the C-terminal face of each barrel. The IMP base is well positioned to stack against the NAD nicotinamide ring to facilitate hydride transfer. The active site cleft is further bounded by a highly flexible flap and loop. These structures reveal enzyme-ligand interactions which suggest strategies for the design of improved inhibitors.
Consequences of IMP Dehydrogenase Inhibition, and its Relationship to Cancer and Apoptosis
Authors: Jayaram Hiremagalur N. , Grusch Michael , Cooney David A. , Krupitza Georg
Published: April 2022

Inosine 5'-monophosphate dehydrogenase (IMPDH) is a rate-limiting enzyme for the synthesis of GTP and dGTP. Two isoforms of IMPDH have been identified. IMPDH Type I is ubiquitous and predominantly present in normal cells, whereas IMPDH Type II is predominant in malignant cells. IMPDH plays an important role in the expression of cellular genes, such as p53, c-myc and Ki-ras. IMPDH activity is transformation and progression linked in cancer cells. IMPDH inhibitors, tiazofurin, selenazofurin, and benzamide riboside share similar mechanism of action and are metabolized to their respective NAD analogues to exert antitumor activity. Tiazofurin exhibits clinical responses in patients with acute myeloid leukemia and chronic myeloid leukemia in blast crisis. These responses relate to the level of the NAD analogue formed in the leukemic cells. Resistance to tiazofurin and related IMPDH inhibitors relate mainly to a decrease in NMN adenylyltransferase activity. IMPDH inhbitors induce apoptosis. IMPDH inhitors are valuable probes for examining biochemical functions of GTP as they selectively reduce guanylate concentration. Incomplete depletion of cellular GTP level seems to down-regulate G-protein function, thereby inhibit cell growth or induce apoptosis.
Inosine 5' -monophosphate dehydrogenase (IMPDH, EC 1.1.1.205) catalyzes the dehydrogenation of IMP to XMP utilizing NAD as the proton acceptor. Studies have demonstrated that IMPDH is a rate-limiting step in the de novo synthesis of guanylates, including GTP and dGTP. The importance of IMPDH is central because dGTP is required for the DNA synthesis and GTP plays a major role not only for the cellular activity but also for cellular regulation. Two isoforms of IMPDH have been demonstrated [1]. IMPDH Type I is ubiquitous and predominately present in normal cells, whereas the IMPDH Type II enzyme is predominant in malignant cells [2]. Although guanylates could be salvaged from guanine by the enzyme hypoxanthine-guanine phosphoribosyltransferase (EC 2.4.2.8), the level of circulating guanine is low in dividing cells and this route is probably insufficient to satisfy the needs of guanylates in the cells [3].
Nucleoside and Non-nucleoside IMP Dehydrogenase- Inhibitors as Antitumor and Antiviral Agents
Authors: Franchetti Palmarisa , Grifantini Mario
Published: April 2022

IMP dehydrogenase (IMPDH) is an enzyme which catalyzes the NAD-dependent conversion of inosine 5'-monophosphate (IMP) to xanthosine 5'-monophosphate (XMP) at the metabolic branch point in the de novo purine nljcleotide synthetic pathway. IMPDH was shown to be increased significantly in cancer cells and therefore considered to be a sensitive target for cancer chemotherapy. By blocking the conversion of IMP
to XMP, IMPDH inhibitors lead to depletion of the guanylate (GMP, GDP, GTP and dGTP) pools.
Two isoforms of human IMPDH, designed type I and type II, have been identified and sequenced. Type I is constitutively expressed and is the predominant isoform in normal cells, while type II is selectively up-regulated in neoplastic and replicating cells. Two types of IMPDH inhibitors, endowed with antineoplastic, antiviral and immunosoppressive activity, have been discovered so far: nucleoside inhibitors, such as ribavirin and tiazofurin, and non-nucleoside, such as mycophenolic acid. Ribavirin produces IMPDH inhibition via its anabolite 5'­ monophosphate. Tiazofurin inhibits the enzyme after metabolic conversion into thiazole-4- carboxamide adenine dinucleotide (TAD), an analogue of the cofactor NAD. It was hypothesized that the inhibitory activity of tiazofurin is due to an attractive electrostatic interaction between the heterocyclic sulphur atom and the furanose oxygen 1' which constrain rotation about the C-glycosidic bond in tiazofurin and in its active anabolite TAD. To check this hypothesis, we studied several C-nucleosides related to tiazofurin and their NAD analogues. Non-nucleoside IMPDH inhibitors are also reviewed.
Novel Mycophenolic Adenine Bis{phosphonate)s as Potential
Immunosuppressants
Authors: Pankiewicz K. W. , Malinowski K. , Jayaram H.  N. , Lesiak­ Watanabe K. , Watanabe K. A.
Published: April 2022

Abstracts:

Mycophenolic acid (MPA) is the most potent and specific inhibitor of inosine monophosphate dehydrogenase (IMPDH). This compound was reported to bind the NAD site of IMPDH and mimic the binding of nicotinamide moiety of nicotinamide adenine dinucleotide. We linked MPA derivatives with the adenine moiety of NAD through a methylenebis(phosphonate) bridge to form novel mycophenolic adenine dinucleotides (MADs) which resemble well the intact natural cofactor. The MAD analogues differ by the length of the side chain (linker) between the aromatic ring of mycophenolic derivative and the -phosphorus atom of the adenosine bis(phosphonate) moiety. Regardless of the linker size, MADs were found to be
potent inhibitors of human IMPDH type I and type II with Ki's = 0.25-0.52 f..LM, an order of
magnitude less potent than MPA itself (Ki = 0.01-0.04 f..LM). The growth of K562 cells was inhibited by MPA (IC50 = 0.3 f..LM) and the MAD analogues (IC50 = 0.1-1.5 f..LM) with a similar
potency. Accordingly, a suppression of alloantigen-induced proliferation of human lymphocytes by the MAD analogues at concentration of 10-20 f..LM was equally effective as that observed for MPA. In contrast to MPA, MAD analogues were found to be resistant to glucuronidation in vitro. Since therapeutic potential of MPA is limited by its undesirable glucuronidation, the glucuronidation-resistant MAD analogues may be superior immunosuppressants if they are not glucuronidated in vivo.
The Structure-Based Design of ATP-Site Directed Protein Kinase
Inhibitors
Authors: Toledo, Leticia M. , Lydon Nicholas B. , Elbaum Daniel
Published: April 2022

The protein kinase family represents both a huge opportunity and a challenge for drug development. The conservation of structural features within the ATP binding cleft initially led to the belief that specificity would be difficult to achieve. This dogma has now been clearly dispelled with the discovery and clinical testing of a group of first generation compounds, which are characterized by a high degree of selectivity towards a variety of oncology targets. The structural basis for selectivity and potency has now been clarified with the crystallization of a number of such targets in complex with inhibitors. The protein kinase inhibitor field is now ripe for the structure based exploitation of additional highly validated targets from a variety of therapeutic areas.
Inhibitors	of	p38	MAP	Kinase:	Therapeutic	Intervention	in
Cytokine-Mediated Diseases
Authors: Salituro Francesco G. , Germann Ursula A. , Wilson Keith P. , Bemis Guy W. , Fox Ted , S.-S. Su Michael
Published: April 2022

p38 MAP kinase is a member of the family of kinases which mediate intracellular transduction pathways. The activation of this particular MAP kinase pathway is in response to a broad variety of extracellular stimuli.
Subsequent downstream events triggered by p38 activation result in the production of IL-1 and TNF-a, suggesting that inhibition of this enzyme may provide a useful therapeutic target for intervention in various diseases mediated by these cytokines. Understanding te ,biological consequences of p38 activation and inhibition has been the subject of intensive research over the past several years and there is now ample evidence to suggest that inhibition of this enzyme represents a valid approach for target intervention in various cytokine-mediated diseases.

Crystal structures of both apo enzyme and enzyme bound to various ligands in conjunction with site specific mutagenesis studies have provided a wealth of information regarding the interactions necessary to result in potent inhibition and selectivity from other kinases. This information has proven useful towards the analysis of previously reported compounds and will provide additional insight towards the design of new compounds and building upon existing SAR.
Peptides: Twisting and Turning
Authors: Gademann Karl , Hintermann Tobias , Schreiber Jurg V.
Published: April 2022

Oligomers of -amino acids ( -peptides), which are readily available by standard meth­ ods either in solution or on solid support, adopt a large variety of different secondary structures in solution and in the solid state. -Peptides 4, 5 and 10 fold into a helix with 3 residues per turn and 14-membered H-bonded rings (314 helix) that is left-handed for 5 and 10 and right-handed
for 2 (due to the reversal of the chirality of the building blocks), as was clearly demonstrated by
two-dimensional NMR-spectroscopy. This helix thermally is very stable in methanol solution upon heating. As shown by NMR- and CO-spectroscopy, it is partially populated even at 1oo•c
(Figure 3). Another helix was discovered for ,mixed' -peptide 8 in methanol solution: it is characterized by 12- and 10- membered turns (Figure 4, left) and its central 10-membered turn has been found in the solid state of a geminally disubtituted -peptide (Figure 4, right). This central 10-membered turn was used as a scaffold to attach -amino acid residues that prefer a linear (non-helical) conformation ( -peptide 21) : a hairpin (pleated sheet-turn-pleated sheet) structure was determined in solution by NMR-spectroscopy (Figure 5). In contrast to this antiparallel pleated-sheet, a parallel pleated sheet was found for a -tripeptide in the solid state. For the first time it was possible to observe reversible peptide folding in MD simulations by studying -peptides (Figure 6) and to determine folding pathways and intermediates.

-Peptides are a new class of promising peptidomimetics. They are resistant against the. degradation by proteolytic enzymes such as pepsin, elastase, carboxypeptidase A, pronase or proteasom 208. A variety of -amino acids (27-34) was shown to be non- mutagenic by Ames' tests and -peptides 47 and 48 reveal large elimination half-lives of 3 h (for 47) and 10 h (for 48) in the serum of rodents (Figure 7). Conjugates of a- and - peptides are efficient ligands for the HLA*B27 MHC Class I protein, a five fold increase of binding (2.0 J.!M for 55) compared to a natural peptidic ligand 51 was observed. Furthermore, -peptides are able to mimic natural a.­ peptidic hormones such as somatostatin. The cyclo- -tetrapeptide 57 binds to the five human somatostatin receptors in the micromolar range.

In addition, several other non-natural oligomers such as -peptide nucleic acids (built from 58 and 59), -peptoids (60), oligomers of anthranilic acids and -sulfonamide peptides are discussed.
Recent Advances in the Medicinal Chemistry of Taxoids with
Novel P-Amino Acid Side Chains
Authors: Ojima lwao , Lin Songnian , Wang Tao
Published: April 2022

Amino acids have been recognized as an important class of compounds in the design and synthesis of potential pharmaceutical drugs and also for the study of enzymatic reaction mechanisms. Among the -amino acid family, isoserines (a-hydroxy- -amino acids) are probably the most important members because many of them are potent enzyme inhibitors and they also serve as essential building blocks for biologically and medicinally important molecules such as Taxol®. Taxol® (paclitaxel) and Taxotere®(docetaxel) are currently considered to be the most important drugs in cancer chemotherapy. This review describes recent advances in the chemistry of isoserines and taxoid anticancer agents at the biomedical interface including (i) the development of highly efficient method for the synthesis of isoserine side chains of taxoids and (ii) the synthesis and structure-activity relationship (SAR) study of taxoids featuring discovery and development of the "second generation" taxoid anticancer agents that possess exceptional activities against drug-resistant cancer cells.
Recent Advances in the Enantioselective Synthesis of β-Amino Acids
Authors: Juaristi Eusebio , López-Ruiz Heraclio
Published: April 2022

The introductory section of this review presents some of the currently most compelling β-amino acid targets, according to their structural types: (α and β-aryl substituted, olefinic and alkynyl, α,α- and α,β-disubstituted, 'cyclic and conformationally restricted, fluorine­ containing, and phosphonic analogous β-amino acids. The main section highlights some of the very new (1996-1998), promising methodology for the enantioselective synthesis of β-amino acids, with especial emphasis on catalytic and enzymatic processes, as well as methods based on "chiral pool", "self-regeneration of stereogenic centers", diastereoselective nucleophilic additions to prochiral double bonds, and enantioselective reactions in the presence of chiral additives.
The Zinc-dependent HDACs: Non-histone Substrates and Catalytic Deacylation Beyond Deacetylation
Authors: Zheng Weiping
Published: April 2022

Protein lysine side chain N(epsilon)-acylation and -deacylation play an important regulatory role in both epigenetic and non-epigenetic processes via a structural and functional regulation of histone and non-histone proteins. The enzymes catalyzing deacylation were traditionally termed as the histone deacetylases (HDACs) since histone proteins were the first substrates identified and the deacetylation was the first type of deacylation identified. However, it has now been known that, besides the seven sirtuins (i.e. SIRT1-7, the β-nicotinamide adenine dinucleotide (β-NAD+)-dependent class III HDACs), several of the other eleven members of the mammalian HDAC family (i.e. HDAC1-11, the zinc-dependent classes I, II, and IV HDACs) have been found to also accept nonhistone proteins as native substrates and to also catalyze the removal of the acyl groups other than acetyl, such as formyl, crotonyl, and myristoyl. In this mini-review, I will first integrate the current literature coverage on the non-histone substrates and the catalytic deacylation (beyond deacetylation) of the zinc-dependent HDACs, which will be followed by an address on the functional interrogation and pharmacological exploitation (inhibitor design) of the zinc-dependent HDAC-catalyzed deacylation (beyond deacetylation).