bluuebunny/crossref_metadata_2025 huggingface dataset:
Grundsätzliches zur therapeutisch-klinischen Versuchsplanung
Authors: Martini P.
Published: March 2018

Wenn irgend möglich, sollte durch die Durchführung eines therapeutischen Versuchs der Kranke einer größeren Heilungschance teilhaftig werden, als sie ihm bisher gegeben war.

Das Grundgesetz jeder therapeutisch-klinischen Versuchsanordnung ist der therapeutische Vergleich. Bei akuten Krankheiten, wie bei akuten Inf ektionskrankheiten, Infarkten usw., wird sich der therapeutische Vergleich zwischen zwei oder mehreren Gruppen — Kollektiven — von Kranken abspielen: kollektiver therapeutischer Vergleich = the between patients, trial. Die Bildung von miteinander zu vergleichenden Kollektiven ist sinngemäß nicht mehr erlaubt, wenn keine Garantie dafür vorliegt, daß es sich überhaupt um eine pathogenetische Krankheitseinheit handelt.

Bei chronischen Krankheiten, die sich über lange Zeit einigermaßen gleichmäßig hinziehen, die aber dennoch reversibel sind, kann der therapeutische Vergleich zwischen 2 oder mehreren Perioden innerhalb des Krankheitsverlaufs des gleichen individuellen Kranken angesetzt werden. Dieser therapeutische Vergleich stützt sich primär, auf eine (veredelte!) Kasuistik und sekundär auf eine abgewandelte Statistik: individueller therapeutischer Vergleich = the within patient trial. Die Herrschaftsbereiche einerseits des kollektiven, andererseits des individuellen therapeutischen Vergleichs überschneiden sich teilweise. Der augenblickliche Effekt einer Therapie ist nicht immer identisch mit dem realen Wert, der ihr auf die Dauer zukommt. Deshalb müssen die Kurzzeitversuche des individuellen therapeutischen Vergleichs des öfteren durch Langzeitversuche ergänzt werden, und diese können nur im Vergleich zweier Kollektive durchgeführt werden. Für eine sehr große Reihe klinischer Forschungen sind Gemeinschaftsarbeiten mehrerer Krankenanstalten unentbehrlich.

Das 2. Grundgesetz der therapeutischen Forschung ist die Au s s chai tun g von Mitursachen Daß die Gefahren der Mitursachen in ambulant durchgeführten therapeutischen Prüfungen noch viel größer sind als bei stationären Beobachtungen muß stärker berücksichtigt werden, als es bisher der Fall war. Zur Ausschaltung der subjektiven Formen der Mitursachen hat Vortragender 1931 die Anwendung von Tarn- oder S c h e i η mittein (Attrappen, Placebo|, dummies), d. h. unwissentliche Versuchsanordnungen, gefordert. Der doppelte Blindversuch ist bei allen Untersuchungen, bei denen psychologische Aufgaben und Probleme im Vordergrund stehen, unentbehrlich. Es ist aber nie bewiesen worden, daß der doppelte Blindversuch ganz allgemein unentbehrlich ist. Deshalb ist es dringend notwendig, daß endlich überzeugende vergleichende Untersuchungen mit dem doppelten Blindversuch einerseits, mit dem einfachen Blindversuch andererseits angestellt werden, um die Anwendungsbereiche der beiden und ihre Grenzen gegeneinander erkennen zu können.

Die zukünftige therapeutische Forschung ist durch eine Gefahr bedroht, nämlich durch das Abgleiten in eine Selbstgenügsamkeit, die schon in der Erfüllung formaler Bedingungen und in formaler Exaktheit ihre Befriedigung findet.
The Organization of Cooperative Effort by Multiple Hospitals, Exemplified by Testing of Therapeutic Agents in Rheumatoid Arthritis
Authors: Herrera Lee
Published: March 2018

The advantage of a multi-center clinical investigation lies in the possibility of obtaining conclusive results on the basis of relatively few numbers of patients from each of the participating institutions. It has the disadvantage of a lack of uniformity of methods among centers, which must be overcome by careful advance planning, including the institution of a central coordinating unit, the biometrical unit. Its functions include (1) participation in the planning of all phases of the investigation, (2) editing and processing of the data, and (3) analysis of the data and evaluation of results.

Three devices for promoting uniformity of methods are: (1) the protocal, (2) specially designed record forms, and (3) visits to participating centers by a team of observers, including the statistician. The protocol is the document which contains all important specification for the conduct of the investigation, including statement of purpose of the study, definition of the study population, and explicit instructions on methods of patient assessment.

In a clinical trial, the biometrical unit prepares the random allocation of treatments to patients. Stratification may be used to make comparisons between strata, and/or increase the sensitivity of the experiment. Stratification by exclusion may increase sensitivity at the cost of restricting the generality of results.

A well-planned multi-center study, in which the members really cooperate, may achieve objectives exceeding the scope of single-center studies and provide a setting for the fruitful exchange of knowledge and ideas.
The Registry on Adverse Reactions of the American Medical Association
Authors: De Nosaquo Norman
Published: March 2018

The events which led to the development by the American Medical Association of an overall Registry on Adverse Reactions are described. The methods of operation involving reporting, collating, and disseminating information on adverse reactions to drugs and chemicals are outlined. A chart showing the organizational relationship of the Registry to the Council on Drugs is given. Copies of the report form, the guide for reporting, the code sheet, and the coding guide are presented. The author recommends that similar activities be undertaken in order to facilitate a free exchange of information throughout the world.
Klinische Befunddokumentation in der Medizinischen Urdversitätsklinik Freiburg
Authors: Reissnek I.
Published: March 2018

Die zunehmende Spezialisierung aller medizinischen Fächer und die immer differenzierter werdenden Aufgaben und Leistungen der Fachabteilungen zwingen zu einer Verbesserung der klinischen Befunddokumentation. Verf. schildert die Prinzipien der an der Medizinischen Universitätsklinik Freiburg geplanten »integrierten Befunddokumentation« mit Lochkarten. Das System ist für die wahlweise Verwendung von konventionellen Lochkartenmaschinen oder von elektronischen Datenverarbeitungsanlagen geeignet.
Die Planung therapeutischer Untersuchungen bei den chronisch rheumatischen Erkrankungen
Authors: Schuler B.
Published: March 2018

Bei der Planung eines therapeutischen Versuches bei den chronisch rheumatischen Erkrankungen bestimmt die voraussichtliche Wirkung des Medikamentes oder des Heilverfahrens, das geprüft werden soll, sowohl die Auswahl der Kranken als auch die für seine Prüfung geeigneten Methoden und die “Wahl der Beurteilungsmerkmale.

Zur Prüfung dürfen nur sorgfältig abgegrenzte Krankheitsbilder in geeigneten Krankheitsstadien herangezogen werden. Sie sollen nicht nur in der Ausprägung der Symptome, sondern auch in der Prognose des Krankheitsverlaufs vergleichbar sein.

Krankheitsstadien mit starkem Wechsel der Krankheitserscheinungen müssen in Kollektiven geprüft werden, deren Zusammensetzung nicht durch willkürliche Auswahl bestimmt sein darf. Auch bei chronisch sich längere Zeit hinziehenden Krankheitsbildern kann man zur Ausschaltung von Remissionen oder Spontanbesserungen auf den Gruppenvergleich nicht verzichten. Er muß aber durch eine kritische kasuistische Bearbeitung jedes Krankheitsbildes ergänzt werden.

Die Kriterien einer therapeutischen Wirkung müssen so gewählt werden, daß sie die Symptome, die durch das Heilmittel verändert werden, möglichst gut zahlenmäßig erfassen. Sie müssen so häufig notiert werden, daß der Verlauf der Prüfung in allen Phasen kontrolliert werden kann.

Nur wenn die Beurteilungsmerkmafe das rheumatische Krankheitsgeschehen und seinen Verlauf unter der Einwirkung des zu prüfenden Heilverfahrens richtig und vollständig erfassen, ist das Ergebnis der Prüfung stichhaltig.
WHO’s International Reference Centres for the Histopathological Definition and Classification of Tumours
Authors: Torloni H.
Published: March 2018

The author presents the work achieved by the World Health Organization in the field of histological .nomenclatiire and classification £f human _ turnours, through International Reference Centres and co-operating centres established in different parts of the world. Pathologists are exchanging material and diagnoses, and testing a proposed classification. A total of 36 pathologists from 21 countries are involved in this type of co-operating work. The following tumour sites are now being worked upon: lung, soft tissues, breast, leukaemias and other neoplastic conditions of the haematopoietic cells and oro-pharynx. Functions and mechanisms are given in detail. The first final classification is expected to be ready by 1964 for international adoption.
Die Eignung des ,,Allgemeinen Krankenblattkopfes” für die pathologisch-anatomische Befunddokumentation
Authors: Thierbach R.
Published: March 2018

Es wird ein Verfahren zur Dokumentation pathologisch-anatomischer Befunde geschildert, das sich an die von der Deutschen Gesellschaft für Dokumentation (Arbeitsausschuß Medizin) ausgearbeitete Empfehlung für einen sog. Allgemeinen Krankenblattkopf anlehnt. Zur Datenspeicherung dienen IBM-Maschinenlochkarten. Auf die berücksichtigten Sachverhalte und die Gestaltung der Formblätter wird näher eingegangen. Abweichungen von der genannten Empfehlung und prinzipielle Probleme werden diskutiert.
The Concepts of Prevalence and Incidence as Applied to the Study of Development and Duration of Disease
Authors: Kashgahian M.
Published: March 2018

The proper use of prevalence and incidence data can result in an effective way to study the history of the disease process. Methodology is given whereby the progression, duration and transition of diseases can be elucidated. Prevalence and incidence have been redefined and used in an unconventional way in view of new types of data which are being generated by mass screening projects for disease which are able to discover presymptomatic and preclinical disease states.
Evaluation of a metal acrylic repair product as a clamp for an external fixator
Authors: Gibson N. R. , Read R. A. , Day R. , Robertson I. D. , Staudte K. L.
Published: March 2018

Mechanical testing was performed to evaluate an acrylic steel repair paste when used in the construction of external fixators. Individual pin-bar-acrylic constructs were compared with those made from Kirschner-Ehmer (KE) clamps or polymethylmethacrylate. The constructs were subjected to cantilever bending forces, pin-pullout tests and cantilever bending after undergoing cyclical fatigue. Forty mm segments of acrylic were significantly stronger than medium ESF clamps. Twenty-five mm segments of acrylic were of equivalent strength to clamps. Ten mm segments failed under physiological loads expected from dogs greater than 20 kg and were less likely to provide adequate pin coverage to protect against pin pull-put. The placement of a wire loop to secure the pin-bar intersects made application of the acrylic easier but did not alter stiffness. There was not any significant variation between different operators in the strength of their constructs nor tolerance of their constructs to pin pullout. Cyclical loading forces were applied to acrylic-pinbar units without significant loss of strength, and acrylic and polymethylmethacrylate units did not show any difference in stiffness after being subjected to cyclical fatigue. The acrylic steel repair paste is a handkneadable, fast setting, inexpensive and readily available acrylic for use in the construction of external fixators. It allows more flexibility in frame design than a clamp and on the basis of mechanical testing offers a very stiff and secure substitute for KE clamps or polymethylmethacrylate.
The radiographic evaluation of repaired canine ilial fractures (69 cases)
Authors: Fitch R. B. , Wallace L. J. , Wells C. S. , Swiderski J. K. , Breshears L. A.
Published: March 2018

A retrospective radiographic evaluation of 69 canine ilial fractures was performed. The patient information, concurrent injuries, fracture description, implant characteristics, fixation, radiographic outcome, and complications were assessed. Ilial fracture repairs were divided into four groups: lateral plate only, lateral plate with ventral interfragmentary screws, lateral plate with ventral plate, and ventral plate only fixation. The number of screws, degree of purchase, use of oversized screws, presence of sacral penetration, alignment, apposition, and pelvic collapse were evaluated. Radiographic follow-up (> 4 weeks) was available in 42 of these cases. Radiographic complications were recognized in 24% of the cases. All implant complications were identified within the lateral component of the fixation, but not necessarily confined to the patients repaired with only a lateral plate. Repairs that utilized ventral fixation had significantly greater screw purchase while providing additional lag screw compression across the fracture site. Of the three groups utilizing ventral stabilization (25 repairs), only one case had implant loosening. Ventral screw fixation appears to provide additional rigidity to ilial fracture repair that may be beneficial in some cases. This report describes additional surgical repair options available for repair of canine ilial fractures.
LISP – ein System zur persönlichen Literaturdokumentation
Authors: Hofferberth B.
Published: March 2018

Es wird ein System zur persönlichen Literaturdokumentation mit Hilfe einer elektronischen Datenverarbeitungsanlage vorgestellt. Das Programm dient zum Speichern und Wiederflnden der vom einzelnen Wissenschaftler gelesenen und gesammelten Literatur. Das Programm beinhaltet ein eigenes alphabetisches Sortierverfahren. Die Datei der abgespeicherten Literaturstellen kann nach eingegebenen Begriffen durchsucht werden. Das Programm ist in allen Wissensgebieten universell einsetzbar und auch durch ED V-unkundige Personen benutzbar, da eine Volltextverarbeitung vorgenommen wird. In dieser Tatsache wird beim Vergleich mit ähnlichen Programm-Systemen der wesentliche Vorteil gesehen.
The Life Table according to Chiang as a Method for the Description and Assessment of the Efficacy of Oral Contraceptives
Authors: Wolfrum Christine
Published: March 2018

At the present time, the Pearl Index is usually calculated for the assessment of the efficacy of an oral contraceptive. The Pearl Index represents an index number for the entire treatment period. The model on which the calculation is based is an urn model with the treatment months of all subjects instead of the balls.

The Pearl Index cannot be interpreted as a probability, since the treatment months are the reference units. Some of these are interdependent (treatment months of one subject), while others are independent of each other (treatment months of various subjects). For an interpretation as probability, the subjects themselves must be the reference units.

In order to render the presentation of only one index number for the entire treatment period meaningful, it must be assumed that the probability of pregnancy is the same for all treatment months. In reality this is not the case.

The »number of pregnancies per treatment month< can be regarded as a non-stationary stochastic process; the assumption of an urn model is, therefore, inappropriate.

The Pearl Index is unsuitable for the description of a stochastic process; instead, a life table analysis according to Chiang is recommended. In the life table, various probabilities are estimated per treatment month. The net probabilities can be chosen as the index number per treatment month. The prerecjuisites for the derivation of those probabilities are described.
Mechanical Allodynia Predicts Better Outcome of Surgical Decompression for Painful Diabetic Peripheral Neuropathy
Authors: Liao Chenlong , Nickerson D. , Visocchi Massimiliano , Yang Min , Liu Pengfei , Zhong Wenxiang , Zhou Han , Zhang Wenchuan
Published: March 2018

Background To determine the role of mechanical allodynia (MA) in predicting good surgical outcome for painful diabetic peripheral neuropathy (DPN).

Materials and Methods Data of 192 patients with painful DPN were collected in this study, with 148 surgical patients and 44 patients in the control group. Both groups were further divided into subgroups based on the presence of MA on admission. Clinical evaluations including the visual analog scale (VAS), the Hospital Anxiety and Depression Scale (HADS), nerve conduction velocity (NCV), and high-resolution ultrasonography (cross-sectional area, CSA) were performed preoperatively and postoperatively.

Results The levels of VAS and HADS and the results of NCV and CSA were improved in the surgical group (p < 0.05). In the surgical subgroups, pain reduction, psychiatric amelioration, improvement in NCVs, and the restoration of the CSA were observed in patients with signs of MA (p < 0.05), whereas only pain reduction, psychiatric amelioration, and restoration of the CSA were noted in patients without signs of MA (p > 0.05). Furthermore, better pain reduction was achieved in patients with MA when compared with those without MA (p < 0.05).

Conclusions MA is proved to be a reliable predictor of good surgical outcome for painful DPN.
Emergency Repair of a Perforated Mycotic Aneurysm with a Self-made Pericardial Tube-graft
Authors: Diab Nawras , Pingpoh Clarence , Siepe Matthias , Beyersdorf Friedhelm , Kharabish Ahmed , Czerny Martin
Published: March 2018

A 63-year-old female with a history of kidney transplantation was admitted for emergency repair of a perforated mycotic aneurysm of the right subclavian artery (RSA) in combination with a paravertebral and posterior mediastinal abscess. After resection of the aneurysm and after radical local debridement, orthotopic repair was performed with a self-made pericardial tube graft from the brachiocephalic bifurcation to the thoracic outlet. The paravertebral and posterior mediastinal abscess was drained. The postoperative course was uneventful. Using a self-made readily available pericardial neo-tube enlarges the armamentarium of handling complex infective surgical scenarios and presents a smart alternative to alloplastic vascular reconstruction.
Transposition of Great Arteries with Left Main Coronary Artery Atresia—Case Report
Authors: Elmahrouk Ahmed , Hamouda Tamer , Ismail Mohamed , Jamjoom Ahmed
Published: March 2018

Background The coronary artery anatomy in patients with transposition of the great artery (TGA) is a contributing factor for outcome in arterial switch procedure.

Case Presentation A full-term, 7-day-old baby boy diagnosed as dextro-TGA (dTGA) with intact ventricular septum. Intraoperatively, the left coronary sinus had a blind indentation from which a firm cord-like left main coronary artery originates. Procedure completed as usual for a routine arterial switch operation.

Conclusion About 5% of patients with D-TGA have a single coronary artery. Assessment of blood flow to all branches intraoperatively is mandatory to choose between either transfer of single ostium or bypass grafting to the other coronary system.
Integrated Advanced Medical Information Systems (IAIMS): Payoffs and Problems
Authors: Clayton P. D.
Published: March 2018

IAIMS (Integrated Advanced Information Management Systems) is an initiative to improve the access to information needed to provide patient care, health-oriented education, biomedical research, and management of large medical center environments. This paper will review the goals, history, and accomplishments of the IAIMS initiative. Shortcomings and frustrations, lessons learned, and the future of such initiatives will also be discussed.
The Harvard-MIT-NEMC Research Training Program in Medical Informatics
Authors: Greenes Robert A. , Octo Barnett G. , Pauker Stephen G. , Szolovits Peter , Weinstein Milton C.
Published: March 2018

The Harvard-MIT-NEMC Research Training Program in Medical Informatics brings together five separate research groups to provide a diversified training experience in Boston with sponsorship by the National Library of Medicine. This program offers predoctoral and postdoctoral programs, supplemented by many opportunities for collegial exchange and interaction among the groups.
Graduate Programs in Medical Informatics at the Paris Universities
Authors: Venot Alain , Auvert Bertran , Grémy François , Degoulet Patrice
Published: March 2018

Most medical schools in France have chairs in Biostatistics and Medical Informatics to coordinate the teaching of these two disciplines both within the regular curriculum of the medical studies and as a specialized teaching. This paper describes the current medical informatics specialized program offered at the Paris Universities. Since 1968 the program has comprised a Master of Science and a Ph.D. degree. At the Master Level, despite several reforms and in-depth program revisions the curriculum is still organized as a set of modules of 100 hours teachins with a large freedom for the medical faculties to define the contents of the courses and for the students to organize their studies and combine medical informatics, biomathematics and biostatistics training. Since 1990, an intensive one-year full-time course is offered, called Advanced Study Diploma in Medical Informatics, which is strongly research oriented. This program seems a good strategy to form medical informatics special1 ists who have initially received a broader education in informatics and statistics.
Medical Informatics Training at Columbia University and the Columbia-Presbyterian Medical Center
Authors: Allen B. A. , Clayton P. D. , Cimino J. J.
Published: March 2018

The Department of Medical Informatics at Columbia University College of Physicians and Surgeons consists of a faculty of 17 full-and part-time faculty. The Department faculty collaborate with the Department of Computer Science and several clinical departments of the medical center. We offer courses in medical informatics, formal degrees (M.A., M.Phil. and Ph.D.) and a postdoctoral training program. In addition to academic offerings, the close affiliation with the Columbia-Presbyterian Medical Center and the primary responsibilities for clinical information systems offers trainees unique opportunities to work with and develop real-world applications. Faculty research programs include work on the Integrated Advanced Information Management System (IAIMS), Unified Medical Language System (UMLS), High-Perfor-mance Computing and Communications (HPCC), Electronic Medical Records, automated decision support and technology transfer through the Center for Advanced Technology.
Clinical workstations: An architectural perspective
Authors: Clayton P.D. , Sengupta S.
Published: March 2018

The role of a clinical workstation is examined as an integral part of a larger, clinical information delivery and acquisition system. Different care scenarios and environmental factors influence the behavior of a workstation. The common functional components of a workstation are information resources, application logic and presentation. A workstation is successful when each of its components operates within an information architecture and contributes to meet user needs. New technologies to integrate and display information are making the workstation functions independent of the actual hardware and software platform.
An Information Mediator Network for Tasks in Dynamic Environments
Authors: Zhang W. , Shen W. , Patil R.
Published: March 2018

Coordination of activities among information workers and services, tracking and managing activities, and intelligent distribution of information are essential to the efficient operation of any large enterprise. This is particularly important in the healthcare domain, where many different organizations must cooperate to provide patient care reliably in a dynamically changing environment. In this review paper we present a distributed system that supports cooperative problem solving, activity management, and intelligent delivery of information in dynamic and unreliable environments. The system consists of a network of task/context managers (TCMs). Each TCM manages a group of related agents. It maintains up-to-date information on availability, operational status, and activities of participating agents, and it acts as a mediator between service requesters and service providers. In addition, the TCM acts as a representative for its agents with other TCMs, allowing different groups of agents to collaborate with one another. This paper describes the system architecture, its implementation and capabilities including matchmaking, plan monitoring, and failure recovery. Our system has been used in prehospital emergency patient information management applications.
Integrating Informatics into the Undergraduate Curriculum: A Report on a Pilot Project
Authors: Murphy J. , Ingram D.
Published: March 2018

Previous case reports in this series on Education and Training have looked at specialist courses for postgraduate students seeking an in-depth know ledge of informatics and a career in the field. By contrast, this review describes a project designed to pilot a series of learning opportunities for undergraduate medical students. Although some UK medical colleges have opted to introduce informatics into the curriculum as a discipline in its own right, the Informatics Department at St Bartholomew’s Hospital Medical College chose a different approach. When a new curriculum was introduced at St Bartholomew’s and at The London Hospital Medical College, the Head of the Informatics Department saw this as an ideal opportunity to explore ways of integrating informatics into the curriculum. The initiatives described in this paper were made possible as a result of an award from the UK government Department of Employment. Money from an Enterprise in Higher Education grant funded a range of programmes, one of which was designed to introduce students to selected aspects of informatics and to demonstrate what is feasible in the undergraduate curriculum. The work carried out over a period of three and a half years was intended to provide the basis for the next phase of curriculum development. However, in the wake of the restructuring which has taken place in London medical colleges, the Informatics Department at what was St Bartholomew’s has relocated to University College London Medical School, and is now called The Centre for Health Informatics and Multi professional Education (CHIME). University College is designing a new medical curriculum and CHIME is drawing on the experience gained through the Enterprise Project to find the best way to integrate informatics into this curriculum.
Robotische Chirurgie – operiert der Roboter?
Authors: Schuler Patrick
Published: March 2018

Der Roboter-assistierten Chirurgie (RAC) im Kopf-Hals-Bereich wird ein großes Potenzial zugeschrieben. Vor allem in der operativen Onkologie wird der Einsatz von Roboter-Systemen als besonders interessant erachtet. Bislang sind 2 Gerätetypen (DaVinci® und FLEX®) für die klinische Anwendung im Kopf-Hals-Bereich zugelassen, und multiple weitere Systeme befinden sich in der präklinischen Erprobungsphase. Auch wenn prinzipiell bestimmte Patientengruppen von der RAC profitieren könnten, finden sich keine systematischen randomisierten Studien. Ein möglicher Vorteil der RAC gegenüber den bisherigen Standardverfahren kann daher bisher nicht nachgewiesen werden. Der begrenzte klinische Nutzen und die finanzielle Zusatzbelastung scheinen aktuell der Hauptgrund zu sein, warum der flächendeckende Einsatz der RAC bislang ausgeblieben ist. Diese Übersichtsarbeit beschreibt die verschiedenen Anwendungsmöglichkeiten der RAC im Kopf-Hals-Bereich. Außerdem werden die finanziellen und technischen Herausforderungen, sowie anstehende Weiterentwicklungen der RAC beleuchtet. Besonderes Augenmerk wird auf spezielle Risiken der Roboter-Chirurgie und aktuell laufende klinische Studien gelegt. Mittelfristig wird davon ausgegangen, dass die RAC Einzug in die klinische Routine erhalten wird und sich das medizinische Personal zunehmend mit den technischen, wissenschaftlichen und auch ethischen Besonderheiten auseinandersetzen muss.
Regeneration – eine neue therapeutische Dimension in der Hals-Nasen-Ohrenheilkunde
Authors: Rotter Nicole , Zenobi-Wong Marcy
Published: March 2018

Die Regeneration als therapeutisches Prinzip und damit die Regenerative Medizin ist ein vielversprechender Ansatz künftig die therapeutischen Optionen der Hals-Nasen-Ohrenheilkunde um eine weitere Dimension zu erweitern. Während heute rekonstruktive chirurgische Verfahren, Medikamente und Prothesen wie bspw. das Cochlea Implantat die Funktionen defekter Gewebe im Kopf-Hals-Bereich ersetzen, sollen durch die Regenerative Medizin die defekten Gewebe und deren Funktion selbst wiederhergestellt werden. In dieser Übersichtsarbeit werden neue Entwicklungen wie das 3D-Bioprinting und dezellularisierte, natürliche Biomaterialien für regenerative Ansätze vorgestellt und durch eine Zusammenstellung aktueller präklinischer und klinischer Studien im Bereich der Regenerativen Medizin in der Hals-Nasen-Ohrenheilkunde ergänzt.
Estradiol: A Steroid with Multiple Facets
Authors: Kumar Anita , Banerjee Antara , Singh Dipty , Thakur Gargi , Kasarpalkar Nandini , Gavali Shubhangi , Gadkar Sushama , Madan Taruna , Mahale Smita , Balasinor N. , Sachdeva Geetanjali
Published: March 2018

Seventy-five glorious years have passed since estradiol was discovered by Edward Doisy. From discovery in the ovaries to delineation of diverse physiological effects, research on estrogens has covered a lot of ground. Estrogen receptors that mediate estrogenic effects, have been detected not only in reproductive organs, but also in other body organs. Estrogen receptors function either as conventional transcription factors or as rapid signal transducers. These different modes of action are opted by estrogens to elicit an array of reproductive and non-reproductive functions. It is well established that estrogens promote cell proliferation in various tissues and hence are also linked to carcinogenesis. Anti-estrogens are being used as adjunct therapies for cancers since several years. On the other hand, estrogen-based strategies are used to alleviate adverse effects of menopause. Apart from estrogens synthesized in various organs, exposure to environmental estrogens can also impact physiology. Thus, too much or too less of estrogens can tip the balance and lead to unfavorable consequences. Multiple estrogen receptors with their tissue- or cell type-specific expression eliciting dose-dependent effects make it perplexing to ‘unify’ estrogenic actions in diverse tissues/organs. This warrants more research on estrogen-mediated effects and their regulation in somatic and reproductive tissues. This review presents physiological and pathological aspects of estrogens thus highlighting the good, bad, and ugly facets of estrogens.
Validation of Anthropometric Muscle Cross-Sectional Area Equation after Spinal Cord Injury
Authors: Wade Rodney , Lester Robert , Gorgey Ashraf
Published: March 2018

The purposes of this study were to cross-validate a previously derived anthropometric estimation equation specific to the spinal cord injury population and determine the ratios of absolute skeletal muscle cross-sectional area (CSA) for the quadriceps, hamstrings, and adductor muscle groups based on magnetic resonance imaging. The validation cohort consisted of eleven men with chronic (>1 yr. post injury) spinal cord injury (SCI). Ten individuals were classified as AIS A or B and one participant was classified as an AIS C. Significant correlations were found between the anthropometrically predicted CSAs and MRI-derived CSAs for the whole muscle including bone and intramuscular fat (r2=0.72, SEE=10.6 cm2, P<0.001), absolute muscle excluding bone and intramuscular fat (r2=0.60, SEE=10.1 cm2, P=0.005), and absolute quadriceps muscle (r2=0.67, SEE=5.5 cm2, P=0.002). The quadriceps, hamstrings and the adductor muscle groups represented 52±5%, 23±6%, and 20±4%, respectively, of the absolute muscle CSA. Our results suggest that the utilization of a previously developed anthropometric equation is applicable to a different validation cohort with SCI. The equation has the ability to predict whole muscle CSA, absolute muscle CSA excluding bone and intramuscular fat, and absolute muscle CSA of the quadriceps in individuals with chronic SCI.
A new high temperature reactor for operando XAS: Application for the dry reforming of methane over Ni/ZrO2 catalyst
Authors: Aguilar-Tapia Antonio , Ould-Chikh Samy , Lahera Eric , Prat Alain , Delnet William , Proux Olivier , Kieffer Isabelle , Basset Jean-Marie , Takanabe Kazuhiro , Hazemann Jean-Louis
Published: March 2018

The construction of a high-temperature reaction cell for operando X-ray absorption spectroscopy characterization is reported. A dedicated cell was designed to operate as a plug-flow reactor using powder samples requiring gas flow and thermal treatment at high temperatures. The cell was successfully used in the reaction of dry reforming of methane (DRM). We present X-ray absorption results in the fluorescence detection mode on a 0.4 wt. % Ni/ZrO2 catalyst under realistic conditions at 750 °C, reproducing the conditions used for a conventional dynamic microreactor for the DRM reaction. The setup includes a gas distribution system that can be fully remotely operated. The reaction cell offers the possibility of transmission and fluorescence detection modes. The complete setup dedicated to the study of catalysts is permanently installed on the Collaborating Research Groups French Absorption spectroscopy beamline in Material and Environmental sciences (CRG-FAME) and French Absorption spectroscopy beamline in Material and Environmental sciences at Ultra-High Dilution (FAME-UHD) beamlines (BM30B and BM16) at the European Synchrotron Radiation Facility in Grenoble, France.
Exploring ferroelectric and magnetic properties of Tb-substituted m = 5 layered Aurivillius phase thin films
Authors: Faraz Ahmad , Ricote Jesus , Jimenez Ricardo , Maity Tuhin , Schmidt Michael , Deepak Nitin , Roy Saibal , Pemble Martyn E. , Keeney Lynette
Published: March 2018

Here, we report the effect of A-site substitution of Tb at the expense of Bi on the ferroelectric and magnetic properties in m = 5 layered 2-D Aurivillius Bi6Ti3Fe2O18 thin films. The nominal stoichiometry of the prepared compound is Tb0.40Bi5.6Fe2Ti3O18, Tb0.90Bi5.1Fe2Ti3O18, and Bi6Ti3Fe2O18. Phase examination reveals that only 0.40 mol. % is successfully substituted forming Tb0.40Bi5.6Fe2Ti3O18 thin films. Lateral and vertical piezoresponse switching loops up to 200 °C reveal responses for Bi6Ti3Fe2O18, Tb substituted Tb0.40Bi5.6Fe2Ti3O18, and Tb0.90Bi5.1Fe2Ti3O18 thin films along the in-plane (±42.31 pm/V, 88 pm/V and ±134 pm/V, respectively) compared with the out-of-plane (±6.15 pm/V, 19.83 pm/V and ±37.52 pm/V, respectively). The macroscopic in-plane polarization loops reveal in-plane saturation (Ps) and remanence polarization (Pr) for Bi6Ti3Fe2O18 of ±26.16 μC/cm2 and ±22 μC/cm2, whereas, ±32.75 μC/cm2 and ±22.11 μC/cm2, ±40.30 μC/cm2 and ±28.5 μC/cm2 for Tb0.40Bi5.6Fe2Ti3O18 and Tb0.90Bi5.1Fe2Ti3O18 thin films, respectively. No ferromagnetic signatures were observed for Bi6Ti3Fe2O18 and Tb0.40Bi5.6Fe2Ti3O18. However, a weak response was observed for the Tb0.90Bi5.1Fe2Ti3O18 at 2 K. Microstructural analysis of Tb0.90Bi5.1Fe2Ti3O18 revealed that it contains 4 vol. % Fe:Tb rich areas forming FexTbyOz, which accounts for the observed magnetic moment. This study demonstrates the importance of thorough microstructural analysis when determining whether magnetic signatures can be reliably assigned to the single-phase system. We conclude that Tb0.40Bi5.6Fe2Ti3O18 and Tb0.90Bi5.1Fe2Ti3O18 samples are not multiferroic but demonstrate the potential for Fe-RAM applications.
Geometric k-nearest neighbor estimation of entropy and mutual information
Authors: Lord Warren M. , Sun Jie , Bollt Erik M.
Published: March 2018

Nonparametric estimation of mutual information is used in a wide range of scientific problems to quantify dependence between variables. The k-nearest neighbor (knn) methods are consistent, and therefore expected to work well for a large sample size. These methods use geometrically regular local volume elements. This practice allows maximum localization of the volume elements, but can also induce a bias due to a poor description of the local geometry of the underlying probability measure. We introduce a new class of knn estimators that we call geometric knn estimators (g-knn), which use more complex local volume elements to better model the local geometry of the probability measures. As an example of this class of estimators, we develop a g-knn estimator of entropy and mutual information based on elliptical volume elements, capturing the local stretching and compression common to a wide range of dynamical system attractors. A series of numerical examples in which the thickness of the underlying distribution and the sample sizes are varied suggest that local geometry is a source of problems for knn methods such as the Kraskov-Stögbauer-Grassberger estimator when local geometric effects cannot be removed by global preprocessing of the data. The g-knn method performs well despite the manipulation of the local geometry. In addition, the examples suggest that the g-knn estimators can be of particular relevance to applications in which the system is large, but the data size is limited.
An investigation on the effects of air on electron energy in atmospheric pressure helium plasma jets
Authors: Liu Yadi , Tan Zhenyu , Chen Xinxian , Li Xiaotong , Zhang Huimin , Pan Jie , Wang Xiaolong
Published: March 2018

In this work, the effects of air on electron energy in the atmospheric pressure helium plasma jet produced by a needle-plane discharge system have been investigated by means of the numerical simulation based on a two-dimensional fluid model, and the air concentration dependences of the reactive species densities have also been calculated. In addition, the synergistic effects of the applied voltage and air concentration on electron energy have been explored. The present work gives the following significant results. For a fixed applied voltage, the averaged electron energy is basically a constant at air concentrations below about 0.5%, but it evidently decreases above the concentration of 0.5%. Furthermore, the averaged densities of four main reactive species O, O(1D), O2(1Δg), and N2(A3Σu+) increase with the increasing air concentration, but the increase becomes slow at air concentrations above 0.5%. The air concentration dependences of the averaged electron energy under different voltage amplitudes are similar, and for a given air concentration, the averaged electron energy increases with the increase in the voltage amplitude. For the four reactive species, the effects of the air concentration on their averaged densities are similar for a given voltage amplitude. In addition, the averaged densities of the four reactive species increase with increasing voltage amplitude for a fixed air concentration. The present work suggests that a combination of high voltage amplitude and the characteristic air concentration, 0.5% in the present discharge system, allows an expected electron energy and also generates abundant reactive species.
Study on data acquisition system based on reconfigurable cache technology
Authors: Zhang Qinchuan , Li Min , Jiang Jun
Published: March 2018

Waveform capture rate is one of the key features of digital acquisition systems, which represents the waveform processing capability of the system in a unit time. The higher the waveform capture rate is, the larger the chance to capture elusive events is and the more reliable the test result is. First, this paper analyzes the impact of several factors on the waveform capture rate of the system, then the novel technology based on reconfigurable cache is further proposed to optimize system architecture, and the simulation results show that the signal-to-noise ratio of signal, capacity, and structure of cache have significant effects on the waveform capture rate. Finally, the technology is demonstrated by the engineering practice, and the results show that the waveform capture rate of the system is improved substantially without significant increase of system’s cost, and the technology proposed has a broad application prospect.
Exploiting elastic anharmonicity in aluminum nitride matrix for phase-synchronous frequency reference generation
Authors: Ghatge Mayur , Tabrizian Roozbeh
Published: March 2018

A matrix of aluminum-nitride (AlN) waveguides is acoustically engineered to realize electrically isolated phase-synchronous frequency references through nonlinear wave-mixing. AlN rectangular waveguides are cross-coupled through a periodically perforated plate that is engineered to have a wide acoustic bandgap around a desirable frequency (f1≈509 MHz). While the coupling plate isolates the matrix from resonant vibrations of individual waveguide constituents at f1, it is transparent to the third-order harmonic waves (3f1) that are generated through nonlinear wave-mixing. Therefore, large-signal excitation of the f1 mode in a constituent waveguide generates acoustic waves at 3f1 with an efficiency defined by elastic anharmonicity of the AlN film. The phase-synchronous propagation of the third harmonic through the matrix is amplified by a high quality-factor resonance mode at f2≈1529 MHz, which is sufficiently close to 3f1 (f2 ≅ 3f1). Such an architecture enables realization of frequency-multiplied and phase-synchronous, yet electrically and spectrally isolated, references for multi-band/carrier and spread-spectrum wireless communication systems.
USAXS analysis of concentration-dependent self-assembling of polymer-brush-modified nanoparticles in ionic liquid: [I] concentrated-brush regime
Authors: Nakanishi Yohei , Ishige Ryohei , Ogawa Hiroki , Sakakibara Keita , Ohno Kohji , Morinaga Takashi , Sato Takaya , Kanaya Toshiji , Tsujii Yoshinobu
Published: March 2018

Using ultra-small angle X-ray scattering (USAXS), we analyzed the higher-order structures of nanoparticles with a concentrated brush of an ionic liquid (IL)-type polymer (concentrated-polymer-brush-modified silica particle; PSiP) in an IL and the structure of the swollen shell layer of PSiP. Homogeneous mixtures of PSiP and IL were successfully prepared by the solvent-casting method involving the slow evaporation of a volatile solvent, which enabled a systematic study over an exceptionally wide range of compositions. Different diffraction patterns as a function of PSiP concentration were observed in the USAXS images of the mixtures. At suitably low PSiP concentrations, the USAXS intensity profile was analyzed using the Percus–Yevick model by matching the contrast between the shell layer and IL, and the swollen structure of the shell and “effective diameter” of the PSiP were evaluated. This result confirms that under sufficiently low pressures below and near the liquid/crystal-threshold concentration, the studied PSiP can be well described using the “hard sphere” model in colloidal science. Above the threshold concentration, the PSiP forms higher-order structures. The analysis of diffraction patterns revealed structural changes from disorder to random hexagonal-closed-packing and then face-centered-cubic as the PSiP concentration increased. These results are discussed in terms of thermodynamically stable “hard” and/or “semi-soft” colloidal crystals, wherein the swollen layer of the concentrated polymer brush and its structure play an important role.
Numerical simulation of the geometrical-optics reduction of CE2 and comparisons to quasilinear dynamics
Authors: Parker Jeffrey B.
Published: March 2018

Zonal flows have been observed to appear spontaneously from turbulence in a number of physical settings. A complete theory for their behavior is still lacking. Recently, a number of studies have investigated the dynamics of zonal flows using quasilinear (QL) theories and the statistical framework of a second-order cumulant expansion (CE2). A geometrical-optics (GO) reduction of CE2, derived under an assumption of separation of scales between the fluctuations and the zonal flow, is studied here numerically. The reduced model, CE2-GO, has a similar phase-space mathematical structure to the traditional wave-kinetic equation, but that wave-kinetic equation has been shown to fail to preserve enstrophy conservation and to exhibit an ultraviolet catastrophe. CE2-GO, in contrast, preserves nonlinear conservation of both energy and enstrophy. We show here how to retain these conservation properties in a pseudospectral simulation of CE2-GO. We then present nonlinear simulations of CE2-GO and compare with direct simulations of quasilinear (QL) dynamics. We find that CE2-GO retains some similarities to QL. The partitioning of energy that resides in the zonal flow is in good quantitative agreement between CE2-GO and QL. On the other hand, the length scale of the zonal flow does not follow the same qualitative trend in the two models. Overall, these simulations indicate that CE2-GO provides a simpler and more tractable statistical paradigm than CE2, but CE2-GO is missing important physics.
Combined action of corrugation and Weibel instabilities from electron-beam interaction with laser-irradiated plasma
Authors: Bai Yafeng , Tian Ye , Zhang Zhijun , Cao Lihua , Liu Jiansheng
Published: March 2018

The combined action of corrugation and Weibel instabilities was experimentally observed in the interaction between energetic electrons and a laser-irradiated insulated target. The energetic electron beam, driven by an ultrashort laser pulse, splits into filaments with a diameter of ∼10 μm while traversing an insulated target, owing to the corrugation instability. The filaments continued to split into thinner filaments owing to the Weibel instability if a preplasma was induced by a heating beam on the rear side of the target. When the time delay between the heating beam and electron beam was larger than 1 ps, a merging of the current filaments was observed. The characteristic filamentary structures disappeared when the time delay between the two beams was larger than 3 ps. A simplified model was developed to analyze this process; the obtained results were in good agreement with the experiment. Two-dimensional particle-in-cell simulations supported our analysis and reproduced the filamentation of the electron beam inside the plasma.
Detecting, anticipating, and predicting critical transitions in spatially extended systems
Authors: Kwasniok Frank
Published: March 2018

A data-driven linear framework for detecting, anticipating, and predicting incipient bifurcations in spatially extended systems based on principal oscillation pattern (POP) analysis is discussed. The dynamics are assumed to be governed by a system of linear stochastic differential equations which is estimated from the data. The principal modes of the system together with corresponding decay or growth rates and oscillation frequencies are extracted as the eigenvectors and eigenvalues of the system matrix. The method can be applied to stationary datasets to identify the least stable modes and assess the proximity to instability; it can also be applied to nonstationary datasets using a sliding window approach to track the changing eigenvalues and eigenvectors of the system. As a further step, a genuinely nonstationary POP analysis is introduced. Here, the system matrix of the linear stochastic model is time-dependent, allowing for extrapolation and prediction of instabilities beyond the learning data window. The methods are demonstrated and explored using the one-dimensional Swift-Hohenberg equation as an example, focusing on the dynamics of stochastic fluctuations around the homogeneous stable state prior to the first bifurcation. The POP-based techniques are able to extract and track the least stable eigenvalues and eigenvectors of the system; the nonstationary POP analysis successfully predicts the timing of the first instability and the unstable mode well beyond the learning data window.