bluuebunny/crossref_metadata_2025 huggingface dataset:
Operating limits for beam melting of glass materials
Authors: Eichler Fabian , Skupin Marco , Katharina Thurn Laura , Kasch Susanne , Schmidt Thomas
Published: December 2019

Laser-based Additive Manufacturing (AM) processes for the use of metals out of the powder bed have been investigated profusely and are prevalent in industry. Although there is a broad field of application, Laser Powder Bed Fusion (LPBF), also known as Selective Laser Melting (SLM) of glass is not fully developed yet. The material properties of glass are significantly different from the investigated metallic material for LPBF so far. As such, the process cannot be transferred, and the parameter limits and the process sequence must be redefined for glass. Starting with the characterization of glass powders, a parameter field is initially confined to investigate the process parameter of different glass powder using LPBFprocess. A feasibility study is carried out to process borosilicate glass powder. The effects of process parameters on the dimensional accuracy of fabricated parts out of borosilicate and hints for the post-processing are analysed and presented in this paper.
Parametric design of a complex part in a FEM environment
Authors: Blaj Mădălina Ioana , Oancea Gheorghe
Published: December 2019

In the recent years, the industry tends to an accelerated evolution in order to maintain the competitiveness on the profile market. As a response to this challenge, engineers and researchers have started to combine multidisciplinary knowledge with solutions provided by programming software so as to obtain immediate and reliable results on each step of a product development. The main advantage is highlighted especially for the optimization phases, when the using of the parametric tools is less time-consuming and the majority of issues of the developed product are solved from the first version of the project. This paper aims to present a case study of a parametric design and meshing in MSC Patran environment, using a programming solution in Visual Basic, of a part with a complex geometry from aerospaceindustry and also to accentuate the minimized risks from the design phase to manufacturing, with a review of the advantages and disadvantages.
Application of industrial robot in 5-axis milling process
Authors: Pollák Martin , Telišková Monika , Kočiško Marek , Baron Petr
Published: December 2019

Present in machining creates constantly new requirements to increase economic efficiency, productivity and product quality. With this advancement, industry is no longer focusing only on commonly used machining technologies, but is paying increasing attention to the implementation of robots in the manufacturing process by machining. The paper describes the design of equipment for the implementation of 5-axis milling with the help of a robot arm ABB IRB 140. It describes the design of the milling head and deals with the creation of NC machining program in software Autodesk Fusion 360. The generated NC program is then used in RoboDK to create a robotic arm control program. At the end of the paper are described laboratory tests of machining using the designed prototype milling head.
Comparative Assessment of Wear Indicators in Grinding Discs During Grinding of Selected Steels
Authors: Józwik Jerzy , Kuric Ivan , Łukaszewicz Andrzej
Published: December 2019

In the paper basic experimental tests were carried out to compare the wear indicators of selected abrasive grinding discs in grinding process of steel. Experimental tests on the wear and efficiency of metal grinding discs were made for four types of steel (S235, NC6, Hadfield steel, WNLV + QT steel). The wear parameter included in the ISO standard (KG) of new abrasive discs from European market were examined. This paper presents an analysis of the efficiency and wear of the company’s „MOST” grinding discs using an angle grinder.
Study on chip fragmentation and hole quality in drilling of aluminium 6061 alloy with high pressure internal cooling
Authors: Popan Ioan Alexandru , Popan Alina Ioana , Carean Alexandru , Fratila Domnita , Trif Adrian
Published: December 2019

The drilling process is one of the most common processes on many manufacturing areas. It is used for high-quality hole drilling of Aluminium 6061 alloy. In this experimental study precise holes were drilled, using drills with high pressure internal cooling (50 Bar). The influence of the process parameters on holes quality is analysed. Another aspect studied is chip shape and evacuation.
Shape distortion analysis of drawing die by optical 3D scanning
Authors: Morovič Ladislav , Urminský Ján , Ridzoň Martin
Published: December 2019

The contribution dealing with analysis of drawing die shape distortion using optical 3D scanning. The wear of drawing die has a significant influence on the shape stability of the produced tubes. Early identification and determination of wear on the drawing die leads to elimination of production errors. Metrological measuring systems can be used to analyse shape distortion. The optical 3D scanner GOM ATOS II TripleScan SO MV170 (measuring volume: 170 × 130 × 130 mm; camera resolution 2448 × 2050 px (5 Mpx); measuring point distance: 0.07059 mm) was used for experimental measurement of drawing die. The 3D scanned weared drawing die was compared with the reference CAD model. The result of the comparison is the colour deviation map of drawing die’s shape and various inspection sections.
Multiaxial and non-proportional microstructure-sensitive fatigue crack nucleation
Authors: Chen Bo , Janssens Koenraad , Dunne Fionn
Published: December 2019

Experimental and crystal plasticity modelling studies have been carried out to investigate non-proportionality and stress state effects in fatigue in a 316 stainless steel and nickel-based superalloy RR1000 which have substantial effects on fatigue life. Stored energy density has provided a reasonably consistent and unifying explanation for the experimental observations of fatigue life in axial, torsional, in-phase proportional tension and torsion, and non-proportional loading regimes. A single fatigue property (the critical stored energy density, equating to new surface energy) has been shown to provide good qualitative and reasonable quantitative prediction of the experimental observations of the complex loading, providing a mechanistic explanation for the fatigue behaviour. For the case where significant densities of GNDs develop (for the fine-grained nickel), the latter is found to differentiate the proportional and non-proportional fatigue lives and its contribution to the local stored energy is crucial for capturing the correct fatigue lives under the differing loadings.
Multi-axial fatigue behaviour of titanium periodic cellular structures produced by Selective Laser Melting (SLM)
Authors: Refai Khalil , Brugger Charles , Montemurro Marco , Saintier Nicolas
Published: December 2019

Additive manufacturing techniques such as selective laser melting (SLM) allow for manufacturing periodic porous titanium structures having complex geometry. The mechanical properties of these structures with diﬀerent elementary cell (ECs) designs have been already studied in literature. However, their fatigue behaviour is not yet well understood. This work aims at proposing a numerical approach to predict the periodic cellular structures fatigue behaviour under multiaxial loadings. The approach is based on an explicit description of the EC combined to an extreme statistical analysis making use of a fatigue indicator parameter to investigate (and compare) diﬀerent EC configurations. On the other hand, the numerical model relies on the use of a general numerical homogenisation scheme to properly apply the multi-axial loading conditions to the EC at the mesoscopic scale. Results show that lattice fatigue strength is strongly aﬀected by the relative density as well as by the geometrical features of the EC.
Investigation of the asperity point load mechanism for thermal elastohydrodynamic conditions
Authors: Everitt Carl-Magnus , Alfredsson Bo
Published: December 2019

The rolling contact fatigue damage called pitting or spalling develops more frequently in surfaces with negative than positive slip. Since normal line loads do not cause any tensile surface stresses this investigation considers the effects of small point shaped asperities. Shear traction causes tensile stresses at the trailing edge of asperities entering the contact at negative slip. At positive slip the tensile stresses appear at the leading edge when the asperities exit the contact. It was found that the trailing edge of the asperity breaks through the lubrication film at contact entry. This causes negative slip to be more detrimental than positive slip. At negative slip the location of large frictional shear stresses and tension stresses from normal asperity contact coincide.
Thermal Gradient Mechanical Fatigue Assessment of a Nickel-Based Superalloy
Authors: Yuan Huang , Sun Jingyu
Published: December 2019

Turbine components generally work under thermomechanical loading conditions with varying temperature and significant temperature gradients. In the present work, a radiation heating system was developed to simulate thermal gradient mechanical fatigue (TGMF) loads in turbines. The specimen is externally heated by radiation and internally cooled by compressed air. Experiments showed that the TGMF life of the nickel-based superalloy is significantly shorter than that of the thermomechanical and the isothermal fatigue, although the thermal stress amplitude related to the temperature gradient is small. It was confirmed that the conventional fatigue models generated seriously deviations and could not catch effects of thermal gradients. The modified TGMF model introduced a correction term of the temperature gradient effects and can describe the TGMF lifetime of Inconel 718 reasonably. The new model provides a uniform description of isothermal and complex thermomechanical fatigue.
Regularizational approach for modeling ductile damage
Authors: Langenfeld Kai , Möhring Kerstin , Walther Frank , Mosler Jörn
Published: December 2019

It is well known, that modeling of material softening behavior can lead to ill-posed boundary value problems. This, in turn, leads to meshdependent results as far as the finite-element-method is concerned [1]. Several solution strategies in order to regularize the aforementioned problem have been proposed in the literature, cf. [2]. However, these strategies often involve high implementational effort. An approach which is very efficient froman implementational point of view is the so-called micromorphic approach by [3, 4]. This regularization technique includes gradients of internal variables implicitly into the framework, while preserving the original structure of the underlying local constitutive model. However, it is shown that a straightforward implementation of the micromorphic approach does not work for single-surface ductile damage models. By analyzing the respective equations, a modification of the micromorphic approach is proposed – first for a scalar internal variable, i.e., isotropic damage. Subsequently, the novel regularization method is extended to tensor valued damage, i.e., anisotropic material degradation.
Influence of internal imperfections on the fatigue resistance of cast steel – testing methodology
Authors: Nagel Sven , Rauber Christof , Veile Ines , Knödel Peter , Ummenhofer Thomas
Published: December 2019

Tensile fatigue specimen of G20Mn5 and G22NiMoCr5-6 were tested to quantify the influence of internal defects on the fatigue resistance of cast steel components. Defects with varying sizes, geometric shapes and distribution were enforced by influencing the solidification and recorded by computer tomography (CT). Besides the characteristics of the detected cavities, the surrounding fungoid microstructure is classified and evaluated. Later the specimens were tested under cyclic tension and S/N-curves are derived. These data form the basis for extensive numerical simulations of the damage process and the crack growth of every individual specimen. Both processes are affected by the local multiaxial stress states and have their origin in the inside of the specimen. For validation, knowledge of the crack initiation time and propagation properties are essential. Therefore, all specimens respectively the properties of the internal defects are monitored during testing with three different state-of-the-art non-destructive testing (NDT) methods. Background and application of these NDT techniques are described within this paper. Finally, fracture surface analyses show different failure modes and provide further information for model validation.
Evaluation of Non-proportional Multiaxial Fatigue Strength of Lead-free Solder with Elements Addition
Authors: Makino Keiwa , Ogawa Fumio , Itoh Takamoto
Published: December 2019

The effect of element addition on creep and fatigue properties of Sn1.0Ag0.7Cu solder with addition of nickel, germanium and bismuth are reviewed. Element additions imporove creep properties although those deteriorate fatigue properties. From above results, necessity of non-proportional multiaxial fatigue tests are discussed. The load cell with high sensitivity was designed by making to detect small load during fatigue test was developed by making the strain detection part hollow circular. The inner diameter and the outer diameter of the load cell satisfying the condition that excessive strain does not occur regardless of high sensitivity was determined by strength calculation.
Fretting Fatigue Behaviour of Alloy Steel in the Very High Cycle Region
Authors: Shimamura Yoshinobu , Kasahara Reo , Ishii Hitoshi , Tohgo Keiichiro , Fujii Tomoyuki , Yagasaki Toru , Sumida Soichiro
Published: December 2019

It is well known that fretting fatigue strength is much lower than the fatigue strength of smooth specimens and the fatigue limit disappears. Many studies on fretting fatigue have been reported but most of the studies have not cover fatigue properties in the very high cycle regime more than 107 cycles. In this study, an accelerated fretting fatigue testing method was developed by using an ultrasonic torsional fatigue testing machine with a clamping fretting pad. Fretting fatigue tests of CrMo steel were conducted by using the developed method. Test results showed that fretting fatigue failure occurs in the very high cycle region.
A notch stress method for fatigue life prediction of spot-welded joints
Authors: Wei Changjian , Kang Hong Tae
Published: December 2019

Spot-welded joints are widely used in the construction of vehicle structures and frequently become critical locations for fatigue failure. Hence, it is essential to have reliable fatigue life prediction method for the spot-welded joints during vehicle structure design. In this paper, a new notch stress approach is developed for fatigue life prediction of the spot-welded joints. Currently, structural stress methods are widely used in automotive industry for fatigue life prediction of spot-welded joints. However, these methods are not well considering local geometry information. This paper introduces a notch stress based method to overcome the limitation of the structural stress methods. In the notch stress method, stress concentration factors for spot-welded joints are calculated from stress intensity factor equations. Then, the notch stress method is validated with fatigue test results of lap-shear and coach peel specimens.
Building Numerical Design Matrix and Managing Functional Couplings for Concept Improvement of The Existing Product
Authors: Wang Chu-Yi , Liu Ang , Lu Stephen
Published: December 2019

Because parametric values are unknown during initial concept generation, the Axiomatic Design Theory uses the binary design matrix (DM) to represent the coupling relationship between functional requirements and design parameters. However, given an existing product, it would be possible to employ the numerical DM that has more detailed information than the binary DM to help improve the design concept. This paper proposed a two-phase method to create a numerical DM in phase I and manage the functional couplings in phase II for concept improvement of existing product. A decomposition-definition-levelling framework and the Puritan-Bennett’s 0-1-3-9 level rating are employed to evaluate the system impact of each functional coupling to create the numerical DM of an existing design concept. The Design Coupling Sequence (DCS) approach was extended to use the numerical DM to improve this design concept. Compared with other numerical matrices for product development and the structured approach by Su et al., our method is more generic and faster, providing useful details yet still able to maintain the dominance of the high-level couplings.
Robust design of web services supporting the home administration of drug infusion in pediatric oncology
Authors: Parretti Chiara , Pourabbas Elaheh , Rolli Fernando , Pecoraro Fabrizio , Citti Paolo , Giorgetti Alessandro
Published: December 2019

Cancer home care is a sector of particular relevance for the Italian health service. The budget ceilings imposed by public finance pose the need to reduce hospitalisation costs, moving patients from treatment to home care as much as possible. This is especially true in the field of pediatric oncology, where a protected family environment offers a variety of benefits to young patients and their families. However, in order to guarantee adequate assistance services, an integrated information system for management must be devised as the center of gravity of a coordinated network of, even heterogeneous, actors. This paper focuses on the identification and evolving development of web services for regulation and control of home administration of drug infusion in pediatric oncology. The Service Oriented Architecture (SOA) remains the software architecture of reference, where as the methodological approach is open to a reconsideration of the continuous improvement of the whole process in light of the ceaseless progress of medical science and information technology. In this paper, his goal is achieved by using a methodological design approach that combines the UML modeling based on Case Stories and the process optimization of Axiomatic Design. Case Stories allow the formalization of end users' requirements in UML language, easily interpreted by software developers. On the other hand, Axiomatic Design allows optimizing the design process by identifying the most robust solutions in terms of greater logical coherence and lesser systemic complexity. We analyze a case study focused on the design of web services supporting the home administration of drug infusion, for young cancer patients in home care. Then, we show how the UML-modeling methodology can be used to design new services on the basis of specific Use Cases. Finally, through theAxiomatic design approach we verify the proposed solutions, by identifying the robust set of web services to be implemented.
Development of a Process for Perceptual Index Establishment based on Axiomatic Design
Authors: Zhang Yilun , Peng Lichao , Shen Jing , Zhinan Zhang , Tao Fei
Published: December 2019

With the increasingly intense competition in the market, more attention has been paid to customer’s perceptual requirements. Combining human sensibility and technology, Kansei Engineering plays a crucial role for industrial designers in making decisions at an earlier design stage in product development. However, sometimes it is challenging to define the customer requirements during the market research phase, especially for the perceptual requirements. Given this problem, this paper develops a process for establishing perceptual indexes based on the axiomatic design approach to improve design efficiency. To achieve this, an initial perceptual index is first built based on data previously collected from designers or design agencies. Then, the theory of axiomatic design is used to classify the schemes. The final perceptual index is filtered and built according to the frequency of occurrence.
Robust capacity planning for accident and emergency services
Authors: Gökalp Elvan
Published: December 2019

Accident and emergency departments (A&E) are the first place of contact for urgent and complex patients. These departments are subject to uncertainties due to the unplanned patient arrivals. After arrival to an A&E, patients are categorized by a triage nurse based on the urgency. The performance of an A&E is measured based on the number of patients waiting for more than a certain time to be treated. Due to the uncertainties affecting the patient flow, finding the optimum staff capacities while ensuring the performance targets is a complex problem. This paper proposes a robust-optimization based approximation for the patient waiting times in an A&E. We also develop a simulation optimization heuristic to solve this capacity planning problem. The performance of the approximation approach is then compared with that of the simulation optimization heuristic. Finally, the impact of model parameters on the performances of two approaches is investigated. The experiments show that the proposed approximation results in good enough solutions.
3-D-Mapping-Systeme und integrierte Bildgebung in der Elektrophysiologie
Authors: Kowalewski Christopher A. B. , Bourier Felix
Published: December 2019

Mit 3-D-Mapping-Systemen lässt sich die genaue Lage elektrophysiologischer Katheter im Herz bestimmen und bei kontinuierlicher Aufzeichnung ihrer Position zu einem anatomischen Bild zusammenfügen. Wird dann noch die intrakardiale „elektrische Information“ farbcodiert ergänzt, kann diese Darstellung sowohl mit Röntgen- als auch mit Schnittbildern fusioniert werden: ein komplexes Werkzeug für komplexe Arrhythmien.
Gastroenterologische Komplikationen der neuen Immuncheckpoint-Inhibitor-Therapien
Authors: Götze Julian , Bitzer Michael , Malek Nisar Peter
Published: December 2019

Was ist neu?

Immuncheckpoint-Inhibitoren In den letzten Jahren haben sich Immuncheckpoint-Inhibitoren (ICPI) als fester Bestandteil der medikamentösen Tumortherapie etabliert. Sie gehören zu einer Gruppe von monoklonalen Antikörpern, die eine gegen Krebszellen gerichtete Immunreaktion fördern. Durch Bindung an CTLA-4 und PD-1 bzw. PD-L1 werden hemmende Signalwege unterbrochen, wodurch die Aktivität zytotoxischer T-Lymphozyten gesteigert und die immunologische Toleranz gegenüber Tumorzellen reduziert wird.

Enterokolitis Diarrhöen – als Symptom einer Enterokolitis – stellen nach dermatologischen Phänomenen die häufigste Nebenwirkung unter ICPI-Therapie dar. Unter kombinierter CTLA-4- und PD-1-Blockade können bis zu 44 % der Patienten betroffen sein. Die Klinik der ICPI-assoziierten Kolitis ähnelt dem klinischen Erscheinungsbild chronisch-entzündlicher Darmerkrankungen.

Diagnostik und Therapie der Enterokolitis Das Management betroffener Patienten sollte nach einem standardisierten Vorgehen erfolgen. Sowohl die europäische als auch die amerikanische Fachgesellschaft für Onkologie bieten dezidierte Handlungsempfehlungen zur Diagnostik und Behandlung ICPI-assoziierter Nebenwirkungen. Nach Ausschluss von Differenzialdiagnosen ist eine rasche immunsuppressive Behandlung (u. a. Steroide, Biologika) notwendig, um die Morbidität zu senken. Möglicherweise kann nachfolgend eine Wiederaufnahme der ICPI-Therapie erfolgen.

Hepatitis und Pankreatitis Als weitere relevante Nebenwirkung tritt die immunvermittelte Hepatitis ca. 6–14 Wochen nach Therapiebeginn auf. Meist präsentiert sie sich asymptomatisch und ist gekennzeichnet durch einen Anstieg der Serum-Transaminasen. Die Lipasämie ohne klinische Zeichen einer akuten Pankreatitis ist ein häufiger Laborbefund, der in der Regel keine therapeutische Konsequenz hat.
Medikamentöse Therapie der Herzinsuffizienz mit reduzierter Ejektionsfraktion bei chronischer Nierenerkrankung
Authors: Heine Gunnar Henrik , Rogacev Kyrill Sebastian
Published: December 2019

Was ist neu?

Etablierte Therapiestrategien Auch wenn die Evidenz für den Einsatz von ACE-Hemmern, Angiotensin-Rezeptorblockern, Betablockern und Mineralokortikoid-Rezeptor-Antagonisten bei HFrEF-Patienten mit schwerer CKD begrenzt ist, macht die schlechte Prognose unbehandelter Patienten einen breiten Einsatz dieser Substanzen oft erforderlich. In den Leitlinien der European Society of Cardiology zur Herzinsuffizienz werden für den klinischen Alltag hilfreiche und konkrete Vorschläge zum Intervall von Laborkontrollen und zu Konsequenzen insbesondere von Hyperkaliämie und Kreatininanstieg unter RAAS-Inhibitoren vorgeschlagen.

Neue Therapiestrategien Neue Therapiestrategien zur Prognoseverbesserung von HFrEF-Patienten lassen sich in unterschiedlicher Weise auf CKD-Patienten übertragen: Der Einsatz von Sacubitril/Valsartan und SGLT-2-Inhibitoren ist bei mittelgradiger CKD (GFR ≥ 30 ml/min/1,73 m²), nicht jedoch bei höhergradiger CKD untersucht. Hingegen liegen für eine hochdosierte intravenöse Eisentherapie Daten aus der PIVOTAL-Studie vor, welche eine Prognoseverbesserung zumindest bei hinsichtlich der Herzfunktion unselektierten Patienten mit dialysepflichtiger CKD suggerieren.
Lungenkrebsscreening – wer, wo und wie?
Authors: Reinmuth Niels
Published: December 2019

Was ist wichtig?

Mögliche Screening-Verfahren Die Notwendigkeit eines Früherkennungsprogramms für Lungenkarzinome gilt als unumstritten. Röntgenübersichtsaufnahmen der Lunge sowie Sputum-Untersuchungen werden nicht empfohlen, jedoch haben jüngst publizierte Daten aus Studien mit Niedrigdosis-CT dieses Thema erneut aufleben lassen. Bei der Bewertung der Daten müssen jedoch verschiedene Besonderheiten dieser Studien berücksichtigt werden. Die aktuelle neue Bewertung stellt eine bedeutsame und notwendige Chance dar, die medizinische Versorgung und Prognose von Patienten mit Lungenkarzinom in Deutschland signifikant zu verbessern.

Implementierung von Lungenkrebsscreening Um ein Screening-Programm möglichst effektiv auszuarbeiten, müssen insbesondere die Einschlusskriterien der Patienten genau definiert sein. Darüber hinaus ist es wichtig, die Zahl der falsch positiven Befunde zum Schutz der Patienten und zur Vermeidung unnötiger Kosten möglichst klein zu halten.

Weitere Ansätze Weitere neue Verfahren zum Lungenkrebsscreening werden derzeit in klinischen Studien untersucht.
Metastasiertes Kolorektalkarzinom
Authors: Schmale Ine
Published: December 2019

Die Entscheidung, welche Therapie für welchen Patienten die erfolgversprechendste ist, steht angesichts der wachsenden Möglichkeiten bei vielen Tumorentitäten im Fokus. So wurden auch beim World Congress on Gastrointestinal Cancer Biomarker- und Subgruppenuntersuchungen präsentiert, die Hinweise auf eine optimierte Patientenselektion beim metastasierten Kolorektalkarzinom (mCRC) geben.
Ethanol Ablation of Neck Metastases from Differentiated Thyroid Carcinoma
Authors: Paz-Fumagalli Ricardo , Li Xi , Smallridge Robert C.
Published: December 2019

Differentiated thyroid cancer often metastasizes to cervical lymph nodes, characteristically with slow growth rate and low-level aggressiveness. Cervical lymph node resection is the treatment of choice, but ethanol ablation offers a therapeutic option for patients with few nodes unresponsive to radioiodine therapy and who are poor surgical candidates. The ethanol ablation procedure is minimally invasive, guided sonographically, easily and safely repeated, and easily implemented with minimal technology and cost. Transient nerve injury is infrequent and virtually the only important complication. Current experience indicates that ethanol ablation has the safest therapeutic profile compared to surgery and thermal ablation, and the effectiveness is comparable to thermal ablation and approaches that of surgery. Well-designed clinical trials are lacking.
A study of variations of anterior belly of digastric muscle
Authors: Khona Pratik , Kulkarni Deepali U , Kulkarni Umesh K
Published: November 2019

Aim : To study the anatomical variations of anterior belly of digastric muscle. Materials & Methods: In the present study, 30 human cadavers from the Department of Anatomy, Belagavi Institute of Medical Sciences, Belagavi were examined for the variations of anterior belly of digastric muscle during routine dissections of undergraduate and postgraduate students. The variations found were neatly dissected and photographs taken wherever necessary. Result: Out of 30 cadavers dissected3 specimens presented with variations. Discussion: First variation found had a unilateral accessory belly of digastric muscle on right side. Second variation was unilateral accessory belly of digastric muscle on left side and the third variation was bilateral accessory slips of digastric muscles. The details of these variations will be dealt in the article. Conclusion: As the variations of anterior belly of digastric muscle are common, the radiologists and the surgeons have to watch out for these while dealing with Sub mandibular region.
Correlation between femoral offset and other morphometric parameters
Authors: Jaiswal Pratima , Verma Lakshmi , Ghulyani Tuhin
Published: November 2019

Background and aims: Surgeries involving the femur are quite common. The clinical importance of femur in sports biomechanics and rehabilitation is well known. Therefore, its morphometries has orthopedic implications. The present study aims at establishing interrelationship among various external parameters in adult dried femora including femoral offset (FO), neck shaft angle [NSA], femoral anteversion angle [FNA], Neck width [NW], Anterior Neck length [ANL], Posterior Neck length [PNL], Oblique length [OL] and trochanteric oblique length [TOL], Materials and Methods: A total of 100 [50 right and 50 left] intact, dried adult human femora from department of Anatomy, Government Medical College, Kota were included in this study. The FO, NSA and FNA were measured by digital image analysis in ‘IMAGEJ’ software. OL and TOL were measured using osteometric board. ANL, PNL and NW were recorded using sliding caliper. Statistical analysis was done using SPSS and Microsoft Excel software. The mean values were calculated, relationship between parameters was measured by Pearson's correlation coefficient ‘r’. Multiple regression equations were derived in order to calculate FO by other variables. Results: FO showed strong negative correlation with NSA; strong positive correlation with ANL, PNL, NW; moderate positive correlation with OL, TOL; but no relationship with FNA. NSA had moderate negative correlation with NW and weak negative correlation with PNL. NW & ANL had positive correlation with OL, TOL. Conclusion: In our method we used dried, intact bone and digital photographs with standardised method. Therefore it should provide accurate results; in addition it is cost effective. However studies on larger scale are warranted to design implants for Indian population.
A study on variations of branching patterns of median nerve in the carpal tunnel
Authors: Biswas Krishna Kanta , Baishya Rupak Jyoti , Talukdar Kunjalal
Published: November 2019

Background & aims: The carpal tunnel, located on the palmar surface of the wrist, is a common site of median nerve compression. The median nerve, on passing through the carpal tunnel, divides into lateral and medial branches. The lateral branch then gives off proper palmar digital branches to the thumb and the radial aspect of the index finger, and a recurrent muscular branch to the thenar muscles. The recurrent muscular branch shows different types of variations of the median nerve. Also, there are other variations of the median nerve in the carpal tunnel. These variations greatly influence the symptoms, as well as the treatment of the carpal tunnel syndrome. So, the present work is carried out to study the variations of branching patterns of median nerve in the carpal tunnel. Materials and methods: 40 wrists [20 right and 20 left] from 20 formaldehyde fixed human perinatal fetuses of 34 - 38 weeks of gestation were dissected in the Department of Anatomy, Gauhati Medical College and Hospital, Guwahati. Due ethical clearance was obtained from the Institutional Ethical Committee, Gauhati Medical College and Hospital, Guwahati. Results: In the present study, 24 [66.7%] hands [11 right and 13 left] showed extraligamentous and 12 [33.3%] hands [8 right and 4 left] showed transligamentous variety of thenar branch of median nerve. Also, 4 [10%] hands showed accessory thenar branch of median nerve, all of which took origin within the flexor retinaculum. The comparisons of numbers of variations of thenar branch of median nerve between right and left hands were found to be statistically non significant [P > 0.05]. Conclusion: A detailed knowledge of the median nerve variations in the carpal tunnel is required for successful diagnosis and treatment of the carpal tunnel syndrome and its complications.
Utility of Web 2.0 tools for self-directed learning among first year MBBS Students
Authors: Shrish Patil , Manjunath S.M , Nidoni Madhumati , Raju G Nagesh
Published: November 2019

Background and aims: To use Web 2.0 tools for learning human histology by First year MBBS students and thus make them aware of the features of these tools. To assess, by way of a feedback, the utility of the web 2.0 tools as instruments for self- directed learning. Materials and Methods:A questionnaire based longitudinal study was administered to sixty students. Their knowledge level about Web 2.0 tools, Self directed learning and Competency based learning were assessed. Then they were asked to participate in online discussions using Web 2.0 tools. Opinion regarding the utility of these Web 2.0 tools was collected using pre-validated questionnaires. Results: Awareness of Web 2.0 tools and Self-Directed Learning [SDL] was low. Even though students found the Web 2.0 tools to be good instruments for learning of that material which was not taught in routine classes, several students preferred their learning to be guided by teachers. Conclusion: Web 2.0 tools are good instruments for Self Directed Learning which leads to better development of competencies required of a professional doctor. Web 2.0 tools need to be integrated into our current curriculum to be fully utilised. These tools are yet to find acceptance by the students.
Morphometrie study of foramen magnum in human dry skulls
Authors: Deshpande Sulabha Hanumant , Nuchhi Ashwini Balasaheb , Bannur Balappa Murigeppa , Patil Babasaheb Gurusiddappagouda
Published: November 2019

Background : Anthropologists are often faced with the task of assigning sex to remains that are incomplete, fragmented or damaged as may result from incidents such as mass disasters, airplane crashes, fire, explosions or physical violence. The size of foramen magnum does not change after puberty, not related to age then after. It is this part of the cranial base which can withstand fire explosions as the area is covered by large amount of soft tissue. Hence the foramen magnum was considered for studying the sexual differences in skull. Aims : To analyse the morphology and morphometry of foramen magnum, and the impact of these variables on sex determination of skull. Materials and Methods : 68 male and 68 female adult dry skulls were used for the study. The shapes of foramen magnum were studied. Results : In total, oval was the most common shape comprising of 61.76%, 16.17% arrow head, 11.76% irregular and 10.29% round. The sagittal diameter was 33.0 [28-40] mm in males and 33.0 [28-43] in females and transverse diameters of foramen magnum were 27[21-31] in males and 26.0[23-33]mm in females. Area of foramen magnum was calculated using Radinsky and Teixeria formulae and foramen magnum index was calculated. Mean, standard deviation and median [where ever required] were calculated. Student t test and Mann Whitney U test/ T test were applied. We did not find significant difference between male and female values. Conclusion : Our study did not demonstrate statistically significant difference in expression of sexual differences in the foramen magnum. However if detailed analysis is done with greater sample size by discriminant function analysis, it may prove useful in predicting sex in severely fragmented cranial bases.
Extra coeliac axis origin of cystic artery: a cadaveric study
Authors:   Vinitha G,   Rajeshwari M S
Published: November 2019

Background: A thorough knowledge of extra hepatic biliary system vasculature is very important for surgeons to avoid iatrogenic bleeding during upper abdominal surgeries. Aim: Cystic artery usually a branch of right hepatic artery rarely has anomalous origin from coeliac trunk or from its branches. Very rarely it has an extracoeliac origin. The aim is to study the incidence of origin of cystic artery other than coeliac trunk. Material and method: The study was done on 50 formalin fixed cadavers [32male, 18 female] in the department of anatomy, Bangalore medical college and research institute during 2014-17. During routine dissection of coeliac trunk, cystic artery was traced and observed for its origin. Results: Cystic artery took its origin from right hepatic artery in 37 [74%], left hepatic artery in 9[18%], hepatic artery in 3[6%] and superior mesenteric artery ini [2%] cadaver. Conclusion: The incidence of extra coeliac axis origin of cystic artery is 2% which arose from superior mesenteric artery. Prior knowledge of these variations is important for surgeons and interventional radiologists during pancreatobiliary surgeries, angiogram and arterial embolization.
Morphometry relevant to Anterior Petrosectomy with special reference to Kawase’s Triangle
Authors: Siddiqui Abu Ubaida , Satapathy Bikash Chandra , Gill Sukhjeet Singh
Published: November 2019

Background and aims :The petrous apex and the middle cranial fossa is a commonly explored area in neurosurgeries and hence require a holistic approach which should include the possibility of anatomical variants and morphometric dissimilarities. Material and Methods:This morphometric study was undertaken on 91 dry adult skulls [182 petrosal apices] to analyze a number of parameters relevant to Anterior Petrosectomy [AP] via the Kawase’s Triangle [KT]. The anatomical landmarks most pertinent to Anterior Petrosectomy [Kawase's approach] were defined, recorded and validated. The findings of the study were compared with earlier workers who have employed other means of investigation viz. dry bones/CT scans or cadaveric studies . Results : The parameters undertaken for the study presented with variable values and moresoever for the surface area of the KT. This can be very logically attributed to the variant anatomy amongst races and also to the physiological status of the individual Conclusions : AP has evolved as a preferred method for approaching petroclival region and thus requires an in depth understanding. The present analysis throws significant light on certain parameters that would be helpful in making anterior petrosectomy safer. Surgeries of the skull base demand for high end precision and proficiency and thus our findings provide enhanced alertness for a better and safe procedure. A methodical approach to the area with the background knowledge of these parameters shall culminate in desired neurosurgical outcomes.
Boosting anatomy teaching of MBBS first year students using a quality circle module-A personalized perspective
Authors: Agnihotri Gaurav
Published: November 2019

Background and aims : In Medical education scenario, a ‘quality circle’ comprises of a small group of individuals who perfonn voluntarily quality control activity. The present study aims to implement the ‘quality circle concept’ in anatomy teaching of first year MBBS students and gauge the effects. The study also assesses the success of the quality circle module based on student satisfaction levels at the end of the course. Materials and methods: A quality circle was fonnulated at the beginning of the MBBS first year course in the anatomy department at Government medical college, Amritsar and a problem pool was identified based on inputs from the class and the author. Using this problem pool a questionnaire was circulated to all students at beginning of course and then again at end of course to assess student satisfaction levels after implementation of the quality circle. The student responses based on a five point Likert scale were tabulated and statistically analyzed. Results: The means for items in questionnaire as determined at beginning and end of course were compared and they came out to be statistically significant [p<0.001]. The responses indicated that there was a statistically significant impact of the ‘quality circle’ on student satisfaction levels. Conclusion: The quality circle module should be utilized for effective achievement of goals in medical institutions. The author advocates that the concept should be tried in all professionals during the MBBS course. Though the results are subtle and limitations are there, it provides opportunities of personality development for the students. The quality circle creates a platfonn wherein the students and facu1ty/authorities can interact and act cohesively and in an unidirectional manner for effective achievement of academic goals and environment.
A study ofthe morphogenesis & mitral cell population of human fetal olfactory bulbs
Authors: Roy Sagoik , Roy Nivedita
Published: November 2019

Background and Aims: Human fetal olfactory bulbs have a six layered laminar architecture where mitral cells are the largest neurons. Volume of the bulbs is considered as an indicator of olfactory function. Fetal bulb cell transplants are used to treat many diseases of the central nervous system. The present study aims to trace the development of the fetal bulbs with respect to it’s gross appearance, volume, arrangement and the number of mitral cells. Materials and Methods: Sixty two normal fresh aborted fetuses were collected from Obstetrics and Gynaecology department of Regional Institute of Medical Sciences, Imphal. The fetuses were dissected and olfactory bulbs were gently taken out and fixed in 10& formal saline. Once fixed, the volume of the bulbs were measured using a measuring cylinder and insulin syringe. This was followed by tissue processing and staining with Toluidine Blue and Cresyl Violet. Stained slides were photographed and number of mitral cells were counted using Image J software. The correlation of bulb volume with fetal age, crown rump length [CRL 1 and fetal body weight was analysed using SPSS software. Similar analysis was also done between mitral cell number and fetal age. Result: Fetal bulbs attained adult morphology at 20 weeks. Bulb volume was found to rise significantly with advancing fetal age until it slowed down 32 weeks onwards. Mitral cells were identifiable at 16 weeks and maintained a laminar arrangement and showed progressive increase in number until 28 weeks. There after the orderly arrangement of cells as well their number declined. Conclusion: Very few studies have been conducted so far regarding the fetal olfactory bulbs in India. The present study is expected to supplement known data and knowledge regarding the development of the fetal bulbs and the mitral cell population and help in the diagnosis and treatment of central nervous system diseases.
Morphological and morphometric features of cuboid bone
Authors: Kumar Suja S ,   Viveka S
Published: November 2019

Background and aims : Morphological and morphometric data of cuboid is of significance in creating 3D model of midfoot alignment and in understanding pathologies and instabilities in the region. There is minimal data on biometric values of cuboid. The objective of the study was to evaluate morphological variations in calcaneal articulating facet and metatarsal articulating facet. The other objective was to report morphometric data of cuboid. Methodology: This descriptive study was conducted in the department of Anatomy, using 24 dry cuboid bones. Each bone was observed for pattern of articular surfaces. Articular surface of each bone was photographed and categorized. Presence of navicular facet was noted. Results: Pattern of calcaneal articular facet was classified into four types: IA – concavo-convex facet with posteromedial projection and overall oval or reniform shaped; 1B – concavo-convex facet without posteromedial projection and rectangular shaped; 2A – plane facet with posteromedial projection and oval or reniform shaped; 2B – plane facet without posteromedial projection and rectangular shaped. Type I was the most common. Pattern of metatarsal articulating facet was classified into three groups: Concave – the edges of metatarsal articulating facet projected anteriorly making a depression for articulation of 4th and 5th metatarsal bones; Plane – articulating facet is flat; Convex – the articulating surface slopes posteriorly. Concave pattern was most common. Mean medial length of cuboid was 33.9 [°3.3] mm, lateral length was 17.9[ °1.6]mm, height was 22[°1.5] mm, length index was 188.8, area of calcaneal articular facet was 124.9 [°10.9] mm2, area of metatarsal articulating facet was 91.9[°5.7]mm2, depth of peroneal groove was 1.83 [°1.3]mm. Conclusion: Morphological characterization of articular surfaces of cuboid, especially the calcaneal facet helps to understand the degree of movement at calcaneocuboid joint and also joint pathologies.
Wettbewerb oder Direktvergabe?: „Geht das trotz der Größe nicht ohne Ausschreibung?“
Authors: Kühn Matthias
Published: December 2019

Sei es, dass rasch externe IT-Beratung erforderlich wird oder dass eine Fachabteilung das neu entwickelte Spezialgerät einer bestimmten Firma wünscht: Die Frage, ob der (Groß-)Auftrag nicht auch ausschreibungsfrei vergeben werden darf, erreicht früher oder später jeden Einkäufer einer Klinik, die öffentlicher Auftraggeber ist. Wesentliche Eckpunkte für die Beantwortung werden hier skizziert.
Europäischer Medizinproduktemarkt: Wie sich Einkauf und Logistik auf die europäische MDR vorbereiten müssen
Authors: Gallmann Thomas
Published: December 2019

Nicht lieferbare Medizinprodukte sind für Kliniken ein Albtraum – mitunter müssen sogar geplante OPs abgesagt werden. Die Folge: Die mit den Kostenträgern vereinbarten Leistungszahlen sind schwieriger zu erfüllen und es könnte zu schwer kompensierbaren Erlöseinbußen für die Leistungserbringer kommen. Die Medical Device Regulation (MDR) wird die Liefersituation von Medizinprodukten ab 2020 wahrscheinlich noch weiter verschärfen.
Nanoparticle-based metasurfaces for angular independent spectral filtering applications
Authors: Lotti Francesco , Mirzaei Ali , Miroshnichenko Andrey E. , Zayats Anatoly V.
Published: December 2019

We designed a metasurface made of a monolayer of spherical nanoparticles embedded in a dielectric slab, which exhibits transmission properties independent of the incidence angle. Adjusting the electromagnetic coupling between high-index dielectric and hybrid core-shell nanoparticles enables the metasurface to operate in low-pass, bandpass, as well as band-stop regimes in the visible and near-infrared spectral ranges. We demonstrate how symmetric properties of spherical nanoparticles determine the response of the metasurface, resulting in a spectral filter with a wide angular acceptance range. We study transmission characteristics of the metasurface, such as frequency selectivity, the slope of filtering at cutoff frequencies, and the robustness of the metasurface against experimental variations in geometrical parameters. Our analyses show that the proposed approach can be used to design angular-independent spectral filters with the same material platform and approach to operate in different regimes and spectral ranges.