bluuebunny/crossref_metadata_2025 huggingface dataset:
Computing Design Rationales by Interpreting Simulations
Authors: Raghavan Anand , Stahovich Thomas F.
Published: February 2021

We describe an approach for automatically computing a class of design rationales. Our focus is computing the purposes of the geometric features on the parts of a device. We first simulate the device with the feature in question removed and compare this to a simulation of the nominal device. The differences in the simulations are indicative of the behaviors that the feature ultimately causes. We then use fundamental principles of mechanics to construct a causal explanation that links the feature to these behaviors. This explanation constitutes one of the rationales for the feature. We have implemented a program that can construct these kinds of causal explanations and have tested it on various examples.
Teaching Engineering Science by Design
Authors: Allen Janet K.
Published: February 2021

Engineering design can provide a vehicle for teaching engineering science, mathematics and engineering material. Building the designs provides a context and offers students opportunities for instant feed-back about the success of their ideas. Careful integration of the required subject matter into a design process is essential for success. An example of a physics course taught through design is presented.
An Infrastructure to Support Closed Loop Product Development Practice Coupled With Rapid Prototyping
Authors: Fukuda Shuichi , Jiang Ping-Yu
Published: February 2021

This paper deals with a methodology to use rapid prototyping and tooling to aid the product development practice. Under the support of the distributive activity scheduling mechanism and the unified product data model, a closed loop is described, which consists of design-phase-oriented requirement analysis of RP/RT applications, multi-criterion decision-making mechanism for selecting the combination of materials, RP method, and RP process chain, process planning for rapid prototyping and tooling, data collections from RP manufacturing, design evaluations based on manufactured prototypes, as well as case-based learning from RP process chain. Here, quality function deployment is used for quality control and assurance of such a design closed cycle. Several such closed loops during product design procedure will make the product go to a optimal solution. In addtion, concurrence and competence issues inside a closed loop design evaluation cycle are also discussed. Finally, a conclusion about this methodology is drawn.
An Automated Assembly Sequence Planing System for Mechanical Parts
Authors: Sarvananthan V. C. , Pandey P. C.
Published: February 2021

This work provides a software system, which can automatically determine the assembly sequence of a product from its parts, given only a geometric description of the assembly. A simple closed envelope method for product geometry representation, and an efficient matrix method to represent contact and interference relations among the parts were successfully used in this work. The possible sub-assemblies are automatically detected by satisfying some mathematical conditions applicable to these matrices. Possible assembly sequences are generated for each sub-assembly and for the whole product. Furthermore, the algorithms are successfully examined with several industrial products.
Computer Aided Geometric Design of Two-Parameter Freeform Motions
Authors: Ge Q. J. , Sirchia M.
Published: February 2021

This paper brings together the notion of analytically defined two-parameter motion in Theoretical Kinematics and the notion of freeform surfaces in Computer Aided Geometric Design (CAGD) to develop methods for computer aided design of two-parameter freeform motions. In particular, a rational Bézier representation for two-parameter freeform motions is developed. It has been shown that the trajectory surface of such a motion is a tensor-product rational Bézier surface and that such a kinematically generated surface has a geometric as well as a kinematic control structure. The results have not only theoretical interest in CAGD and kinematics but also applications in CAD/CAM and Robotics.
Synthesis of Spatial Two-Link Coupled Serial Chains
Authors: Krovi Venkat , Ananthasuresh G. K. , Kumar Vijay
Published: February 2021

We address the synthesis of serial chain spatial mechanisms with revolute joints in which the rotations about the joints are coupled via cables and pulleys. Such coupled serial chain mechanisms offer a middle ground between the more versatile and compact serial chains and the simpler closed chains by combining some of the advantages of both types of systems. In particular, we focus on the synthesis of single degree-of-freedom, coupled serial chains with two revolute joints. We derive precision point synthesis equations for two precision points by combining the loop closure equations with the necessary geometric constraints in terms of the unknown mechanism parameters. This system of equations can now be solved linearly for the link vectors after a suitable selection of free choices. We optimize over the free choices to generate an end effector trajectory that closely approximates a desired end effector trajectory for motion generation and path following applications.
Assembly Configurations of Spatial Single-Loop Mechanisms With Revolute, Cylindric, and Prismatic Joints
Authors: Foster David E. , Cipra Raymond J.
Published: February 2021

This paper examines the problem of identifying the assembly configurations (ACs), also called circuits, of certain spatial single-loop mechanisms. First, the spherical mechanism is considered; it is believed that such a mechanism has one AC if every pair of adjacent links can line up; otherwise, it has 2 ACs. Next, general spatial mechanisms with revolute, cylindric, and prismatic points are considered. If the mechanism has three or more sliding (cylindric or prismatic) joints, it is possible to find an equivalent spherical mechanism which has the same angular motions. However, it is also possible that at certain positions, some of the links may have to slide an infinite distance, which is not possible. Therefore, the mechanism may have more ACs than the equivalent spherical mechanism. Several examples are given, and some general conclusions are drawn.
Convolution Metrics for Rigid Body Motion
Authors: Chirikjian Gregory S.
Published: February 2021

Recently, the importance of metrics on the group of rigid body motions has been addressed in a number of works in the kinematics and robotics literature. This paper defines a new kind of metric on motion which is particularly easy to compute. It is shown how this metric is applicable to path generation for rigid body motions.
On the Coupler Curve of RCPCR Linkages
Authors: Yan Hong-Sen , Hsieh Wen-Hsiang
Published: February 2021

The purpose of this paper is to investigate the properties of the coupler curves generated by all RCPCR linkages. First, the 3 × 3 matrix with dual elements is used to establish the loop closure equation, the displacement equations are derived, and all joints variables are expressed in terms of input and output variables. Then, the parametric equations of the coupler curve are found by the D-H matrix. Finally, homogeneous coordinate is introduced to those displacement equations, and the order and some critical properties of the coupler curve are investigated based on the theories of algebraic curve and analytical geometry of three dimensions. In addition, RCPCR and RRCPC linkages are used as examples for illustrations. Moreover, the results on the application of dimensional synthesis are discussed.
An Investigation of Screw Systems in the Finite Displacements of Bennett-Based 6R Linkages
Authors: Huang Chintien , Sun Chi-Chih
Published: February 2021

This paper investigates, via numerical simulations, the finite displacements of all the known Bennett-based 6R overconstrained linkages: Goldberg’s linkages, variant Goldberg linkages, Waldron’s linkages, and Wohlhart’s linkages. An investigation of the finite displacements of nine distinct linkages reveals that every Bennett-based linkage, except for Wohlhart’s isomerization linkage, inherits the linear properties of the Bennett mechanism. The relative finite displacement screws of some non-adjacent links of these linkages form screw systems of the second order.
An Investigation Into Compliant Bistable Mechanisms
Authors: Opdahl Patrick G. , Jensen Brian D. , Howell Larry L.
Published: February 2021

This paper proposes a new class of bistable mechanisms: compliant bistable mechanisms. These mechanisms gain their bistable behavior from the energy stored in the flexible segments which deflect to allow mechanism motion. This approach integrates desired mechanism motion and energy storage to create bistable mechanisms with dramatically reduced part count compared to traditional mechanisms incorporating rigid links, joints, and springs. This paper briefly reviews bistable mechanism theory, introduces some additional bistable mechanism characteristics, and integrates this theory with compliant mechanism theory. The resulting theory of bistable compliant mechanisms is validated by measuring the force and motion characteristics of several test mechanisms and comparing them to predicted values.
An Introduction to Burmester Field Theory
Authors: Mlinar John R. , Erdman Arthur G.
Published: February 2021

This paper introduces the Burmester field for motion-generation dyads with four design positions. The Burmester field is the region swept by a Burmester curve as one or more of the design positions varies. The Burmester field’s geometric features are shown to be related to the poles. The most significant feature are anchor poles that remain stationary as the design positions are changed. The envelope of the Burmester field found with the variation of a single design parameter is presented. This work demonstrates that the envelope of the Burmester field consists of segments of Burmester curves and segments found using envelope theory. A number of examples are presented and discussed.
A Computer Implementation of the Position Solution of Planar Linkages Using Vector Loop Decomposition
Authors: Kahler Clint A. , Nisbett J. Keith , Goodin Clement R.
Published: February 2021

A general closed-form approach to the solution of loop equations of planar n-bar linkages is presented. Each loop of a set of canonical independent loops is decomposed to a set of vectors. Several common combinations of revolute and prismatic joints are defined. By evaluating the types of joints at each end of a vector, the magnitude and direction of the vector are determined to be known constants or unknown variables. This leads to an identification of the number of unknowns and the distribution of unknowns in the loop. This identification allows the unknowns to be found by matching the situation to one of the unique, closed-form cases for a solvable loop. A computer software application has been developed and is analyzed for efficiency.
A Proposed Categorization Method and Category Domain Inequality Development Procedure for Ground Joints of Five Bar Linkages
Authors: Lin Chuen-Sen , Lee Terry , Jia Bao-Ping
Published: February 2021

This paper presents a method for the development of sets of symbolic inequalities in terms of link lengths for the prediction of the rotation capabilities of ground joints of single-loop five-bar linkages. The inequalities are obtained from the combination of the loop equation of a five-bar linkage and its derivatives and the application of simple logic operations. The rotation capabilities of ground joints are divided into three categories: the incomplete-rotation ground joints, the conditioned complete-rotation ground joints, and the unconditioned complete-rotation ground joints. The derived sets of inequalities define the domain, in a five-dimension space of the five link lengths, for each of the rotation categories. In this paper, the definition of each category is clearly described and the derivations of sets of inequalities are explained in details. A computer program was constructed to examine the completeness and correctness of the categorization method and to analyze the given five-bar linkages to determine the appropriate categories for their ground joints.
Mass Center of Planar Mechanisms Using Auxiliary Parallelograms
Authors: Gökçe Ali , Agrawal Sunil K.
Published: February 2021

Center of mass is an important characteristic of a mechanism during motion. In some studies of biomechanics, it is necessary to monitor the motion of this point. The physical location of the center of mass during motion may have importance in the development of gravity compensated exercise machines. Also, a mechanism with the center of mass constrained to be inertially fixed has the same motion as if it was in zero gravity. This property may be exploited to develop test beds on earth that mimic the behavior of systems in space.

In this paper, a method is described to augment planar mechanisms with auxiliary parallelograms in order to identify a physical point on the augmented mechanism which is the center of mass of the original mechanism. The original and the augmented mechanisms have the same degrees-of-freedom. If the links of the augmented mechanism are massless, the original and augmented mechanisms have the same motion. During motion, the center of mass is a physical point on the mechanism which can be monitored or used for other purposes motivated from the application. In practice, however, if such an augmented mechanism is constructed, its links will have finite masses. As a result, under the same inputs, the motion of the original and augmented mechanisms will be different. In this paper, the effects of finite masses of the additional links on the original mechanism are also discussed.
Static Balancing of a Class of Spatial Parallel Platform Mechanisms
Authors: Ebert-Uphoff Imme , Gosselin Clément M. , Laliberté Thierry
Published: February 2021

This article discusses the development of statically balanced spatial parallel platform mechanisms. A mechanism is statically balanced if its potential energy is constant for all possible configurations. This property is very important for robotic manipulators with large payloads, since it means that the mechanism is statically stable for any configuration, i.e. zero actuator forces are required whenever the manipulator is at rest. Furthermore, only inertial forces have to be sustained while the manipulator is moving. The application that motivates this research is the use of parallel platform manipulators as motion bases in commercial flight simulators, where the weight of the cockpit results in a large static load.

We first present a class of spatial parallel platform mechanisms of novel architecture that is suitable for static balancing. Then sufficient conditions on the kinematic parameters that guarantee static balancing are derived for this class. Finally a particular mechanism is studied in more detail to show the practicability of its design.
Determination of Individual Foot-Placement Space for Modular Platform Manipulators
Authors: Ji Zhiming , Li Zhenqun
Published: February 2021

Reconfigurability of a modular platform manipulator makes it possible for the manipulator to adapt to different applications. How should the actual configuration be selected? Practical reconfiguration of platform manipulators can only be achieved when users are provided with information to guide their selection process. This paper defines the foot-placement space and presents a method for determining individual Foot-Placement Spaces (FPSs) for a given set of leg modules, based on a desired workspace. Implementation of construction method for Foot-Placement Space is discussed and illustrated with an example.
Differential Geometric Analysis of Singularities of Point Trajectories of Serial and Parallel Manipulators
Authors: Ghosal Ashitava , Ravani Bahram
Published: February 2021

In this paper, we present a differential-geometric analysis of singularities of point trajectories of two and three-degree-of-freedom serial and parallel manipulators. At non-singular configurations, the first order local properties are characterized by the metric coefficients, and, geometrically, by the shape and size of a velocity ellipse and ellipsoid for two and three-degree-of-freedom motions respectively. At singular configurations, the definition of a metric is no longer valid and the velocity ellipsoid degenerates to an ellipse, a line or a point, and the area or the volume of the velocity ellipse or ellipsoid becomes zero. The second and higher order properties, such as curvature, are also not defined at a singularity. In this paper, we use the rate of change of the area or volume to characterize the singularities of the point trajectory. For parallel manipulators, singularities may lead to either loss or gain of one or more degrees-of-freedom. For loss of degree of freedom, the ellipsoid degenerates to an ellipse, a line, or a point as in serial manipulators. For a gain of degree-of-freedom the singularities can be pictured as growth to lines, ellipses, and ellipsoids. The method presented gives a clear geometric picture as to the possible directions and magnitude of motion at a singularity and the local geometry near a singularity. The theoretical results are illustrated with the help of a general spatial 2R manipulator and a three-degree-of-freedom RPSSPR-SPR parallel manipulator.
Determination of Closed Form Solution to the Workspace of Stewart Parallel Manipulators
Authors: Huang T. , Wang J. S. , Yuan J. X.
Published: February 2021

A novel methodology is presented in this paper for the workspace analysis of Stewart parallel manipulators. The workspace is defined in such a way that enables a description to be made in a unified framework of both the position and orientation capabilities of the mobile platform. Given the orientation capability of the mobile platform which is described by the minimum reachable yaw angle, the piecewise closed solution to the position workspace boundary is formulated by means of differential geometry. It is indicated that the workspace boundary is in fact the cap of twelve envelope surfaces, each of which is generated by a family of spherical surfaces with the center moving along a two branch closed spherical curve. Two examples are given to illustrate the effectiveness of this approach.
Robust Design of Gears
Authors: Dippery Richard E. , Echempati Raghu
Published: February 2021

The terms “Robust Design” or sensitivity of a design to variance of design parameters is gaining importance in design of mechanical components and structures. This paper has been written as the result of an introductory investigation to determine the applicability of robust design for a given gear system and development of a model to perform the evaluations. Work has been performed based upon evaluation of a design being performed using AGMA standards.
Real-time in situ process monitoring and characterization of GaN films grown on Si (100) by low-temperature hollow-cathode plasma-atomic layer deposition using trimethylgallium and N2/H2 plasma
Authors: Shukla Deepa , Mohammad Adnan , Ilhom Saidjafarzoda , Willis Brian G. , Okyay Ali Kemal , Biyikli Necmi
Published: February 2021

In this work, we report on the in situ process monitoring and materials characterization of low-temperature self-limiting grown gallium nitride (GaN) thin films. GaN samples were synthesized on Si (100) substrates via remote hollow-cathode plasma-atomic layer deposition (HCP-ALD) using trimethylgallium and N2/H2 plasma as a metal precursor and a nitrogen coreactant, respectively. A multiwavelength in situ ellipsometer was employed to monitor the saturating surface reactions and determine the self-limiting growth conditions. The subangstrom thickness resolution of ellipsometry enabled the real-time observation of single chemical adsorption and plasma-induced ligand removal/exchange events. Taking advantage of this in situ capability, saturation experiments have been carried out within the 120–240 °C temperature range without interruption featuring 10-cycle subruns for each parameter change. Plasma power, plasma exposure duration, and plasma chemistry (gas composition) are the main process parameters that have been investigated. Ex situ optical, structural, and chemical characterization is carried out on 600-cycle HCP-ALD-grown GaN films as a function of substrate temperature. Hexagonal single-phase polycrystalline GaN films with (002) preferred orientation was obtained at substrate temperatures higher than 200 °C. The crystalline GaN films exhibited below-detection-limit carbon content and slightly gallium rich stoichiometry. Substrate temperature and plasma power played a critical role on GaN film properties with 200 °C and 150 W as threshold values for crystallization. Moreover, we observed that Ar-free N2/H2 plasma gas composition led to a slightly stronger (002) dominant crystal orientation.
Waiting for data: Barriers to executing data use agreements
Authors: Mello Michelle M. , Triantis George , Stanton Robyn , Blumenkranz Erik , Studdert David M.
Published: February 2021

Delays stem from institutional factors and negotiating challenges, some of which appear amenable to reform
Flipping carbon monoxide on a salt surface
Authors: Wu Shiwei
Published: February 2021

Advanced mid-infrared techniques identify orientational isomers
CRB1-associated retinal dystrophies in a Belgian cohort: genetic characteristics and long-term clinical follow-up
Authors: Talib Mays , Van Cauwenbergh Caroline , De Zaeytijd Julie , Van Wynsberghe David , De Baere Elfride , Boon Camiel J F , Leroy Bart Peter
Published: February 2021

Aim

To investigate the natural history in a Belgian cohort of CRB1-associated retinal dystrophies.

Methods

An in-depth retrospective study focusing on visual function and retinal structure.

Results

Forty patients from 35 families were included (ages: 2.5–80.1 years). In patients with a follow-up of >1 year (63%), the mean follow-up time was 12.0 years (range: 2.3–29.2 years). Based on the patient history, symptoms and/or electroretinography, 22 patients (55%) were diagnosed with retinitis pigmentosa (RP), 15 (38%) with Leber congenital amaurosis (LCA) and 3 (8%) with macular dystrophy (MD), the latter being associated with the p.(Ile167_Gly169del) mutation (in compound heterozygosity). MD later developed into a rod-cone dystrophy in one patient. Blindness at initial presentation was seen in the first decade of life in LCA, and in the fifth decade of life in RP. Eventually, 28 patients (70%) reached visual acuity-based blindness (<0.05). Visual field-based blindness (<10°) was documented in 17/25 patients (68%). Five patients (13%) developed Coats-like exudative vasculopathy. Intermediate/posterior uveitis was found in three patients (8%). Cystoid maculopathy was common in RP (9/21; 43%) and MD (3/3; 100%). Macular involvement, varying from retinal pigment epithelium alterations to complete outer retinal atrophy, was observed in all patients.

Conclusion

Bi-allelic CRB1 mutations result in a range of progressive retinal disorders, most of which are generalised, with characteristically early macular involvement. Visual function and retinal structure analysis indicates a window for potential intervention with gene therapy before the fourth decade of life in RP and the first decade in LCA.
Improvement of asymmetric thyroid eye disease with teprotumumab
Authors: Ugradar Shoaib , Wang Yao , Mester Tunde , Kahaly George J , Douglas Raymond
Published: February 2021

Purpose

Teprotumumab, a specific blocking antibody to the insulin like growth factor 1 receptor, significantly reduced proptosis in patients with thyroid eye disease (TED) in recent clinical trials. Given its specificity, we expect it to demonstrate greater efficacy on the worse affected orbit, in patients with asymmetric TED. Herein, we investigate the differential impact of teprotumumab on the orbits of such patients.

Methods

In this pooled analysis of patients who were enrolled in the recent phase 2 (NCT01868997) and phase 3 (NCT03298867) trials, all patients with asymmetric TED (difference in exophthalmometry of ≥3 mm) were screened for eligibility. The primary outcomes of the trials, proptosis, diplopia and Clinical Activity Score (CAS) response, were evaluated in both orbits of patients who had received treatment or placebo, to examine the differential response from baseline to week 24.

Results

From a pooled group of 84 patients randomised to receive teprotumumab and 87 randomised to placebo, 10 (12%) and 12 (14%), respectively, met the inclusion criteria. The teprotumumab-treated patients demonstrated significant reductions in proptosis, CAS and diplopia in both orbits of each patient and this was not seen with placebo. The reduction in proptosis and CAS was significantly greater in the worse affected orbit, improving symmetry. In the placebo arm, while the mean CAS in the study eye reduced over time, proptosis and diplopia did not change in either orbit.

Conclusion

The findings in this study suggest the differential impact of teprotumumab on orbits that are clinically more affected by TED, suggesting that teprotumumab reduces asymmetry.
Longitudinal effects of ivacaftor and medicine possession ratio in people with the
Gly551Asp
mutation: a 5-year study
Authors: Mitchell Ruth Marian , Jones Andrew M , Stocking Katie , Foden Philip , Barry Peter J
Published: February 2021

Introduction

Ivacaftor was the first therapy licensed to address the underlying defect in cystic fibrosis (CF). The improvements in lung function, nutritional status and pulmonary exacerbations in patients carrying a
Gly551Asp
mutation were greater than previously seen in clinical trials for other therapies. Limited data are available regarding long-term outcomes and adherence to ivacaftor outside clinical trials.

Methods

We conducted a 5-year single-centre retrospective study of people with CF carrying the
Gly
551
Asp
mutation who received ivacaftor. Clinical outcome data were extracted from medical notes and databases. Drug delivery data were used to assess medicine possession ratio (MPR).

Results

35 people were included. After commencing ivacaftor, FEV
1
improved by 9.6% (SE±1.59%) predicted by 6 months. Thereafter, FEV
1
declined, and at 5 years had returned to pre-ivacaftor baseline. Ivacaftor did not alter annual rate of FEV
1
decline (1.57% pre vs 1.82% post, p=0.74). Body mass index (BMI) increased for 4 years. There was a significant reduction in inpatient and total intravenous antibiotic days sustained over 5 years. MPR remained high but declined over time (−2.5±0.9% per year, p=0.007). FEV
1
was better maintained in patients with higher MPRs.

Conclusion

The addition of ivacaftor provides acute benefits for people with the
Gly551Asp
mutation and established lung disease. We report a sustained reduction in intravenous antibiotic use but following acute improvement in lung function, decline continues, and patients will continue to require medical observation and optimisation. Strategies to maintain high adherence should be a priority to prolong the benefits of ivacaftor.
Expressway Traffic Flow Missing Data Repair Method Based on Coupled Matrix-Tensor Factorizations
Authors: Jiang Hui , Deng Hongxing
Published: February 2021

Traffic flow data is the basis of traffic management, planning, control, and other forms of implementation. Once missing, it will directly affect the monitoring and prediction of expressway traffic status. Regarding this, this paper proposes a repair method for the traffic flow missing data of expressway, combined with the idea of coupled matrix-tensor factorizations (CMTF), to couple the auxiliary traffic flow data into the main traffic flow data and to construct the coupling matrix-tensor expression of traffic flow data, and the alternating direction multiplier algorithm is used to realize the repair of missing traffic flow data. Combined with the measured data of expressway traffic flow, the experimental results show that, under different missing data types and missing rates, the proposed method outperforms the methods lacking auxiliary traffic flow data and achieves a good repair effect, especially for high miss data rates.
An Improved Feature Extraction Approach for Web Anomaly Detection Based on Semantic Structure
Authors: Cheng Zishuai , Cui Baojiang , Qi Tao , Yang Wenchuan , Fu Junsong
Published: February 2021

Anomaly-based Web application firewalls (WAFs) are vital for providing early reactions to novel Web attacks. In recent years, various machine learning, deep learning, and transfer learning-based anomaly detection approaches have been developed to protect against Web attacks. Most of them directly treat the request URL as a general string that consists of letters and roughly use natural language processing (NLP) methods (i.e., Word2Vec and Doc2Vec) or domain knowledge to extract features. In this paper, we proposed an improved feature extraction approach which leveraged the advantage of the semantic structure of URLs. Semantic structure is an inherent interpretative property of the URL that identifies the function and vulnerability of each part in the URL. The evaluations on CSIC-2020 show that our feature extraction method has better performance than conventional feature extraction routine by more than average dramatic 5% improvement in accuracy, recall, and F1-score.
Chyle Leak after Right Axillary Lymph Node Dissection in a Patient with Breast Cancer
Authors: Sarawagi Ankita , Maxwell Jessica
Published: February 2021

Background. A female patient was diagnosed with a right-sided chyle leak following right skin sparing mastectomy, axillary lymph node dissection, and immediate tissue expander placement in the setting of invasive ductal carcinoma status post neoadjuvant chemotherapy. Summary. Our patient underwent a level I and II right axillary lymph node dissection followed by an axillary drain placement. On the first postoperative day, a change from serosanguinous to milky fluid in this drain was noted. The patient was diagnosed with a chyle leak based on the milky appearance and elevated triglyceride levels in the fluid. While chyle leaks are rare after an axillary dissection and even rarer to present on the right side, it is a complication of which breast surgeons should be aware. The cause of this complication is thought to be due to injury of the main thoracic duct, its branches, the subclavian duct, or its tributaries. Management is usually conservative; however, awareness of this potential complication even on the right side is of the utmost importance Conclusion. Chyle leaks are an uncommon complication of axillary node dissections and even rarer for them to present on the right side. It can be diagnosed by monitoring the drainage for changes in appearance and volume and by conducting supporting laboratory tests. Conservative management is generally suggested.
A Moving Target: Inactivating BTK Mutations as Drivers of Follicular Lymphoma
Authors: Afaghani Jumana , Taylor Justin
Published: February 2021

Drugs that target Bruton tyrosine kinase (BTK) have been highly successful and changed the landscape of therapies in B-cell lymphomas. However, their lower rates of effectiveness in follicular lymphoma are unexplained. Recent work describes inactivating BTK mutations that show that at least some follicular lymphomas do not require BTK.

See related article by Hu et al., p. 2301
ДОСЛІДЖЕННЯ ФЕНОЛЬНИХ СПОЛУК РИЖІЮ ПОСІВНОГО (CAMELINA SATIVA (L.) CRANTZ) ТА РИЖІЮ ДРІБНОПЛОДОГО (CAMELINA MICROCARPA ANDRZ.)
Authors: Tsykalo T. O. , Trzhetsynskyi S. D.
Published: February 2021

Мета роботи. Дослідити склад фенольних сполук в траві та насінні видів роду Camelina (L.) Crantz.

Матеріали і методи. Для дослідження використовували траву та насіння рижію посівного сорту Славутич і рижію дрібноплодого. Для досліджень готували водно-спиртові витяжки,  як екстрагент використовували 70 % етиловий спирт. Для попередньої оцінки якісного складу витяжок використовували якісні реакції та ТШХ-дослідження у системі розчинників н-бутанол – кислота оцтова льодяна – вода (4:1:2). Хроматограми переглядали у денному та УФ-світлі до і після обробки парами амоніаку. Визначення якісного складу та кількісного вмісту окремих фенольних сполук виконували методом ВЕРХ. Кількісне визначення загального вмісту флавоноїдів, гідроксикоричних кислот і поліфенолів виконували спектрофотометричним методом.

Результати й обговорення. В результаті ТШХ-дослідження встановлено, що у траві та насінні всіх зразків представників роду Camelina (L.) Crantz присутній рутин. В траві обох видів ідентифіковано хлорогенову кислоту. Методом ВЕРХ підтверджено наявність даних сполук і встановлено, що вміст рутину є вищим у насінні рижію дрібноплодого (0,361±0,001) %, а хлорогенової кислоти – в траві рижію дрібноплодого (0,279±0,004) %. У результаті спектрофотометричного визначення вмісту фенольних сполук в сировині даних видів встановлено, що більший вміст флавоноїдів, похідних гідроксикоричних кислот та загальний вміст фенольних сполук характерний для трави рижію посівного і складає (1,17±0,08) %, (1,47±0,03) % і (2,11±0,003) % відповідно.

Висновки. Методом ТШХ ідентифікували та методом ВЕРХ визначили кількісний вміст рутину та хлорогенової кислоти у траві та насінні рижію посівного (Camelina sativa (L.) Crantz) і рижію дрібноплодого (Camelina microcarpa Andrz.). Спектрофотометричним методом визначили загальну суму флавоноїдів, гідроксикоричних кислот та поліфенолів у досліджуваній сировині обох видів.
Catching up through comparison: The making of Finland as a political unit, 1809–1863
Authors: Kurunmäki Jussi , Marjanen Jani
Published: February 2021

The creation of Finland as a grand duchy within the Russian Empire in 1809 opened up the question of what Finland was, in fact. Comparing Finland synchronously with other countries and diachronically with itself before and after its elevation into a grand duchy gained temporal features in which its level of development was assessed. Such temporal comparisons during the first half of the 19th century were used to shape Finland as a political unit, as they facilitated assessment of which parts of society needed to improve in order to make the country comparable with imagined or real others. Given that the Diet (the Estate Assembly) was not convened between 1809 and 1863, these comparative notions largely dealt with questions of political constitution and state institutions. The comparative mindset of the Finnish actors also developed in the process of conducting temporal comparisons. These comparisons can be analyzed through the analytical categories of descriptive synchronization, comparative synchronization, and participative synchronization, the last mentioned being possible only when Finnish actors began to think that Finland, indeed, had developed to a level of maturity.
Professional Competence Among Registered Nurses Working in Hospitals in Saudi Arabia and Their Experiences of Quality of Nursing Care and Patient Safety
Authors: Halabi Jehad O. , Nilsson Jan , Lepp Margret
Published: February 2021

Introduction:

The Kingdom of Saudi Arabia (KSA) plans to become self-sufficient, generating a national nursing workforce. The study’s purpose was to assess nurses’ self-reported professional competence and illuminate experiences of the quality of nursing care and patient safety.

Methodology:

A cross-sectional design with 469 nurses working in different units from two public hospitals and Regions of the KSA participated. The Nurse Professional Competence Scale short version including six professional areas of nursing care was used.

Results:

There are significant relationships between self-reported professional competence and the quality of nursing care, patient safety, nurse’s characteristics, and workplace.

Discussion:

Registered nurses’ professional competence is related to the clinical areas in which they work and the nature of their involvement in patient care. The Nurse Professional Competence Scale can identify professional competence areas for further development, which is important for culturally congruent health care in KSA for their transformation process.
Multiple-testing correction in metabolome-wide association studies
Authors: Peluso Alina , Glen Robert , Ebbels Timothy M. D.
Published: February 2021

Background

The search for statistically significant relationships between molecular markers and outcomes is challenging when dealing with high-dimensional, noisy and collinear multivariate omics data, such as metabolomic profiles. Permutation procedures allow for the estimation of adjusted significance levels without assuming independence among metabolomic variables. Nevertheless, the complex non-normal structure of metabolic profiles and outcomes may bias the permutation results leading to overly conservative threshold estimates i.e. lower than those from a Bonferroni or Sidak correction.

Methods

Within a univariate permutation procedure we employ parametric simulation methods based on the multivariate (log-)Normal distribution to obtain adjusted significance levels which are consistent across different outcomes while effectively controlling the type I error rate. Next, we derive an alternative closed-form expression for the estimation of the number of non-redundant metabolic variates based on the spectral decomposition of their correlation matrix. The performance of the method is tested for different model parametrizations and across a wide range of correlation levels of the variates using synthetic and real data sets.

Results

Both the permutation-based formulation and the more practical closed form expression are found to give an effective indication of the number of independent metabolic effects exhibited by the system, while guaranteeing that the derived adjusted threshold is stable across outcome measures with diverse properties.
Preoperative anxiety predicted the incidence of postoperative delirium in patients undergoing total hip arthroplasty: a prospective cohort study
Authors: Ma Jun , Li Chuanyao , Zhang Wei , Zhou Ling , Shu Shuhua , Wang Sheng , Wang Di , Chai Xiaoqing
Published: February 2021

Background

Delirium was characterized with a series of symptoms of a sudden onset of disturbances in attention, a loss in memory loss and defects in other cognitive abilities that were also appeared in the syndrome of anxiety. Even though there are overlapped clinical symptoms existed in anxiety and delirium, the relationship between anxiety and delirium was still unclear. The propose of this study was to investigated the effect of preoperative anxiety on postoperative delirium.

Methods

Three hundred and seventy-two adults undergoing total hip arthroplasty were enrolled from October 2019 to May 2020 in the study. The preoperative anxiety was measured with the Hospital Anxiety and Depression Scale-Anxiety (HADS-A). The participants were allocated into anxiety group (HADS-A≧7) and non-anxiety group (HADS-A < 7). The primary outcome was the incidence of the postoperative delirium assessed with the Confusion Assessment Method (CAM). The secondary outcomes were the duration and the severity of delirium evaluated with the Memorial Delirium assessment Scale (MDAS). The risks of delirium were also evaluated with logistic regression analysis.

Results

There were 325 patients enrolled in the end, 95 of whom met the criteria for anxiety. The incidence of delirium was 17.8% in all participants. The patients with anxiety had a higher incidence of delirium than the non-anxiety patients (25.3% vs. 14.8%, odds ratio (OR) = 0.51, 95% confidence interval (CI) = 0.92–0.29,p = 0.025). However, no significant differences were found in the duration and the severity of the delirium between the above two groups. The age, alcohol abuse, history of stroke, scores of the HADS-A, and education level were considered to be predictors of delirium.

Conclusions

The preoperative anxiety predicted the incidence of the postoperative delirium in total hip arthroplasty patients. The related intervention may be a good point for delirium prophylaxis.

Trial registration

It was registered at Chinese Clinical Trial Registry (www.chictr.org.cn) with the name of “the effect of preoperative anxiety on the postoperative cognitive function” (
ChiCTR1900026054) at September 19, 2019.
Development of a novel lipid metabolism-based risk score model in hepatocellular carcinoma patients
Authors: Wang Wenjie , Zhang Chen , Yu Qihong , Zheng Xichuan , Yin Chuanzheng , Yan Xueke , Liu Gang , Song Zifang
Published: February 2021

Background

Liver cancer is one of the most common malignancies worldwide. HCC (hepatocellular carcinoma) is the predominant pathological type of liver cancer, accounting for approximately 75–85 % of all liver cancers. Lipid metabolic reprogramming has emerged as an important feature of HCC. However, the influence of lipid metabolism-related gene expression in HCC patient prognosis remains unknown. In this study, we performed a comprehensive analysis of HCC gene expression data from TCGA (The Cancer Genome Atlas) to acquire further insight into the role of lipid metabolism-related genes in HCC patient prognosis.

Methods

We analyzed the mRNA expression profiles of 424 HCC patients from the TCGA database. GSEA(Gene Set Enrichment Analysis) was performed to identify lipid metabolism-related gene sets associated with HCC. We performed univariate Cox regression and LASSO(least absolute shrinkage and selection operator) regression analyses to identify genes with prognostic value and develop a prognostic model, which was tested in a validation cohort. We performed Kaplan-Meier survival and ROC (receiver operating characteristic) analyses to evaluate the performance of the model.

Results

We identified three lipid metabolism-related genes (ME1,MED10,MED22) with prognostic value in HCC and used them to calculate a risk score for each HCC patient. High-risk HCC patients exhibited a significantly lower survival rate than low-risk patients. Multivariate Cox regression analysis revealed that the 3-gene signature was an independent prognostic factor in HCC. Furthermore, the signature provided a highly accurate prediction of HCC patient prognosis.

Conclusions

We identified three lipid-metabolism-related genes that are upregulated in HCC tissues and established a 3-gene signature-based risk model that can accurately predict HCC patient prognosis. Our findings support the strong links between lipid metabolism and HCC and may facilitate the development of new metabolism-targeted treatment approaches for HCC.
Diagnostic yield of colonoscopy surveillance in testicular cancer survivors treated with platinum-based chemotherapy: study protocol of a prospective cross-sectional cohort study
Authors: Ykema Berbel L. M. , Bisseling Tanya M. , Spaander Manon C. W. , Moons Leon M. G. , van der Biessen-van Beek Dorien , Saveur Lisette , Kerst Martijn , Mulder Sasja F. , de Wit Ronald , Zweers Danielle , Meijer Gerrit A. , Beijnen Jos H. , Lansdorp-Vogelaar Iris , van Leeuwen Flora E. , Snaebjornsson Petur , van Leerdam Monique E.
Published: February 2021

Background

Testicular cancer (TC) survivors have an increased risk of various second primary malignancies. A recent cohort study detected an increased risk of colorectal cancer (CRC) in TC survivors treated with platinum-based chemotherapy with a hazard ratio of 3.9. CRC risk increased with higher cisplatin-dose. We know that colonoscopy surveillance in high-risk populations results in reduced incidence and mortality of CRC. TC survivors treated with platinum-based chemotherapy can potentially benefit from colonoscopy surveillance; however, to which extent is unknown. Furthermore, the pathogenesis of these secondary CRCs is unknown, and better insights into the carcinogenesis may affect surveillance decisions.

Methods

This prospective multicenter study will be performed in four Dutch hospitals. TC survivors are eligible if treated with ≥ 3 cycles of cisplatin before age 50. Colonoscopy will be performed ≥ 8 years after initial treatment (minimum and maximum ages at colonoscopy, 35 and 75 years, respectively). The primary aim of the study is the diagnostic yield of advanced neoplasia detected during colonoscopy. As secondary aim, we will evaluate the molecular profile of advanced colorectal neoplasia and will assess current platinum levels in blood and urine and correlate blood-platinum levels with prevalence of colorectal lesions. Furthermore, we will investigate effectiveness of fecal immunochemical testing (FIT) and burden of colonoscopy by two questionnaires. Demographic data, previous history, results of colonoscopy, hemoglobin level of FIT and results of molecular and platinum levels will be obtained. Yield of colonoscopy will be determined by detection rate of adenoma and serrated lesions, advanced adenoma detection rate and CRC detection rate. The MISCAN model will be used for cost-effectiveness analyses of CRC surveillance. With 234 participants undergoing colonoscopy, we can detect an absolute difference of 6% of advanced neoplasia with 80% power.

Discussion

TC survivors treated with cisplatin-based chemotherapy can benefit from CRC surveillance. Evaluation of the diagnostic performance and patient acceptance of CRC surveillance is of importance to develop surveillance recommendations. Insight into the carcinogenesis of cisplatin-related advanced colorectal lesions will contribute to CRC prevention in the increasing number of TC survivors. The results may also be important for the many other cancer survivors treated with platinum-based chemotherapy.

Trial registration

Clinical Trials: NCT04180033, November 27, 2019,https://clinicaltrials.gov/ct2/show/NCT04180033.
Determinants of ectopic pregnancy among pregnant women attending referral hospitals in southwestern part of Oromia regional state, Southwest Ethiopia: a multi-center case control study
Authors: Gerema Urge , Alemayehu Tilahun , Chane Getachew , Desta Diliab , Diriba Amenu
Published: February 2021

Background

Ectopic pregnancy is an abnormal condition in which implantation of the blastocyst occurs outside the endometrium of the uterus. It is gynecological important, particularly in the developing world, because of associated with enormous rate of high morbidity, during the first trimester of pregnancy. A better understanding of its risk factors can help to prevent its prevalence. However, the determinants of ectopic pregnancy are not well understood and few researches conducted in our country were based on secondary data covering small scale area. This study aimed to identify determinants of ectopic pregnancy among pregnant women attending referral hospitals in Southwestern part of Oromia regional state, Southwest Ethiopia.

Methods

Hospital-based case control study was employed from June 1 to September 30, 2019. The study was conducted in five referral hospitals in Southwestern part of Oromia regional state. Final sample size includes 59 cases and 118 controls. Data were entered by using Epidata version 3.1 and analyzed using SPSS version 23. Descriptive statistics were used to explore the data. All explanatory variables with p-value of < 0.25 in bi-variable analysis, then entered into multivariable logistic regression. Associated factors were identified at 95% confidence interval (p < 0.05).

Results

Out of 177 (59 cases and 118 controls) participants, 174 (58 cases and 116 controls) were participating in the study. Prior two or more induced abortions [AOR = 3.95:95% CI: 1.22–13.05], previous history of caesarean section [AOR = 3.4:95% CI: 1.11–10.94], marital status (being single) [AOR = 4.04:95%CI: 1.23–13.21], reporting prior recurrent sexual transmitted infection [AOR = 2.25:95%CI: 1.00–5.51], prior history of tubal surgery [AOR = 3.32:95%CI: 1.09–10.13], were more likely to have an ectopic pregnancy with their respective AOR with 95%CI.

Conclusion

It was found that having a history of more than two induced abortions during previous pregnancies, marital status (single), recurrent sexual transmitted infection, prior history of tubal surgery and experiencing prior caesarean section were found to be determinants of ectopic pregnancy. Hospitals should give emphasis on prevention and early detection of risks of ectopic pregnancy and create awareness in order to reduce the burden of ectopic pregnancy.