bluuebunny/crossref_metadata_2025 huggingface dataset:
Time-varying stiffness model of spur gear considering the effect of surface morphology characteristics
Authors: Liu Zhifeng , Zhang Tao , Zhao Yongsheng , Bi Shuxin
Published: May 2018

The nonuniform cantilever beam and Hertzian contact model have been widely used to derive the mesh stiffness of spur gear assuming that the contact surface is absolutely frictionless. However, studies have confirmed that machined surfaces are rough in microscale and can be simulated by the Weierstrass–Mandelbort function. In order to get a reasonable and precise mesh stiffness model, the M-B contact model and finite element method are combined to express the local contact stiffness Kh. Through the simulation and comparison, the analytical finite element method is proved to be consistent with the traditional models and introduces the roughness parameters of machined tooth surface into the meshing process. Furthermore, the results also show that it is advantageous to improve the total mesh stiffness by increasing the fractal dimension D and input torque T as well as decreasing the roughness parameter G. In this paper, a relationship is built between the total mesh stiffness of gear sets with tooth surface characters and input torque, which can be a guidance in the design of the tooth surface parameters and the choice of the processing method in the future.
Analysis of vertical vibration characteristics of the vehicle-flexible track coupling system under wind load and track irregularity
Authors: Ji Zhanling , Yang Guowei , Liu Yubiao , Jiang Qian
Published: May 2018

In this study, to overcome the inherent problem caused by simulating infinite rail using finite rail, a method that combines flexible rail embedded in SIMPACK and a flexible track board imported from ANSYS on a SIMPACK platform is first proposed, by which vehicle-flexible track coupling is effectively realized. The method takes into account the simulation precision and computational efficiency. Using the proposed method, and comprehensively considering wind load, track irregularity, and minor track elasticity, the dynamic characteristics of high-speed train are solved conveniently and quickly. They are simulated under the conditions close to the objective reality. On this basis, the influences of many factors on the vibration characteristics of the train are analyzed, which include car body state, track state, mode numbers of the car body, wind load, track irregularity, and vehicle speed. In addition, the simulation results are basically consistent with the test results. This work lays a solid foundation for subsequent research on noise, fatigue, and the reliability of the train.
Energy-efficient operation of pump drives in a cement plant
Authors: Choudhary PK , Dubey SP
Published: May 2018

Electric motors consume a large share of electricity in cement industries. Traditionally, most of the motor applications use variable frequency drive to save electricity, but they do not optimally minimize power consumption always. Pumps and fans are the applications where significant energy savings can be obtained at partial load by implementing optimal flux control. The present work identifies 10 large-size pump motors of an integrated cement manufacturing unit and proposes optimal flux control in a novel way during their operation. The proposed method eliminates run-time optimal flux computations, perturbations, and convergence issues as compared to conventional techniques along with excellent dynamic response. Significant savings of $0.237 million in annual energy cost, 3261.6 tons of combusted coal, and reduction of 3359.5 tons green-house gas emissions in a year are estimated at an average 90% loading condition. The estimated energy saving will be in line with “good practice” benchmarks for industries.
Failure modes and face instability of shallow tunnels under soft grounds
Authors: Zhang Zhiqiang , Li Huayun , Yang Hongyu , Wang Bo
Published: May 2018

For shallow tunnels under soft grounds, it is very difficult to gain a complete understanding on all the load-bearing arch effects during excavation, since such tunnels can easily deform or even collapse. Among these effects, the tunnel face stability plays the most important role and has not been understood and handled very well; therefore, the design and construction of such tunnels under soft grounds remain as a challenge. In this work, the different failure models of face instability of the shallow tunnels were established based on the upper-bound theorem of limit analysis for the formation of clayey and sandy soils, respectively, and the analytical equations for determining the limit support force for the face stability were also derived. Furthermore, the influences of various factors on the stability were analyzed and compared. For the sandy soil formation, an equivalent pressure coefficient was proposed for the tunnel faces of bolt reinforcement. Finally, taking the face stability of the shallow tunnels in sandy soils as an example, a complete numerical simulation was conducted to verify the accuracy and effectiveness of the analytical results based on the theoretical models as well as their application conditions.
On the gyroscopic and centrifugal effects in the free vibration of rotating beams
Authors: Yang Xiao-Dong , Li Zhen , Zhang Wei , Yang Tian-Zhi , Lim CW
Published: May 2018

This paper addresses the gyroscopic and centrifugal effects on vibrations of rotating Bernoulli–Euler beams. The gyroscopically coupled system is established as a complex eigenvalue problem. It is concluded that there exist three types of velocity-dependent terms that contribute to the natural frequencies with different effects. In particular, the contribution of gyroscopic terms and static and dynamic centrifugal terms to the natural frequencies are discussed for free vibrations of rotating beams with constant angular velocity. On the other hand, the vibrations in different directions coupled through the gyroscopic terms are investigated. Some numerical examples for the elliptic vibration modes in the rotating plane are presented and the results reveal the actual vibration contour of the rotating beams.
A modified energy-saving skyhook for active suspension based on a hybrid electromagnetic actuator
Authors: Ding Renkai , Wang Ruochen , Meng Xiangpeng , Chen Long
Published: May 2018

This study proposes a modified energy-saving skyhook consisting of active control, energy regeneration, and switch. The modified skyhook coordinates the contradiction between dynamic performance and energy consumption of electromagnetic active suspension. The control principle is analyzed, the switch condition between active control and energy recovery is provided, and the switch control system is designed for simulation. Results demonstrate that the presented strategy can coordinate the dynamic performance and energy consumption effectively. The realization structure, namely, a hybrid electromagnetic actuator, is then designed to satisfy the control requirements. It integrates a linear motor and a hydraulic damper. The linear motor is used for active control or energy regeneration, while the hydraulic damper is used to guarantee basic dynamic performance. The structural dimension of hybrid electromagnetic actuator is optimized to increase air gap flux density with the volume and weight limitation. A prototype is fabricated, and a bench test is conducted. Results show that the structure can satisfy the control requirements. Some errors within a reasonable range are also observed between the test and the simulation because the simulation model is prepared under ideal conditions.
Effect of frequency scaling granularity on energy-saving strategies
Authors: Sundriyal Vaibhav , Keipert Kristopher , Sosonkina Masha , Gordon Mark S
Published: May 2018

Energy efficiency and energy proportional computing have become major constraints in the design of modern exascale platforms. Dynamic voltage and frequency scaling (DVFS) is one of the most commonly used and effective techniques to dynamically reduce power consumption based on workload characteristics. Many energy-saving strategies, however, employ DVFS without considering its applicability level in a given multicore processor. The present work demonstrates that disregarding the DVFS granularity as a design constraint while developing energy-saving strategies may reduce the efficacy of the strategy for certain application classes. Specifically, DVFS applicability levels (called granularities) are determined here for three different Intel processor microarchitectures. Then, the degradation in energy savings is evaluated if the DVFS granularity is disregarded. Experiments were conducted on the widely used quantum chemistry packages, General Atomic and Molecular Electronic Structure System (GAMESS) and NWChem, and show that, for granularity unaware energy-saving techniques, the overall energy consumption may increase by as much as 19%.
More care out of hospital? A qualitative exploration of the factors influencing the development of the district nursing workforce in England
Authors: Drennan Vari M
Published: May 2018

Objectives

Many countries seek to improve care for people with chronic conditions and increase delivery of care outside of hospitals, including in the home. Despite these policy objectives in the United Kingdom, the home visiting nursing service workforce, known as district nursing, is declining. This study aimed to investigate the factors influencing the development of district nursing workforces in a metropolitan area of England.

Methods

A qualitative study in a metropolitan area of three million residents in diverse socio-economic communities using semi-structured interviews with a purposive sample of senior nurses in provider and commissioning organizations. Thematic analysis was framed by theories of workforce development. Findings: All participants reported that the context for the district nursing service was one of major reorganizations in the face of wider National Health Service changes and financial pressures. The analysis identified five themes that can be seen to impact the ways in which the district nursing workforce was developed. These were: the challenge of recruitment and retention, a changing case-mix of patients and the requirement for different clinical skills, the growth of specialist home visiting nursing services and its impact on generalist nursing, the capacity of the district nursing service to meet growing demand, and the influence of the short-term service commissioning process on the need for long-term workforce development.

Conclusion

There is an apparent paradox between health policies which promote more care within and closer to home and the reported decline in district nursing services. Using the lens of workforce development theory, an explanatory framework was offered with factors such as the nature of the nursing labour market, human resource practices, career advancement opportunities as well as the contractual context and the economic environment.
An economic cost analysis of an expanding, multi-state behavioural telehealth intervention
Authors: Yilmaz Siobhan K , Horn Brady P , Fore Chris , Bonham Caroline A
Published: May 2018

Introduction

In this paper the economic costs associated with a growing, multi-state telepsychiatry intervention serving rural American Indian/Alaska Native populations were compared to costs of travelling to provide/receive in-person treatment.

Methods

Telepsychiatry costs were calculated using administrative, information-technology, equipment and technology components, and were compared to travel cost models. Both a patient travel and a psychiatrist travel model were estimated utilising ArcGIS software and unit costs gathered from literature and government sources. Cost structure and sensitivity analysis was also calculated by varying modeling parameters and assumptions.

Results and Discussion

It is estimated that per-session costs were $93.90, $183.34, and $268.23 for telemedicine, provider-travel, and patient-travel, respectively. Restricting the analysis to satellite locations with a larger number of visits reduced telemedicine per-patient encounter costs (50 or more visits: $83.52; 100 or more visits: $80.41; and 150 or more visits: $76.25). The estimated cost efficiencies of telemedicine were more evident for highly rural communities. Finally, we found that a multi-state centre was cheaper than each state operating independently.

Conclusions

Consistent with previous research, this study provides additional evidence of the economic efficiency associated with telemedicine interventions for rural American Indian/Alaska Native populations. Our results suggest that there are economies of scale in providing behavioural telemedicine and that bigger, multi-state telemedicine centres have lower overall costs compared to smaller, state-level centres. Additionally, results suggest that telemedicine structures with a higher number of per-satellite patient encounters have lower costs, and telemedicine centres delivering care to highly rural populations produce greater economic benefits.
Door to needle time and functional outcome for mild ischemic stroke over telestroke
Authors: Harvey Jillian , Al Kasab Sami , Almallouhi Eyad , Guerrero Waldo R , Debenham Ellen , Turner Nancy , Aysse Patricia , Holmstedt Christine A
Published: May 2018

Introduction

Faster intravenous alteplase (tPA) administration from time of symptom onset is associated with better functional outcome. Lack of recognition of mild ischemic stroke (MIS) might result in delay in treatment with tPA. We hypothesise that patients with MIS have a longer door to needle (DTN) time when compared to patients with severe stroke symptoms.

Methods

Data on all patients who received tPA at spoke hospitals through the Medical University of South Carolina (MUSC) telestroke network were analysed. Collected data included baseline characteristics, stroke severity on presentation measured by the National Institute of Health Stroke Scale (NIHSS), the rate of symptomatic intracerebral haemorrhage, discharge location, and discharge functional outcome measured by the modified Rankin scale.

Results and Discussion

Of the 454 patients treated with tPA through the MUSC telestroke network in the period from January 2013 to April 2017, 98 (22%) had MIS defined as NIHSS ≤ 5 on presentation; the remaining 356 (78%) patients were found to have severe stroke defined as NIHSS > 5 on presentation. Patients presenting with MIS were found to have a delay in receiving intravenous tPA by ∼10 min ( p = 0.007) and approximately 15% of them had poor functional outcome at discharge. Patients with a MIS on presentation have significantly more prolonged DTN time. Nearly 15% of low severity strokes had poor outcome even after receiving tPA.
Cardiology electronic consultation (e-consult) use by primary care providers at VA medical centres in New England
Authors: Kim Eun Ji , Orlander Jay D , Afable Melissa , Pawar Sumeet , Cutrona Sarah L , Simon Steven R , Strymish Judith , Vimalananda Varsha G
Published: May 2018

Introduction

E-consultations (e-consults) were implemented at VA medical centers to improve access to specialty care. Cardiology e-consults are among the most commonly requested, but little is known about how primary care providers (PCPs) use cardiology e-consults to access specialty care.

Methods

This is a retrospective analysis of 750 patients’ medical charts with cardiology e-consults requested by medical providers (October 2013–September 2015) in the VA New England Healthcare System. We described the patients and referring provider characteristics, and e-consult questions. We reviewed cardiologists’ responses and examined their recommendations.

Results

Among the 424 e-consults requested from PCPs, 92.7% were used to request answers to clinical questions, while 7.3% were used for administrative purposes. Among the 393 e-consults with clinical questions, 60 e-consults were regarding preoperative management; these questions most commonly addressed general risk assessment ( n = 44), anti-coagulation/anti-platelet management ( n = 33), and EKG interpretation ( n = 20). Cardiologists provided answers for the majority (89.6%) of clinical questions. Among the e-consults in which cardiologists did not provide answers or clinical guidance ( n = 41), the reasons included missing or insufficient clinical information ( n = 18), medical complexity ( n = 6), and deferment to the patient’s non-VA primary cardiologist ( n = 7). Cardiologists recommended that the patients be seen as face-to-face consults for 7.9% of e-consults.

Discussion

Primary care providers are the most frequent requesters of cardiology e-consults, using them primarily to obtain input on clinical questions. Cardiologists did not provide answers for one in ten, owing principally to insufficient available clinical information. Educating PCPs and standardizing the template for requesting e-consultation may help to reduce the number of unanswered e-consults.
Cirrhosis increases complication rate and overall mortality in patients with traumatic lung injury
Authors: Grigorian Areg , Albertson Spencer , Delaplain Patrick T , Gabriel Viktor , Maithel Shelley , Dosch Austin , Schubl Sebastian , Joe Victor , Nahmias Jeffry
Published: May 2018

Introduction

Hepatic cirrhosis is associated with an increased mortality in trauma. However, the association between cirrhosis and outcomes in traumatic lung injury has not been investigated. We hypothesize that cirrhosis adversely affects mortality and increases complications after traumatic lung injury.

Methods

A retrospective analysis of the National Trauma Data Bank was performed between 2007 and 2015. Patients ≥ 18 years of age with traumatic lung injury were identified and grouped by the presence or absence of cirrhosis. Patients that died in the emergency department or those with a severe (grade > 3) abbreviated injury scale for head trauma were excluded. The primary outcome was mortality.

Results

Out of 6,774,260 patients, 578,883 (8.5%) presented with traumatic lung injury. Of these, 1971 (0.3%) had a concomitant diagnosis of cirrhosis. The cirrhotic group was significantly older (median age, 56 versus 42 years, p < 0.001) and more likely to be hypotensive on admission (9.3% versus 6.7%, p < 0.001). There was no difference in injury severity score (p > 0.05). Patients with cirrhosis had a significantly longer median length of stay (12.5 versus 8.8 days, p < 0.001), rates of acute kidney injury (7.6% versus 1.4%, p < 0.001), acute respiratory distress syndrome (7.3% versus 2.9%, p < 0.001), pneumonia (12.9% versus 5.9%, p < 0.001), and overall mortality (20.6% versus 5.6%, p < 0.001). After adjusting for significant covariates, cirrhosis (OR = 6.26, 95% CI = 5.49–7.14, p < 0.001) was found to be an independent risk factor for mortality in patients with traumatic lung injury.

Conclusion

Cirrhosis in patients with traumatic lung injury is associated with more than a sixfold higher risk of mortality and increased rates of complications such as acute kidney injury and acute respiratory distress syndrome. While much focus has been on increased mortality of cirrhosis in patients with concomitant abdominal solid organ or traumatic brain injury, our study suggests cirrhosis with traumatic lung injury to possibly be an even worse prognosticator.
The influence of incorporation of silica and carbon nanoparticles on the mechanical properties of hybrid glass fiber reinforced epoxy
Authors: Megahed M , Megahed AA , Agwa MA
Published: May 2018

Recently, the study of hybrid nanocomposites has attracted much attention because they are highly expected for being used in many applications. In this context, there is an insisting need to investigate the effect of incorporation of silica and carbon particulates nanofillers into epoxy reinforced with woven and nonwoven tissue glass fiber. The influence of incorporation of silica (SiO2) and carbon black nanoparticles (C) with different weight fractions on the tensile properties, impact strength and fatigue performance of epoxy matrix reinforced with two types of E-glass fiber was investigated. The results showed an improvement in tensile properties, impact strength and fatigue life with addition of almost all nanoparticles contents considerably with respect to that of the neat glass fiber reinforced epoxy composites (NGFRE). Hybrid composites filled with 0.5 wt.% C exhibited the highest tensile strength and fatigue performance with an enhancement of 19% and 60% compared to NGFRE, respectively. An increase of 57% and 28% in tensile modulus and impact strength over NGFRE was obtained respectively with hybrid composites filled with 1 wt.% C. Adding 0.25 wt.% SiO2 and 0.25 wt.% C simultaneously showed an improvement in mechanical properties. SEM images of tensile and impact fracture surfaces are presented for CS 0.5 specimens which in turn reveal weak fiber/matrix interface.
Spider peptide toxin lycosin-I induces apoptosis and inhibits migration of prostate cancer cells
Authors: Shen Hongwei , Xie Yuan , Ye Senlin , He Kancheng , Yi Lu , Cui Rongrong
Published: May 2018

Spider toxins are molecularly diverse and some display not only a strong antibacterial effect but also exhibit significant inhibition of tumor growth and promote tumor cell apoptosis. The aim of the present investigation was to explore different antitumor effects of the spider peptide toxin lycosin-I through different pathways at different concentrations. It was found that by inactivating STAT3 pathway, high concentrations of lycosin-I induce apoptosis in prostate cancer cells and low concentrations of lycosin-I inhibit the migration of prostate cancer cells. This finding provides favorable evidence for further study of the molecular diversity of spider toxins.

Impact statement

The spider peptide toxin has become an important research topic. These toxins are molecularly diverse and some display not only a strong antibacterial effect but also exhibit significant inhibition of tumor growth and promote tumor cell apoptosis. Inspired by previous studies, the present study aims to investigate the effects of different concentrations of lycosin-I on the invasiveness and apoptosis of human prostate cancer cells. The findings provide favorable evidence for further study of the molecular diversity of spider toxins.
Novel interleukin-33 and its soluble ST2 receptor as potential serum biomarkers in parotid gland tumors
Authors: Pawel Sowa , Maciej Misiolek , Maciej Zielinski , Bogdan Mazur , Monika Adamczyk-Sowa
Published: May 2018

An increasing number of patients with parotid gland tumors have been observed in recent years. The relationship between the immune system and tumor formation is thoroughly investigated. However, newly discovered molecules offer a new insight into the pathophysiology of malignancies. It would be ideal to find an easily determinable biomarker of tumor existence, its malignant potential or a biomarker suggesting the probability of disease recurrence. Our study is the first to examine serum concentrations of IL-33 and its sST2 receptor in patients with various types of parotid gland tumors. Serum IL33, sST2, IL-4 and IL-10 concentrations were determined in patients with benign and malignant parotid gland tumors (pleomorphic adenoma, Warthin’s tumor, myoepithelioma and acinic cell carcinoma). We observed for the first time that serum IL-33 level was significantly elevated in patients with various types of parotid gland tumors and sST2 levels were significantly higher in pleomorphic adenoma and acinic cell carcinoma patients compared to the controls. Our results demonstrate for the first time that serum IL-33 and its sST2 receptor may be important factors in the pathology of parotid gland tumors. Although our results are promising, further investigations are required to detect if serum concentrations of those molecules may be a biomarker in parotid gland tumors.

Impact statement

Parotid gland tumors seem to be an increasingly important medical challenge, mostly due to a noticeable increase in the incidence. It would be crucial to find an easily determinable biomarker of tumor existence, its recurrence or malignant potential. We observed for the first time that serum IL-33 level was significantly elevated in patients with various types of parotid gland tumors and its sST2 receptor levels were significantly higher in pleomorphic adenoma and acinic cell carcinoma patients compared to the controls. We believe that our study helps to understand the biology of the tumors and a potential role of a relatively newly identified cytokine IL-33 in the pathophysiology of the parotid gland tumors.
Matrix metalloproteinase-9 gene polymorphisms and their interaction with environment on subarachnoid hemorrhage risk
Authors: Wang Tao , Fu Wanxing , Song Shuang , Han Yanlong , Yao Lihong , Lu Youkui , Zheng Junshuai , Wang Jing
Published: May 2018

The current study aimed to investigate the relations of three single nucleotide polymorphisms of matrix metalloproteinase-9 gene, and single nucleotide polymorphisms-smoking interaction to subarachnoid hemorrhage risk. The optimal pattern of the interaction among single nucleotide polymorphisms and smoking was selected by generalized multifactor dimensionality reduction. The association between the three single nucleotide polymorphisms within the matrix metalloproteinase-9 gene was analyzed by logistic regression test. As well as genetic risk of subarachnoid hemorrhage interactions with smoking, the risk of subarachnoid hemorrhage in carriers with the rs3918242 (T) was significantly higher than in carriers carrying CC (genotype: CT + TT vs. CC), adjusted OR (95% CI) = 1.58 (1.25–2.03), and in carriers carrying rs17576- (genotype: AG + GG vs. AA), adjust OR (95% CI) = 1.62 (1.19–2.13). However, after adjusting for covariates, we did not find any direct association between rs17577 and subarachnoid hemorrhage risk. The generalized multifactor dimensionality reduction model shows a potential relation between rs3918242 and smoking risk for subarachnoid hemorrhage ( P = 0.0010). After covariates adjustment, current smokers with rs3918242-CT or TT genotype, compared to never-smokers with rs3918242-CC genotype, OR (95% CI) = 2.57 (1.74–3.46), have a higher subarachnoid hemorrhage risk. Our study showed that the rs3918242 (T) and rs17576 (G), the cross reaction between rs3918242 and smoking increased the risk of subarachnoid hemorrhage.

Impact statement

Matrix metalloproteinase-9 ( MMP-9) is a possible candidate gene for some diseases, including metabolic syndrome, stroke, coronary artery disease (CAD). But to date, limited data focused on the relationship between MMP-9 gene SNPs and SAH susceptibility. The purpose of this study was to evaluate SNPs of MMP-9 gene and their interaction with environmental factors with SAH risk based on a Chinese population.
Acute retinal hemorrhage after Pipeline embolization device placement for treatment of ophthalmic segment aneurysm: A case report
Authors: Adeeb Nimer , Moore Justin , Griessenauer Christoph J , Gupta Raghav , Fazelat Ahad A , Ogilvy Christopher S , Thomas Ajith J
Published: May 2018

Introduction

Ophthalmic segment aneurysms may present with visual symptoms due to direct compression of the optic nerve. Treatment of these aneurysms with the Pipeline embolization device (PED) often results in visual improvement. Flow diversion, however, has also been associated with occlusion of the ophthalmic artery and visual deficits in a small subset of cases.

Case report

A 49-year-old Caucasian female presented with subarachnoid hemorrhage due to a ruptured anterior communicating artery aneurysm. On follow-up imaging, the patient was found to have a right asymptomatic ophthalmic segment aneurysm. Due to the irregular shape of the aneurysm and history of aneurysmal subarachnoid hemorrhage, the decision was made to treat the aneurysm with a PED. Postoperatively, the patient complained of floaters in the right eye. Detailed ophthalmologic examination showed retinal hemorrhage and cotton-wool spots on the macula. Such complication after PED placement has never been reported in the literature.

Conclusion

Visual complications after PED placement for treatment of ophthalmic segment aneurysms are rare. It is thought that even in cases where the ophthalmic artery occludes, patients remain asymptomatic due to the rich collateral supply from the external carotid artery branches. Here we report a patient who developed an acute retinal hemorrhage after PED placement.
Spontaneous direct carotid-cavernous sinus fistula secondary to a persistent primitive trigeminal artery treated by trans-venous coil embolisation
Authors: Imrie Andrew , Redmond Kendal , Leggett David
Published: May 2018

A healthy 51-year-old female presented with a spontaneous direct carotid-cavernous sinus fistula associated with a persistent primitive trigeminal artery. She had no history of connective tissue or cerebrovascular disorders or significant head trauma. This is a rare lesion with only 18 previously reported cases. It had similar clinical presentation and imaging appearance to a high-flow direct carotid-cavernous fistula and was uncovered after successful trans-venous coil embolisation of the fistula. It therefore needs to be considered in cases of direct carotid-cavernous fistula without history of trauma. Knowledge of types of persistent primitive trigeminal artery is also important for their critical treatment implications.
Charting the practical dimensions of understaffing from a managerial perspective: The everyday shape of the UK’s sonographer shortage
Authors: Waring Lorelei , Miller Paul K , Sloane Charles , Bolton Gareth
Published: May 2018

Introduction

Across the last two decades, ultrasound services in many healthcare sectors have become increasingly pressurised as a consequence of upsurging demand and difficulties in recruiting viable clinicians. Indeed by 2013, the UK government’s Migration Advisory Committee had listed sonography as an official ‘shortage specialty’. Comparatively little research has to date, however, explored the impacts of this situation upon the departments themselves, and the individuals working therein. The core purpose of this study is, thus, to lend qualitative depth to current understandings of the frontline situation in the UK’s ultrasound units, many of which are understaffed, from the perspective of their managers.

Methods

Using a thematic analysis informed by a Straussian model of Grounded Theory, N = 20 extended accounts provided by ultrasound department leads in public ( n = 18) and private ( n = 2) units were explored.

Results

Four global themes emerged from the analysis of which the first two (the broadly sociological matters) are described in this paper. Theme 1 addresses how a lack of staff in the broader ultrasound economy has created a troublesome migratory system in contemporary UK ultrasound. Theme 2 addresses how this economy works chiefly to the advantage of the most junior and the most senior clinicians, often leaving mid-career professionals in the borderline impossible situation of having to concurrently occupy both junior and senior roles.

Conclusions

The findings ideally open up debate on some key practical contingencies of the UK’s sonographer shortage, and reflect upon literature regarding the nuanced aspects of a shifting healthcare workplace constitution.
Clinical measurement of the dart throwing motion of the wrist: variability, accuracy and correction
Authors: Vardakastani Vasiliki , Bell Hannah , Mee Sarah , Brigstocke Gavin , Kedgley Angela E.
Published: May 2018

Despite being functionally important, the dart throwing motion is difficult to assess accurately through goniometry. The objectives of this study were to describe a method for reliably quantifying the dart throwing motion using goniometric measurements within a healthy population. Wrist kinematics of 24 healthy participants were assessed using goniometry and optical motion tracking. Three wrist angles were measured at the starting and ending points of the motion: flexion–extension, radial–ulnar deviation and dart throwing motion angle. The orientation of the dart throwing motion plane relative to the flexion–extension axis ranged between 28° and 57° among the tested population. Plane orientations derived from optical motion capture differed from those calculated through goniometry by 25°. An equation to correct the estimation of the plane from goniometry measurements was derived. This was applied and differences in the orientation of the plane were reduced to non-significant levels, enabling the dart throwing motion to be measured using goniometry alone.
Factors affecting surgical outcomes of digital glomus tumour: a multicentre study
Authors: Kim Young Jun , Kim Dong Hee , Park Jin Sung , Baek Jong Hun , Kim Kyu Jin , Lee Jae Hoon
Published: May 2018

This was a retrospective, multicentre study using data from four medical institutions of 72 patients of histologically confirmed digital glomus tumour removed by surgical excision. Mean follow-up period was 5.4 years. We investigated clinical outcomes and analysed the relationship between primary glomus tumour size, radiographic bony erosion, anatomic location, surgical approach, and surgical method as risk factors for recurrence. Complications and recurrence rate according to surgical approach and surgical method were compared. At final follow-up, recurrence was observed in five (6.9%) patients. Postoperative complications were observed in nine (12.5%), with two patients having numbness of fingertips, and seven having nail deformities. In a group with pulp lesions for which a direct approach was used and in a surgical loupe group, recurrence rates were high, however, this was not statistically significant. A nail-sparing approach and microscopic excision did not lower the incidence of nail deformities. No risk factors that significantly predicted recurrence were found.

Level of evidence: IV
Sites of fractures in explanted NeuFlex® silicone metacarpophalangeal joint prostheses
Authors: Joyce Thomas J. , Giddins Grey
Published: May 2018

Single-piece silicone implants dominate metacarpophalangeal joint arthroplasty. The NeuFlex® implant was introduced to improve on the clinical performance of other silicone implants by having a pre-flexed hinge. By visually examining a cohort of 30 explanted NeuFlex® metacarpophalangeal joint prostheses we sought to identify the failure modes of these implants. Seven were not fractured, 11 had fractured across the hinge, nine had fractured at the junction of the distal stem and the hinge, and three showed fractures at both the hinge and at the junction of the distal stem and the hinge. These data may prove helpful in identifying how the performance of single-piece silicone implant designs can be improved.
Long-term results of arthroscopic and mini-open repair of small- to medium-size full-thickness rotator cuff tears
Authors: van Deurzen DFP , Scholtes VAB , Willems WJ , Geerdink HH , van der Woude HJ , van der Hulst VPM , van den Bekerom MPJ
Published: May 2018

Background

This retrospective cohort study evaluated functional outcome and structural integrity after arthroscopic- or mini-open repair of small- to medium-size rotator cuff tears assessed at long-term follow-up.

Methods

All patients operated between 2001 and 2004 were invited to participate. Functional outcome was measured by Constant–Murley Score, Disability of Arm, Shoulder and Hand and Oxford Shoulder Score. Quality of life was assessed with EuroQol Health 5 Dimension. Patient satisfaction was assessed in terms of pain and overall result. Structural integrity of the rotator cuff repair was determined using ultrasound.

Results

Of the eligible 62 patients, 44 patients were available for follow-up. After a mean of 11.3 years, 76% of the patients had good to excellent functional outcome on the Constant–Murley Score (median 82, range 29–95). The majority of patients reported good results on both Disability of Arm, Shoulder and Hand and Oxford Shoulder Score (median Disability of Arm, Shoulder and Hand 5.0, range 1.0–54; median Oxford Shoulder Score 19, range 13–39). The quality of life was also good (mean EuroQol Health 5 Dimension utility score 0.88, standard deviation 0.12). Eighty per cent was satisfied with the overall result. Ultrasound examination revealed structural integrity in 76% of all cases.

Conclusion

This study shows that functional outcome is good and structural integrity is high for the majority of patients 11.3 years after repair of small- to medium-size rotator cuff lesions.
The short-term effect of swimming training load on shoulder rotational range of motion, shoulder joint position sense and pectoralis minor length
Authors: Higson Emma , Herrington Lee , Butler Carl , Horsley Ian
Published: May 2018

Background

Shoulder pain or injury is the most common issue facing elite competitive swimmers and the most frequent reason for missed or modified training. Literature suggests that highly repetitive upper limb loading leads to inappropriate adaptations within the shoulder complex. The most likely maladaptations to occur are variations in shoulder rotational range of motion, reduction in joint position sense and shortened pectoralis minor length. This has yet to have been confirmed in experimental studies. The aim of this study was to investigate the short-term effects of swimming training load upon internal and external rotation range of motion, joint position sense and pectoralis minor length.

Method

Sixteen elite swimmers training in the British Swimming World Class programme participated. Measures of internal and external range of motion, joint position sense error score and pectoralis minor length were taken before and after a typical 2 h swimming session.

Results

Following swimming training shoulder external rotation range of motion and pectoralis minor length reduced significantly (−3.4°, p = <0.001 and −0.7 cm, p = <0.001, respectively), joint position sense error increased significantly (+2.0° error angle, p = <0.001). Internal rotation range of motion demonstrated no significant change (−0.6, p = 0.53).

Discussion

This study determined that elite level swimming training results in short-term maladaptive changes in shoulder performance that could potentially predispose them to injury.
Endoscopic full‐thickness resection of duodenal lesions—a retrospective analysis of 20 FTRD cases
Authors: Bauder Markus , Schmidt Arthur , Caca Karel
Published: May 2018

Background

Endoscopic resections in the duodenum harbor a significant risk of complications. The full‐thickness resection device (FTRD) has shown favorable results concerning efficacy and safety in the resection of colorectal lesions. Data of its use in the duodenum are limited to a single, small case series (n = 4).

Methods

Data of all consecutive patients scheduled for endoscopic full‐thickness resection (EFTR) of duodenal lesions by FTRD in our institution were collected and analyzed retrospectively. Primary endpoint was technical success.

Results

Between March 2014 and June 2017 EFTR of a duodenal lesion was planned in a total of 20 patients. Overall technical success was 17/20 (85.0%). Indication for EFTR was: adenomas (n = 13, seven treatment naïve, six pretreated), subepithelial tumors (n = 5) and T1 adenocarcinoma (n = 1). The FTRD could be advanced to the lesion in 19/20 cases (95.0%). R0‐resection rate was 12/19 (63.2%). During follow‐up after 3 and 12 months there were two recurrent adenomas that were successfully re‐resected by FTRD. Minor bleedings occurred at the first postinterventional day in 3/19 (15.8%). There were no major bleedings and perforations.

Conclusion

This study confirmed the feasibility of duodenal EFTR and indicates good efficacy and safety. Larger studies are needed to further investigate this novel technique.
The distal radius palmar cortical angle in adolescent versus adult populations
Authors: Breheny Shane , Chang Angela Christine , De Silva April , Allcock Paul
Published: May 2018

Purpose:

Volar distal radius plates are pre-contoured to aid restoration of anatomy during open reduction internal fixation of distal radius fractures. Incorrectly contoured plates can result in malreduction, leading to malunion, pain, and loss of function. The purpose of this study was to investigate whether adolescent distal radius anatomy on the palmar cortical surface differs from that in adults, in order to determine whether adult plates are suitable for use in adolescents.

Methods:

Lateral wrist radiographs were used to measure the distal radius palmar cortical angle (PCA) in adolescent age groups (12–13, 14–15, and 16–17 years old) and compared to a skeletally mature control group (30–50 years old). Two assessors measured 423 PCAs twice.

Results:

There was a statistically significant ( p = <0.05) difference in the PCA of the control group compared to each adolescent group. The mean PCA for both males and females decreased as age increased (increasing curvature of the volar distal radius with age). The mean PCA (male/female) was 164.38°/163.00° in ages 12–13, 162.14°/160.92° in ages 14–15, 157.52°/158.18° in ages 16–17, and 149.65°/154.03° in the control group aged 30–50 years. Agreement between assessors was high with an Interclass correlation coefficient (ICC) of 0.97.

Conclusion:

There is a statistically significant and potentially clinically important difference in the curvature of the distal radius volar cortex between adolescents and adults. This difference persists even in the 16–17 age group. As the PCA curvature is significantly greater in adults compared to adolescents, plates pre-contoured for adults may lead to malreduction of distal radius fractures into flexion in adolescent patients.
Designing With Purpose: Advocating Innovation, Impact, Sustainability, and Scale in Social Entrepreneurship Education
Authors: Kickul Jill , Gundry Lisa , Mitra Paulami , Berçot Lívia
Published: May 2018

Social entrepreneurship is an emerging and rapidly changing field that examines the practice of identifying, starting, and growing successful mission-driven for-profit and nonprofit ventures, that is, organizations that strive to advance social change through innovative solutions. For educators teaching in this field, we advocate for a design thinking approach that can be integrated into social entrepreneurship education. Specifically, we believe that many of the design thinking principles are especially suitable and useful for educators to facilitate student learning as they create and incubate social ventures. We also advance a broader conceptual framework, which we describe as the four main mega-themes in social entrepreneurship education, namely innovation, impact, sustainability, and scale. We offer ways in which the design thinking steps can be integrated and applied to each of these themes and accelerate the social venture creation process. We conclude by discussing and presenting how design thinking can complement an overall systems thinking perspective.
The Perioperative Care of the Transgender Patient
Authors: Tollinche Luis Etienne , Walters Chasity Burrows , Radix Asa , Long Michael , Galante Larissa , Goldstein Zil Garner , Kapinos Yvonne , Yeoh Cindy
Published: May 2018

An estimated 25 million people identify as transgender worldwide, approximately 1 million of whom reside in the United States. The increasing visibility and acceptance of transgender people makes it likely that they will present in general surgical settings; therefore, perioperative health care providers must develop the knowledge and skills requisite for the safe management of transgender patients in the perioperative setting. Extant guidelines, such as those published by the World Professional Association for Transgender Health and the University of California San Francisco Center of Excellence for Transgender Health, serve as critical resources to those caring for transgender patients; however, they do not address their unique perioperative needs. It is essential that anesthesia providers develop the knowledge and skills necessary for safely managing transgender patients in the perioperative setting. This review provides an overview of relevant terminology, the imperative for the provision of culturally sensitive care, and guidelines for preoperative, intraoperative, and postoperative management of the transgender patient.
A Contemporary Analysis of Medicolegal Issues in Obstetric Anesthesia Between 2005 and 2015
Authors: Kovacheva Vesela P. , Brovman Ethan Y. , Greenberg Penny , Song Ellen , Palanisamy Arvind , Urman Richard D.
Published: May 2018

BACKGROUND:

Detailed reviews of closed malpractice claims have provided insights into the most common events resulting in litigation and helped improve anesthesia care. In the past 10 years, there have been multiple safety advancements in the practice of obstetric anesthesia. We investigated the relationship among contributing factors, patient injuries, and legal outcome by analyzing a contemporary cohort of closed malpractice claims where obstetric anesthesiology was the principal defendant.

METHODS:

The Controlled Risk Insurance Company (CRICO) is the captive medical liability insurer of the Harvard Medical Institutions that, in collaboration with other insurance companies and health care entities, contributes to the Comparative Benchmark System database for research purposes. We reviewed all (N = 106) closed malpractice cases related to obstetric anesthesia between 2005 and 2015 and compared the following classes of injury: maternal death and brain injury, neonatal death and brain injury, maternal nerve injury, and maternal major and minor injury. In addition, settled claims were compared to the cases that did not receive payment. χ2, analysis of variance, Student t test, and Kruskal-Wallis tests were used for comparison between the different classes of injury.

RESULTS:

The largest number of claims, 54.7%, involved maternal nerve injury; 77.6% of these claims did not receive any indemnity payment. Cases involving maternal death or brain injury comprised 15.1% of all cases and were more likely to receive payment, especially in the high range (P = .02). The most common causes of maternal death or brain injury were high neuraxial blocks, embolic events, and failed intubation. Claims for maternal major and minor injury were least likely to receive payment (P = .02) and were most commonly (34.8%) associated with only emotional injury. Compared to the dropped/denied/dismissed claims, settled claims more frequently involved general anesthesia (P = .03), were associated with delays in care (P = .005), and took longer to resolve (3.2 vs 1.3 years; P < .0001).

CONCLUSIONS:

Obstetric anesthesia remains an area of significant malpractice liability. Opportunities for practice improvement in the area of severe maternal injury include timely recognition of high neuraxial block, availability of adequate resuscitative resources, and the use of advanced airway management techniques. Anesthesiologists should avoid delays in maternal care, establish clear communication, and follow their institutional policy regarding neonatal resuscitation. Prevention of maternal neurological injury should be directed toward performing neuraxial techniques at the lowest lumbar spine level possible and prevention/recognition of retained neuraxial devices.