bluuebunny/crossref_metadata_2025 huggingface dataset:
PP39 What is the risk of major trauma following a fall down stairs? – A systematic review
Authors: Holt Christopher , Keating Samuel , Tonkins Michael , Bradbury Daniel , Fuller Gordon
Published: August 2021

Background

Specific mechanisms of injury are stated in pre-hospital triage tools to identify suspected cases of major trauma. Falls down stairs are common presentations in UK emergency departments, yet are frequently overlooked as a causative mechanism of major trauma. No prior systematic review has examined this association.

Methods

Seven internationally recognised literature databases and seven grey literature databases were screened utilising a common search strategy from inception until 31 December 2019. Abstracts were screened for relevance by a single reviewer. Full texts were screened and subsequently extracted by 3 separate reviewers against strict inclusion/exclusion criteria. A risk of bias assessment based on GRADE recommendations was performed. In the absence of study heterogeneity, a narrative synthesis was planned. The reporting of this systematic review followed PRISMA 2009 statement guidelines.

Results

5240 articles were identified from database searching, 89 articles had their full texts assessed for eligibility and 6 articles were included for qualitative synthesis. All studies were retrospective in nature and originated from more economically developed countries. 7431 patients who fell down stairs were analysed, of which, 707 (9.5%) met major trauma definitions. Falls down stairs resulted in a significantly increased risk of serious injury compared to other fall mechanisms (OR: 1.621, 95% CI: 1.381 – 1.902, p<0.0005). Analysis of confounding factors demonstrated age (OR: 2.59, 95% CI: 1.57 – 4.28, p<0.001) and alcohol intoxication (OR: 2.6, 95% CI: 1.4 – 4.7, p=0.001) to be significantly associated with major trauma. Risk of bias was moderate to high across all 6 studies.

Conclusion

This systematic review highlighted the paucity of literature surrounding the incidence of major trauma following falls down stairs.

A retrospective cohort study is currently being undertaken to analyse the risk of major trauma following falls down stairs. On completion, the results will be incorporated with the results of this systematic review.
04 Improving the prehospital identification and management of people presenting to the ambulance service with COVID 19 symptoms
Authors: Fitzpatrick David , Moore Matthew , Best Catherine , Andreis Federico , Duncan Edward , Esposito Martin , Corfield Alasdair , Dcobbie Richard , Lowe David
Published: August 2021

Background

Little is known about how patients with COVID-19 present to ambulance services or their outcomes. Between 1st March and 31st August 2020 we investigated individuals who called the Scottish Ambulance Service (SAS) with COVID-19 symptoms and those that were later tested COVID-19 positive. We analysed i) their demographic and clinical characteristics; ii) their disposal; and iii) their admission and mortality outcomes.

Methods

SAS and NHS Scotland Health Board data are routinely linked in a national database. These data evidence a patients journey from ambulance call to hospital attendance and subsequent outcome. Evidence of COVID-19 testing was identified 10 days either side of the call.

Results

171,169 patients made 257,207 calls during the study period. Of these, 2.8% (n=7,305) were categorised as possible COVID-19 patients during telephone triage. From the flagged +ve patient calls 6% had a COVID-19 positive result, 29% had a negative COVID-19 result and the other 65% had no evidence of being tested. The majority (54%) were taken to the Emergency Department; 73% received further hospital care. The proportion of patient calls admitted within 10 days of the call was 31% for those not conveyed against 82% for conveyed. Final prehospital physiology for COVID-19 positive patients demonstrated lower oxygen saturations, higher respiratory rates and temperatures. 4.9% and 11.7% of patients conveyed to hospital died within 3 and 30 days vs 5.2% and 19.6% of patients not conveyed respectively.

Conclusions

This study suggests telephone triage is not a reliable identifier of COVID-19 patients reinforcing existing requirements for Personal Protective Equipment. 30-day mortality rates differed between those patients initially conveyed vs not conveyed. Clinical characteristics of COVID-19 positive patients suggest they were clinically less well than other patients.
PP41 British columbia emergency health services assess, see treat and refer palliative clinical pathway
Authors: Helmer Jennie , Baranowski Leon , Armour Richard , Tallon John , Williscroft David , Brittain Michelle
Published: August 2021

Background/Research Objectives

Paramedic services have experienced a steadily increasing demand from palliative patients accessing 911 during times of acute crisis, and not wishing subsequent conveyance to ED. Early data indicates that many of these patients are NOT already connected to palliative care teams.

To address this demand and to connect patients to care, BCEHS introduced the Assess, See, Treat and Refer (ASTAR)-Palliative Clinical Pathway. Objectives are to reduce patient conveyance to ED, reduce hospitalizations and improve patient care through referral after non-conveyance.

Intervention

Paramedic activation of the ASTaR Palliative Clinical Pathway results in referral of non-conveyed palliative patients to local Home and Community Care teams and BCEHS paramedics. The referral occurs within 1-6 hours of paramedic contact and follow up occurs over the next 24-48 hours by telephone. This referral action provides safe, effective, patient-centred care for non-conveyed patients, and also fills a gap for connecting patients to local palliative care teams.

Impact

A retrospective case review of 183 cases was conducted. Symptom improvement was achieved in 70% of cases, the ED non-conveyance rate was 19%, and the time on task when palliative patients were treated at home and not conveyed was 37% less (52 minutes) than if palliative patients were transported (82 minutes). All 183 patients were connected to either the local home and community care team or BCEHS Rural Advanced Care Community Paramedics (RACCP).

Lessons Learned

Palliative patients frequently call 911 for help during acute crisis events and many of these patients do not wish conveyance to ED. The introduction of the ASTaR palliative clinical pathway provided safety netting and referral to appropriate care teams.
05 Co-design of a logic model describing components, mechanisms of change and expected impacts of case management for people who frequently call ambulance services
Authors: Aslam Rabeea’h , Cole Robert , Diethart Berni , Edwards Adrian , Edwards Bethan M , Evans Bridie A , Foster Theresa , Fothergill Rachael , Gripper Penny , Hughes Heather , John Ann , Khanom Ashra , Petterson Robin , Phillips Ceri J , Porter Alison , Rees Nigel , Rosser Andy , Scott Jason , Tee Anna , Watkins Alan , Snooks Helen
Published: August 2021

Background

Multi-agency case management is being introduced by ambulance services and their partners in the UK to try to identify and address the needs of those who call 999 ambulance services frequently. However, there is a lack of evidence about what works well in this setting and how. Based on current nationally agreed definitions, calling frequently is defined as 5 or more times in a month, or 12 or more times in a three-month period. The STRETCHED study (STRategies to manageEmergency ambulanceTelephoneCallers with sustainedHigh needs – anEvaluation using linkedData) study seeks to evaluate clinical and cost-effectiveness, safety, and efficiency of case management for people who frequently call the emergency ambulance service.

We developed a logic model to describe key components, mechanisms of change and expected impacts of cross-sectoral case management approaches to the management of people who call 999 frequently.

Method

We conducted a stakeholder event with 37 people from Wales, England and Northern Ireland including patient representatives and professional staff involved in commissioning, planning and delivering case management for people who call 999 services frequently. The aggregated responses from the participants was used as the basis for developing a logic model.

Results

Components:dedicated staff time for case management, availability and knowledge of relevant services for referral, multidisciplinary collaboration, organisational support, and clear information sharing protocols

Mechanisms:provision of space for a clear understanding of reasons for calling, tailoring of multi–sectoral management to individual needs, offering therapeutic support and assistance in development of self–efficacy

Impacts:improvement in access to appropriate and timely care, increase in efficiency and accessibility of the healthcare system, reduction in emergency calls, costs and mortality

Conclusion

Case management is a developing area of provision in prehospital emergency care for people who call ambulance services frequently. Our logic model provides a firm foundation for evaluation to build the urgently needed evidence base for case management of people who call ambulance services frequently.
06 Speak to me: a literature review examining the participation of people living with dementia during healthcare interactions
Authors: Lindley Daniel , Baxter John
Published: August 2021

Background

People living with dementia have frequent encounters with ambulance services and have a high risk of mortality when admitted to hospital. The Mental Capacity Act and the National Institute for Health and Care Excellence (NICE) guidance provide a framework for all healthcare practitioners to support the person living with dementia into making their own healthcare decisions and encourages participation regardless of capacity status.

The purpose of this study was to understand if people living with dementia are afforded these opportunities to participate in healthcare decisions during interactions with paramedics and what key themes affect participation.

Methods

Electronic database search of literature, based on keywords, of EBSCO (searching MEDLINE and CINAHL), hand-sifting, and grey literature.

Articles were searched for pre-hospital care, Paramedic, EMS, EMT but yielded few results and the terms Doctor, Nurse, Healthcare Professional were added to search matrix. Included articles focused on decision making, participation, were under 10 years old and UK based. 1 exception was made for a Norwegian study focusing on participation.

Articles were reviewed multiple times in a meta-synthesis to find themes within each article. Data was grouped, coded and categorised based on themes.

Results

The findings illustrate that people living with dementia wish to retain autonomy and should be afforded the opportunity to participate in their own decision making regardless of capacity. Good and bad practice occurs, but many people living with dementia are marginalised, manipulated or have decisions taken from them.

Conclusion

Paramedics need to engage with people living with dementia during all encounters regardless of the severity of the person’s dementia or capacity status. They need to take time to give the person every opportunity to participate, not be influenced by someone who is not the patient and aim to be more inclusive of the patient. Further primary research is required to fully understand the quality of interactions between paramedics and people with dementia.
OP07 On the effectiveness and costs of inhaled methoxyflurane versus usual analgesia for prehospital injury and trauma
Authors: Smith Murray D , Siriwardena Aloysius Niroshan , Spaight Robert , Rowan Elise
Published: August 2021

Background

Acute pain is often inadequately treated in adults with traumatic injury. Inhaled methoxyflurane, newly licensed in Europe for this indication, has limited evidence of clinical effectiveness in the prehospital setting. We aimed to investigate clinical effectiveness and costs of methoxyflurane administered by ambulance staff compared with usual analgesic practice (UAP) for patients with trauma.

Methods

We used a non-randomised control group pragmatic design comparing methoxyflurane versus Entonox® and parenteral analgesics. Verbal numerical pain scores (VNPS) were gathered over time in adults with moderate to severe trauma pain attended by ambulance staff trained in administering and supplied with methoxyflurane. Comparator VNPS were obtained from database records of UAP in similar patients. Clinical efficacy was tested using an Ordered Probit panel regression model of pain linked by observational rules to VNPS. Scenario analyses were used to compare durations under analgesia spent in severe pain, and costs.

Results

Over 12 months, 96 trained paramedics and technicians prepared 510 doses of methoxyflurane for administration to 483 patients. 32 patients reported side-effects, 19 of whom discontinued early. 13 patients, 10 aged over 75 years, were nonadherent to inhaler use instructions.

Modelling results showed statistically significant clinical effectiveness of methoxyflurane over each comparator (all p-values<0.001). Methoxyflurane’s time to achieve maximum pain relief was significantly faster (all p-values<0.001): 26.4 mins (95%CI 25.0-27.8) versus Entonox® 44.4 (39.5-49.3); 26.5 (25.0-27.9) versus IV morphine sulfate 41.8 (38.9-44.7); 26.5 (25.1-28.0) versus IV paracetamol 40.8 (34.7-46.9).

Scenario analyses of durations spent in severe pain were significantly less for methoxyflurane to comparators. Benefits of methoxyflurane were achieved at higher cost to comparators.

Conclusions

Methoxyflurane reduced pain more rapidly and to a greater extent than Entonox® and more quickly than parenteral analgesics in adults with moderate or severe pain due to trauma attended by ambulance clinicians. Methoxyflurane provides a useful addition to prehospital analgesia.
OP08 Levels and sources of stress reported by first year paramedic students associated with their first ambulance placement
Authors: Warren-James Matthew , Hanson Julie , Flanagan Belinda , Katsikitis Mary , Lord Bill
Published: August 2021

Background

Whilst there is evidence to suggest paramedics experience significant stress when working in the ambulance setting little is known about the experiences of first year paramedic students. This research aimed to: (i) identify whether levels of stress, anxiety and depression experienced by first year paramedic students changed after ambulance placement compared to a control group, and (ii) identify the main perceived and actual sources of stress around ambulance placement.

Methods

A before-and-after quasi-experimental design was used to compare whether the experience of ambulance placement altered the levels of stress, anxiety and depression in an experimental group that attended an ambulance placement (n = 20) and the control group who did not (n = 10). Online surveys encompassing the Depression, Anxiety and Stress Scale (DASS-21) and qualitative questions about sources of stress were concurrently deployed to both the experimental and control groups before and after the ambulance placement. Participants were first year paramedic students working in Queensland Ambulance Service, Australia.

Results

There was a significant reduction in levels of stress in participants after undertaking their first ambulance placement (Mdn = -4.00) when compared to a control group (Mdn = 0.00),U= 52.5,p= .035,n2= 0.15. Responses to survey questions suggest anticipation about experiencing death and dying of patients was the most frequently reported stressor of student paramedics before undertaking ambulance placements, however insecurity about knowledge, competence and fear of failure was the most frequently experienced stressor reported after completing ambulance placements.

Conclusions

The findings from this study suggest that the fear of the unknown may be worse than the reality. Anticipatory stress is the foremost problem for first year paramedic students attending their first ambulance placement. Placement pre-briefing should focus on educational interventions to build knowledge and skills competency to reduce stress levels and fear of failure.
OP09 An investigation of the clinical decision-making challenges experienced by ambulance clinicians during the management of patients presenting with COVID-19 symptoms
Authors: Fitzpatrick David , Ikegwuonu Theresa , Duncan Edward , Esposito Martin , Moore Matthew , Corfield Alasdair , Best Catherine , Andreis Federico , Dobbie Richard , Lowe David
Published: August 2021

Background

As well as patient impact, COVID-19 also considerably impacts on staff who have been required to make challenging patient care decisions in uncertain circumstances. This study investigated ambulance clinicians’ experiences and use of decision support strategies during the COVID-19 pandemic.

Methods

Forty-eight percent (16/33) of paramedics invited agreed to be interviewed. Telephone/video interviews were undertaken between September and December 2020. Framework analysis was undertaken. Data were indexed and charted by one researcher. A sample was then checked by two other researchers. Analytical interpretation was collectively undertaken by all three researchers to identify a higher-level conceptual understanding.

Results

Four key themes were identified:

Impact on clinical decision making– Deciding whether to take a patient to an Emergency Department is often challenging. Paramedics reported that COVID-19 increased the complexity of this process.

Decision Support– Enhanced decision support was perceived as unequally available across the ambulance service. Where present, several paramedics reported that it was highly valuable.

Use of Personal Protective Equipment (PPE)– Routine use of extensive PPE was a very new experience for all participants. Some reported that the number of calls initially exceeded PPE availability.

Personal impact of dealing with COVID-19– Several paramedics stated that media reports combined with paramedics appearing in full PPE increased levels of anxiety among many patients they attended. Some participants were worried about catching COVID-19 and the possibility of taking the virus home to their families.

Conclusions

Our findings suggest that COVID-19 has placed considerable stress on the ambulance service at both organisational and individual levels. These findings could inform implementation processes surrounding rapid clinical guideline development and communication.

*This abstract was presented by Edward Duncan
The need for speed
Authors: Kieffer Jean-Claude
Published: August 2021

This paper reviews the challenges posed by the physics of the interaction of high-peak power femtosecond lasers with ultrathin foil targets. Initially designed to produce warm solid-density plasmas through the isochoric heating of solid matter, the interaction of an ultrashort pulse with ultrathin foils is becoming more and more complex as the laser intensity is increased. The dream of achieving very hot solid density matter with extreme specific energy density faces several bottlenecks discussed here as related to the laser technology, to the complexity of the physical processes, and to the limits of our current time-resolved instrumentations.
Enhancement of anomalous boundary current by high temperature
Authors: Guo Ruiping , Miao Rong-Xin
Published: August 2021

Recently it is found that Weyl anomaly leads to novel anomalous currents in the spacetime with a boundary. However, the anomalous current is suppressed by the mass of charge carriers and the distance to the boundary, which makes it difficult to be measured. In this paper, we explore the possible mechanisms for the enhancement of anomalous currents. Interestingly, we find that the anomalous current can be significantly enhanced by the high temperature, which makes easier the experimental detection. For free theories, the anomalous current is proportional to the temperature in the high temperature limit. Note that the currents can be enhanced by thermal effects only at high temperatures. In general, this is not the case at low temperatures. For general temperatures, the absolute value of the current of Neumann boundary condition first decreases and then increases with the temperature, while the current of Dirichlet boundary condition always increases with the temperature. It should be mentioned that the enhancement does not have an anomalous nature. In fact, the so-called anomalous current in this paper is not always related to Weyl anomaly. Instead, it is an anomalous effect due to the boundary.
Algorithmic aspects of outer independent Roman domination in graphs
Authors: Sharma Amit , Kumar Jakkepalli Pavan , Subba Reddy P. Venkata , Arumugam S.
Published: August 2021

Let [Formula: see text] be a connected graph. A function [Formula: see text] is called a Roman dominating function if every vertex [Formula: see text] with [Formula: see text] is adjacent to a vertex [Formula: see text] with [Formula: see text]. If further the set [Formula: see text] is an independent set, then [Formula: see text] is called an outer independent Roman dominating function (OIRDF). Let [Formula: see text] and [Formula: see text]. Then [Formula: see text] is called the outer independent Roman domination number of [Formula: see text]. In this paper, we prove that the decision problem for [Formula: see text] is NP-complete for chordal graphs. We also show that [Formula: see text] is linear time solvable for threshold graphs and bounded tree width graphs. Moreover, we show that the domination and outer independent Roman domination problems are not equivalent in computational complexity aspects.
Structure and dielectric properties of solid solutions Bi7−2xNd2xTi4NbO21(x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0)
Authors: Zubkov S. V.
Published: August 2021

The electrophysical and structural characteristics of bismuth titanate oxides of a number of phases of solid solutions of the Aurivillius phases Bi[Formula: see text]Nd[Formula: see text]Ti4[Formula: see text] ([Formula: see text] = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) having a layered structure of the perovskite type have been investigated. According to the XRD data, all studied compounds are single-phase and have a mixed-layer structure of Aurivillius phases ([Formula: see text] = 2.5) with a rhombic crystal lattice (space group I2cm, [Formula: see text] = 2). A relationship has been established between changes in the chemical composition of solid solutions and orthorhombic and tetragonal distortions of perovskite-like layers. The temperature dependences of the relative permittivity [Formula: see text]/[Formula: see text](T) are measured. It was found that the change in the phase transition temperature — Curie temperature [Formula: see text] synthesized Aurivillius phases Bi[Formula: see text]Nd[Formula: see text]Ti4[Formula: see text] ([Formula: see text] = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) has a close to linear dependence on the change in the parameter [Formula: see text]. The activation energies of charge carriers in different temperature ranges were calculated. It was found that three clearly defined temperature ranges with different activation energies can be distinguished, which is associated with the different nature of charge carriers in the studied solid solutions of the perovskite type. The effect of substitution of Nd[Formula: see text] ions for Bi[Formula: see text] ions is investigated.
Source-side Reordering to Improve Machine Translation between Languages with Distinct Word Orders
Authors: Arora Karunesh Kumar , Agrawal Shyam Sunder
Published: August 2021

English and Hindi have significantly different word orders. English follows the subject-verb-object (SVO) order, while Hindi primarily follows the subject-object-verb (SOV) order. This difference poses challenges to modeling this pair of languages for translation. In phrase-based translation systems, word reordering is governed by the language model, the phrase table, and reordering models. Reordering in such systems is generally achieved during decoding by transposing words within a defined window. These systems can handle local reorderings, and while some phrase-level reorderings are carried out during the formation of phrases, they are weak in learning long-distance reorderings. To overcome this weakness, researchers have used reordering as a step in pre-processing to render the reordered source sentence closer to the target language in terms of word order. Such approaches focus on using parts-of-speech (POS) tag sequences and reordering the syntax tree by using grammatical rules, or through head finalization. This study shows that mere head finalization is not sufficient for the reordering of sentences in the English-Hindi language pair. It describes various grammatical constructs and presents a comparative evaluation of reorderings with the original and the head-finalized representations. The impact of the reordering on the quality of translation is measured through the BLEU score in phrase-based statistical systems and neural machine translation systems. A significant gain in BLEU score was noted for reorderings in different grammatical constructs.
Notes on writing from writers of note
Authors: Yaffe Philip
Published: August 2021

Each "Communication Corner" essay is self-contained; however, they build on each other. For best results, before reading this essay and doing the exercise, go to the first essay "How an Ugly Duckling Became a Swan," then read each succeeding essay.

A distinction is often made between creative writing (fiction) and expository writing(non-fiction). However, they are more alike than most people think. Creative writers can learn from expository writers, and vice versa.
GABAA receptor activation modulates the muscle sympathetic nerve activity responses at the onset of static exercise in humans
Authors: Teixeira André L. , Fernandes Igor A. , Millar Philip J. , Vianna Lauro C.
Published: August 2021

In this study, we found that the reduction in muscle sympathetic nerve activity at the onset of static handgrip exercise was blunted following GABAA receptor activation with oral administration of diazepam in young, healthy individuals. The present findings provide novel insight into neural circuitry mechanisms controlling muscle sympathetic outflow during exercise in humans.
Case Studies in Physiology: Using premature ventricular contractions to understand the regulation of carotid artery longitudinal wall motion
Authors: Stevens Kailey A. , Au Jason S.
Published: August 2021

Benign arrhythmias can be a useful tool to probe new hypotheses in physiology. We tested the control of longitudinal motion of the common carotid artery wall using observations from spontaneous premature ventricular contractions in a healthy male. Forwards wall motion remained unchanged despite large deviations in local blood velocity and backwards wall motion mirrored changes in pulse pressure, blood velocity, and cardiac motion, thereby revising our original hypothesis of the control of longitudinal wall motion.
[Retracted] LATS2 Deletion Attenuates Myocardial Ischemia‐Reperfusion Injury by Promoting Mitochondrial Biogenesis
Authors: Chen Yi , Liu Chen , Li Jiannan , Zhou Peng , Zhao Xiaoxiao , Chen Runzhen , Song Li , Zhao Hanjun , Yan Hongbing
Published: August 2021

Reperfusion therapy is the most effective treatment for acute myocardial infarction, but it can damage cardiomyocytes through a mechanism known as myocardial ischemia/reperfusion injury (MIRI). In this study, we investigated whether the large tumor suppressor kinase 2 (LATS2) contributes to the development of myocardial MIRI by disrupting mitochondrial biogenesis. Our in vitro data demonstrate that cardiomyocyte viability was reduced and apoptosis was increased in response to hypoxia/reoxygenation (H/R) injury. However, suppression of LATS2 by shRNA sustained cardiomyocyte viability by maintaining mitochondrial function. Compared to H/R‐treated control cardiomyocytes, cardiomyocytes transfected with LATS2 shRNA exhibited increased mitochondrial respiration, improved mitochondrial ATP generation, and more stable mitochondrial membrane potential. LATS2 suppression increased cardiomyocyte viability and mitochondrial biogenesis in a manner dependent on PGC1α, a key regulator of mitochondrial metabolism. These results identify LATS2 as a new inducer of mitochondrial damage and myocardial MIRI and suggest that approaches targeting LATS2 or mitochondrial biogenesis may be beneficial in the clinical management of cardiac MIRI.
The Application and Evaluation of Effective Quality Management by Objectives in Patient Care for Persistent Vacuum Sealing Drainage
Authors: Zhao Lili , Yang Jianing , Nie Mingyang , Wang Dan , Yan Guojie , Li Shuying
Published: August 2021

To investigate the application and evaluation of effective quality management by objectives in patient care for persistent vacuum sealing drainage (VSD), a total of 164 patients with fractures of the hands and feet combined with soft tissue damage admitted to the department of hand and foot surgery in a provincial tertiary hospital from January 2018 to January 2020 were selected as study subjects. The patients were randomly divided into observation and control groups based on the types of fractures, with 82 patients in each group, and both groups underwent VSD surgery for treatment. Both of the groups were cared for VSD using the original nursing model and were compared in terms of treatment compliance, wound recovery, the occurrence of complications, and patient satisfaction with nursing work. The treatment compliance of patients in the observation group was higher than that of the control group (

P

 < 0.05). Moreover, the wound healing condition in the observation group and the postoperative wound recovery data were better. The hospitalization time and the number of replacement suckers were less (

P

 < 0.05), which met the requirements of statistical research. This confirmed that the application of quality management by objectives in patient care can improve patient compliance with treatment, promote wound healing, reduce the occurrence of corresponding postoperative complications in patients, and improve patient satisfaction with health nursing, which can be promoted for use in the workplace.
Anti-Interference Heartbeat Measurement Based on a Miniaturized Doppler Radar Sensor
Authors: Min Lingtong , Lv Qinyi , Nie Laisen , Zhou Deyun
Published: August 2021

It is a hot topic to utilize the Doppler radar sensor in noncontact biosignal monitoring nowadays. Unfortunately, most detections are easily affected by interference or strong noise. Even slight body movements can cause serious demodulation distortion. In this paper, we proposed a novel algorithm to solve the sudden and unexpected interference. Firstly, the one-dimensional signal detected by the sensor is divided into segments to form a two-dimensional data matrix. In both the intrasegment and intersegment domains of the data matrix, a robust algorithm is employed to suppress unwanted interference, which significantly improves the robustness of demodulation. Experiments show the effectiveness of the proposed algorithm, based on which weak heartbeat signal hidden in the interference can be well extracted.
Investigations of Coal‐Rock Parting‐Coal Structure (CRCS) Slip and Instability by Excavation
Authors: Liu Guang-Jian , Zhang Heng , Zhu Ya-Wei , Cao Wen-Hao , Ji Xian-Jun , Lu Cai-Ping , Liu Yang
Published: August 2021

Slip and instability of coal‐rock parting‐coal structure (CRCS) subjected to excavation disturbance can easily induce coal‐rock dynamic phenomena in deep coal mines. In this paper, the failure characteristics and influencing factors of CRCS slip and instability were investigated by theoretical analysis, numerical simulations, and field observations. The following main results are addressed: (1) the slip and instability of CRCS induced by excavation are due to stress release, and the damage of the rock parting is partitioned into three parts: shear failure zone, slipping zone, and splitting failure zone from inside to outside with slip; (2) the slip and instability process of CRCS is accompanied by initiation, expansion, and intersection of shear and tensile cracks. The development of the cracks is dominated by shear behaviour, while the tensile crack is the main factor affecting fracture and instability of CRCS; and (3) slip and instability of CRCS are characterized by stick‐slip first and then stable slip, accompanied with high P‐wave velocity and rockburst danger coefficient based on microseismic tomography.
Simulation Analysis of Void Defect Detection in Sandwich‐Structured Immersed Tunnel Using Elastic Wave
Authors: Liu Ruiqiang , Li Songhui , Zhang Guoxin , Song Shenyou , Xin Jianda
Published: August 2021

Void defects can be easily generated between a steel plate and concrete joint due to the complicated internal structure of a sandwich‐structured immersed tunnel (SSIT), which affect the overall bearing capacity of the main structure of the immersed tube tunnel. A prototype experiment was conducted to study the application of impact imaging method in the nondestructive detection of void defects in SSITs. The detection criterion for the impact imaging method was established based on the features of the waveform data. Nevertheless, the influence of steel plate thickness, material properties, void location, and structure on the detection accuracy of the impact imaging method is unclear. Therefore, numerical simulation was applied to study the influencing factors by establishing a different condition model. Good agreement between the experimental and numerical results was observed for the response waveform collected from the inspection area. Using the calculation model and identified material parameters validated in the active prototype experiment, numerical simulations of several sets, which considered all influencing factors, were performed. The application scope and sensitivity of the impact image method were recommended to reduce misjudgement in practical applications and improve detection accuracy.
Similarity Network Fusion Based on Random Walk and Relative Entropy for Cancer Subtype Prediction of Multigenomic Data
Authors: Liu Jian , Liu Wenfeng , Cheng Yuhu , Ge Shuguang , Wang Xuesong
Published: August 2021

It is a crucial task to design an integrated method to discover cancer subtypes and understand the heterogeneity of cancer based on multiple genomic data. In recent years, some clustering algorithms have been proposed and applied to cancer subtype prediction. Among them, similarity network fusion (SNF) can integrate multiple types of genomic data to identify cancer subtypes, which improves the understanding of tumorigenesis. SNF uses a dense similarity matrix to obtain the global information of the data, and the interconnection of samples between different categories will cause noise interference. Therefore, how to construct a more robust dense similarity matrix is an important research content to improve the performance of cancer subtype identification. In this paper, we proposed similarity network fusion based on random walk and relative entropy (R2SNF) for cancer subtype prediction. Firstly, the random walk algorithm was used to capture the complex relationship between samples in each genomic data. And the transition probability distribution of samples in the network was obtained. If two samples belong to the same class, the transition probability between the two samples is great. On the contrary, if the two samples do not belong to the same class, the transition probability between the two samples is small. In this way, the degree of correlation between samples can be well obtained, thereby reducing the noise interference caused by the interconnection of samples between different categories. Secondly, relative entropy was used to calculate the difference in the transition probability distribution between samples to construct a better dense similarity matrix which contains structural similarity information between samples. Thirdly, we iteratively fused the obtained dense similarity matrix with the KNN similarity matrix to construct the fused similarity matrix of all genomic data. Finally, by using spectral clustering, the fused similarity matrix was grouped into multiple clusters, which indicates the cancer subtypes. Experiments on seven cancer omics datasets show that the R2SNF algorithm performs well in identifying cancer subtypes.
Antidyslipidemic Potential of Water-Soluble Polysaccharides of Ganoderma applanatum in MACAPOS-2-Induced Obese Rats
Authors: Mfopa Adamou , Mediesse Francine K. , Mvongo Clémence , Nkoubatchoundjwen Sandrine , Lum Ambe A. , Sobngwi Eugène , Kamgang René , Boudjeko Thaddée
Published: August 2021

Increased consumption of high-calorie foods leads to obesity usually associated with metabolic disorders including diabetes, hyperglycemia, and dyslipidemia. Ganoderma applanatum is a nonedible mushroom traditionally used in West Cameroon for the treatment of many diseases including hypertension, diabetes, and hepatitis. This study was designed to investigate the antidyslipidemic potential of water-soluble polysaccharides of G. applanatum in MACAPOS-2- (maize, cassava, palm oil, and sugar) induced obese rats. For this purpose, obesity was induced on 6–8-week-old male Wistar rats with a local high-fat diet for four months. G. applanatum polysaccharides (GAPs) obtained by hot water extraction were orally administered to obese rats for two months at different dose levels (50, 100, and 150 mg/kg bodyweight), and its potential was investigated on food consumption, bodyweight gain, serum, and tissue lipids parameters. GAP extract increased the bodyweight gain by raising the food intake of obese rats. Furthermore, the administration of GAP extract at different dose levels significantly decreased the total cholesterol, triglyceride, low-density lipoprotein cholesterol levels, and the atherogenic index from 50 to 150 mg/kg bodyweight. Conversely, GAP extract improved the high-density lipoprotein cholesterol level in obese rats compared with untreated rats after two months’ study period. These results indicated that GAP extract may be considered as a novel bioactive compound against dyslipidemia and its associated complications.
[Retracted] Mobile Communication Procurement Platform Optimization Decision Based on Overseas Retailer Investment under Supply and Demand Disruption Risk
Authors: Wang Deli , Li Wuwei
Published: August 2021

With the rapid development of mobile communication procurement platform, it is faced with many risks, such as national policy differences, regional market differentiation, trade control, and technical barriers. Among them, the risk of supply and demand interruption will lead to the disconnection between upstream and downstream enterprises and consumers in the crossborder supply chain, making it difficult for them to achieve the profit target of the supply chain and meet the market demand. In order to reduce the risk of supply and demand disruption in mobile communication procurement platform and improve the ability to prevent and deal with disruption emergencies, a two‐level supply chain composed of crossborder suppliers, overseas suppliers, and overseas retailers is established, and the procurement decision optimization of crossborder supply chain under the condition of single channel procurement and dual channel procurement before and after investment is studied. The research show that when overseas retailers invest in crossborder suppliers and choose a dual‐source ordering strategy, it is more conducive to overseas retailers to reduce the risk of crossborder supply chain interruption and obtain higher expected profits.
Numerical Simulation of the Influence of the Distance between the Diamond Sawblade and Free Surface on Cutting Performance
Authors: Zeng Qingliang , Wang Zhiwen , Lu Zhenguo , Wan Lirong , Zhang Xin
Published: August 2021

The diamond sawblade has been widely used in the field of rock mining and processing. This article, through the establishment of a numerical simulation model of diamond sawblade cutting rock, studies the influence of the distance between the diamond sawblade and free surface on cutting performance. In the process of diamond sawblade cutting rock, with the increase of the distance from the sawblade to the free surface, the average cutting force, normal force, and tangential force of the sawblade increase at first and then stabilize, and the axial force gradually decreases and tends to be stable. In the process of cutting rock with fixed depth, cutting force and rock damage are positively related to feed speed and cutting depth of the diamond sawblade. Through the statistical analysis of rock damage by image recognition program statistics, it is concluded that the feed speed and cutting depth of the sawblade have a significant impact on the rock damage value. When the distance increases to 12 mm, there is a relatively complete rock plate between the sawblade and free surface. The rock free surface damage disappears when distance reaches 16 mm. The research results provide a theoretical basis for the sawblade processing rock plate.
Optimizing Information Dissemination Model for Improvement of College Students’ Education Based on Learning Community
Authors: Chang Jing , Huang Jian , Hu Ying
Published: August 2021

In the context of the popularization and diversified application of information technology in higher education, efficient information dissemination has a significant impact on the learning effect of the learning community. Improving the efficiency of information dissemination and driving the force of learning to enhance the learning effect are the hot issues in the field of higher education data analysis. This paper proposes a new method of feature fusion using information entropy and ReliefF algorithm, applies the improved PageRank algorithm and K-means algorithm to optimize the information transfer mode, and finally develops a new and efficient network information model. The comparative test results show that the new model can complete the dissemination of the same amount of information with a smaller delivery ratio. The research results can play an advantageous role in information interaction feedback, curriculum quality analysis, and teaching information transmission.
Near Optimality of Linear Delayed Doubly Stochastic Control Problem
Authors: Xu Jie , Lin Ruiqiang
Published: August 2021

In this paper, we study a kind of near optimal control problem which is described by linear quadratic doubly stochastic differential equations with time delay. We consider the near optimality for the linear delayed doubly stochastic system with convex control domain. We discuss the case that all the time delay variables are different. We give the maximum principle of near optimal control for this kind of time delay system. The necessary condition for the control to be near optimal control is deduced by Ekeland’s variational principle and some estimates on the state and the adjoint processes corresponding to the system.
A Novel Brain Image Segmentation Method Using an Improved 3D U-Net Model
Authors: Yang Zhuqing
Published: August 2021

Medical image segmentation (IS) is a research field in image processing. Deep learning methods are used to automatically segment organs, tissues, or tumor regions in medical images, which can assist doctors in diagnosing diseases. Since most IS models based on convolutional neural network (CNN) are two-dimensional models, they are not suitable for three-dimensional medical imaging. On the contrary, the three-dimensional segmentation model has problems such as complex network structure and large amount of calculation. Therefore, this study introduces the self-excited compressed dilated convolution (SECDC) module on the basis of the 3D U-Net network and proposes an improved 3D U-Net network model. In the SECDC module, the calculation amount of the model can be reduced by 1 × 1 × 1 convolution. Combining normal convolution and cavity convolution with an expansion rate of 2 can dig out the multiview features of the image. At the same time, the 3D squeeze-and-excitation (3D-SE) module can realize automatic learning of the importance of each layer. The experimental results on the BraTS2019 dataset show that the Dice coefficient and other indicators obtained by the model used in this paper indicate that the overall tumor can reach 0.87, the tumor core can reach 0.84, and the most difficult to segment enhanced tumor can reach 0.80. From the evaluation indicators, it can be analyzed that the improved 3D U-Net model used can greatly reduce the amount of data while achieving better segmentation results, and the model has better robustness. This model can meet the clinical needs of brain tumor segmentation methods.
Saikosaponin D Inhibits the Proliferation and Promotes the Apoptosis of Rat Hepatic Stellate Cells by Inducing Autophagosome Formation
Authors: Jiang Hong , Liu Jia , Zhang Kun , Zeng Qingxin
Published: August 2021

Objective. This study aimed to investigate the effects of saikosaponin D (SSd) on the proliferation and apoptosis of the HSC-T6 hepatic stellate cell line and determine the key pathway that mediates SSd’s function. Methods. Cell viability was detected using the CCK-8 kit. The EdU kit and flow cytometry were used to examine cell proliferation. The Annexin V-FITC/PI double staining kit and flow cytometry were used to examine cell apoptosis. Western blot analysis was performed to analyze the expression levels of LC3, Ki67, cleaved caspase 3, Bax, and Bcl2. Autophagosome formation was detected by LC3-GFP adenovirus transfection. Results. SSd inhibits the proliferation and promotes the apoptosis of acetaldehyde-activated HSC-T6 cells. SSd treatment increased the expression of cleaved caspase 3 and Bax but reduced that of Ki67 and Bcl2. The same concentration of SSd barely influenced the growth of normal rat liver BRL-3A cells. SSd upregulated LC3-II expression and induced autophagosome formation. Autophagy agonist rapamycin had the same effect as SSd and autophagy inhibitor 3-methyladenine could neutralize the effect of SSd in acetaldehyde-activated HSC-T6 cells. Conclusions. SSd could inhibit the proliferation and promote the apoptosis of HSC-T6 cells by inducing autophagosome formation.
Deformation Mechanism and Control of the Surrounding Rock during Gob-Side Entry Driving along Deeply Fully Mechanized Caving Island Working Face
Authors: Liu Fei , Han Yongsheng
Published: August 2021

The deformation control of the surrounding rock during gob-side entry driving along deeply fully mechanized caving island working face is one of the main bottlenecks affecting the successful and efficient production in modern mining. The prior ordinary fully mechanized caving theories have been difficult in ensuring the safe and efficient mining along island working face during gob-side entry driving under the complex conditions in the west. Therefore, it is of great theoretical and practical significance to carry out the research on the deformation mechanism and control of the surrounding rock during gob-side entry driving along deeply fully mechanized caving island working face. This paper, by means of experimental research, theoretical analysis, numerical calculation, and field industrial test, systemically researched the deformation characteristics of the surrounding rock and the law of strata behaviors during gob-side entry driving along deeply fully mechanized caving island working face.