bluuebunny/crossref_metadata_2025 huggingface dataset:
A recursive expectation-maximization algorithm for speaker tracking and separation
Authors: Schwartz Ofer , Gannot Sharon
Published: December 2021

The problem of blind and online speaker localization and separation using multiple microphones is addressed based on the recursive expectation-maximization (REM) procedure. A two-stage REM-based algorithm is proposed: (1) multi-speaker direction of arrival (DOA) estimation and (2) multi-speaker relative transfer function (RTF) estimation. The DOA estimation task uses only the time frequency (TF) bins dominated by a single speaker while the entire frequency range is not required to accomplish this task. In contrast, the RTF estimation task requires the entire frequency range in order to estimate the RTF for each frequency bin. Accordingly, a different statistical model is used for the two tasks. The first REM model is applied under the assumption that the speech signal is sparse in the TF domain, and utilizes a mixture of Gaussians (MoG) model to identify the TF bins associated with a single dominant speaker. The corresponding DOAs are estimated using these bins. The second REM model is applied under the assumption that the speakers are concurrently active in all TF bins and consequently applies a multichannel Wiener filter (MCWF) to separate the speakers. As a result of the assumption of the concurrent speakers, a more precise TF map of the speakers’ activity is obtained. The RTFs are estimated using the outputs of the MCWF-beamformer (BF), which are constructed using the DOAs obtained in the previous stage. Next, using the linearly constrained minimum variance (LCMV)-BF that utilizes the estimated RTFs, the speech signals are separated. The algorithm is evaluated using real-life scenarios of two speakers. Evaluation of the mean absolute error (MAE) of the estimated DOAs and the separation capabilities, demonstrates significant improvement w.r.t. a baseline DOA estimation and speaker separation algorithm.
An overview of generic tools for information-theoretic secrecy performance analysis over wiretap fading channels
Authors: Kong Long , Ai Yun , Lei Lei , Kaddoum Georges , Chatzinotas Symeon , Ottersten Björn
Published: December 2021

Physical layer security (PLS) has been proposed to afford an extra layer of security on top of the conventional cryptographic techniques. Unlike the conventional complexity-based cryptographic techniques at the upper layers, physical layer security exploits the characteristics of wireless channels, e.g., fading, noise, interference, etc., to enhance wireless security. It is proved that secure transmission can benefit from fading channels. Accordingly, numerous researchers have explored what fading can offer for physical layer security, especially the investigation of physical layer security over wiretap fading channels. Therefore, this paper aims at reviewing the existing and ongoing research works on this topic. More specifically, we present a classification of research works in terms of the four categories of fading models: (i) small-scale, (ii) large-scale, (iii) composite, and (iv) cascaded. To elaborate these fading models with a generic and flexible tool, three promising candidates, including the mixture gamma (MG), mixture of Gaussian (MoG), and Fox’sH-function distributions, are comprehensively examined and compared. Their advantages and limitations are further demonstrated via security performance metrics, which are designed as vivid indicators to measure how perfect secrecy is ensured. Two clusters of secrecy metrics, namely (i) secrecy outage probability (SOP), and the lower bound of SOP; and (ii) the probability of nonzero secrecy capacity (PNZ), the intercept probability, average secrecy capacity (ASC), and ergodic secrecy capacity, are displayed and, respectively, deployed in passive and active eavesdropping scenarios. Apart from those, revisiting the secrecy enhancement techniques based on Wyner’s wiretap model, the on-off transmission scheme, jamming approach, antenna selection, and security region are discussed.
Beyond private 5G networks: applications, architectures, operator models and technological enablers
Authors: Maman Mickael , Calvanese-Strinati Emilio , Dinh Lam Ngoc , Haustein Thomas , Keusgen Wilhelm , Wittig Sven , Schmieder Mathis , Barbarossa Sergio , Merluzzi Mattia , Costanzo Francesca , Sardellitti Stefania , Klessig Henrik , Kendre Savita Vitthalrao , Munaretto Daniele , Centenaro Marco , di Pietro Nicola , Liang Shuo-Peng , Chih Kuan-Yi , Luo Jack Shi-Jie , Kao Ling-Chih , Huang Jiun-Cheng , Huang Jen-Sheng , Wang Tzu-Ya
Published: December 2021

Private networks will play a key role in 5G and beyond to enable smart factories with the required better deployment, operation and flexible usage of available resource and infrastructure. 5G private networks will offer a lean and agile solution to effectively deploy and operate services with stringent and heterogeneous constraints in terms of reliability, latency, re-configurability and re-deployment of resources as well as issues related to governance and ownership of 5G components, and elements. In this paper, we present a novel approach to operator models, specifically targeting 5G and beyond private networks. We apply the proposed operator models to different network architecture options and to a selection of relevant use cases offering mixed private–public network operator governance and ownership. Moreover, several key enabling technologies have been identified for 5G private networks. Before the deployment, stakeholders should consider spectrum allocation and on-site channel measurements in order to fully understand the propagation characteristic of a given environment and to set up end-to-end system parameters. During the deployment, a monitoring tools will support to validate the deployment and to make sure that the end-to-end system meet the target KPI. Finally, some optimization can be made individually for service placement, network slicing and orchestration or jointly at radio access, multi-access edge computing or core network level.
Shape adaptive IRS based SAG IoT network
Authors: Qi Fei , Li Wenjing , Yu Peng , Feng Lei , Zhou Fanqin
Published: December 2021

6G technology connects physical and digital, and ubiquitous 6G services will provide convenience to users around the world. The concept of the world-earth integrated network is to seamlessly integrate these three subnets to better adapt to future development. This article introduces the world-earth integrated network and shape-adaptive IRS antenna technology. The shape-adaptive IRS antenna described in this article is made of flexible materials, and the physical shape of the antenna can be changed according to different situations, and specific radiation beams can be generated according to functional requirements. And the effectiveness of the shape-adaptive IRS antenna technology has been proven in the simulation results.
Effective capacity analysis of reconfigurable intelligent surfaces aided NOMA network
Authors: Li Geng , Liu Huiling , Huang Gaojian , Li Xingwang , Raj Bichu , Kara Ferdi
Published: December 2021

The future sixth generation (6G) is going to face the significant challenges of massive connections and green communication. Recently, reconfigurable intelligent surfaces (RIS) and non-orthogonal multiple access (NOMA) have been proposed as two key technologies to solve the above problems. Motivated by this fact, we consider a downlink RIS-aided NOMA system, where the source aims to communicate with the two NOMA users via RIS. Considering future network supporting real-time service, we investigate the system performance with the view of effective capacity (EC), which is an important evaluation metric of delay sensitive systems. Specifically, we derive the analytical expressions of the EC of the near and far users. To obtain more useful insights, we deduce the analytical approximation expressions of the EC in the low signal-to-noise-ratio approximation by utilizing Taylor expansion. Moreover, we provide the results of orthogonal multiple access (OMA) for the purpose of comparison. It is found that (1) The number of RIS components and the transmission power of the source have important effects on the performance of the considered system; (2) Compared with OMA, NOMA system has higher EC due to the short transmission time.
Existence of ground state solutions for a class of Choquard equations with local nonlinear perturbation and variable potential
Authors: Zhang Jing , Zhang Qiongfen
Published: December 2021

In this paper, we focus on the existence of solutions for the Choquard equation$$\begin{aligned} \textstyle\begin{cases} {-}\Delta {u}+V(x)u=(I_{\alpha }* \vert u \vert ^{\frac{\alpha }{N}+1}) \vert u \vert ^{ \frac{\alpha }{N}-1}u+\lambda \vert u \vert ^{p-2}u,\quad x\in \mathbb{R}^{N}; \\ u\in H^{1}(\mathbb{R}^{N}), \end{cases}\displaystyle \end{aligned}$${−Δu+V(x)u=(Iα∗|u|αN+1)|u|αN−1u+λ|u|p−2u,x∈RN;u∈H1(RN),where$\lambda >0$λ>0is a parameter,$\alpha \in (0,N)$α∈(0,N),$N\ge 3$N≥3,$I_{\alpha }: \mathbb{R}^{N}\to \mathbb{R}$Iα:RN→Ris the Riesz potential. As usual,$\alpha /N+1$α/N+1is the lower critical exponent in the Hardy–Littlewood–Sobolev inequality. Under some weak assumptions, by using minimax methods and Pohožaev identity, we prove that this problem admits a ground state solution if$\lambda >\lambda _{*}$λ>λ∗for some given number$\lambda _{*}$λ∗in three cases: (i)$2< p<\frac{4}{N}+2$2<p<4N+2, (ii)$p=\frac{4}{N}+2$p=4N+2, and (iii)$\frac{4}{N}+2< p<2^{*}$4N+2<p<2∗. Our result improves the previous related ones in the literature.
Stability criteria for nonlinear Volterra integro-dynamic matrix Sylvester systems on measure chains
Authors: Ayyalappagari Sreenivasulu , Bhogapurapu Venkata Appa Rao
Published: December 2021

In this paper, we establish sufficient conditions for various stability aspects of a nonlinear Volterra integro-dynamic matrix Sylvester system on time scales. We convert the nonlinear Volterra integro-dynamic matrix Sylvester system on time scale to an equivalent nonlinear Volterra integro-dynamic system on time scale using vectorization operator. Sufficient conditions are obtained to this system for stability, asymptotic stability, exponential stability, and strong stability. The obtained results include various stability aspects of the matrix Sylvester systems in continuous and discrete models.
Strategies for managing spring frost risks in orchards: effectiveness and conditionality—A systematic review protocol
Authors: Drepper Bianca , Bamps Brecht , Gobin Anne , Van Orshoven Jos
Published: December 2021

Background

Spring frosts pose an important threat to orchard productivity in temperate zones and predictions of future occurrences do not exclude damaging events. However, there is no up-to-date and systematic comparison of the effectiveness and conditionality of the existing passive and active damage prevention strategies. This review seeks to answer the questions “How do the performances of spring frost damage reduction strategies in temperate fruit orchards compare?” and “How do environmental conditions affect frost damage reduction strategies in temperate fruit orchards?”.

Methods and output

The review covers on-site frost damage prevention mechanisms and interventions for the most important temperate pome, stone and citrus fruit trees as well as grapevine. Searches include the core collection and regional databases on the Web of Science platform, Scopus, as well as specialized libraries like Agris, Agricola, CAB Abstracts, Groenekennis and selected institutional websites. Included studies report on the effectiveness of at least one intervention in reducing spring frost damage or increasing temperatures in the field. The validity of the studies will be evaluated based on their risk of general research bias and on topic-specific, stakeholder co-designed validity criteria. Data will be extracted regarding the study setup (study design, location, characteristics of frosts) and the resulting temperature increase, crop development alteration and/or damage reductions. The effectiveness of interventions will be evaluated in terms of yields, damage to flowers, ambient temperature and/or crop development. An Evidence Atlas will identify general and geographic research gaps, as well as research trends. Meta-regression of effectiveness on environmental conditions will be attempted.
Eco-friendly High-Strength Refractory Concrete Containing Calcium Alumina Cement by Reusing Granite Waste as Aggregate
Authors: Shirani Kourosh , Reisi Mohammad , Savadkoohi Mohammad Safari
Published: December 2021

Besides preventing valuable natural resources from going to waste, using stone waste from stone processing plants in concrete helps reduce environmental pollution and, therefore, offers a convenient route to sustainable development. The present study aims to use granite waste (GW) in high-strength refractory concrete. Sixteen high-strength refractory concrete mixes, including two water-to-binder ratios (W/B = 0.17 and 0.2), two silica-fume-to-binder ratios (SF/B = 0.15 and 0.2), two binder contents (B = 1200 and 1400 kg/m3), and two replacement ratios of silica sand by granite waste (GW/Agg = 0 and 50%) were designed and prepared with high-alumina cement (HAC). The concrete specimens were exposed to 1200 °C. Compressive and flexural strength and scanning electron microscopy (SEM) tests were performed on specimens of concrete mixes before and after heating. It was found that in specimens with high binder content (1400 kg/m3), replacing 50% silica sand with GW (GW/Agg = 50%) in refractory concrete improves compressive and flexural strengths by 3–15 and 4–24% before heating, respectively. It was also shown that using GW to replace silica aggregates in concrete specimens with a 1200 kg/m3 binder content not only did not undermine, but also improved the compressive and flexural strengths of refractory concrete after heating by 20–78% and 15–60%, respectively, as a result of sintering. Meanwhile, in the case of the concrete with 1400 kg/m3 binder content, adding GW exacerbated its loss of compressive and flexural strengths after heating due to little or lack of sintering.
Clean room microbiome complexity impacts planetary protection bioburden
Authors: Hendrickson Ryan , Urbaniak Camilla , Minich Jeremiah J. , Aronson Heidi S. , Martino Cameron , Stepanauskas Ramunas , Knight Rob , Venkateswaran Kasthuri
Published: December 2021

Background

The Spacecraft Assembly Facility (SAF) at the NASA’s Jet Propulsion Laboratory is the primary cleanroom facility used in the construction of some of the planetary protection (PP)-sensitive missions developed by NASA, including the Mars 2020 Perseverance Rover that launched in July 2020. SAF floor samples (n=98) were collected, over a 6-month period in 2016 prior to the construction of the Mars rover subsystems, to better understand the temporal and spatial distribution of bacterial populations (total, viable, cultivable, and spore) in this unique cleanroom.

Results

Cleanroom samples were examined for total (living and dead) and viable (living only) microbial populations using molecular approaches and cultured isolates employing the traditional NASA standard spore assay (NSA), which predominantly isolated spores. The 130 NSA isolates were represented by 16 bacterial genera, of which 97% were identified as spore-formers via Sanger sequencing. The most spatially abundant isolate was Bacillus subtilis, and the most temporally abundant spore-former was Virgibacillus panthothenticus. The 16S rRNA gene-targeted amplicon sequencing detected 51 additional genera not found in the NSA method. The amplicon sequencing of the samples treated with propidium monoazide (PMA), which would differentiate between viable and dead organisms, revealed a total of 54 genera: 46 viable non-spore forming genera and 8 viable spore forming genera in these samples. The microbial diversity generated by the amplicon sequencing corresponded to ~86% non-spore-formers and ~14% spore-formers. The most common spatially distributed genera were Sphinigobium, Geobacillus, and Bacillus whereas temporally distributed common genera were Acinetobacter, Geobacilllus, and Bacillus. Single-cell genomics detected 6 genera in the sample analyzed, with the most prominent being Acinetobacter.

Conclusion

This study clearly established that detecting spores via NSA does not provide a complete assessment for the cleanliness of spacecraft-associated environments since it failed to detect several PP-relevant genera that were only recovered via molecular methods. This highlights the importance of a methodological paradigm shift to appropriately monitor bioburden in cleanrooms for not only the aeronautical industry but also for pharmaceutical, medical industries, etc., and the need to employ molecular sequencing to complement traditional culture-based assays.
Systematic review of validated parent-reported questionnaires assessing swallowing dysfunction in otherwise healthy infants and toddlers
Authors: Baqays Abdulsalam , Zenke Julianna , Campbell Sandra , Johannsen Wendy , Rashid Marghalara , Seikaly Hadi , El-Hakim Hamdy
Published: December 2021

Objectives

There has been increasing interest in the management of oropharyngeal swallowing dysfunction (SwD). Its prevalence, particularly in otherwise healthy infants and toddlers (OHITs), is underappreciated. As the standard diagnostic tests are either invasive or scarce, valid parent-reported outcome (PRO) questionnaires could play a pivotal role in the understanding and managing SwD in this group. This article reviewed the literature on PRO questionnaires pertaining to SwD in OHITs.

Data source

A librarian searched Prospero, Cochrane Library, Embase, Medline, PsycINFO, HaPI, CINAHL, and SCOPUS until February 2021 using the MeSH terms for deglutition and screening methods.

Review method

Questionnaires that examined disease-specific or eating and feeding concerns or difficulties were excluded. Two reviewers independently identified PRO questionnaires for SwD that were used in OHITs and extracted the author names, publication year, questionnaire name, the studied population, and the reported psychometric assessments. A quality assessment was performed based on consensus-based standards for the selection of health measurement instruments (COSMIN) and updated criteria for good measurement properties.

Results

Of the 3488 screened articles, we identified only two questionnaires, the pediatric version of the Eating Assessment Tool (PEDI-EAT-10) and the PRO questionnaire for Swallowing Dysfunction in OHITs. The PEDI-EAT-10 authors assessed the validity and reliability on children with cerebral palsy. However, concerns were identified regarding the developmental process and the internal structure validity. The PRO questionnaire for SwD in OHITs meets criteria but has not yet been validated in the population of interest nor its psychometric properties assessed.

Conclusion

Two instruments were identified. The PED-EAT-10 exhibits methodological flaws, while Edmonton PRO questionnaire for SwD in OHITs awaits construct validation and could fill the current knowledge gap.
Migration routes, behavior and protection status of Eurasian Spoonbills (Platalea leucorodia) wintering in China
Authors: Xi Jire , Deng Xueqin , Zhao Gerelt , Batbayar Nyambayar , Damba Iderbat , Zhao Qingshan , Cui Shoubin , Jiang Chao , Chen Yiwen , Yu Yat-tung , Cao Lei , Fox Anthony David
Published: December 2021

Background

The Eurasian Spoonbill (Platalea leucorodia) occurs throughout Eurasia and North and sub-Saharan Africa, with three recognized subspecies and six geographically distributed populations. However, in China, we knew almost nothing about migration routes, habitat use and effectiveness of current site protection measures for this species.

Methods

We deployed Global Positioning System/Global System for Mobile Communications (GPS/GSM) satellite trackers on 29 Eurasian Spoonbills captured in summer in Mongolia and northeastern China, to obtain complete migration routes data from 10 individuals from 19 complete migration episodes.

Results

Tracking data showed no geographical overlap during the annual cycle in Eurasian Spoonbills marked in the two main summering areas. Birds marked in the Naoli River Basin in Heilongjiang Province, China, wintered along the Jiangsu coastline in China, while Eurasian Spoonbills from two discrete summering areas (in Inner and western Mongolia) overwintered inland in the Yangtze River floodplain of China. Excluding the single Inner Mongolian bird, spring migration was significantly faster than autumn migration in the other two groups of birds. Eurasian Spoonbills mainly used water, wetland and grassland habitats in summer, but almost exclusively water in winter. Lack of protection of staging sites used by all the birds in spring and poor levels of protection throughout the annual cycle for western Mongolian birds (5–22%) gives considerable cause for concern, although sites used in other time by East Mongolian and Naoli River birds in the rest of their annual life cycle enjoyed good levels of protection (49–95%).

Conclusions

These results revealed previously unknown relationships between summering and wintering areas, migration routes and stopover sites for Eurasian Spoonbills wintering in China, suggesting the existence of discrete biogeographical population units. They also identified winter habitat use of Eurasian Spoonbills in China, confirming open water habitats as being critical throughout the annual cycle, although based on small sample size, gaps in current site safeguard networks for these populations.
Exercise-Based Cardiac Rehabilitation: Secondary Data Analyses of Mortality and Working Capacity in Germany, 2010–2017
Authors: Gabrys Lars , Soff Johannes , Thiel Christian , Schmidt Christian , Swart Enno , Peschke Dirk
Published: December 2021

Background

Exercise-based cardiac rehabilitation is safe and implemented in international cardiac rehabilitation guidelines. Evidence for long-term health effects is scarce and rare for health care service research.

Objective

The aim of this study is to evaluate the effectiveness of exercise-based phase III cardiac rehabilitation programs in improving mortality and working capacity outcomes.

Methods

The present analyses used claims data of the German pension fund from 2010 to 2017. Overall, 54,163 patients with coronary heart disease (ICD10 I20.–I25.) were included and followed up for exercise-based cardiac rehabilitation participation (mean 4.3 ± 1.9 years). All patients were categorized according to participation duration (long: ≥ 90 days, short: < 90 days, no). The effectiveness of exercise-based rehabilitation was analyzed by calculating adjusted hazard ratios for mortality and reduced working capacity in relation to program participation.

Results

Of all the cardiac patients, 57.6% received medical recommendations for exercise-based phase III rehabilitation, and 16.8% participated in this rehabilitation. In total, 1776 (3.3%) patients died during the study period, and 3050 (5.5%) received reduced earning capacity pensions. Mortality risk was nearly doubled for those who did not participate in exercise-based cardiac rehabilitation compared to those who participated for a long duration (HR 1.97, 95% CI 1.60–2.43) and 44% higher compared to a short participation (HR 1.44, 95% CI 1.03–2.01). Furthermore, the risk of reduced working capacity was higher for those who did not participate compared to those who participated for a short duration (HR 1.24, 95% CI 1.00–1.54).

Conclusion

Exercise-based phase III cardiac rehabilitation is independently associated with reduced mortality and reduced loss in working capacity. Strong efforts should be made to increase participation rates to improve cardiac patients care.
Development and evaluation of a virtual patient-centered outcomes research training program for the cystic fibrosis community
Authors: Godfrey Emily M. , Thayer Erin K. , Mentch Laura , Kazmerski Traci M. , Brown Georgia , Pam Molly , Al Achkar Morhaf
Published: December 2021

Background

Patient-centered outcomes research (PCOR) emphasizes patient-generated research priorities and outcomes, and engages patients throughout every stage of the research process. In the cystic fibrosis (CF) community, patients frequently provide input into research studies, but rarely are integrated onto research teams. Therefore, we developed and evaluated a virtual pilot PCOR training program to build PCOR capacity in the CF community (patients, caregivers, researchers, nonprofit stakeholders and providers). We aimed to show changes among participants’ perceived PCOR knowledge (a.k.a PCOR knowledge), confidence in engaging stakeholders, and post-training session satisfaction.

Methods

Guided by a prior CF community educational needs assessment, our researcher and patient-partner team co-developed a four-part virtual online training program. We structured the program towards two learner groups: patients/caregivers and researchers/providers. We evaluated participants’ PCOR knowledge, confidence in engaging stakeholders, and session satisfaction by administering 5-point Likert participant surveys. We tested for significant differences between median ratings pre- and post-training.

Results

A total of 28 patients/caregivers, and 31 researchers/providers participated. For both learner groups, we found the training resulted in significantly higher PCOR knowledge scores regarding “levels of engagement” (p = .008). For the patient/caregiver group, training significantly increased their PCOR knowledge about the barriers/enablers to doing PCOR (p = .017), effective PCOR team elements (p = .039), active participation (p = .012), and identifying solutions for successful PCOR teams (p = .021). For the researcher/healthcare provider group, training significantly increased participants’ ability to describe PCOR core principles (p = .016), identify patient-partners (p = .039), formulate research from patient-driven priorities (p = .039), and describe engagement in research grants (p = .006). No learner group had significant changes in their confidence score. Most participants were either “satisfied” or “very satisfied” with the training program.

Conclusions

Overall, our virtual pilot PCOR training program was well received by patients, caregivers, researchers and providers in the CF community. Participants significantly improved their perceived knowledge with core PCOR learning items.

Trial registrationRetrospectively registered at clinicaltrials.gov (NCT04999865).
The mutual benefits of patient and public involvement in research: an example from a feasibility study (MoTaStim-Foot)
Authors: Aries Alison M. , Bailey Paul , Hunter Susan M.
Published: December 2021

Background

Patient and public involvement (PPI) in research has increased steadily over the last two decades and is now both expected and appropriately resourced by many funding bodies, including the National Institute for Health Research (NIHR). However, PPI in research occurs in many different capacities and numerous frameworks exist for reporting or appraising patient involvement activities. The aim of this article is to describe processes involving PPI contributions to an NIHR-funded mixed-methods feasibility study (MoTaStim-Foot). Details of PPI advisors’ input, from initial identification and prioritisation of research ideas, to research delivery and dissemination, are discussed.

Methods

Extensive PPI for MoTaStim-Foot is reported, with consideration of Research Design Service (RDS) advice for PPI for research, involving identifying and prioritising: design; grant proposal development; undertaking/managing research; analysing and interpreting; dissemination; implementation; monitoring and evaluation. Two PPI workshops were undertaken; success in meeting UK standards for public involvement was audited against specific success criteria by two researchers, with discussion and consideration regarding how well our PPI achieved inclusive opportunities, working together, support and learning, governance, communications and impact. How PPI can be improved for future trials was also considered. Although the advantages of PPI for researchers were considered, the benefits for PPI advisors were also analysed.

Results

UK standards for public involvement were achieved, along with seven relevant research processes suggested by the RDS. PPI advisor contributions: informed study design; contributed to successful funding; enhanced trial delivery by informing participant information sheets and daily diaries; added value through undertaking note-taker roles in focus groups and helping to analyse focus group transcripts; and assisted in dissemination. However, benefits were mutual with PPI advisors reporting feeling valued and respected, a sense of pride with renewed confidence and purpose in life.

Conclusions

Importance and value of PPI, to researchers and patient advisors, have been highlighted, reinforcing the benefits of working in partnership with PPI advisors.

Trial registrationISRCTN 13676183; Central Portfolio Management System ID 30449. Registered 02/01/2015,https://www.isrctn.com/ISRCTN13676183.
Urgent-start peritoneal dialysis for end-stage renal disease patients: literature review and worldwide evidence-based practice
Authors: Phongphithakchai Atthaphong , Dandecha Phongsak , Raksasuk Sukit , Srithongkul Thatsaphan
Published: December 2021

The prevalence of end-stage renal disease (ESRD) is on the rise worldwide. Meanwhile, the number of older people requiring dialysis therapy is increasing as a result of this population. We found that starting dialysis in an unplanned manner is a common occurrence, even for patients with nephrology follow-up. Most centers choose hemodialysis with a high rate of central venous catheter use at the time of initiation of dialysis. Current data has found that central venous catheter use is independently associated with increased mortality and high bacteremia rates. Peritoneal dialysis is one option to avoid bacteremia. The International Society for Peritoneal Dialysis guidelines suggests a break-in period of at least two weeks prior to an elective start of peritoneal dialysis, without mentioning urgent-start peritoneal dialysis. For unplanned ESRD patients, it is unrealistic to wait for two weeks before initiating peritoneal dialysis therapy. Urgent-start peritoneal dialysis has been suggested to be a practical approach of prompt initiation of peritoneal dialysis after catheter insertion, which may avoid an increased risk of central venous catheter-related complications, including bacteremia, central venous stenosis, and thrombosis associated with the temporary use of hemodialysis. Peritoneal dialysis is the alternative option, and many studies have presented an interest in urgent-start peritoneal dialysis. Some reports have compared urgent-start hemodialysis to peritoneal dialysis and found that urgent-start peritoneal dialysis is a safe and effective alternative to hemodialysis for an unplanned dialysis patient. This review aims to compare each literature report regarding techniques, prescriptions, outcomes, complications, and costs of urgent-start peritoneal dialysis.
Developing a patient-driven chronic obstructive pulmonary disease (COPD) research agenda in the U.S.
Authors: Gruß Inga , McCreary Gretchen M. , Ivlev Ilya , Houlihan Mary Ellen , Yawn Barbara P. , Pasquale Cara , Clark William , Mularski Richard A.
Published: December 2021

Background

To document a generalizable process for developing a patient-prioritized chronic obstructive pulmonary disease (COPD) research agenda and to provide an overview of domains that were developed in response to people living with COPD and caregivers’ suggestions for research.

Methods

Adults with COPD and caregivers who are members of the COPD Patient-Powered Research Network (PPRN) provided suggestions for COPD-related research through a self-administered, online survey. These responses were analyzed with a content analysis approach: domains for categorizing all survey responses were created, then all responses were categorized independently by a group of researchers, then these categorizations were adjudicated, and finally a density map was created that represented the number of responses in each of the domains.

Results

At the time of analysis, 6157 adults had fully completed the baseline survey. Survey responses were categorized across seven domains as follows: 22.5% of all responses fell into the domain family/social/community research, 20.8% of all responses fell into the domain well-being, 15% of all responses fell into the domain curative research, 14.6% of all responses fell into the domain biomedical therapies, 10.5% of all responses fell into the domain policy concerns, 6% of all responses fell into the domain holistic therapies and 10.7% of all responses fell into the domain ambiguous comments that could not be translated into concrete research topics.

Conclusion

Using qualitative open-ended survey responses from the COPD PPRN registrants, we were able to identify six key domains of research about COPD that are considered most important by patients. These domains differ in content from prior scientist-led efforts to develop priorities for COPD research, demonstrating the ongoing importance of involving patients and their caregivers in determining research priorities. The results suggest the field can more closely align research efforts to patient priorities by considering the identified domains.
Phytochemical competence and pharmacological perspectives of an endangered boon—Costus speciosus (Koen.) Sm.: a comprehensive review
Authors: Sohrab Saima , Mishra Pratibha , Mishra Sanjay Kumar
Published: December 2021

Background

Costus speciosus (Koen) Sm. popularly known as crepe ginger or spiral ginger and insulin plant is a perennial rhizomatous herb contain variable number of medicinally important bioactive phytochemicals having intensive pharmacological effects due to antioxidant, antimicrobial, insecticidal, anticancerous, and antidiabetic properties. This plant is widely distributed throughout India and has tremendous ethnobotanical uses. This review article is the coalescence of the distribution, morphology, phytochemistry, pharmacology, effect, and mode of action of pharmacologically active principles of Costus speciosus.

Main body

The therapeutic potential possessed by the plant is mainly the attribution of the bioactive compounds such as phenolics, steroids, alkaloids, flavonoids, saponins, terpenoids, and tannins, which are found to be present in different parts of the plant. Bioactive constituents like diosgenin, gracillin, dioscin, prosapogenins A and B of dioscin, eremanthin, costunolide, β-sitosterol, β-D-glucoside, β-carotene, α-tocopherol quinine, dihydrophytylplastoquinone, 5α-stigmast-9(11) en3β-ol, tetracosanyl octadecanoate, methyl hexadecanoate, methyl octadecanoate, cycloartenol, cycloartanol, and cycloalaudenol are specifically found in C. speciosus. This review also focuses on the possible mechanisms followed by these bioactive compounds while exhibiting various pharmacological properties. Because of the presence of diosgenin, this plant is given the name “insulin plant.” Diosgenin along with an important sesquiterpene, costunolide, performs significantly high antioxidant, anticancer, and antidiabetic activities. Besides these properties, insecticidal, antifungal, antibacterial, and anthelminthic properties have also been discussed. This plant needs to be given more emphasis as it is exploited at the commercial level by the pharmaceutical industries, conservation status is getting poorer, and it is already in a near-threatened state. Therefore, more systematic and intensive research should be done in a sustainable manner.

Conclusion

Spiral ginger plant shows diverse pharmacological effects due to presence of variety of bioactive phytochemicals, but the compounds like diosgenins, costunolides, eremanthin, and arbusculin are highly specific that exhibit effective antidiabetic, anticancerous, and antioxidative properties through different mechanism. Thus, C. speciosus can be exploited as an economically sustainable source of effective drugs against deadly diseases like diabetes and cancers with less or no side effects, and further research is needed to explore the intricacy of its pharmacological actions with human trials.

Graphical Abstract
An in vitro approach to combat multidrug resistance in Salmonella typhi and human colon cancer with Excoecaria agallocha L. extract
Authors: Sultana Tamanna , Mitra Arup Kumar , Das Satadal
Published: December 2021

Background

The incidence of antibacterial resistance and colon cancer is increasing in India. Antibacterial resistance and chemoresistance demand the need of developing herbal or natural chemotherapeutic agents. Our study thus, aims to determine the antibacterial and anticancer activities of the leaf extracts of the mangrove Excoecaria agallocha.

Results

Liquid chromatography–mass spectroscopy analysis of the ethanolic E. agallocha extracts revealed the presence of Bergenin. The plant extract fraction containing Bergenin had potent antibacterial action against a resistant strain of Salmonella typhi with an MIC value of 15.7 ± 0.04 µg/mL. Treatment of the bacteria with the plant extract made it moderately susceptible to the antibacterial drugs ampicillin, aztreonam, cefotaxime, chloramphenicol and imipenem. The plant extract caused membrane damage and disrupted the expression of a 33 kDa outer membrane protein (OmpA) in S. typhi. It was plausibly due to this mechanism of the plant extract that made the bacteria susceptible to the antibacterial drugs to a certain extent. Further, fluorescence microscopy analysis revealed the anticancer property of the extract against a human colon cancer (DLD-1) cell line by activation of Caspase-3followed by subsequent apoptosis and exhibited cytotoxicity against the cancerous cell line with an IC50 value of 17.99 ± 1.12 µg/mL. Caspase-3 activity was observed to increase in a dose-dependent manner as determined by spectrophotometric assays. Moreover, the expression of the metalloproteinase-7 (MMP-7) was significantly reduced in plant extract treated DLD-1 colon cancer cells.

Conclusion

The results indicate that E. agallocha is a novel source of Bergenin, and the plant extract fraction under study may be used in combination therapy along with antibacterial drugs to combat antibacterial resistance of S. typhi and also to alleviate the risks of colon cancers in human. However, further investigations may be undertaken for its therapeutic application and to explore its potential bioactivity against other bacterial strains and human cancer cell lines.
Learning needs assessment for multi-stakeholder implementation science training in LMIC settings: findings and recommendations
Authors: Turner Mallory Wolfe , Bogdewic Stephanie , Agha Erum , Blanchard Carrie , Sturke Rachel , Pettifor Audrey , Salisbury Kathryn , Marques Andrea Horvath , Excellent Marie Lina , Rajagopal Nitya , Ramaswamy Rohit
Published: December 2021

Background

Despite significant progress in the field of implementation science (IS), current training programs are inadequate to meet the global need, especially in low-and middle-income countries (LMICs). Even when training opportunities exist, there is a “knowledge-practice gap,” where implementation research findings are not useful to practitioners in a field designed to bridge that gap. This is a critical challenge in LMICs where complex public health issues must be addressed. This paper describes results from a formal assessment of learning needs, priority topics, and delivery methods for LMIC stakeholders.

Methods

We first reviewed a sample of articles published recently in Implementation Science to identify IS stakeholders and assigned labels and definitions for groups with similar roles. We then employed a multi-step sampling approach and a random sampling strategy to recruit participants (n = 39) for a semi-structured interview that lasted 30–60 min. Stakeholders with inputs critical to developing training curricula were prioritized and selected for interviews. We created memos from audio-recorded interviews and used a deductively created codebook to conduct thematic analysis. We calculated kappa coefficients for each memo and used validation techniques to establish rigor including incorporating feedback from reviewers and member checking.

Results

Participants included program managers, researchers, and physicians working in over 20 countries, primarily LMICs. The majority had over 10 years of implementation experience but fewer than 5 years of IS experience. Three main themes emerged from the data, pertaining to past experience with IS, future IS training needs, and contextual issues. Most respondents (even with formal training) described their IS knowledge as basic or minimal. Preferences for future training were heterogeneous, but findings suggest that curricula must encompass a broader set of competencies than just IS, include mentorship/apprenticeship, and center the LMIC context.

Conclusion

While this work is the first systematic assessment of IS learning needs among LMIC stakeholders, findings reflect existing research in that current training opportunities may not meet the demand, trainings are too narrowly focused to meet the heterogeneous needs of stakeholders, and there is a need for a broader set of competencies that moves beyond only IS. Our research also demonstrates the timely and unique needs of developing appropriately scoped, accessible training and mentorship support within LMIC settings. Therefore, we propose the novel approach of intelligent swarming as a solution to help build IS capacity in LMICs through the lens of sustainability and equity.
Improved production of titanate nanotubes by hydrothermal method for adsorption of organic dyes
Authors: Zaki Ayman H. , Adel Sara , Abd El-hafiez Mahmoud M. , Abdel-Khalek Ahmed A.
Published: December 2021

Background

Increasing the yield of nanomaterials using the same reactor size and fixing most of the reactants and conditions will greatly improve the production process by saving time, energy and efforts. Titanate nanotubes are mainly prepared by hydrothermal process, in which TiO2powder reacts with NaOH at certain conditions to form the desired nanotubes. It was reported that it is a must to use high concentrations of NaOH (10 N) to enable the tubular form formation, and the amount of NaOH from the stoichiometry point of view is much higher than that of TiO2; this means excess amounts of NaOH are not used and washed off. This work was designed to improve the production yield by making use of this excess amount of NaOH.

Results

More than 60 g of sodium titanate nanotubes was prepared using simple hydrothermal method. The prepared nanotubes were characterized by X-ray powder diffraction, high-resolution transmission electron microscopy, Fourier-transform infrared spectroscopy and BET surface area analysis. The adsorption capacity of these nanotubes was tested against three commonly used dyes: methyl orange, crystal violet and thymol blue. The samples showed great affinity toward crystal violet and lower activity toward methyl orange and thymol blue, where they achieved more than 90% removal efficiency under different experimental conditions.

Conclusions

Sodium titanate nanotubes were prepared in large amounts using modified hydrothermal method. The obtained nanotubes efficiently removed crystal violet from water. This improved synthesis of titanate nanotubes will reduce the total cost of nanomaterials production, and subsequently the treatment process, since titanate nanotubes are used in adsorption and photocatalysis processes.
Simple spectrophotometric methods for the determination of amlodipine and atorvastatin in bulk and tablets
Authors: Abu Reid Imad Osman , Farid Hind Mohamed , Eltayeb Sara Osman
Published: December 2021

Background

Simultaneous spectrophotometric determination of samples containing more than one analyte presents analytical challenge; the choice of an analytical procedure is strictly related to the extent of overlapping between the individual absorption peaks of these components; if the absorption peaks are satisfactorily resolved, the determination is not problematic, but if the individual component signals are partly or totally overlapped, then powerful techniques are needed. Combined amlodipine and atorvastatin are typical example where special techniques are needed to resolve bands overlapping.

Results

Application of multiwavelength regression and absorbance factor methods to the analysis of atorvastatin and amlodipine combination proved to be satisfactorily capable of accurate and precise determination of the two analytes. The two methods recoveries were very close to the expected analytes concentrations, and the precision of the methods was < 2% relative standard deviation. Statistical comparison indicated that there is no significant difference between the assay results obtained by the two method as the calculated t values 0.91 and 1.13 for amlodipine and atorvastatin, respectively, were less than the tabulated t value 2.23 at 95% confidence level.

Conclusion

The proposed methods are accurate, precise, simple and inexpensive. They can be applied successfully to the analysis of the two drugs in combined dosage form.
Characterization of novel stress degradation products of Bempedoic acid and Ezetimibe using UPLC–MS/MS: development and validation of stability-indicating UPLC method
Authors: Vejendla Anuradha , Talari Subrahmanyam , Ramu G. , Rajani Ch
Published: December 2021

Background

A receptive and easily comprehended technique was evolved for simultaneous assessment of Bempedoic acid and Ezetimibe and its impurities characterized by UPLC–MS/MS.

Results

This technique involves chromatographic separation with a C18 column of water symmetry (150 mm × 4.6 mm, 3.5 µm). A mobile phase of 0.1% OPA (orthophosphoric acid) and acetonitrile in 50:50 v/v with 1 mL/min flow rate and ambient temperature was used. UV observation was taken at 230 nm. The recoveries, linearity, and quantification limits were found to be within the acceptable limit.

Conclusions

This technique was successfully tested with UPLC–MS to confirm the chemical structures of newly formed degradation products of Bempedoic acid and Ezetimibe and stress studies as per ICH Q2 (R1) guidelines.
Audiological findings of a patient with H syndrome: case report
Authors: Hussein Diala , Altın Büşra , Bajin Münir Demir
Published: December 2021

Background

H syndrome is an autosomal recessive disorder caused by mutations in SLC29A3. Hyperpigmentation, hypertrichosis, hyperglycemia, and hearing loss are some characteristics of this disorder, and it has a prevalence of < 1/1000. The aim of this report is to spread awareness among otologists, audiologists, and pediatricians about this syndrome and its audiological features.

Case presentation

An 8-year-old male with a diagnosed H syndrome registered to our clinic with a complaint of hearing loss. The patient was diagnosed with hearing loss in a different clinic using only the air-conducted click auditory brainstem response test which showed wave V at 60 dB nHL for the right ear and at 80 dB nHL for the left ear. The initially performed pure tone audiometry (PTA) test in our clinic revealed a bilateral asymmetric hearing loss with a moderate sensorineural hearing loss in the right ear and a profound mixed hearing loss in the left ear. The performed air conducted click auditory brainstem response (ABR) result showed wave V at 55 dB nHL for the right ear and at 70 dB nHL for the left ear. Then, the repeated PTA test revealed a mild-severe sensorineural sloping hearing loss in the right ear and a severe sensorineural hearing loss in the left ear.

Conclusion

Although hearing thresholds in H syndrome could be within normal limits in some patients, sensorineural hearing loss is an important characteristic feature for this syndrome. Sensorineural hearing loss could be progressive or of sudden onset and ranges from mild to profound. Thus, it must be taken into consideration to apply the audiological follow-up regularly and paying attention to the patient’s complaints; also, a regular follow-up for language development of children with H syndrome and for the hearing aids is advised.