bluuebunny/crossref_metadata_2025 huggingface dataset:
Matematika Keuangan
Authors: Darmanto Darmanto , Astutik Suci , Sumarminingsih Eni , Darti Isnani , Amaliana Luthfatul , Rahmi Nur Silviyah , Irsandy Diego
Published: November 2023

Buku Matematika Keuangan merupakan buku yang berisi tentang penjelasan secara teori matematis dan terapannya pada bidang keuangan. Buku Matematika Keuangan ini dirancang dengan sistematika penjelasan dan penggunaan bahasa yang runtun dan mudah dipahami oleh pembaca. Pada awal buku, pembaca disuguhkan secara detail konsep dasar bunga dan perhitungannya. Selain itu, teori matematis dan turunan serta keterkaitan antar rumus diulas dengan kalimat yang lugas dan mudah dipahami sehingga pembaca mampu memverbalkan tiap besaran dan angka yang diperoleh. Konsep lain yang dibahas secara detail pada buku ini dan menjadi dasar pemahaman kalkulasi transaksi keuangan adalah anuitas. Dasar-dasar teori bunga dan anuitas selanjutnya menjadi bekal pembaca untuk memahami implementasi keduanya seperti pada yield rates, perhitungan pelunasan hutang dengan metode amortisasi dan sinking fund, serta pemahaman terhadap obligasi. Untuk lebih memudahkan para pembaca dalam memahami dan menerapkan teori matematika, buku ini dilengkapi dengan contoh yang bervariasi berserta solusi dengan tahapan yang rinci dan mudah untuk dipahami. Selain itu, penurunan rumus pada buku ini juga memberikan penguatan matematis bagi para pembaca sehingga secara konseptual mudah memahami kompleksitas permasalahan yang sering muncul pada transaksi keuangan. Kompetensi matematis yang disuguhkan di buku Matematika Keuangan ini juga mempermudah pembaca dalam memverbalkan angka atau besaran yang didapatkan dalam setiap perhitungan.
Fashioning Persian Identity: Asadi’s Staged Dispute between a Zoroastrian and a Muslim
Authors: Seyed-Gohrab Asghar
Published: November 2023

This paper focuses on the earliest surviving specimens of Persian debate poetry (monāzara), a genre which deals with controversial topics such as the Persians’ supremacy over the Arabs or the superiority of Islam over Zoroastrianism. Focusing on one panegyric by the poet Asadi Tusi (1010–70), this paper contextualizes such debates in a cultural milieu of eleventh-century Persia. It shows how poets, as an indispensable part of the court hierarchy, participated in constructing a new identity for Persians by formulating a Persian standpoint on controversies of the day.
Analysing Online Reviews Using NVivo: A Study of e-Tailing
Authors: Juneja Kanika , Choudhary Farah S.
Published: November 2023

Today, online consumers play an important role in the field of marketing. The word of mouth spread by them through online mode helps the marketers in understanding the consumer behaviour. Marketers rely on the information provided by the consumers in the form of online reviews or comments. The purpose of this article is to analyse the online reviews using Nvivo and to validate the scale used for measuring electronic word of mouth. The data were collected from 420 online consumers from Jammu city, who consider online reviews before purchasing. Both qualitative and quantitative techniques, such as NVivo and Exploratory Factor Analysis (EFA), were used. The research showed that the secondary data collected from Amazon India website in the form of online reviews matched the scale that was considered by the researchers from extant literature. The study thus helped in validating the scale for measuring electronic word of mouth communication. This research is of its kind that has been done in India. The present study may be used by the marketers for measuring the electronic word of mouth communication that would further help them in understanding consumer behaviour and, ultimately, knowing about the present and future needs of online consumers.
Developing a person-centred care environment aiming to enhance the autonomy of nursing home residents with physical impairments, a descriptive study
Authors: van Loon Jolande , Janssen Meriam , Janssen Bienke , de Rooij Ietje , Luijkx Katrien
Published: November 2023

Background

Enhancing autonomy is important within the context of the care environment in nursing homes. A nursing home is a place for older adults with physical impairments, who need assistance, to live and where staff work who help them to exercise autonomy. Previous research shows that older adults and staff are influenced by the care environment to apply autonomy-enhancing activities. Therefore, organisational policies regarding the care environment seem promising for enhancing autonomy. The aim is to gain a deeper insight into the development and implementation of organisational policies aimed to enhance the autonomy of older adults with physical impairments.

Methods

A qualitative descriptive design was chosen, using two methods. A document study was conducted on the policies, plans and proceedings in two care organisations. Moreover, interviews were conducted with 17 stakeholders involved in the policies, such as managers and members of the client council. The fragments of the 137 documents and 17 verbatim transcripts were coded and deductively categorised into the seven aspects (i.e., power-sharing, supportive organisational systems, appropriate skill mix, potential for innovation and risk-taking, the physical environment, effective staff relationships and shared decision-making systems) of the key domain care environment, as defined in the person-centred practice (PCP) framework developed by McCormack and McCance.

Results

The aspect of power-sharing was used the most in the policies of the two participating organisations. The organisations expected much from the implementation of indirect interventions, such as access to the electronic care plan for residents and the development of staff towards self-managing teams. Less attention was paid to interventions in the physical environment, such as the interior of the building and privacy, and the collaboration processes between staff.

Conclusions

The PCP framework poses that all aspects of the key domain care environment are important to develop a person-centred practice. This is not yet the case in practice and the authors therefore recommend using all seven aspects of the care environment in a balanced combination with the other key domains of the PCP framework to achieve person-centred practice and as a result the enhancement of the autonomy of nursing home residents with physical impairments.
The value of a dual-energy CT Iodine map radiomics model for the prediction of collagen fiber content in the ccRCC tumor microenvironment
Authors: Li Zhongyuan , Wang Ning , Bing Xue , Li Yuhan , Yao Jian , Li Ruobing , Ouyang Aimei
Published: November 2023

Background and purpose

Renal cell carcinoma (RCC) is a heterogeneous group of cancers. The collagen fiber content in the tumor microenvironment of renal cancer has an important role in tumor progression and prognosis. A radiomics model was developed from dual-energy CT iodine maps to assess collagen fiber content in the tumor microenvironment of ccRCC.

Methods

A total of 87 patients with ccRCC admitted to our hospital were included in this retrospective study. Among them, 59 cases contained large amounts of collagen fibers and 28 cases contained a small amount of collagen fibers. We established a radiomics model using preoperative dual-energy CT scan Iodine map (IV) imaging to distinguish patients with multiple collagen fibers from those with few collagen fibers in the tumor microenvironment of ccRCC. We extracted features from dual-energy CT Iodine map images to evaluate the effects of six classifiers, namely k-nearest neighbor (KNN), support vector machine (SVM), extreme gradient boosting (XGBoost), random forest (RF), logistic regression (LR), and decision tree (DT). The effects of the models built based on the dynamic and venous phases are also compared. Model performance was evaluated using quintuple cross-validation and area under the receiver operating characteristic curve (AUC). In addition, a clinical model was developed to assess the clinical factors affecting collagen fiber content.

Results

Compared to KNN, SVM, and LR classifiers, RF, DT, and XGBoost classifiers trained with higher AUC values, with training sets of 0.997, 1.0, and 1.0, respectively. In the validation set, the highest AUC was found in the SVM classifier with a size of 0.722. In the comparative test of the active and intravenous phase models, the SVM classifier had the best effect with its validation set AUC of 0.698 and 0.741. In addition, there was a statistically significant effect of patient age and maximum tumor diameter on the collagen fiber content in the tumor microenvironment of kidney cancer.

Conclusion

Radionics features based on preoperative dual-energy CT IV can be used to predict the amount of collagen fibers in the tumor microenvironment of renal cancer. This study better informs clinical prognosis and patient management. Iodograms may add additional value to dual-energy CTs.
Corneal characteristics of Mongolian population with type 2 diabetic peripheral neuropathy in inner Mongolia, China: an assessment using corneal confocal microscopy
Authors: Zhang Chi , Zhu Lei , Liang Xiuwen , Li Yue , Sun Guotong , Hu Ji , Zhang Honghong
Published: November 2023

Objective

To quantify corneal nerve fiber parameters in a Mongolian population with diabetic peripheral neuropathy (DPN) by corneal confocal microscopy.

Methods

This study conducted a comprehensive evaluation of 114 participants from Hulunbuir between January 2020 and December 2021. The participants included healthy controls, Mongolian and Han patients with type 2 diabetes mellitus. Demographic, medical, and laboratory data were collected, and neuropathy was evaluated by confocal corneal microscopy. And compare various parameters between Han and Mongolian were performed using SPSS software.

Results

The average waist circumference of Mongolian diabetic patients was larger than that of Han diabetic patients (P < 0.05). The mean HbA1c of Mongolian was 9.30 (8.15, 10.30) %, and that of Han was 8.30 (7.20, 9.40) % (P = 0.023). The average values of Corneal Nerve Fiber Density (CNFD), Corneal Nerve Fiber Length (CNFL) and corneal nerve branch density (CNBD) in Mongolian diabetic patients were significantly lower than those in Han diabetic patients (P < 0.05). The correlation coefficient between CNFL and age was − 0.368. ROC results show that CNBD has a certain diagnostic value for DPN in Mongolian patients with type 2 diabetes and the optimal cut-off point value is 24.99(no./mm2), the sensitivity is 80.0%, and the specificity is 77.8%.

Conclusion

The corneal confocal microscopy could possibly represent a promising adjuvant technique for the early diagnosis and assessment of PDN in Mongolian T2DM patients.
The role of imaginary companion in the life of only children: a qualitative study
Authors: Panah Zahra Yazdi , Mahmoodabadi Hassan Zareei , Dehghani Fahimeh
Published: November 2023

Introduction

An imaginary companion is an invisible or personified entity created by children for themselves. An imaginary companion typically serves as a companion to the child and plays a significant role in their life, especially for only children who may experience more loneliness compared to other children. This research was conducted to investigate the role of an imaginary companion in the lives of only children.

Method

The present study was conducted using a qualitative method and a content analysis approach. Through purposeful sampling, a total of 34 preschool and primary school children, aged 6 to 9 years, from schools in Mashhad city, were selected until saturation was reached. They were subjected to semi-structured interviews. After data collection, the data were coded, and then the main and sub-themes were extracted.

Results

The research findings were represented in the form of 196 statements, 28 sub-themes, and 9 main themes. The main themes included the role of an imaginary companion in alleviating loneliness, the role of an imaginary companion in amusement, the role of an imaginary companion in emotional regulation, conversations with an imaginary companion, guidance from an imaginary companion for good and bad behaviors, the assistance of an imaginary companion in tasks, helping to generate new scenarios, the advantages of having an imaginary companion, and the disadvantages of having one.

Conclusion

Based on the aforementioned findings, it can be concluded that the presence of an imaginary companion can not only support children but also promote creativity and distance them from the virtual space and realities of the real world. Parental awareness of this matter can aid in the child’s growth, fulfill their needs, and, on the other hand, prevent potential harm to children.
The role of bone morphology of the greater tuberosity and lateral acromion on subacromial space during scaption: a three-dimensional dynamic simulation analysis
Authors: Brandariz Rodrigo , Charbonnier Caecilia , Culebras Almeida Alejandro , Lädermann Alexandre , Cunningham Gregory
Published: November 2023

Background

The bone morphology of the greater tuberosity and lateral acromion plays a central role in subacromial impingement syndrome. The critical shoulder angle (CSA) and greater tuberosity angle (GTA) are two-dimensional measurement parameters that have been validated to evaluate it radiologically. These markers are, however, static and don’t consider the dynamic effect of glenohumeral motion.

Objectives

This study aimed to better understand the biomechanics in subacromial impingement with a dynamic simulation based on a validated 3D biomechanical model coupling joint kinematics and 3D reconstructed computed tomography.

Study design & methods

Sixty-one patients were included in this study: a case group of 44 patients with degenerative rotator cuff tears involving only the supraspinatus, and a control group of 17 without a rotator cuff tear. Patients with previous surgeries, traumatic cuff tears, and cuff tear arthropathy were excluded. CSA, GTA, and impingement-free range of motion (IF-ROM) of the glenohumeral joint in scaption were calculated. Correlation tests were used to determine the relationship between ROM and CSA, GTA, and combined CSA and GTA values.

Results

CSA and GTA were significantly higher in the rotator cuff tear group (p = 0.001 and < 0.001), while IF-ROM was significantly higher in the control group (p = 0.001). There was no overall correlation between CSA and GTA (R = 0.02, p = 0.8). Individual correlation between both angles with IF-ROM was negatively weak for CSA (R = -0.4, p < 0.001) and negatively moderate for GTA and IF-ROM (R = -0.5, p < 0.001). However, combining both angles resulted in a negatively high correlation with IF-ROM (R = -0.7, p < 0.001).

Conclusion

Subacromial space narrowing during scaption is highly correlated to the cumulative values of GTA and CSA. These findings suggest that the combined bony morphology of the lateral acromion and greater tuberosity plays an important role in subacromial impingement.

Level of evidence

III
Urethral length and its relationship with anthropometric parameters in adult male Nigerians
Authors: Ojewola Rufus Wale , Ogunjimi Moses Adebisi , Animashaun Emmanuel Abayomi , Afolayan Michael Olatunji , Osi Sixtus Ogbonnia , Jeje Emmanuel Ajibola , Tijani Kehinde Habeeb
Published: November 2023

Background

The available literature on urethral length in adult males is limited. To the best of our knowledge, such measurement has never been carried out amongst Nigerian and African men. This study aimed to document average urethral length as well as the relationship between urethral length and age, and anthropometric parameters amongst the Nigerian male adult population to add to the database for urethral length.

Methods

It was a prospective cross-sectional study amongst adult male Nigerians who had an indication for urethral catheterization as part of their regular treatment at the urologic clinics as well as male adult patients who required urethral catheterization in the theatre and the wards for various reasons. All patients had anthropometric parameters measured or calculated. The total usable length (A) of the catheter was measured before catheterization and the unused catheter length (B) was measured after catheterization for each patient. The calculated urethral length (C) was obtained by subtracting B from A. Data were analyzed using SPSS version 26.0. Mean urethral length was determined while the correlation between urethral length and age as well as anthropometric parameters were determined using Pearson Correlation.

Results

A total of 450 adult males were recruited. The mean age of subjects was 63.58 years with a range of 22–91 years. The average total usable and unused catheter lengths were 30.01 and 8.97 cm respectively. The mean urethral length among participants was 21.32 cm (8.4 Inches) with a range of 16.5 to 28 cm (6.5–11.0 Inches). There were no statistically significant correlations between urethral length and age ([r (450) = − 0.029, p = 0.546]) as well as with anthropometric parameters (height: r (450) = − 0.088, p = 0.61; weight: [r (450) = − 0.047, p = 0.324 and BMI: r (450) = − 0.082, p = 0.08) in adult males.

Conclusion

This study suggests that there may be racial differences in adult male urethral length but no relationship with age and anthropometric parameters. Further research is needed to explore these findings.
Evaluation of the adsorption behavior and divalent metal ions removal efficiency of ceramic point-of-use water filter materials
Authors: Apea Ohene B. , Akorley Bennet Edem , Oyelude Emmanuel O. , Ampadu Boateng
Published: November 2023

Ceramic water filters (CWFs) are point-of-use devices mostly used in developing countries as a result of their effectiveness in the treatment of household water. However, there is a dearth of knowledge on the metal ions adsorption behavior of the filter materials. Therefore, this study investigates the adsorption behavior of the divalent metal ions using commercially available ceramic water filters as adsorbents, in a batch experiment and compared the data, to the extent of metal ion removal during filtration. The ceramic water filters were characterized with x-ray fluorescence spectrometer, x-ray powder diffractometer and fourier-transform infrared spectrophotometer. An adsorption batch experiment was conducted and filtration experiments were performed to determine the extent of divalent metal ions removed. The results of the study showed that divalent metal ions were adsorbed efficiently by ceramic water filters. The pseudo-second-order kinetic model best described the kinetic behavior of metal ion removal process. The extent of adsorption of ceramic water filters was in the range: 7.015–335.77 mgg−1. The adsorption patterns fitted the Freundlich isotherm model while the entropy, enthalpy, and Gibbs free energy, indicate that the processes for all CWF-adsorbents are endothermic, feasible and spontaneous. The kinetic and thermodynamic behavior of CWF-adsorbents indicate that the mechanism of the sorption process is chemisorption. There was a significant difference in the amount of divalent metal ions adsorbed in batch experiments compared to filtration experiments for ceramic water filter materials (Pot filter and candle filter). The metal ions adsorption potentials of ceramic water filters are found to be rate dependent; hence the rate of filtration must be of concern to manufacturers.
Leucovorin and Fluorouracil With or Without Oxaliplatin as First-Line Treatment in Advanced Colorectal Cancer
Authors: de Gramont A. , Figer A. , Seymour M. , Homerin M. , Hmissi A. , Cassidy J. , Boni C. , Cortes-Funes H. , Cervantes A. , Freyer G. , Papamichael D. , Le Bail N. , Louvet C. , Hendler D. , de Braud F. , Wilson C. , Morvan F. , Bonetti A.
Published: November 2023

PURPOSE

In a previous study of treatment for advanced colorectal cancer, the LV5FU2 regimen, comprising leucovorin (LV) plus bolus and infusional fluorouracil (5FU) every 2 weeks, was superior to the standard North Central Cancer Treatment Group/Mayo Clinic 5-day bolus 5FU/LV regimen. This phase III study investigated the effect of combining oxaliplatin with LV5FU2, with progression-free survival as the primary end point.

PATIENTS AND METHODS

Four hundred twenty previously untreated patients with measurable disease were randomized to receive a 2-hour infusion of LV (200 mg/m2/d) followed by a 5FU bolus (400 mg/m2/d) and 22-hour infusion (600 mg/m2/d) for 2 consecutive days every 2 weeks, either alone or together with oxaliplatin 85 mg/m2 as a 2-hour infusion on day 1.

RESULTS

Patients allocated to oxaliplatin plus LV5FU2 had significantly longer progression-free survival (median, 9.0 v 6.2 months; P = .0003) and better response rate (50.7% v 22.3%; P = .0001) when compared with the control arm. The improvement in overall survival did not reach significance (median, 16.2 v 14.7 months; P = .12). LV5FU2 plus oxaliplatin gave higher frequencies of National Cancer Institute common toxicity criteria grade 3/4 neutropenia (41.7% v 5.3% of patients), grade 3/4 diarrhea (11.9% v 5.3%), and grade 3 neurosensory toxicity (18.2% v 0%), but this did not result in impairment of quality of life (QoL). Survival without disease progression or deterioration in global health status was longer in patients allocated to oxaliplatin treatment ( P = .004).

CONCLUSION

The LV5FU2-oxaliplatin combination seems beneficial as first-line therapy in advanced colorectal cancer, demonstrating a prolonged progression-free survival with acceptable tolerability and maintenance of QoL.
Pathologic Exploration of the Axillary Soft Tissue Microenvironment and Its Impact on Axillary Management and Breast Cancer Outcomes
Authors: Naoum George E. , Oladeru Oluwadamilola , Ababneh Hazim , Shui Amy , Ly Amy , Taghian Alphonse G.
Published: November 2023

PURPOSE

Axillary soft tissue (AXT) involvement with tumor cells extending beyond the positive lymph node (LN+) and extracapsular extension (ECE) has been overlooked in breast pathology specimen analysis.

MATERIALS AND METHODS

We analyzed 2,162 LN+ patients, dividing them into four groups on the basis of axillary pathology: (1) LN+ only, (2) LN+ and ECE only, (3) LN+ and AXT without ECE, and (4) LN+ with both AXT and ECE. The primary end points were 10-year locoregional failure (LRF), the 10-year axillary failure, and 10-year distant metastasis rates. Multivariable Cox models, accounting for clinical factors, were fitted using the entire cohort, and subgroups analyses were conducted.

RESULTS

The median follow-up was 9.4 years. The 10-year distant metastasis incidence was 42% for LN + AXT + ECE, 23% for both LN + AXT and LN + ECE only, and 13% for LN+ only. The 10-year axillary failure rates were 4.5% for LN + AXT + ECE, 4.6% for LN + AXT, 0.8% for LN + ECE only, and 1.6% for LN+ only. The 10-year LRF rates were 14% for LN + AXT + ECE, 10% for LN + AXT, 5.7% for LN + ECE only, and 6.2% for LN+ only. Multivariable analysis revealed that AXT was significantly associated with distant metastasis (hazard ratio [HR], 1.6; P < .001), locoregional failure (HR, 2.3; P < .001), and axillary failure (HR, 3.3; P = .003). Subgroup analyses showed that regional LN radiation (RLNR) improved locoregional tumor outcomes with AXT, ECE, or both (HR, 0.5; P = .03). Delivering ≤50 Gy to the axilla in the presence of AXT/ECE increased axillary failure (HR, 3.0; P = .04). Moreover, when delivering RLNR, axillary LN dissection could be de-escalated to sentinel node biopsy even in the presence of features such as AXT or ECE without significantly increasing any failure outcome: (HR, 1.0; P = .92) for LRF, (HR, 1.1; P = .94) axillary failure, and (HR, 0.4; P = .01) distant metastasis.

CONCLUSION

Routine reporting of axillary tissue involvement, beyond LNs and ECE, is crucial in predicting breast cancer outcomes. Ruling out the presence of AXT is imperative before any form of axillary de-escalation, especially RLNR omission.
Ενταξιακή ηγεσία στη δημόσια διοίκηση στο πλαίσιο των κατευθύνσεων της Ευρωπαϊκής Ένωσης
Authors: Πάντα Ευαγγελία
Published: November 2023

Η ηγεσία αποτελεί κεντρική έννοια του διοικητικού φαινομένου και σκοπός της παρούσας διατριβής είναι να διερευνήσει, στο περιβάλλον της ελληνικής δημόσιας εκπαιδευτικής διοίκησης, το θέμα της ενταξιακής ηγεσίας. Η ενταξιακή ηγεσία εγγράφεται στο πλαίσιο των σύγχρονων θεωρητικών προσεγγίσεων της ηγεσίας ως σχεσιακής κατασκευής και αποτελεί έννοια που βρίσκεται ακόμη σε αρχικό στάδιο ανάπτυξης. Αξιοποιώντας το υφιστάμενο θεωρητικό υπόβαθρο για την ηγεσία, και ιδίως για την εκπαιδευτική ηγεσία, στην παρούσα διατριβή η ενταξιακή ηγεσία ορίζεται λειτουργικά, ως μια ηγεσία κατανεμημένη και ηθική, και επιχειρείται ο έλεγχος αυτής της υπόθεσης. Με δεδομένο ότι η ελληνική δημόσια διοίκηση μετέχει στην ενωσιακή βαθμίδα διακυβέρνησης, λαμβάνεται υπόψη και το ζήτημα του ευρωπαϊκού διοικητικού χώρου καθώς και οι ενωσιακές κατευθύνσεις για την εκπαιδευτική ηγεσία. Η έρευνα εστιάζει στο επίπεδο της διοικητικής ηγεσίας με μονάδα ανάλυσης το άτομο. Διενεργήθηκε στην Κεντρική Υπηρεσία του Υπουργείου Παιδείας και Θρησκευμάτων (ΚΥ), κατά τα έτη 2021 και 2022. Επελέγη ένας σχεδιασμός μικτών μεθόδων. Η ποσοτική έρευνα διενεργήθηκε με ερωτηματολόγια και εστίασε στο τρίπτυχο ηγεσία (ως προαιπαιτούμενο), ένταξη στο εργασιακό περιβάλλον και συναισθηματική οργανωσιακή δέσμευση (ως συνέπεια), το οποίο βασίζεται στο μοντέλο των Shore et al. (2011) για την ένταξη στα εργασιακά περιβάλλοντα. Η ποιοτική έρευνα πραγματοποιήθηκε με ημιδομημένες συνεντεύξεις και επικεντρώθηκε στους εξής θεματικούς άξονες: ρόλος ηγεσίας, πρόσληψη ενταξιακής ηγεσίας, πρακτικές μιας ενταξιακής ηγεσίας, σχέση ανάμεσα στην ηθική και την κατανεμημένη ηγεσία για την ανάπτυξη μιας ενταξιακής ηγεσίας, προτεινόμενες αλλαγές στη δημόσια διοίκηση και στην ΚΥ προκειμένου να διευκολυνθεί η ανάπτυξη μιας ενταξιακής ηγεσίας. Τα αποτελέσματα των δύο μεθοδολογικών προσεγγίσεων τεκμηριώνουν ότι μια ενταξιακή ηγεσία εδράζεται στην κατανεμημένη και ηθική ηγεσία. Πιο συγκεκριμένα, η στατιστική ανάλυση επιβεβαιώνει ότι μια ηγεσία κατανεμημένη και ηθική σχετίζεται με την ένταξη του εργαζόμενου, η οποία σχετίζεται με τη συναισθηματική οργανωσιακή δέσμευση. Κατά την ποιοτική φάση της έρευνας, προέκυψε ένα προβάδισμα στην ηθική ηγεσία για την άσκηση μιας ενταξιακής ηγεσίας, καθώς θεωρήθηκε από τους εργαζόμενους απαραίτητη προϋπόθεση για να μπορεί να διενεργηθεί και μια ουσιαστική κατανομή της ηγεσίας.
Διερεύνηση της αποτελεσματικότητας της εφαρμογής προγράμματος διαχείρισης αντιβιοτικών (antibiotics stewardship program) σε τριτοβάθμιο γενικό νοσοκομείο
Authors: Χρύσου Κωνσταντίνα
Published: November 2023

Σκοπός αυτής της μελέτης ήταν να διερευνήσει την επίδραση και την αποτελεσματικότητα της εφαρμογής ενός προγράμματος διαχείρισης αντιβιοτικών (Antibiotic Stewardship Program - ASP) στην κατανάλωση αντιβιοτικών, σε ένα τριτοβάθμιο νοσοκομείο 427 κλινών. Η Επιτροπή Νοσοκομειακών Λοιμώξεων του Τζανείου Γενικού Νοσοκομείου Πειραιά εφάρμοσε ένα ASP από τον Ιανουάριο του 2016, έχοντας ως στόχο τη μείωση της ακατάλληλης χρήσης αντιβιοτικών με τη χρήση βελτιωμένων πρακτικών συνταγογράφησης, αποβλέποντας στην ανακοπή της αυξανόμενης μικροβιακής αντοχής και μακροπρόθεσμα στη μείωσή της. Το πρόγραμμα περιελάμβανε τόσο στρατηγικές προέγκρισης, όσο και στρατηγικές προοπτικού ελέγχου και επανελέγχου (ανατροφοδότησης). Αρχικά συλλέχθηκαν από το φαρμακείο και το τμήμα πληροφορικής του Νοσοκομείου τα δεδομένα σχετικά με την κατανάλωση αντιβιοτικών του έτους 2015, πριν από την παρέμβαση, και στη συνέχεια τα αντίστοιχα δεδομένα για κάθε έτος από τα επόμενα 4 έτη (2016-2019), μετά την παρέμβαση. Η κατανάλωση αντιβιοτικών εκφράστηκε ως ημερήσιες καθορισμένες δόσεις ανά 100 ασθενο-ημέρες (Defined Daily Doses-DDD / 100 patient-days-PD) και οι μεταβολές μεταξύ των ετών 2015 και 2016-19 αξιολογήθηκαν στατιστικά με το paired t-Test. Τα ποσοστά αντοχής στα αντιβιοτικά για τα σημαντικότερα νοσοκομειακά παθογόνα παρακολουθήθηκαν και καταγράφηκαν ετησίως για όλη την περίοδο 2015-2019. Η εφαρμογή του ASP οδήγησε σε σημαντική μείωση της κατανάλωσης των περισσότερων αντιβιοτικών. Η συνολική χρήση αντιβιοτικών μειώθηκε κατά 14,83% (από 90,88 το 2015 σε 77,40 DDDs/100 PD το 2016, με μείωση κατά 16,03% για τα κοινά (μη προστατευόμενα) και κατά 13,76% για τα προστατευόμενα αντιβιοτικά. Η μέση μείωση για τα έτη 2016-2019 ήταν 8,23% (p=0,034), ήτοι 7,87% για τα κοινά (p=0,138) και 8,58% (p=0,05) για τα προστατευόμενα. Αρκετά αντιβιοτικά υπό περιορισμό, όπως η κολιστίνη, οι καρβαπενέμες, οι κινολόνες και η τιγεκυκλίνη παρουσίασαν σημαντικά μειωμένη χρήση μετά την παρέμβαση. Δεν παρατηρήθηκαν σημαντικές μεταβολές στα ποσοστά αντοχής, εκτός από μια φθίνουσα τάση για την κολιστίνη και την τιγεκυκλίνη που αφορούσε στα Acinetobacter baumannii και Klebsiella pneumoniae και επίσης για τη βανκομυκίνη όσον αφορά στους εντεροκόκκους. Το ASP πέτυχε τη μείωση της κατανάλωσης αντιβιοτικών, ιδιαίτερα κατά το πρώτο έτος εφαρμογής του, η οποία διατηρήθηκε και στα επόμενα τρία έτη. Είναι ενδιαφέρον ότι κάποια αντιβιοτικά, για τα οποία χρειαζόταν προέγκριση, παρουσίασαν χαμηλότερη μείωση της κατανάλωσης σε σύγκριση με τα υπόλοιπα αντιβιοτικά, προφανώς διότι για τα συγκεκριμένα αντιβιοτικά χρειαζόταν προέγκριση και πριν από την εφαρμογή του προγράμματος. Οι πιθανές επιπτώσεις του ASP στη μείωση των ποσοστών αντοχής αναμένεται να φανούν στο μέλλον.
Ο ρόλος της βακτηριδιακής υπερανάπτυξης του λεπτού εντέρου σε ασθενείς που νοσηλεύονται στη Μονάδα Εντατικής Θεραπείας
Authors: Μπουσβάρος Κωνσταντίνος
Published: November 2023

Σκοπός: Το σύνδρομο υπερανάπτυξης βακτηριδίων του εντέρου (SIBO), αν και έχει συσχετιστεί με δυνητικά σοβαρές επιπλοκές, δεν έχει μελετηθεί επαρκώς έως σήμερα, ειδικά σε ασθενείς νοσηλευόμενους σε Μονάδα Εντατικής Θεραπείας (ΜΕΘ). Ο πρωταρχικός στόχος αυτής της μελέτης ήταν η αξιολόγηση του επιπολασμού του SIBO σε βαριά πάσχοντες ασθενείς νοσηλευόμενους σε ΜΕΘ. Οι δευτερεύοντες στόχοι περιελάμβαναν την αξιολόγηση της επίδρασής του SIBO στην πνευμονία που σχετίζεται με τον αναπνευστήρα (VAP), στη διάρκεια παραμονής στη ΜΕΘ και στο ποσοστό ενδονοσοκομειακής θνησιμότητας από όλες τις αιτίες (all-cause in-hospital mortality rate).Υλικό & Μέθοδος: Η μελέτη φέρει έγκριση Επιτροπής Βιοηθικής. Συμπεριελήφθησαν 52 βαριά πάσχοντες ασθενείς ΜΕΘ υπό μηχανικό αερισμό. Η διάγνωση του SIBO πραγματοποιήθηκε με ειδική, μη επεμβατική δοκιμή εκπνοής Η2, η οποία επαναλαμβάνονταν σε προκαθορισμένα, βάσει πρωτοκόλλου, χρονικά διαστήματα (1η/ημέρα εισαγωγής, 3η, 5η και 7η ημέρα νοσηλείας). Από τη μελέτη αποκλείστηκαν ασθενείς με θετικό SIBO τεστ την ημέρα εισαγωγής. Οι συμμετέχοντες στη μελέτη χωρίστηκαν σε δύο ομάδες (ασθενείς με θετικό και ασθενείς με αρνητικό SIBO τεστ την 3η, 5η ή/και 7η ημέρα νοσηλείας), στους οποίους πραγματοποιήθηκε συγκριτική αξιολόγηση των δημογραφικών τους δεδομένων, του APACHE II score, της επίπτωσης VAP, της διάρκειας νοσηλείας και της έκβασης. Αποτελέσματα: Οι ομάδες ήταν ομοιογενείς ως προς τα βασικά τους χαρακτηριστικά, συμπεριλαμβανομένων των δημογραφικών (p>0.05). Συνολικά, συμμετείχαν 34 (65,4%) άντρες και 18 γυναίκες (34.6%), με μέση ηλικία(τυπική απόκλιση) 62.65(16,31) έτη. Η επίπτωση του SIBO στο δικό μας πληθυσμό ήταν 36,5%. Δέκα-οκτώ (34,6%) ασθενείς καταλήξανε, ενώ 32 (61.5%) ανέπτυξαν VAP κατά τη νοσηλεία τους. Η παρουσία SIBO συσχετίστηκε με αυξημένη επίπτωση VAP (p<0,001) και με αυξημένη διάρκεια νοσηλείας στη ΜΕΘ (p<0,03). Δεν φάνηκε συσχέτιση του SIBO με τους λοιπούς παράγοντες που μελετήθηκαν, όπως φύλο, ηλικία, Apache II score και αντιμικροβιακό σχήμα. Συμπέρασμα: Η παρουσία SIBO σε ασθενείς που νοσηλεύονται σε ΜΕΘ φαίνεται να είναι αρκετά συχνή. Τόσο η έγκαιρη διάγνωση αυτού του συνδρόμου, όσο και η αποτελεσματική αντιμετώπισή του είναι υψίστης σημασίας, ειδικά για τους βαριά πάσχοντες ασθενείς, εφόσον φαίνεται να σχετίζεται με VAP και παράταση της διάρκειας νοσηλείας.
Ανάπτυξη ερωτηματολογίου αξιολόγησης κινδύνου πτώσης στον ελληνικό γενικό πληθυσμό άνω των 60 ετών
Authors: Αργυρού Χρυσούλα
Published: November 2023

Εισαγωγή: Οι πτώσεις των ηλικιωμένων αποτελούν σημαντικό πρόβλημα υγείας, με υψηλό αντίκτυπο στη νοσηρότητα, τη θνησιμότητα και την ποιότητα ζωής. Μέχρι τώρα, δεν έχει αναπτυχθεί κανένα εργαλείο που να μπορεί να αναγνωρίσει αξιόπιστα τα άτομα υψηλού κινδύνου αντιμετωπίζοντας όλους τους προδιαθεσικούς παράγοντες ταυτόχρονα. Σκοπός αυτής της μελέτης ήταν η ανάπτυξη ενός ερωτηματολογίου που θα μπορεί να αναγνωρίζει αξιόπιστα τα άτομα ηλικίας άνω των 60 ετών, στην Ελλάδα, με αυξημένο κίνδυνο πτώσεων. Μέθοδοι Αναπτύχθηκε και παραδόθηκε σε 200 άτομα ένα ερωτηματολόγιο 11 σημείων (LRMS). Τα δεδομένα που συλλέχθηκαν συγκρίθηκαν με την κλίμακα Timed Up and Go (TUG), Falls Eficacy Scale-International (FES-I), Tinetti Assessment Tool, Geriatric Depression Scale-15 (GDS-15) και Morse Fall Scale. Τα αποτελέσματα αναλύθηκαν στατιστικά. Αποτελέσματα: Η συσχέτιση μεταξύ του LRMS και των εργαλείων που εξετάστηκαν ήταν υψηλή TUG (r = 0,831), FES-I (r = –0,820), Tinetti balance (r = – 0,812), Tinetti gait (r = – 0,789), GDS-15 (r = – 0,562), και Morse Fall Scale (r = 0,795). O συντελεστής Cronbach alpha για τη συνολική βαθμολογία LRMS ήταν 0,807. Η βαθμολογία ICC του LRMS ήταν 0,991. Η περιοχή κάτω από την καμπύλη του LRMS ήταν 0,930 (σημείο αποκοπής 10,5, 95% C.I. 0,88 - 0,98, p < 0,001, ευαισθησία = 86%, ειδικότητα = 98%) με το TUG ως εργαλείο εκλογής, 0,919 (σημείο αποκοπής 11,5 , 95% C.I. 0,88 - 0,96, p < 0,001, ευαισθησία = 85%, ειδικότητα = 89%) με το FES-I και 0,947 (σημείο αποκοπής 10,5, 95% C.I. 0,91 - 0,98, p < 0,093%, ευαισθησία = 93%, ειδικότητα = 91%) με το Tinetti. Συμπεράσματα: Το ερωτηματολόγιο LRMS έδειξε επαρκή εσωτερική συνέπεια, εξαιρετική αξιοπιστία και υψηλή συσχέτιση με τα ήδη καθιερωμένα εργαλεία για την εκτίμηση του κινδύνου πτώσης. Είναι σύντομο και εύκολο στη χρήση χωρίς βοήθεια από ειδικά εκπαιδευμένο προσωπικό.
COMPARATIVE STUDY OF COMPACTION AND VOIDS DEVELOPMENT DURING THE OUT-OF-AUTOCLAVE CURING FOLLOWED BY CT-SCAN: EFFECTS UPON ILSS
Authors: OLIVIER PHILIPPE , SERRANO LEONARD
Published: November 2023

The main challenges with composite parts manufacturing are related to the curing means, mainly autoclaves, the length of their cycles and their operating costs. In order to decrease this dependency, out of autoclave materials have been considered a solution for high production rate parts such as spars, flaps, etc. However, most out-of-autoclave process do not possess the same maturity as their counterpart, especially concerning achievable part quality. The absence of external pressure during cure has an impact on the part quality if the parameters such as the temperature and vacuum are not set correctly. In this work, the behaviour of 2 prepreg materials developed for out-of-autoclave curing is analysed by CT-Scan during precompaction under vacuum and during curing steps, with a focus on the manufactured laminates void content. The way mechanical properties are affected by void content is then studied by measuring the interlaminar shear stress of VBO processed parts.
HYGROTHERMAL AGING OF STRUCTURAL EPOXY ADHESIVES USED IN WIND TURBINE BLADE COMPOSITE JOINTS
Authors: ALIHEIDARI NAHAL , AMELI AMIR
Published: November 2023

Two different epoxy adhesives that are widely used in wind turbine blades were studied. The aim was to investigate the adhesives moisture absorption and desorption behaviors and assess their mechanical performance degradation with the environmental exposure conditions. The cured adhesives were conditioned at 50 ºC and three different relative humidity levels of 43, 75, and 96% for 17 days, followed by vacuum drying at 40 °C for another 17 days. During moisture absorption and desorption tests, periodic gravimetric measurements were conducted to obtain moisture saturation concentrations, diffusion coefficients, and residual moisture concentrations. The results revealed that the moisture saturation concentration increased 3-4 folds as the RH level was changed from 43 to 96%, while the diffusion coefficient was decreased. The permanent damage related to the environmental conditioning was then measured by tensile testing of fully conditioned samples. A significant drop in both the modulus of elasticity and the strength as well as a mild decrease in the strain at break were observed for both adhesive systems.
EFFECTS OF BONDLINE AND SUBSTRATE THICKNESSES ON THE MODE II FRACTURE TOUGHNESS OF COMPOSITE/ADHESIVE JOINTS
Authors: ALIHEIDARI, NAHAL , AMELI AMIR
Published: November 2023

Glass fiber reinforced plastics (GFRPs) are commonly used in wind turbine blades (WTB). The joining of several GRFP components in a WTB is usually obtained using structural adhesives. The GFRP/adhesive joint usually experiences mixed-mode loading (opening and shear) conditions, with mode II being a major phase. The experimental evaluation of the joint failure under shear is usually conducted using end-notched flexure (ENF) test, which provides the value of the fracture energy required for the onset of interlaminar crack propagation by shear forces. There are standard methods such as ASTM D7905 that have provided the procedure for the ENF test. This standard test method has been particularly developed for the evaluation of crack growth from a precrack within a fiber reinforced composite, not composite/adhesive joints. However, this method has also been used for Mode II fracture energy evaluations in composite/adhesive joints. To better understand the applicability of the standard ENF method for composite/adhesive joints of WTBs, this work focuses on the dependency of the measured mode II critical strain energy release rate (GIIc) on the specimen geometry, in particular, substrate thickness and adhesive layer thickness. The substrate effect on the fracture behavior was assessed using three different substrate thicknesses of about 3, 5, and 6.3 mm, and the bondline thickness was examined from 0.25 to 3.55 mm.Overall, it was found that both substrate thickness and the bondline thicknesssignificantly affect the fracture energy and failure mode. The results showed that withan increase in the substrate thickness, GIIc was increased, and the fracture surfaceexamination suggested a more cohesive failure behavior. Moreover, with an increase inthe bondline thickness, GIIc first was increased up to a maximum value of 6.90 kJ/m2 ata thickness of 1.05 mm beyond which it started to decline. These findings suggest thatthe measured fracture energy for composite/adhesive joints using ENF standard testmethod is strongly geometry dependent and thus the geometry should be considered inthe design for failure under crack growth.
INVESTIGATING THE STRUCTURE OF CVD DEPOSITED AMINO SILANE ON SILICA SUBSTRATE VIA HIGH RESOLUTION CHARACTERIZATION METHODS
Authors: BISHT ANKITA , KUBOTA MUNETAKA , GILLESPIE, JR. JOHN W.
Published: November 2023

The interphase between glass fiber and an epoxy matrix is a nanometer scale region that governs the load transfer between these constituents in composites. Traditionally, sizing packages are multifunctional and are applied to a fiber surface to protect fibers during handling and weaving while improving wettability and adhesion through covalent bonds between the fiber surface and the matrix. The most conventional sizing application approach is to use epoxy emulsion of silanes and surfactants; however, it leads to non-uniform coating (i.e., coverage and thickness) and a structure that is not well understood. An adhesion promoter like organofunctionalized silanes is often a part of these sizing packages, and they can help achieve desirable interphase properties. Molecular dynamics (MD) simulation studies have shown that these glass-silane-epoxy interphase strength and energy absorption is highly dependent on bond density, interphase-coating thickness, and strain rate (monolayer and full saturation of bond density resulted in highest interphase strength). To create such thin coatings, a chemical vapor deposition (CVD) approach may be well suited since it can achieve both a uniform silane coating and control of the thickness range as low as a monolayer. A CVD method developed previously to deposit the silane coating on glass fiber surfaces, has shown improvements to the interphase strengths, though the deposited coating morphology was not well understood nor optimized. Quantifying/characterizing the uniformity and thickness of coating on a fiber surface is an experimental challenge due to its cylindrical shape. Hence, a Si substrate with an oxide layer was used as a surrogate. The current study focuses on understanding the relationship between CVD process exposure time (5 min, 30 min and 60 min) and structure of the amino silane coating on Si substrate to develop an approach for depositing a uniform and thin coatings.
ANALYSIS OF FIBER FLOW, FIBER ORIENTATION, AND VOID FORMATION AT SYRINGE-NOZZLE JUNCTION IN MATERIAL EXTRUSION ADDITIVE MANUFACTURING OF SHORT CARBON FIBER EPOXY COMPOSITES
Authors: MONDAL ANIRBAN , SAHA MRINAL C. , MAITY KUNTAL , ALTAN M. CENGIZ , LIU YINGTAO
Published: November 2023

Material extrusion additive manufacturing of short carbon fiber epoxy composite ink should exhibit thixotropic behavior which enables the fabrication of complex as well as simple 3D structures with controlled and tailored fiber arrangement within the composite part. This study investigates a method to automatically segregate fibers from voids and epoxy allowing fiber flow analysis and fiber orientation distribution. Validation of this method is used to present the experimental results for fiber orientation/alignment and void formation at the syringe-nozzle junction for a stitched (entire cross-section) and representative image. Further, the results were compared to assess the significance of the stitched image analysis over a representative image. Specimens were extracted as is from the syringe-nozzle juncture, followed by polishing and imaging. Qualitative visualization and quantitative analysis of the cross-section of the fibers were carried out using image-processing techniques for both images to identify the fiber orientation and alignment corresponding to the ink material flow direction at this junction. Bay and Tucker's method was used to quantitatively measure the 3D orientation and alignment of fibers. Similarly, qualitative, and quantitative analysis was carried out to identify and measure void area fraction for both the images. This study provides insight into the fiber alignment, arrangement, and dispersion within the epoxy matrix at this section as the ink material flows into the nozzle, followed by extrusion. Lastly, the experimental results reported in this study could be used to validate computational models used for analyzing flows within the ME-AM system for short fiber-reinforced epoxy composites.
THE LOW VELOCITY DYNAMIC ENERGY ABSORPTION OF COMPOSITE-LATTICE SANDWICH STRUCTURES
Authors: JACKSON AARON , DAVIDSON PAUL , ADNAN ASHFAQ
Published: November 2023

sheets, and Kevlar fabrics may provide enhanced energy absorption at a lighter weight compared to existing helmet material and structural systems.Recent advances in additive manufacturing have allowed the investigation of the static and dynamic performance of 3-dimensional cellular structures for the application of absorbing mechanical energy. The inclusion of lattice structures in energy absorbers allows lighter weight design that can sustain large elastic deformation. Structures that perform well under static loading may not perform well under dynamic loads due to kinetic energy and wave propagation effects. Thus, the complexity of the design process increases when designing energy absorbing structures through a range of strain rates and impacting inertias. In this study we investigate the dynamic performance of existing and novel lattice structures sandwiched between carbon fiber composites and Kevlar fabrics for the application of lighter weight, better protecting armor and helmets. The results of this novel sandwich design are directly compared to the performance of the material layers used in United States Army’s standard issue Advanced Combat Helmet (ACH). Dynamic low velocity impact experiments are conducted using a drop tower system. The energy absorbed by the sandwich structure is recorded based on the difference in acceleration from the top impacted surface and the base of the structure. A base-level study of the existing lattice structure energy absorption is conducted prior to the testing of composite sandwich structures. The existing structures tested include body center cubic (BCC), face center cubic (FCC), kelvin truss (KT), and diamond cubic (DC). Across all tests the BCC reduced the most acceleration followed by the DC, FCC, and KT lattice. It is observed for all tests that at constant impacting mass and strain a lower relative density allows more deformation of the lattice resulting in a higher acceleration reduction. The lower relative density structures undergo compression for a longer period yielding higher impulse or momentum change. This study provides insights into how the use of cellular materials, carbon fiber composite
RECYCLABLE CELLULOSE FIBER REINFORCED VITRIMER COMPOSITE
Authors: SINGH ROHEWAL SARGUN SINGH , SEO JIHO , KANBARGI NIHAL , NASKAR AMIT K.
Published: November 2023

Vitrimer is an innovative class of polymeric materials which demonstrates traditional thermoset-like mechanical and chemical resilience while still being able to flow on demand like a traditional thermoplastic through covalently adaptive dynamic linkages. Herein, high-performance cellulose fiber reinforced vitrimer composites are developed using an epoxy-based vitrimer and natural cellulose paper. The reinforced vitrimer composite was fabricated by impregnating the porous structure of cellulose paper with two curable monomers, followed by in-situ polymerization of the monomers inside the fibrous scaffold. The introduction of hydroxyl group present on the cellulosic framework assisted in a faster topological rearrangement of the crosslinked matrix through transesterification exchange reaction, thus imparting various sought-after properties like shape recovery and recyclability via simple thermal reprocessing. Moreover, the reinforced vitrimer composite exhibits superior tensile properties as high as 90 MPa with 15-25 volume% vitrimer loading due to the interfacial adhesion via ester exchange reaction between the epoxy matrix and functionalities on the cellulosic fibers. Noteworthily, the key ingredients of the resulting composite (i.e., epoxy-based vitrimer and cellulose fibers) can be comfortably recycled without using aggressive chemical treatment, enabling composite to be easily recycled or disposed of at the end of service life and assist in reducing the subsequent manufacturing cost. This study would shed light on the development of a recyclable polymer composite with exceptional mechanical properties while simultaneously demonstrating self-healing and shape memory capabilities.