bluuebunny/crossref_metadata_2025 huggingface dataset:
Estenosis e insuficiencia tricúspide
Authors: Vera García Pamela Lourdes , Ávila Vinueza Johanna Priscila , Romero Galabay Ignacia Margarita
Published: February 2024

Introducción: El corazón forma parte del sistema cardiovascular y posee cuatro válvulas; la tricúspide, la pulmonar, la mitral y la aórtica. Las condiciones que afectan a la fisiología de la válvula tricúspide son originadas por patologías genéticas o adquiridas y se clasifican en estenosis e insuficiencia tricúspide, los grupos más vulnerables son las mujeres, adultos mayores y personas que tengan comorbilidades de cardiopatía izquierda, los síntomas más comunes son: hepatoesplenomegalia, ascitis, astenia, disnea y edema. Objetivo: Determinar el manejo de Insuficiencia tricúspide en un caso clínico para presentar aspectos nuevos e instructivos de la enfermedad. Metodología: La dirección metodológica utilizada en este estudio es de revisión y análisis de caso clínico. Resultados: Una persona de sexo femenino de 74 años diagnosticada de cardiopatía congénita y valvular no dilatada con función sistólica conservada, FEVI 67% tratada con cierre quirúrgico de comunicación interauricular e insuficiencia tricúspide severa sintomática con fibrilación auricular, el objetivo de este estudio es determinar el manejo de la insuficiencia tricúspide y presentar aspectos nuevos o instructivos de la enfermedad con sus respectivos antecedentes, historia clínica, examen físico, tratamiento quirúrgico, plan de atención de enfermería y evolución con la finalidad de ampliar los conocimientos del personal de salud, comunidad científica y público general. Conclusión: La ET es una condición valvular de poco impacto en la población general, a diferencia de la IT que el porcentaje de prevalencia es más alto, por lo regular, comparten de manera similar el cuadro clínico, el diagnóstico y el tratamiento. Área de estudio general: medicina. Área de estudio específica: cardiología. Tipo de estudio: Casos clínicos.
Arritmia sinusal: Caso clínico
Authors: Calle Bermeo Jessica Marcela , Mesa Cano Isabel Cristina , Hernandez Mendoza David Eugenio
Published: February 2024

Introducción. La arritmia sinusal es una alteración del ritmo cardiaco, que no presenta sintomatología ni muestra anomalía en el nódulo sinusal. La causa más común es una lesión cerebral, provocada por el aumento de la presión intracraneal o hipoxia, que con frecuencia se manifiesta en personas jóvenes sanas por la variabilidad en la frecuencia cardiaca por debajo de lo normal y aumento del tono vagal. Objetivo. Determinar el manejo de la arritmia sinusal mediante el análisis de un caso clínico para presentar aspectos nuevos e instructivos de la enfermedad.   Metodología. estudio de tipo descriptivo retrospectivo mediante el análisis de un caso clínico y para la recolección de información acerca de la patología se realizará las búsquedas en las distintas fuentes científicas de los últimos 5 años en las plataformas como son: Scopus, PorQuest, PudMed, Web of Science, Lilacs, Redalyc, Medigraphic, Scielo, entre otros.  Resultados. Paciente de 14 de edad sexo masculino en Guatemala acude por urgencias cardiología para valoración del ritmo cardiaco le toman 3 electrocardiogramas y diagnostican electrocardiograma de deportista frecuencia cardiaca de 28 lpm. Conclusión. La importancia de este trabajo de investigación es describir el caso clínico de un paciente masculino de 14 años de edad con arritmia sinusal y analizar aspectos nuevos e instructivos de la enfermedad y adquirir nuevos conocimientos acerca de la patología. Área de estudio general: medicina. Área de estudio específica: cardiología. Tipo de estudio: Casos clínicos.
Insuficiencia aórtica: caso clínico
Authors: Calle Mora Eulalia Alexandra , Mesa Cano Isabel Cristina , Hernandez Mendoza David Eugenio
Published: February 2024

Introducción. La insuficiencia aórtica (IA) se trata de una afección cardiovascular frecuente en la vida. Los casos crónicos permanecen asintomáticos a medida que el Ventrículo Izquierdo se agranda; hasta llegar a la insuficiencia aguda sintomática.  Objetivo. Determinar el manejo de la insuficiencia aórtica para presentar aspectos nuevos e instructivos de la enfermedad. Metodología. Análisis de estudio de caso clínico; descriptivo, retrospectivo. Para la construcción se realizó una revisión bibliográfica en bases de dados como scopus, pubmed, Redalyc. Se hizo la descripción del caso y se estableció una discusión de la información científica con los hallazgos del caso. Resultados. paciente masculino de 83 años con diagnóstico de Insuficiencia aórtica severa, con tratamiento resolutivo de reemplazo de válvula Transcateter. La patología se caracteriza por la regurgitación de sangre de la aorta al ventrículo izquierdo durante la diástole. Se atribuye a anomalías congénitas o adquiridas de la válvula o la raíz aórticas. Conclusión. No hay una fórmula escrita que sea lo suficientemente exacta para determinar la severidad del padecimiento, por lo cual es necesario aplicar una visión integradora en el abordaje, además del seguimiento sistemático y el control ecocardiográfico. Área de estudio general: medicina.
Infective complications in the renal transplant recipients
Authors: Rosso Giuseppina , Salvadori Maurizio
Published: February 2024

Infections remain a common complication of solid-organ transplantation and are a major factor of morbidity and mortality in renal transplant recipients.
The incidence of infection in renal transplant patients is directly related to the net immunosuppressive effect achieved and the duration of the administration of immunosuppressive therapy.
The major types of infections can be categorized according to the time post-transplant during which they occur: in the first month after transplantation post-surgical bacterial infections and in the period from one to four months post-transplant opportunistic infections, overall cytomegalovirus; late infections, beyond 6-12 months, are community-acquired infections.
Opportunistic infections (like Pneumocystis carini, Listeria monocytogenes, and Aspergillus fumigatus) most frequently occur in the first 12 months post-transplant and can be modulated by prior exposures and the use of prophylaxis.
Impact of Study Skills on Accountancy Achievement
Authors: Karodia Mohamed
Published: February 2024

Despite its perceived difficulty, accountancy remains a popular choice for students at Higher Education Institutions (HEIs). However, poor student performance persists. This study explored the impact of study skills on accountancy achievement, focusing on second-year diploma students at the University of Johannesburg. Several factors hinder success, including students needing an accountancy background, the high school-HEI gap, and English language barriers. A literature review was conducted to investigate scholarly suggestions about general study skills and, in particular, for the study of Accountancy to succeed. The study adopted the quantitative research method to determine which study skills second-year accountancy students apply when learning and why they fail Accountancy examinations and formal class tests. A questionnaire focussing upon the various aspects of study skills used when studying Accountancy and, in general, was furnished to 800 students in their Second Year Diploma in Accountancy at the University of Johannesburg’s Soweto Campus. Descriptive statistics in proportions, frequencies, means, standard deviations and t-tests were used to compare the differences between the two groups of these students. In addition, correlations between variables were used to analyse the quantitative data collected. Findings revealed significant correlations between solid study skills and superior academic performance. Based on this, the study recommends: Study skills courses: Equipping students with time management, note-taking, and test preparation skills, along with specific accountancy study techniques. Early intervention: Integrating comprehensive study skills training into First Year, ideally as a dedicated course. Enhanced teaching: Encouraging lecturers to dedicate time to teaching effective study methods alongside accountancy concepts. Institutional support: Implementing a university-wide study skills program to offer ongoing support. By addressing the challenges and prioritising adequate study skills training, HEIs can significantly improve accountancy students' success and academic performance.
Speech Acts Revisited: Examining Illocutionary Speech Acts in Speeches of Mustafa Kemal Ataturk
Authors: Oder Alp Bugra
Published: February 2024

Pragmatics is an interdisciplinary subfield of applied linguistics that investigates the meaning in context. One of its research areas, speech acts, provides important implications on how the meaning behind the utterances is perceived and what effect it may have on the hearer. Theories and classifications proposed by Austin (1962) and Searle (1979) are particularly useful in understanding the hidden meaning and its effect on the audience. Political discourse is directly connected with speech acts and there is a body of research that focuses on the classification of illocutionary acts embedded within speeches of politicians. In this regard, the present research aimed to analyze illocutionary speech acts of two speeches of Mustafa Kemal Ataturk;speech at the 10th anniversary of Turkish Republic and  Address to Turkish Youth which was a part of his great speech that he delivered to deputies and representatives of the Republican Party on 15th-20th October 1927 by employing qualitative content analysis on English translations of the speeches. Subsequent to meticulous analysis, the present qualitative study concluded that Ataturk used more speech acts in his speech at the 10th anniversary of the Turkish Republic than his Address to Turkish Youth. Speech acts in his speech at the 10th anniversary of the Turkish Republic primarily featured expressive, representative, commissive and directive speech acts while his Address to Turkish Youth featured representative and commissive, directive, expressive speech acts, respectively.In total, the most used speech acts were representatives, followed by expressives, commissives and directives. No declaration speech act was observed in either speech.
The EntreComp Bias: A Qualitative Study on Entrepreneurial Competence in Entrepreneurship Training
Authors: Sandberg Berit
Published: February 2024

As entrepreneurship is seen as a catalyst for innovation, economic growth and social progress, European public authorities are promoting entrepreneurial activity through education and training. Despite extensive research on academic entrepreneurship education, entrepreneurship training has received less attention. Entrepreneurship education refers to structured educational interventions designed to equip potential and existing entrepreneurs with the knowledge, skills and attitudes needed to start and run successful businesses. Entrepreneurship training is designed to promote the entrepreneurial competences identified in the European Commission’s Entrepreneurship Competence Framework (EntreComp). In a qualitative study of training activities, a content analysis was conducted to assess the compliance of the learning content with this policy standard. An internet search identified 194 courses in the Berlin-Brandenburg metropolitan region, Germany. The course descriptions were systematically analyzed and coded using the EntreComp framework. The results indicate that the courses primarily convey management knowledge rather than an entrepreneurial mindset. More than 50% of the content is related to start-up preparation, legal issues, finance and marketing, with less emphasis on creativity and interpersonal skills. Most courses prioritize knowledge acquisition, often neglecting the development of skills and attitudes. The entrepreneurship training programs studied adhere to a traditional approach to education in terms of educational paradigms. The study highlights a discrepancy between recommended policies and educational practices and suggests implications for the design of entrepreneurship training programs.
Pengaruh Ekstrak Kulit Umbi Bawang Merah (Allium cepa) dan Bawang Putih (Allium sativum) untuk Pertumbuhan Anggrek Dendrobium
Authors: Marista Bilqis , Rahayu Tintrim , Jayanti Gatra Ervi
Published: February 2024

Genetic and physiological factors influence dendrobium orchids growth and flowering. In maintaining Dendrobium orchids, the cultivation process after acclimatization greatly affects growth and development, so its quality and sustainability can be threatened. Onion bulb skin and garlic bulb skin were able to increase germination and growth variables. This research aims to determine the effect of the most effective concentration on the growth of Dendrobium orchids. This research method used an experimental method with a completely randomized design (CRD) with 24 plants, research parameters included the number of new shoots, number of new shoots, number of new roots, new root length, leaf length, total number of leaves, plant height, and weight. Plants were analyzed descriptively, and multivariate correlation tests were using IBM software. The results showed that the M40: P20 treatment was the best treatment with parameters that responded, namely the number of new shoots, length of new roots, length of leaves, total number of leaves and plant height. This shows that the administration of shallot bulb skin extract and garlic bulb skin extract positively affected several parameters.
Keywords : acclimatization, Dendrobium, effectiveness, parameters, plants.
 
ABSTRAK
Anggrek Dendrobium dalam pertumbuhan dan pembungaan dipengaruhi faktor genetik dan faktor fisiologis. Dalam pemeliharaan anggrek Dendrobium proses budidaya setelah aklimatisasi sangat mempengaruhi pertumbuhan dan perkembangan, sehingga kualitas dan kelestraiannya dapat terancam. Kulit umbi bawang merah dan kulit umbi bawang putih mampu meningkatkan perkecambahan dan variabel pertumbuhan. Tujuan penelitian ini yaitu untuk mengetahui pengaruh dari konsentrasi yang paling efektif terhadap pertumbuhan anggrek Dendrobium. Metode penelitian menggunakan eksperimental Rancangan Acak Lengkap (RAL) dengan 24 tanaman, parameter penelitian meliputi jumlah tunas baru, jumlah daun tunas baru, jumlah akar baru, panjang akar baru, panjang daun, total jumlah daun, tinggi tanaman, dan berat kering tanaman yang dianalisis secara deskriptif dan uji korelasi multivariat test menggunakan software IBM. Hasil penelitian menunjukkan perlakuan M40: P20 adalah perlakuan terbaik dengan parameter yang merespon yaitu jumlah daun tunas baru, panjang akar baru, panjang daun, jumlah total daun dan tinggi tanaman. Hal ini menunjukkan bahwa pemberian ekstrak kulit umbi bawang merah dan kulit umbi bawang putih memberikan pengaruh positif pada beberapa perameter.
Kata kunci: aklimatisasi, Dendrobium, efektif, parameter, tanaman.
Perencanaan Serta Pengembangan Sumber Daya Manusia Dalam Inovasi Pendidikan kemaritiman
Authors: Utami Tini , Luhur Pambudi M.Aji
Published: February 2024

Perbincangan mengenai inovasi pendidikan kemaritiman menunjukkan bahwa inovasi pendidikan kemaritiman yang sedang dilaksanakan mendapat perhatian dan tanggapan dari banyak pihak. akhir-akhir ini pelaksanaan inovasi pendidikan kemaritiman telah banyak dilakukan diantaranya waktu belajar, isi pelajaran, cara mengajar atau tujuan pengajaran, tetapi masih nampak bahwa hasilnya belum berjalan seperti yang diharapkan. Penelitian ini bertujuan untuk mengetahui perencanaan dan pengembangan sumber daya manusia yang efektif dalam inovasi pendidikan kemaritiman, sehingga dengan inovasi pendidikan kemaritiman yang tepat maka tujuan pendidikan kemaritiman akan tercapai seperti yang diharapkan. Metode yang digunakan adalah metode kualitatif yang berfokus pada permasalahan atas dasar fakta yang dilakukan dengan cara pengamatan, wawancara dan mempelajari dokumen. Hasil penelitian menggambarkan bahwa dalam beberapa hal masih harus diadakan perubahan, dan hal-hal tertentu masih perlu dimantapkan serta dikembangkan, terutama bagi sumber daya manusia sebagai pelaksananya, banyak yang berpendapat bahwa dasar untuk pengembangan inovasi pendidikan kemaritiman masih perlu banyak perbaikan dan diperkuat. Untuk memantapkan dasar itu perlu diperhatikan semua komponen yang terlibat di dalamnya. Salah satu komponen itu adalah tenaga pengajar sebagai sumber daya manusia yang melaksanakan inovasi itu. Masih ada tenaga pengajar terutama yang senior belum terlibat secara optimal. Oleh karena itu dalam menghadapi masa depan seharusnya juga melihat masa lampau dan membuat perencanaan sekaligus pengembangan mengenai inovasi pendidikan kemaritiman.
Fungsi Sumber Daya Manusia Untuk Peningkatan Produktivitas Kinerja Pegawai Pelabuhan Tanjung Perak
Authors: Rosalita E. , Soedarmanto Soedarmanto , Dwi Priyohadi Nugroho , Priyanto Edi
Published: February 2024

Produktivitas pegawai yang tinggi dapat dicapai jika seluruh elemen-elemen yang ada dalam perusahaan terintegrasi dengan baik, dan mampu menjalankan peranannya sesuai dengan kebutuhan dan keinginan publik dan pegawai. Oleh sebab itu diperlukan dukungan disiplin kerja guna meningkatkan kinerja pegawai tersebut. Penelitian ini mengambil lokasi di Pelabuhan Tanjung Perak. Jenis pendekatan penelitian dalam studi ini yaitu jenis kuantitatif. Sampel yang dilakukan mengambil sampel dari seluruh populasi pegawai sebanyak 450 orang dengan sampel sebesar 15% sebanyak 70 pegawai sebagai responden penelitian. Alat analisis yang digunakan dalam penelitian ini adalah analisis regresi logistik. Perhitungan program SPSS (Statistical Package for the Social Sciences) diperoleh nilai R Square 0,392 berarti variabel disiplin kerja dan pemberian penghargaan memberikan pengaruh sebesar 39,2% terhadap produktivitas pegawai, sedangkan sisanya sebesar 60,8% dipengaruhi oleh faktor lain di luar variabel yang diteliti, misalnya seperti faktor lingkungan kerja, komunikasi, gaya kepemimpinan, pendidikan dan lain-lain. Hasil penelitian ini menunjukan bahwa Disiplin Kerja tidak memiliki pengaruh signifikan terhadap Kinerja Pegawai, sedangkan Pemberian Penghargaan berpengaruh signifikan terhadap Kinerja Pegawai.
Aktivitas Freight Forwarding Dalam Proses Ekspor Melalui Transportasi Laut Untuk Meningkatkan Pengiriman Barang Ekspor
Authors: Rizqiyani Septika , Rustina Evada , Susanto Hanggoro , Agustina Vita , Tajul Khalwaty Daeng Yusuf
Published: February 2024

Penelitian ini bertujuan menganalisis aktivitas freight forwarding dalam proses ekspor melalui transportasi laut untuk meningkatkan pelayanan pengiriman barang ekspor di PT. Multi Terminal Indonesia (MTI). Dalam penelitian yang dilakukan ini menerapkan metode deskriptif kualitatif. Dimana analisis data dilakukan dengan pengumpulan data mengenai aktivitas, proses ekspor impor dan semua dokumen yang dibutuhkan. Kemudian data tersebut diolah dalam hasil deskripsi data berbentuk tulisan. Pengumpulan data yang valid melalui hasil wawancara, observasi dan studi pustaka. Munculnya kendala-kendala dalam aktivitas dan keberlangsungnya proses ekspor-impor. Hasil penelitian dapat diketahui bahwa PT. Multi Terminal Indonesia (MTI) memiliki peranan penting dalam membantu kegiatan eksportir dan importir. Dalam hal ini juga berperan sebagai wakil dari shipper sekaligus pihak penghubung antara shipper dan consigneee. PT. Multi Terminal Indonesia (MTI) ini membantu pengiriman barang eksportir dan importir berupa konsolidasi muatan, pengangkutan, dokumentasi, pengepakan (Packing), serta asuransi. Khusus bagian ekspor-impor di PT. Multi Terminal Indonesia (MTI) dalam proses pengiriman atau pengapalan dengan penerbitan dokumen ekspor-impor berupa Bill Of Lading.
TECHNICAL TRANSLATION COURSEBOOK. Strategies of Oral and Written Translation:Lexico-grammatical Aspects of Transport Sublanguage for Students of Higher Technical Institutions
Authors:   National Transport University, SHEVCHUK Lesia ,   National Transport University, MOSHKOVSKA Liudmyla
Published: February 2024

Навчальний посібник укладено на засадах кредитно-трансферної системи навчання. Мета посібника – навчання різним видам усного та письмового перекладу науково-технічних та публіцистичних текстів транспортної тематики, удосконалення перекладацьких навичок студентів за допомогою виконання лексико-граматичних вправ з перекладу. Лексичне наповнення текстів відображає сучасні тенденції розвитку транспортної системи академічної англійської мови. Призначається для студентів закладів вищої технічної освіти.
Mathematical modelling of a silicon carbide (SiC) pilot furnace
Authors: Andrews James , Azemar Aitor , Bhattacharya Atrayee , Egan Charlie , Lacey Andrew , Metherall Brady , Ryan Nicholas
Published: February 2024

This report proposes a one-dimensional mathematical model of a novel silicon carbide furnace designed by Elkem ASA. The model consists of balance equations for volume fractions of three solids -- silicon dioxide, carbon, and silicon carbide -- and molar concentrations of two gases -- silicon monoxide and carbon monoxide -- within the furnace, which are coupled by reaction rate functions. Preliminary numerical results for steady-state solutions of these equations are presented. A simplified model involving two gas species is considered; the reaction rate for silicon monoxide formation is constant in places within the furnace where the temperature exceeds the minimum temperature for the reaction to proceed, and the presented solution can deal with the known carbon concentrations. The two-gas model is utilized to identify the residence time for the gas to vent from the top of the furnace.
Sources of continuous tremor associated with jökulhlaups and eruptions of Grímsvötn volcano, Iceland
Authors: Einarsson Páll , Pálsson Finnur , Pálsson Magnús , Magnússon Eyjólfur , Brandsdóttir Bryndís , Winder Tom
Published: February 2024

.
Afkoma íslenskra jökla (Mass balance measurements) 2022–2023
Authors: Gunnarsson Andri , Pálsson Finnur , Þorsteinsson Þorsteinn
Published: February 2024

.
Jöklarannsóknir Hans Ahlmann og samstarfsmanna á öndverðri 20. öld (19th century glacier research by Hans Ahlmann and coworkers)
Authors: Björnsson Helgi
Published: February 2024

.
Development of a test bench for biomechanical simulation—a preliminary study of mandibular forces
Authors: Ben Achour Anas , Apfeld Florian , Lauer Günter , Bräuer Christian , Leonhardt Henry , Franke Adrian , Lipphaus Andreas , Teicher Uwe , Witzel Ulrich , Schröder Tom Alexander
Published: February 2024

Purpose: The aim of this study is to develop a test bench, which integrates different complexity levels and enables in that way a flexible and dynamic testing for mid and long term intervals as well as testing of maximum loads till implant failure of different osteosynthesis systems on the mandible.

Material and Methods: For this purpose, an analysis of the state of the art regarding existing test benches was combined with interviews of clinical experts to acquire a list of requirements. Based on these requirements a design for a modular test bench was developed. During the implementation of the test stand, functional tests were continuously carried out and improvements made. Depending on the level of complexity, the test bench can be used either as an incorporated variant or as a standalone solution. In order to verify the performance and the degree of fulfilment of the requirements of these two variants of the test bench, preliminary studies were carried out for all levels of complexity. In these preliminary studies, commercially available osteosynthesis and reconstruction plates were investigated for their biomechanical behaviour and compared with data from the literature.

Results: In total, fourteen test runs were performed for the different levels of complexity. Firstly, five test runs were executed to test the simplified load scenario in the incorporated variant of the test bench. High forces could be transmitted without failure of the miniplates. Secondly a quasi-static test scenario was examined using the incorporated variant with simplified load insertion. Five experiments with a number of cycles between 40,896 and 100,000 cycles were carried out. In one case the quasi-static testing resulted in a fracture of the tested reconstruction plate with a failure mode similar to the clinical observations of failure. The last four test runs were carried out using the standalone variant of the test bench simulating complex load patterns via the insertion of forces through imitated muscles. During the test runs joint forces were measured and the amplitude and vector of the resulting joint forces were calculated for both temporomandibular joints. Differences in the force transmission depending on the implant system in comparison to the zero sample could be observed.

Conclusion: The presented modular test bench showed to be applicable for examination of the biomechanical behavior of the mandible. It is characterized by the adjustability of the complexity regarding the load patterns and enables the subsequent integration of further sensor technologies. Follow-up studies are necessary to further qualify and optimize the test bench.
Amnion-derived hydrogels as a versatile platform for regenerative therapy: from lab to market
Authors: Kafili Golara , Niknejad Hassan , Tamjid Elnaz , Simchi Abdolreza
Published: February 2024

Graphical Abstract

The Figure was partly generated using Servier Medical Art, provided by Servier, licensed under a Creative Commons Attribution 3.0 unported license.
Characteristics of head frequency response in blunt impacts: a biomechanical modeling study
Authors: Li Guibing , Xu Shengkang , Xiong Tao , Li Kui , Qiu Jinlong
Published: February 2024

Existing evaluation criteria for head impact injuries are typically based on time-domain features, and less attention has been paid to head frequency responses for head impact injury assessment. The purpose of the current study is, therefore, to understand the characteristics of human body head frequency response in blunt impacts via finite element (FE) modeling and the wavelet packet analysis method. FE simulation results show that head frequency response in blunt impacts could be affected by the impact boundary condition. The head energy peak and its frequency increase with the increase in impact; a stiffer impact block is associated with a higher head energy peak, and a bigger impact block could result in a high proportion of the energy peak. Regression analysis indicates that only the head energy peak has a high correlation with exiting head injury criteria, which implies that the amplitude–frequency aggregation characteristic but not the frequency itself of the head acceleration response has predictability for head impact injury in blunt impacts. The findings of the current study may provide additional criteria for head impact injury evaluation and new ideas for head impact injury protection.
Plasmid-encoded gene duplications of extended-spectrum β-lactamases in clinical bacterial isolates
Authors: Sobkowiak Annika , Scherff Natalie , Schuler Franziska , Bletz Stefan , Mellmann Alexander , Schwierzeck Vera , van Almsick Vincent
Published: February 2024

Introduction

The emergence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is an urgent and alarming One Health problem. This study aimed to investigate duplications of plasmid-encoded ESBL genes and their impact on antimicrobial resistance (AMR) phenotypes in clinical and screening isolates.

Methods

Multi-drug-resistant bacteria from hospitalized patients were collected during routine clinical surveillance from January 2022 to June 2023, and their antimicrobial susceptibility patterns were determined. Genotypes were extracted from long-read whole-genome sequencing data. Furthermore, plasmids and other mobile genetic elements associated with ESBL genes were characterized, and the ESBL genes were correlated to ceftazidime minimal inhibitory concentration (MIC).

Results

In total, we identified four cases of plasmid-encoded ESBL gene duplications that match four genetically similar plasmids during the 18-month surveillance period: five Escherichia coli and three Klebsiella pneumoniae isolates. As the ESBL genes were part of transposable elements, the surrounding sequence regions were duplicated as well. In-depth analysis revealed insertion sequence (IS)-mediated transposition mechanisms. Isolates with duplicated ESBL genes exhibited a higher MIC for ceftazidime in comparison to isolates with a single gene copy (3–256 vs. 1.5–32 mg/L, respectively).

Conclusion

ESBL gene duplications led to an increased phenotypic resistance against ceftazidime. Our data suggest that ESBL gene duplications by an IS-mediated transposition are a relevant mechanism for how AMR develops in the clinical setting and is part of the microevolution of plasmids.
The Mla system and its role in maintaining outer membrane barrier function in Stenotrophomonas maltophilia
Authors: Coves Xavier , Mamat Uwe , Conchillo-Solé Oscar , Huedo Pol , Bravo Marc , Gómez Andromeda-Celeste , Krohn Ines , Streit Wolfgang R. , Schaible Ulrich E. , Gibert Isidre , Daura Xavier , Yero Daniel
Published: February 2024

Stenotrophomonas maltophilia are ubiquitous Gram-negative bacteria found in both natural and clinical environments. It is a remarkably adaptable species capable of thriving in various environments, thanks to the plasticity of its genome and a diverse array of genes that encode a wide range of functions. Among these functions, one notable trait is its remarkable ability to resist various antimicrobial agents, primarily through mechanisms that regulate the diffusion across cell membranes. We have investigated the Mla ABC transport system of S. maltophilia, which in other Gram-negative bacteria is known to transport phospholipids across the periplasm and is involved in maintaining outer membrane homeostasis. First, we structurally and functionally characterized the periplasmic substrate-binding protein MlaC, which determines the specificity of this system. The predicted structure of the S. maltophilia MlaC protein revealed a hydrophobic cavity of sufficient size to accommodate the phospholipids commonly found in this species. Moreover, recombinant MlaC produced heterologously demonstrated the ability to bind phospholipids. Gene knockout experiments in S. maltophilia K279a revealed that the Mla system is involved in baseline resistance to antimicrobial and antibiofilm agents, especially those with divalent-cation chelating activity. Co-culture experiments with Pseudomonas aeruginosa also showed a significant contribution of this system to the cooperation between both species in the formation of polymicrobial biofilms. As suggested for other Gram-negative pathogenic microorganisms, this system emerges as an appealing target for potential combined antimicrobial therapies.
Droplet digital PCR as alternative to microbiological culture for Mycobacterium tuberculosis complex detection in bovine lymph node tissue samples
Authors: Sánchez-Carvajal José María , Vera-Salmoral Eduardo , Huerta Belén , Galán-Relaño Ángela , Ruedas-Torres Inés , Larenas-Muñoz Fernanda , Luque Inmaculada , Carrasco Librado , Gómez-Laguna Jaime
Published: February 2024

Introduction

Bovine tuberculosis (bTB) caused by Mycobacterium tuberculosis complex (MTC) remains a significant concern for public health. Direct real-time PCR and droplet digital PCR (ddPCR) are proposed as alternative tools to enhance diagnostic precision and efficiency. This study aims to assess the diagnostic performance of a ddPCR assay targeting IS6110 for the detection of MTC DNA in both microbiological culture and fresh lymph node (LN) tissue samples obtained from cattle, in comparison with the established reference standard, the microbiological culture followed by real-time PCR.

Methods

The fresh LNs (N=100) were collected each from a different cattle carcass at the slaughterhouse. The limit of detection of ddPCR-IS6110 was set to 101 copies per 20 μl reaction.

Results

DdPCR-IS6110 detected 44 out of 49 reference-standard positive samples and yielded negative results in 47 out of 51 reference-standard negative samples, resulting in adjusted sensitivity (Se) and specificity (Sp) of 90.76% [95% confidence interval (CI): 82.58 - 98.96%)], and 100% (95% CI: 100%) respectively. The estimated adjusted false negative rate (FNR) was 9.23% (95% CI: 1.04 - 17.42%) and the false positive rate (FPR) was 0% (95% CI: 0%). When directly applied from fresh bovine LN tissues, ddPCR-IS6110 identified 47 out of 49 reference-standard positive samples as ddPCR-IS6110-positive and 42 out of 51 reference-standard negative samples as ddPCR-IS6110-negative, resulting in adjusted Se and Sp values of 94.80% [95% (CI): 88.52 - 100%] and 100% (95% CI: 100%), respectively. The adjusted FNR was 5.20% (95% CI: 0 - 11.50%) and the FPR was 0% (95% CI: 0%). Noteworthy, ddPCR-IS6110 disclosed as positive 9 samples negative to reference-standard.

Discussion

DdPCR-IS6110 proved to be a rapid, highly sensitive, and specific diagnostic tool as an alternative to reference-standard method.
Operator decision-making in angiography-only guided revascularization for lesions not indicated for FFR: a QFR-based functional assessment in chronic coronary syndrome
Authors: Kanoun Schnur Sadeek S. , Pranevičius Robertas , Stark Cosima , Prunea Dan , Andreka Judit , Schmidt Albrecht , Harb Stefan , Ruzsa Zoltan , Zweiker Robert , Kane Jesse , Toth Gabor G.
Published: February 2024

Background

Discordance between coronary angiographic findings and invasive functional significance is well-established. Yet, the prevalence of this mismatch in an era increasingly utilizing invasive functional assessments, such as fractional flow reserve (FFR), remains unclear. This study examines the extent of such discrepancies in current clinical practice.

Methods

This single-center prospective registry included consecutive patients with chronic coronary syndrome (CCS) who underwent elective coronary angiography, with or without revascularization. Coronary angiograms deemed not requiring FFR due to clear anatomical distinctions, either anatomically severe indicating a need for revascularization or mild suggesting no need for intervention, were selected for evaluation. These were then subjected to post-hoc analysis by three independent operators who were blinded to the definitive treatment strategies. Importantly, the post-hoc analysis was conducted in two distinct phases: firstly, a re-evaluation of coronary stenosis, and secondly, a separate functional assessment, each carried out independently. Coronary stenosis severity was assessed visually, while functional relevance was determined by quantitative flow ratio (QFR), calculated using a computational fluid dynamics algorithm applied to angiographic images. Analysis focused on discrepancies between QFR-based functional indications and revascularization strategies actually performed.

Results

In 191 patients, 488 vessels were analyzed. Average diameter stenosis (DS) was 37 ± 34%, and QFR was 0.87 ± 0.15, demonstrating a moderate correlation (r = −0.84; 95% CI: −0.86 to −0.81, p < 0.01). Agreement with QFR at conventional anatomical cutoffs was 88% for 50% DS and 91% for 70% DS. Mismatches between revascularization decisions and QFR indications occurred in 10% of cases. Discrepancies were more frequent in the left anterior descending artery (14%) compared to the left circumflex (6%) and the right coronary artery (9%; p = 0.07).

Conclusion

In a cardiac-center where FFR utilization is high, discordance between coronary angiography and functional significance persists, even when operators are confident in their decisions not to use functional interrogation. This gap, most evident in the left anterior descending artery, highlights the potential need for integrated angiography-based functional assessments to refine revascularization decisions in CCS.
Diagenetic controls over reservoir quality of tight sandstone in the lower Jurassic reservoir in the Lenghu area, the north margin of Qaidam basin
Authors: Li Wenhuan , Hu Dandan , Chang Yuwen , Li Ya’nan , Guo Bin , Shi Qi , Zhang Bin
Published: February 2024

The Lower Jurassic Reservoir (LJR) in the Lenghu area on the northern margin of the Qaidam Basin (NMoQB) has become the most promising target for hydrocarbon exploration. The reservoir has experienced complex diagenesis; however, the porosity evolution and the influence of different diagenesis events on reservoir densification remains unclear. In this study, various analytical methods was first used to clarify the diagenetic stage and sequence, establish a porosity evolution model, quantitatively analyze the time and influence of different diagenesis events on reservoir densification, and illustrate the densification mechanism of tight sandstone reservoir in the Lenghu area. The results showed that the dominant rock types in the LJR were feldspathic litharenite, followed by litharenite, lithic arkose, and a small amount of subarkose and sublitharenite. The reservoir is a typical tight sandstone reservoir (TSR), with average porosity and permeability of 5.5% and 0.08 mD, respectively. The pore types were primarily secondary pores, followed by residual intergranular pores and occasional fractures. Diagenesis of LJR has entered the meso-diagenetic stage A, with minor progression into meso-diagenetic stage B. Quantitative calculation showed that the initial porosity of LJR is 32.2%. In eo-diagenetic stage A, compaction is the main factor for porosity reduction. In eo-diagenetic stage B, the porosity loss rates caused by compaction and cementation were 81.5% and 11.8%, respectively. In this stage, the LJR in the Lenghu area has almost been densified, mainly affected by compaction, calcite cementation and clay minerals cementation. Additionally, cementation is an important factor causing reservoir heterogeneity and is dominated by calcite and clay mineral cementation. After entering the meso-diagenetic stage A, dissolution is the main diagenesis event, which can increase porosity by 6.0%. This stage is the critical period for forming high-quality reservoir of LJR in the Lenghu area, mainly in the 4,400 m depth. In meso-diagenetic stage B, the influence of dissolution gradually decreased. Simultaneously, in this stage, the cementation of iron-bearing calcite further strengthened the densification of the LJR in the Lenghu area.
Soot-on-snow experiment: artificial deposition of light-absorbing particles onto snow surfaces in 2018
Authors: Svensson Jonas , Leppänen Leena , Hannula Henna-Reetta , Kontu Anna , Shen Yi-cheng , Meinander Outi , Dagsson-Waldhauserová Pavla , Mesceriakovas Arunas , Heikkinen Enna , Ruppel Meri , Sippula Olli , Ström Johan , Asmi Eija , Virkkula Aki
Published: February 2024

The absorption of shortwave irradiance in snow depends on the physical properties of snow (e.g., snow grain size and shape, liquid water content, etc.) and light-absorbing particles (LAP). Originating from natural and anthropogenic sources, LAP has been reported to accelerate snowmelt significantly in different regions globally. Yet, our process-level understanding of LAP after deposition onto snow remains rather limited. Here we investigate the impacts of artificial deposition of different LAP onto snow surfaces in an outdoor environment of northern Finland. Following LAP dry deposition into a custom-made tent standing on top of the snowpack, the albedo was followed along with the properties of snow in snow pit measurements throughout the spring season. The results showed that the albedo decay at the end of the season for the different spots were linked to the initial amount and type of LAP that were deposited onto the snowpack. Measured snow temperature profiles from LAP doped snow versus natural reference snow illustrated that the LAP affected snow had higher temperatures in the subsurface snow layers. Collected snow samples analyzed for size distribution of soot particles revealed no apparent agglomeration of soot particles during thaw-freezing events taking place during the experiment. Despite the relatively large perturbation of the experimentally deposited LAP, their impact on the season length was only up to 3 days. Additional experiments are, nevertheless, needed to better constrain the effects of LAP on snow albedo, melt rate, and other associated processes.
Reasoning in classroom dilemma situations: how pre-service teachers judge performance assessment
Authors: Greiner Ulrike , Katstaller Michaela , Oitner Theresa
Published: February 2024

This study examines pre-service teachers’ reasoning structures based on their beliefs in the context of school performance assessment. We used reflective writing to investigate pre-service teachers’ judgment and reasoning regarding different functions of performance assessment. Forty-five undergraduate pre-service teachers participated in our study. Using a mixed-method approach, we conducted categorial and reconstructive text analyses as well as exploratory statistical analyses to describe the participants’ reasoning structures. Such cognitive structures comprise potential solutions to the performance assessment dilemmas that teachers face in their everyday teaching practice. We found varying distributions of and relationships between (individual-, objective-, social-, and ability-related) reference norms (neutral, student-, and teacher-centered) reference perspectives as well as (causal-analytic, normative, descriptive, and effect-oriented) modes of argumentation. Our discussions related to future research activities on teachers’ reasoning structures in the classroom.
Transcriptome profiling reveals superovulation with the gonadotropin-releasing hormone agonist trigger impaired embryo implantation in mice
Authors: Li Meng , Han Jingmei , Yang Nana , Li Xiangyun , Wu Xinglong
Published: February 2024

Introduction

Superovulation is a critical step in assisted reproductive technology, but the use of human chorionic gonadotropin (hCG) as a trigger for superovulation can result in ovarian hyperstimulation. Thus, the use of Gonadotropin-releasing hormone agonist (GnRHa) trigger has been increasingly adopted, although it has been associated with a higher rate of pregnancy failure compared to natural cycles. This study aimed to investigate the effect of GnRHa trigger on embryo implantation in a mouse model.

Methods

Mice in the superovulation (PG) group were administered 7.5 IU of PMSG, followed by the injection of 3.5 μg of GnRHa (Leuprorelin) 48 h later, while mice in the control group (CTR) mated naturally. We compared the number of oocytes, blastocysts, and corpus luteum between the two groups and the implantation sites after the transfer of natural blastocysts. Ovaries, uterus, and serum 2 and 4 days after mating were collected for qRT-PCR, transcriptome sequencing, and hormone assays.

Results

The PG group had more oocytes, blastocysts, and corpus luteum after superovulation than the CTR group. However, the mRNA expression of leukemia inhibitory factor (Lif) and the number of implantation sites were reduced in the PG group. The ELISA assay revealed that superovulation increased ovarian estrogen secretion. The transcriptome analysis showed that superphysiological estrogen led to a response of the uterus to a high estrogen signal, resulting in abnormal endometrium and extracellular matrix remodeling and up-regulation of ion transport and inflammation-related genes.

Conclusion

Our findings suggest that a combination of PMSG and GnRHa trigger impaired embryo implantation in mice, as the excessive uterine response to superphysiological estrogen levels can lead to the change of gene expression related to endometrial remodeling, abnormal expression of uterine ion transport genes and excessive immune-related genes.
Impacts of urbanization on land use, air quality, and temperature dynamics in Dehradun district of Uttarakhand, India: a comprehensive analysis
Authors: Dhankar Sneha , Singh Gayatri , Kumar Krishan
Published: February 2024

The present study investigates the impact of urbanization on land surface temperature and air quality in Dehradun district of the Uttarakhand state in India. We utilized data from LANDSAT, TROPOMI, OMI, MODIS, MOPITT, and CHIRPS, for spatio-temporal and trend analyses along with the assessment of correlation matrix. Our findings revealed a significant increase in the built-up area of Dehradun district in 2023 as compared to 2003. This expansion was particularly prominent in the southern and south-eastern regions of the district. The findings highlight the impact of rapid urban expansion on land use and land cover, leading to a rise in land surface temperature (LST) and the formation of surface urban heat islands (SUHI). Notably, the study reveals distinct spatial and temporal patterns, with lower regions of Dehradun district experiencing higher temperatures and pollutant concentrations due to intensified urbanization. Dehradun city also emerged as a hotspot for nitrogen dioxide within the district. Long-term trends indicate a rise in formaldehyde and nitrogen dioxide, attributed to both urbanization and increasing temperatures, while carbon monoxide levels decrease due to reduced biomass burning and the adoption of cleaner household fuels. Correlation matrix analysis underscores the complex relationships between land use, temperature, and pollutants, with built-up areas exhibiting strong positive correlations with all pollutants. This comprehensive study highlights the importance of sustainable urban planning and management to mitigate the adverse effects of rapid urbanization on air quality and overall environmental health in the Dehradun district.
External proficiency testing for histocompatibility and immunogenetics in today and future
Authors: Oguz Fatma Savran
Published: February 2024

The Histocompatibility and Immunogenetics laboratories provide disease association and pharmacogenetic analyses as well as the tests required for transplantation immunology and transfusion medicine. They perform Human Leukocyte Antigen (HLA) genotyping in patients/recipients and potential donor candidates for solid organ and stem cell transplants using various molecular methods, and determine mismatches. In addition, they also perform HLA antibody tests to detect anti-HLA antibodies in patients and flow cross-matches to evaluate donor-recipient compatibility. Evidence-based clinical guidelines have emphasized the importance of laboratory tests in clinical practices for a long time. Understanding the principles of Quality Control and External Quality Assurance is a fundamental requirement for the effective management of Tissue Typing laboratories. When these processes are effectively implemented, errors in routine assays for transplantation are reduced and quality is improved. In this review, the importance of Quality Assurance, Quality control and proficiency testing in Histocompatibility and Immunogenetic testing, the necessity of external proficiency testing (EPT) for accreditation, and existing and potential EPT programmes will be reviewed and evaluated in the light of the literature.