bluuebunny/crossref_metadata_2025 huggingface dataset:
Cadaveric surgery in core gynaecology training: a feasibility study
Authors: Lim Chou Phay , Roberts Mark , Chalhoub Tony , Waugh Jason , Delgaty Laura
Published: January 2018

Background

Fresh frozen cadaver training has been proposed as a better model than virtual reality simulators in laparoscopy training. We aimed to explore the relationship between cadaveric surgical training and increased surgical confidence.

To determine feasibility, we devised two 1-day cadaveric surgical training days targeted at trainees in obstetrics and gynaecology. Seven defined surgical skills were covered during the course of the day. The relationship between surgical training and surgical confidence was explored using both quantitative (confidence scores) and qualitative tools (questionnaires).

Results

Participants rated a consistent improvement in their level of confidence after the training. They universally found the experience positive and three overarching themes emerged from the qualitative analysis including self-concept, social persuasion and stability of task.

Conclusions

It is pragmatically feasible to provide procedure-specific cadaveric surgical training alongside supervised clinical training. This small, non-generalisable study suggests that cadaveric training may contribute to an increase in surgical self-confidence and efficacy. This will form the basis of a larger study and needs to be explored in more depth with a larger population.
Overview of the 2015 Gorkha, Nepal, Earthquake and the Earthquake Spectra Special Issue
Authors: Lizundia Bret , Davidson Rachel A. , Hashash Youssef M. A. , Olshansky Rob
Published: January 2018

On 25 April 2015, a Mw7.8 earthquake struck near Gorka, Nepal. The earth-quake and its aftershocks caused over 8,790 deaths and 22,300 injuries; a half a million homes were destroyed; and hundreds of historical and cultural monuments were destroyed or extensively damaged ( NPC 2015 ). Triggered landslides blocked access to road networks, and other lifelines were significantly impacted. Damage occurred in the capital of Kathmandu and the surrounding valley basin, but the most heavily affected areas were in more rural regions of central Nepal where losses to some towns were severe. Recovery has been slow, but progress is being made in rebuilding and repairing lost and damaged buildings and infrastructure. This Earthquake Spectra special issue provides a compendium of research papers on the Gorkha earthquake. They are organized into five topics: (1) seismology, ground motion, and geotechnical issues; (2) lifelines; (3) buildings; (4) cultural heritage structures; and (5) social science and public policy related topics. This overview summarizes key aspects of the earthquake and highlights findings from the special issue papers.
New-Onset Cardiovascular Morbidity in Older Adults With Stage I to III Colorectal Cancer
Authors: Kenzik Kelly M. , Balentine Courtney , Richman Joshua , Kilgore Meredith , Bhatia Smita , Williams Grant R.
Published: January 2018

Purpose

We sought to determine the long-term risk of cardiovascular disease (CVD)—stroke and myocardial infarction—and congestive heart failure (CHF) in older patients with colorectal cancer, as well as to understand the roles that preexisting comorbidities and cancer therapy play in increasing this risk.

Patients and Methods

We evaluated individuals from the SEER-Medicare database with incident stage I to III colorectal cancer at age older than 65 years between January 1, 2000, and December 31, 2011 (n = 72,408) and compared these patients with a matched cohort of Medicare patients without cancer (n = 72,408).

Results

Median age at diagnosis of colorectal cancer was 78 years (range, 66 years to 106 years), and median follow-up was 8 years since diagnosis. The 10-year cumulative incidence of new-onset CVD and CHF were 57.4% and 54.5% compared with 22% and 18% for control, respectively ( P < .001). The interaction between hypertension and chemotherapy was significant ( P < .001) for CVD, and that between diabetes and chemotherapy was significant ( P < .001) for CHF. Within the first 2 years since diagnosis, exposure to capecitabine alone increased CHF hazard (hazard ratio [HR], 3.6; 95% CI, 12.76 to 4.38) compared with exposure to fluorouracil alone. Conversely, patients who were treated with fluorouracil alone had a higher CVD hazard at < 2 years and > 2 years since diagnosis compared with patients who received capecitabine alone (< 2 years HR, 0.63; 95% CI, 0.53 to 0.75; > 2 years HR, 0.72; 95% CI, 0.62 to 0.84).

Conclusion

Older patients with colorectal cancer are at increased risk of developing CVD and CHF. Diabetes and hypertension interact with chemotherapy to increase the risk of cardiovascular morbidity. Future studies should assess the potential for personalized therapeutic options for those with preexisting morbidities and for structured monitoring for patients with a history of exposure to chemotherapy regimens, as well as explore the management of preexisting comorbidities to address long-term cardiovascular morbidity.
Molecular Determinants of Response to Anti–Programmed Cell Death (PD)-1 and Anti–Programmed Death-Ligand 1 (PD-L1) Blockade in Patients With Non–Small-Cell Lung Cancer Profiled With Targeted Next-Generation Sequencing
Authors: Rizvi Hira , Sanchez-Vega Francisco , La Konnor , Chatila Walid , Jonsson Philip , Halpenny Darragh , Plodkowski Andrew , Long Niamh , Sauter Jennifer L. , Rekhtman Natasha , Hollmann Travis , Schalper Kurt A. , Gainor Justin F. , Shen Ronglai , Ni Ai , Arbour Kathryn C. , Merghoub Taha , Wolchok Jedd , Snyder Alexandra , Chaft Jamie E. , Kris Mark G. , Rudin Charles M. , Socci Nicholas D. , Berger Michael F. , Taylor Barry S. , Zehir Ahmet , Solit David B. , Arcila Maria E. , Ladanyi Marc , Riely Gregory J. , Schultz Nikolaus , Hellmann Matthew D.
Published: January 2018

Purpose

Treatment of advanced non–small-cell lung cancer with immune checkpoint inhibitors (ICIs) is characterized by durable responses and improved survival in a subset of patients. Clinically available tools to optimize use of ICIs and understand the molecular determinants of response are needed. Targeted next-generation sequencing (NGS) is increasingly routine, but its role in identifying predictors of response to ICIs is not known.

Methods

Detailed clinical annotation and response data were collected for patients with advanced non–small-cell lung cancer treated with anti–programmed death-1 or anti–programmed death-ligand 1 [anti-programmed cell death (PD)-1] therapy and profiled by targeted NGS (MSK-IMPACT; n = 240). Efficacy was assessed by Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, and durable clinical benefit (DCB) was defined as partial response/stable disease that lasted > 6 months. Tumor mutation burden (TMB), fraction of copy number–altered genome, and gene alterations were compared among patients with DCB and no durable benefit (NDB). Whole-exome sequencing (WES) was performed for 49 patients to compare quantification of TMB by targeted NGS versus WES.

Results

Estimates of TMB by targeted NGS correlated well with WES (ρ = 0.86; P < .001). TMB was greater in patients with DCB than with NDB ( P = .006). DCB was more common, and progression-free survival was longer in patients at increasing thresholds above versus below the 50th percentile of TMB (38.6% v 25.1%; P < .001; hazard ratio, 1.38; P = .024). The fraction of copy number–altered genome was highest in those with NDB. Variants in EGFR and STK11 associated with a lack of benefit. TMB and PD-L1 expression were independent variables, and a composite of TMB plus PD-L1 further enriched for benefit to ICIs.

Conclusion

Targeted NGS accurately estimates TMB and elevated TMB further improved likelihood of benefit to ICIs. TMB did not correlate with PD-L1 expression; both variables had similar predictive capacity. The incorporation of both TMB and PD-L1 expression into multivariable predictive models should result in greater predictive power.
Triazasumanene: An Isoelectronic Heteroanalogue of Sumanene
Authors: Tan Qitao , Kaewmati Patcharin , Higashibayashi Shuhei , Kawano Masaki , Yakiyama Yumi , Sakurai Hidehiro
Published: January 2018

Buckybowls, which are represented by sumanene and corannulene, have attracted considerable attention for their unique bowl structures and interesting physicochemical properties. However, still few heteroatom-doped buckybowls have been reported to date. Here we show the successful synthesis of triazasumanene, an isoelectronic heteroanalogue of sumanene, which possesses a deeper bowl with stable bowl chirality and unique helical columnar packing in the crystal as an enantiopure form. In contrast, the crystal packing of the racemate shows a unidirectional columnar structure, which resembles that of the pristine sumanene. Doping of nitrogen atoms into the periphery of the sumanene framework also leads to perturbations of the electronic structure as shown by a significant decrease of the lowest unoccupied molecular orbital (LUMO) level and the optical band gap in comparison to all-carbon sumanene. The pyridine ring of triazasumanene shows unusual susceptibility towards acidic hydrolysis due to the highly strained curved structure.
Detection of Amine Vapors using Luminescent Xerogels from Supramolecular Metal-Containing Gelator
Authors: Sasaki Junpei , Suzuki Masahiro , Hanabusa Kenji
Published: January 2018

Supramolecular fluorescent gelators containing a tris(β-diketonato) complex are synthesized by using gelation-driving chelates, and their gelation abilities are studied with 15 solvents. Thin-layer films are prepared on quartz plates from the solutions and they are studied as chemosensors for amines. Fluorescence-quenching of the thin-layer films upon exposure to saturated primary and secondary amine vapors is monitored to evaluate the abilities of the chemosensors to detect amines. The morphologies of the thin-layer films are observed by transmission electron microscopy (TEM) and discussed in relation to their fluorescence-quenching. The fluorescence-quenching efficiencies upon exposure to saturated primary and secondary amines depend on the basicity and bulkiness of the amines rather than the vapor pressure. The fluorescence-quenching is caused by decomposition of a complex through nucleophilic addition of primary or secondary amines to its carbonyl group. The detection of tertiary amines is performed by monitoring the fluorescence emission from the thin-layer films, which are composed of a ligand and EuCl3. The emergence of fluorescence originates from the formation of fluorescent Eu3+-containing gelator, in which dehydrochloric acid by tertiary amines is a trigger for the complexation.
Making a Case for Cardiorespiratory Fitness Surveillance Among Children and Youth
Authors: Lang Justin J. , Tomkinson Grant R. , Janssen Ian , Ruiz Jonatan R. , Ortega Francisco B. , Léger Luc , Tremblay Mark S.
Published: January 2018

We review the evidence that supports cardiorespiratory fitness (CRF) as an important indicator of current and future health among school-aged children and youth, independent of physical activity levels. We discuss the merit of CRF measurement for population health surveillance and propose the development of CRF guidelines to help support regional, national, and international surveillance efforts.
Recent advances in understanding and managing aortic stenosis
Authors: Van Hemelrijck Mathias , Taramasso Maurizio , De Carlo Carlotta , Kuwata Shingo , Regar Evelyn , Nietlispach Fabian , Ferrero Adolfo , Weber Alberto , Maisano Francesco
Published: January 2018

Over the last few years, treatment of severe symptomatic aortic stenosis in high-risk patients has drastically changed to adopt a less-invasive approach. Transcatheter aortic valve implantation (TAVI) has been developed as a very reproducible and safe procedure, as shown in many trials. When compared to surgery, TAVI has produced superior, or at least comparable, results, and thus a trend to broaden treatment indications to lower-risk patients has erupted as a natural consequence, even though there is a lack of long-term evidence. In this review, we summarize and underline aspects that still remain unanswered that are compulsory if we want to enhance our understanding of this disease.
A comparison of physical activity and nutrition in young women with and without primary dysmenorrhea
Authors: Abadi Bavil Dina , Dolatian Mahrokh , Mahmoodi Zohreh , Akbarzadeh Baghban Alireza
Published: January 2018

Background: Dysmenorrhea is the most common gynecological disorder in young women and is seen in almost 50% of women. The present study was conducted to investigate the relationship between physical activity and nutrition with primary dysmenorrhea in students at Mazandaran University of Medical Sciences (Sari, Iran) in 2015.

Methods: This comparative descriptive study was conducted on 250 students with and without primary dysmenorrhea. Data were collected using personal-demographic, nutrition and physical activity questionnaires. The output was then analyzed in SPSS-18 using independent t-test, Chi-square test and logistic regression analysis.

Results: The results showed significant differences between the two groups in terms of nutrition and physical activity, as the mean score of nutrition was 57.91 in the group with dysmenorrhea and 61.68 in the group without, while the mean intensity of physical activity was 5518.75 metric in the group with dysmenorrhea and 4666.42 metric in the group without. Physical activity was calculated by MET scale (minutes/week). This index measured the amount of consumed energy at the time of activity relative to that consumed at resting time.

Conclusions: A healthier and more favorable nutrition style and more regular physical activity reduces the severity of dysmenorrhea in girls. Therefore, educational measures are required to raise awareness among young women about the effects of proper nutrition and physical activity on the prevention and reduction of dysmenorrhea complications.
Case Report: Acute amyopathic dermatomyositis presenting with isolated facial edema
Authors: Pappa Efthymia , Gkeka Marina , Protogerou Asimina , Marinos Leonidas , Loupa Chariclia , Christopoulos Constantinos
Published: January 2018

A 45-year-old Asian man presented with acute-onset periorbital and facial edema associated with pyrexia. Muscle weakness was absent. Initial laboratory investigations showed an inflammatory reaction, while screening for infections was negative. Serum muscle enzyme levels were normal. He was hospitalized and treated empirically with antibiotics and corticosteroids, pending the result of facial skin and muscle biopsy. He showed a good clinical and laboratory response but an attempt to discontinue corticosteroids led to a prompt relapse of facial edema and pyrexia, associated with rising laboratory indices of inflammation. Biopsy findings were typical of dermatomyositis. Reintroduction of corticosteroid treatment resulted in complete clinical and laboratory remission.

Facial edema as the sole clinical manifestation of dermatomyositis is extremely rare. There have been no previous reports of isolated facial edema in the setting of acute amyopathic dermatomyositis. A high level of suspicion is required to make the diagnosis in the absence of myopathy and the hallmark cutaneous manifestations of the disease (heliotrope rash, Gottron papules).
“Giving something back”: A systematic review and ethical enquiry of public opinions on the use of patient data for research in the United Kingdom and the Republic of Ireland
Authors: Stockdale Jessica , Cassell Jackie , Ford Elizabeth
Published: January 2018

Background: Use of medical data for secondary purposes such as health research, audit, and service planning is well established in the UK. However, the governance environment, as well as public opinion and understanding about this work, have lagged behind. We aimed to systematically review the literature on UK and Irish public opinions of medical data use in research, critically analysing such opinions though an established biomedical ethics framework, to draw out potential strategies for future good practice guidance and inform ethical and privacy debates.

Methods: We searched three databases using terms such as patient, public, opinion, and electronic health records. Empirical studies were eligible for inclusion if they surveyed healthcare users, patients or the wider public in UK and Ireland and examined attitudes, opinions or beliefs about the use of patient data for medical research. Results were synthesised into broad themes using a Framework Analysis.

Results: Out of 13,492 papers and reports screened, 20 papers or reports were eligible. While there was a widespread willingness to share EHRs for research for the common good, this very rarely led to unqualified support. The public expressed two generalised concerns through a variety of hypothetical examples. The first of these concerns related to a party’s competence in keeping data secure, while the second was associated with the motivation a party might have to use the data.

Conclusions: The public evaluates trustworthiness of research organisations by assessing their competence in data-handling and motivation for accessing the data. Public attitudes around data-sharing exemplified several principles which are also widely accepted in biomedical ethics. This provides a framework for understanding public attitudes, which should be considered in the development in any guidance for regulators and data custodians. We propose four salient questions which data guardians should address when evaluating proposals for the secondary use of data.
Literary Education and the Ethics of Expansion: Principles, Processes and Examples
Authors: Caballero Aceituno Yolanda
Published: January 2018

This contribution is rooted in my vision of literary education as a humanistic practice devoted to expanding the students’ ideological and imaginative horizons. My efforts as a lecturer have always been aimed at exemplifying what, from my point of view, could be considered one of the main beliefs articulating ethical literary criticism: the power of literature to bring about meaningful social changes by empowering readers to extend their cosmovision beyond reductionist macro-discourses. This potential of literature can be activated by fostering a teaching practice based on some ethical principles, the anatomy of which will be modestly examined in this essay out of my personal experience and exemplified with references to the works by some writers. From a theoretical point of view, this contribution also drinks from Jüri Talvet’s “call for cultural symbiosis” (2005) between ‘self ’ and ‘other’ as a way of overcoming interested separations and impoverishing mutilations. Likewise, and following Yuri M. Lotman’s cultural semiotics, my approach sees the literature classroom as a space where the valuable tensions between ‘centre’ and ‘periphery’ within a given semiosphere can be analysed and seen as opportunities for the generation and addition of new meanings and ideas.
Once in the Door: Gender, Tryouts, and the Initial Salaries of Managers
Authors: Sterling Adina D. , Fernandez Roberto M.
Published: January 2018

Although women pursue managerial credentials at nearly the same rate as men, gender disparities in wages exist because of the shortfall in wages women sustain relative to men at the onset of their careers. This article develops a tryout approach to test for the presence of demand-side contributions to initial wage inequality while also developing and testing theory on why it may be lessened through internships. Using detailed data on graduates from an elite management program from 2009–2010, our analyses reveal that internships are associated with the gap in men’s and women’s initial salaries. For men, there is no difference in salary offers from employers where an internship occurs versus one where an internship does not occur. However, women receive higher salaries from employers where an internship first takes place.

This paper was accepted by Olav Sorenson, organizations.
Airway management and endotracheal intubation by paramedics for cardiac arrest
Authors: Cross Sarah J
Published: January 2018

Paramedics are trained to perform endotracheal intubation (ETI), though a step-wise airway management approach has led to the use of supraglottic airway devices (SGAs), often in place of ETI. The current article considers airway management by paramedics during cardiopulmonary resuscitation (CPR). A case-note review relating to adult out-of-hospital cardiac arrests was carried out, with the collection of data over the period of a year, in one region of the UK. The results indicate that airway management is inconsistent during CPR, though simple adjuncts are used successfully. In a cohort of 2779 patients, in resuscitated cardiac arrest, attempts to intubate were made in less than half of the patients. Less than a third of patients were successfully intubated. Reasons for not attempting intubation need further investigation, alongside reasons for unsuccessful attempts.
Report lays bare influence of social media on year 7 pupils
Authors: Henshaw Pete
Published: January 2018

Investigation warns of a generation of children who are growing up chasing ‘likes’ and online validation to make them feel happy
Three challenges for 2018
Authors: Skipper Richard
Published: January 2018

As the new year begins, what changes do you need to prepare for? Richard Skipper discusses three major challenges waiting for school leaders in 2018
Allele-Specific Droplet Digital PCR Combined with a Next-Generation Sequencing-Based Algorithm for Diagnostic Copy Number Analysis in Genes with High Homology: Proof of Concept Using Stereocilin
Authors: Amr Sami S , Murphy Elissa , Duffy Elizabeth , Niazi Rojeen , Balciuniene Jorune , Luo Minjie , Rehm Heidi L , Abou Tayoun Ahmad N
Published: January 2018

BACKGROUND

Copy number variants (CNVs) can substantially contribute to the pathogenic variant spectrum in several disease genes. The detection of this type of variant is complicated in genes with high homology to other genomic sequences, yet such genomics regions are more likely to lead to CNVs, making it critical to address detection in these settings.

METHODS

We developed a copy number analysis approach for high homology genes/regions that consisted of next-generation sequencing (NGS)-based dosage analysis accompanied by allele-specific droplet digital PCR (ddPCR) confirmatory testing. We applied this approach to copy number analysis in STRC, a gene with 98.9% homology to a nonfunctional pseudogene, pSTRC, and characterized its accuracy in detecting different copy number states by use of known samples.

RESULTS

Using a cohort of 517 patients with hearing loss, we prospectively demonstrated the clinical utility of the approach, which contributed 30 of the 122 total positives (6%) to the diagnostic yield, increasing the overall yield from 17.6% to 23.6%. Positive STRC genotypes included homozygous (n = 15) or compound heterozygous (n = 8) deletions, or heterozygous deletions in trans with pathogenic sequence variants (n = 7). Finally, this approach limited ddPCR testing to cases with NGS copy number findings, thus markedly reducing the number of costly and laborious, albeit specific, ddPCR tests.

CONCLUSIONS

NGS-based CNV detection followed by allele-specific ddPCR confirmatory testing is a reliable and affordable approach for copy number analysis in medically relevant genes with homology issues.
Specific Substrate for the Assay of Lysosomal Acid Lipase
Authors: Masi Sophia , Chennamaneni Naveen , Turecek Frantisek , Scott C Ronald , Gelb Michael H
Published: January 2018

BACKGROUND

Deficiency of lysosomal acid lipase (LAL) causes Wolman disease and cholesterol ester storage disease. With the recent introduction of enzyme replacement therapy to manage LAL deficiency comes the need for a reliable assay of LAL enzymatic activity that can be applied to dried blood spots (DBS).

METHODS

We prepared and tested a library of analogs of palmitoyl 4-methylumbelifferyl esters to find a highly active and specific substrate for LAL in DBS. The LAL assay was optimized leading to both LC-MS/MS and fluorometric assay of LAL. We tested the new assay on DBS from healthy and LAL-deficient patients.

RESULTS

The ester formed between palmitic acid and 4-propyl-8-methyl-7-hydroxycoumarin (P-PMHC) was found to be >98% selective for LAL in DBS based on the sensitivity of its activity to the LAL-specific inactivator Lalistat-2 and the fact that the activity was close to zero using DBS from patients previously shown to be LAL-deficient. Use of P-PMHC and heavy isotope-labeled internal standard with optimized assay conditions led to an approximately 2-fold increase in the specific activity of LAL compared with the previously reported LAL assay. Patients deficient in LAL were readily distinguished from normal persons with the new LAL assay using UPLC-MS/MS or fluorometric assay platforms.

CONCLUSIONS

The new assay can measure LAL in DBS with a single measurement compared with the previous method involving 2 assays done in parallel.
Synthesis and evaluation of antitumor activity of new 4-substituted thieno[3,2-d]pyrimidine and thienotriazolopyrimidine derivatives
Authors: Hafez Hend N. , El-Gazzar Abdel-Rhman B. A.
Published: January 2018

3-Methyl-6-phenyl-2-thioxo-2,3-dihydrothieno[3,2-d]pyrimidin- 4(1H)-one (2), on treatment with phosphorous oxychoride, affored 4-chloro-3-methyl-6-phenyl -thieno[3,2-d]pyrimidine- 2(3H)-thione (3). A series of novel 6-phenyl-thieno[3,2-d]pyrimidine derivatives 4-9 bearing different functional groups were synthesized via treatment of compound 3 with different reagents. On the other hand, compound 2 was used to synthesize ethyl-[(3-methyl-6-phenyl-2-thioxo-2,3-dihydrothieno[ 3,2-d]pyrimidin-4-yl)-oxy]acetate (10), 2-hydrazinyl- -3-methyl-6-phenyl-thieno[3,2-d]pyrimidin-4(3H)-one (11), 3-methyl-2-(methyl-sulfanyl)-6-phenyl-thieno[3,2-d]pyrimidin- 4(3H)-one (12) and N-(phenyl)/4-chlorophenyl or methoxy- phenyl)-2-[(3-methyl-4-oxo-6-phenyl-3,4-dihydrothieno[ 3,2-d]pyrimidin-2-yl)-sulfanyl]-acetamide (13a-c). In addition, compound 12 was used to synthesize thieno[1,2,4] triazolopyrimidine derivatives 14 and 15 and 3-methyl-2-(methyl-sulfonyl)-6-phenyl-thieno[3,2-d]pyrimidin-4(3H)-one (16) through the reaction with the respective reagents. Moreover, the reaction of 16 with 4-phenylenediamine gave 2-[(4-aminophenyl)-amino]-3-methyl-6-phenyl-thieno[3,2-d] pyrimidin-4(3H)-one (17), which reacted with methanesulfonyl chloride to afford N-{4-[(3-methyl-4-oxo-6-phenyl-3H,4H- -thieno[3,2-d]pyrimidin-2-yl)-amino]phenyl}-methanesulfonamide (18). The majority of the newly synthesized compounds displayed potent anticancer activity, comparable to that of doxorubicin, on three human cancer cell lines, including the human breast adenocarcinoma cell line (MCF-7), cervical carcinoma cell line (HeLa) and colonic carcinoma cell line (HCT- 116). Compounds 18, 13b and 10 were nearly as active as doxorubicin whereas compounds 6, 7b and 15 exhibited marked growth inhibition, but still lower than doxorubicin.
The Effect of Cooling Agent on Stress and Deformation of Charge-loaded Cast Pallets
Authors: Bajwoluk A. , Gutowski P.
Published: January 2018

The results of research on the effect of the type of cooling agent used during heat treatment and thermal-chemical treatment on the formation of temperature gradient and stress-deformation distribution in cast pallets, which are part of furnace accessories used in this treatment, are disclosed. During operation, pallets are exposed to the effect of the same conditions as the charge they are carrying. Cyclic thermal loads are the main cause of excessive deformations or cracks, which after some time of the cast pallet operation result in its withdrawal due to damage. One of the major causes of this damage are stresses formed under the effect of temperature gradient in the unevenly cooled pallet construction. Studies focused on the analysis of heat flow in a charge-loaded pallet, cooled by various cooling agents characterized by different heat transfer coefficients and temperature. Based on the obtained temperature distribution, the stress distribution and the resulting deformation were examined. The results enabled drawing relevant conclusions about the effect of cooling conditions on stresses formed in the direction of the largest temperature gradient.
TG/DTG/DTA, FTIR and GC/MS Studies of Oil Sand for Artistic and Precision Foundry with the Emission of Gases Assessment
Authors: Bobrowski A. , Żymankowska-Kumon S. , Drożyński D. , Grabowska B. , Kaczmarska K.
Published: January 2018

The paper presents the results of thermoanalytical studies by TG/DTG/DTA, FTIR and GC/MS for the oil sand used in art and precision foundry. On the basis of course of DTG and DTA curves the characteristic temperature points for thermal effects accompanying the thermal decomposition reactions were determined. This results were linked with structural changes occurred in sample. It has been shown that the highest weight loss of the sample at temperatures of about 320°C is associated with destruction of C-H bonds (FTIR). In addition, a large volume of gases and high amounts of compounds from the BTEX group are generated when liquid metal interacts with oil sand. The results show, that compared to other molding sands used in foundry, this material is characterized by the highest gaseous emissions and the highest harmfulness, because benzene emissions per kilogram of oil sand are more than 7 times higher than molding sand with furan and phenolic binders and green sand with bentonite and lustrous carbon carrier.
Taguchi Approach for Optimization of Parameters that Effect Grain Size of Cast A357 Alloy
Authors: Çolak M. , Dışpınar D.
Published: January 2018

Grain refining and modification are common foundry practice for improving properties of cast Al-Si alloys. In general, these types of treatments provide better fluidity, decreased porosity, higher yield strength and ductility. However, in practice, there are still some discrepancies on the reproducibility of the results from grain refining and effect of the refiner’s additions. Several factors include the fading effect of grain refinement and modifiers, inhomogeneous dendritic structure and non-uniform eutectic modification. In this study, standard ALCAN test was used by considering Taguchi’s experimental design techniques to evaluate grain refinement and modification efficiency. The effects of five casting parameters on the grain size have been investigated for A357 casting alloy. The results showed that the addition of the grain refiner was the most effective factor on the grain size. It was found that holding time, casting temperature, alloy type and modification with Sr were less effective over grain refinement.
Study of Thermal Properties of Cast Metal- Ceramic Composite Foams
Authors: Gawdzińska K. , Chybowski L. , Przetakiewicz W.
Published: January 2018

Owing to its properties, metallic foams can be used as insulation material. Thermal properties of cast metal-ceramic composite foams have applications in transport vehicles and can act as fire resistant and acoustic insulators of bulkheads. This paper presents basic thermal properties of cast and foamed aluminum, the values of thermal conductivity coefficient of selected gases used in foaming composites and thermal capabilities of composite foams (AlSi11/SiC). A certificate of non-combustibility test of cast aluminum-ceramic foam for marine applications was included inside the paper. The composite foam was prepared by the gas injection method, consisting in direct injection of gas into liquid metal. Foams with closed and open cells were examined. The foams were foaming with foaming gas consisting of nitrogen or air. This work is one of elements of researches connected with description of properties of composite foams. In author's other works acoustic properties of these materials will be presented.
Polymer Binder BioCo3 with Silicates and its Application to Microwave-Cured Moulding Sand
Authors: Grabowska B. , Kaczmarska K. , Bobrowski A. , Drożyński D. , Żymankowska-Kumon S. , Cukrowicz S.
Published: January 2018

The effects of silica additive (Poraver) on selected properties of BioCo3 binder in form of an aqueous poly(sodium acrylate) and dextrin (PAANa/D) binder were determined. Based on the results of the thermoanalytical studies (TG-DTG, FTIR, Py-GC/MS), it was found that the silica additive results in the increase of the thermostability of the BioCo3 binder and its contribution does not affect the increase in the level of emissions of organic destruction products. Compounds from group of aromatic hydrocarbons are only generated in the third set temperature range (420-838°C). The addition of silicate into the moulding sand with BioCo3 causes also the formation of a hydrogen bonds network with its share in the microwave radiation field and they are mainly responsible for maintaining the cross-linked structures in the mineral matrix system. As a consequence, the microwave curing process in the presence of Poraver leads to improved strength properties of the moulding sand (Rum). The addition of Poraver's silica to moulding sand did not alter the permeability of the moulding sand samples, and consequently reduced their friability. Microstructure investigations (SEM) of microwave-cured samples have confirmed that heterogeneous sand grains are bonded to one another through a binder film (bridges).
Influence of High-Temperature Treatment of Melt on the Composition and Structure of Aluminum Alloy
Authors: Grachev V. A. , Turakhodjaev N. D.
Published: January 2018

The aim of the current study was to examine the structure of an alloy treated at various temperatures up to 2,000-2,100 °C. Among research techniques for studying alloy structure there were the electron and optical microstructure, X-ray structure, and spectral analysis, and for studying the developed furnace geometric parameters the authors employed mathematical modeling method. The research was performed using aluminum smelting gas-fired furnaces and electric arc furnaces. The objects of the study were aluminum alloys of the brand AK7p and AK6, as well as hydrogen and aluminum oxide in the melt. For determining the hydrogen content in the aluminum alloy, the vacuum extraction method was selected. Authors have established that treatment of molten aluminum alloy in contact with carbon melt at high temperatures of 2,000-2,100 °C has resulted in facilitating reduction of hydrogen and aluminum oxide content in the melt by 40- 43% and 50-58%, respectively, which is important because hydrogen and aluminum oxide adversely affect the structure and properties of the alloy. Such treatment contributes to the formation of the extremely fine-grained microstructure of aluminum alloy.
Theory of the Stereological Analysis of Spheroid Size Distribution – Validation of the Equations
Authors: Gurgul D. , Burbelko A. , Wiktor T.
Published: January 2018

The paper presents validation tests for method which is used for the evaluation of the statistical distribution parameters for 3D particles’ diameters. The tested method, as source data, uses chord sets which are registered from a random cutting plane placed inside a sample space. In the sample space, there were individually generated three sets containing 3D virtual spheres. Each set had different Cumulative Distribution Function (CDF3) of the sphere diameters, namely: constant radius, normal distribution and bimodal distribution as a superposition of two normal distributions. It has been shown that having only a chord set it is possible, by using the tested method, to calculate the mean value of the outer sphere areas. For the sets of data, a chord method generates quite large errors for around 10% of the smallest nodules in the analysed population. With the increase of the nodule radii, the estimation errors decrease. The tested method may be applied to foundry issues e.g. for the estimation of gas pore sizes in castings or for the estimation of nodule graphite sizes in ductile cast iron.
Gases Emission From Surface Layers of Sand Moulds and Cores Stored Under the Humid Air Conditions
Authors: Kaźnica N. , Zych J. , Mocek J.
Published: January 2018

A large number of defects of castings made in sand moulds is caused by gases. There are several sources of gases: gases emitted from moulds, cores or protective coatings during pouring and casting solidification; water in moulding sands; moisture adsorbed from surroundings due to atmospheric conditions changes. In investigations of gas volumetric emissions of moulding sands amounts of gases emitted from moulding sand were determined - up to now - in dependence of the applied binders, sand grains, protective coatings or alloys used for moulds pouring. The results of investigating gas volumetric emissions of thin-walled sand cores poured with liquid metal are presented in the hereby paper. They correspond to the surface layer in the mould work part, which is decisive for the surface quality of the obtained castings. In addition, cores were stored under conditions of a high air humidity, where due to large differences in humidity, the moisture - from surroundings - was adsorbed into the surface layer of the sand mould. Due to that, it was possible to asses the influence of the adsorbed moisture on the gas volumetric emission from moulds and cores surface layers by means of the new method of investigating the gas emission kinetics from thin moulding sand layers heated by liquid metal. The results of investigations of kinetics of the gas emission from moulding sands with furan and alkyd resins as well as with hydrated sodium silicate (water glass) are presented. Kinetics of gases emissions from these kinds of moulding sands poured with Al-Si alloy were compared.
The Influence of Mg Additive on the Structure and Electrical Conductivity of Pure Copper Castings
Authors: Kranc M. , Sikora G. , Górny M. , Garbacz-Klempka A.
Published: January 2018

The aim of this paper was to attain defect free, pure copper castings with the highest possible electrical conductivity. In this connection, the effect of magnesium additives on the structure, the degree of undercooling (ΔTα = Tα-Tmin, where Tα - the equilibrium solidification temperature, Tmin - the minimum temperature at the beginning of solidification), electrical conductivity, and the oxygen concentration of pure copper castings have been studied. The two magnesium doses have been investigated; namely 0.1 wt.% and 0.2 wt.%. A thermal analysis was performed (using a type-S thermocouple) to determine the cooling curves. The degree of undercooling and recalescence were determined from the cooling and solidification curves, whereas the macrostructure characteristics were conducted based on a metallographic examination. It has been shown that the reaction of Mg causes solidification to transform from exogenous to endogenous. Finally, the results of electrical conductivity have been shown as well as the oxygen concentration for the used Mg additives.
Influence of the Al2O3 Solid Phase on the Kinetics of Binding Ceramic Moulds
Authors: Kolczyk J. , Zych J. , Jamrozowicz Ł.
Published: January 2018

The investigation results of the kinetics of binding ceramic moulds, in dependence on the solid phase content in the liquid ceramic slurries being 67, 68 and 69% - respectively, made on the basis of the aqueous binding agents Ludox AM and SK. The ultrasonic method was used for assessing the kinetics of strengthening of the multilayer ceramic mould. Due to this method, it is possible to determine the ceramic mould strength at individual stages of its production. Currently self-supporting moulds, which must have the relevant strength during pouring with liquid metal, are mainly produced. A few various factors influence this mould strength. One of them is the ceramic slurry viscosity, which influences a thickness of individual layers deposited on the wax model in the investment casting technology. Depositing of layers causes increasing the total mould thickness. Therefore, it is important to determine the drying time of each deposited layer in order to prevent the mould cracking due to insufficient drying of layers and thus the weakening of the multilayer mould structure.
Computer Simulation of the Solidification Process Including Air Gap Formation
Authors: Skrzypczak T. , Węgrzyn-Skrzypczak E. , Sowa L.
Published: January 2018

The paper presents an approach of numerical modelling of alloy solidification in permanent mold and transient heat transport between the casting and the mold in two-dimensional space. The gap of time-dependent width called "air gap", filled with heat conducting gaseous medium is included in the model. The coefficient of thermal conductivity of the gas filling the space between the casting and the mold is small enough to introduce significant thermal resistance into the heat transport process. The mathematical model of heat transport is based on the partial differential equation of heat conduction written independently for the solidifying region and the mold. Appropriate solidification model based on the latent heat of solidification is also included in the mathematical description. These equations are supplemented by appropriate initial and boundary conditions. The formation process of air gap depends on the thermal deformations of the mold and the casting. The numerical model is based on the finite element method (FEM) with independent spatial discretization of interacting regions. It results in multi-mesh problem because the considered regions are disconnected.
Microstructure Characteristic of TiCReinforced Cast Steel after GTAW Remelting
Authors: Sobula S. , Kwiecień A. , Olejnik E. , Pałka P.
Published: January 2018

In this study, low-carbon cast steel was reinforced with TiC by SHS-B method, also known as combustion synthesis during casting method. The composite zone was then subjected to surface remelting by Gas Tungsten Arc Welding (GTAW) method. The remelting operation was realized manually, at 150 A current magnitude. Microstructure, phase composition and hardness of remelted zone were investigated. XRD results reveal that the phases of the composite zone in initial state consist of TiC and Feα. Surface remelting resulted in formation of thick layers containing TiC carbides, Feα and Feγ. Microstructural examination has shown strong refinement of titanium carbides in remelted zone and complete dissolution of primary titanium carbides synthetized during casting. The average diameter of carbides was below 2 μm. The structural changes are induced by fast cooling which affects crystallization rate. The hardness (HV30) of the remelted layer was in the range between 250 HV and 425 HV, and was lower than hardness in initial state.
The Concept of Optimizing the Decopperisation of Slag Slurry in Electrical Furnace
Authors: Wędrychowicz M. , Bydałek A. W. , Wołczyński W.
Published: January 2018

This paper presents the idea of increasing the effectiveness of slag decopperisation in an electric furnace in the "Głogów II" Copper Smelter by replacing the currently added CaCO3with a less energy-intensive technological additive. As a result of this conversion, one may expect improved parameters of the process, including process time or power consumption per cycle. The incentives to optimize the process are the benefits of increasing copper production in the company and the growing global demand for this metal. The paper also describes other factors that may have a significant impact on the optimization of the copper production process. Based on the literature analysis, a solution has been developed that improves the copper production process. The benefits of using a new technology additive primarily include increased share of copper in the alloy, reduced production costs, reduced amount of power consumed per cycle and reduced time it takes to melt. At the conclusion of the paper, the issues raised are highlighted, stressing that mastering the slag slurry process in electric furnaces requires continuous improvement.
The effects of physical activity on chronic subclinical systemic inflammation
Authors: Tir Alba Maria Dalbello , Labor Marina , Plavec Davor
Published: January 2018

Chronic subclinical systemic inflammation (CSSI) is a pathogenic event and a common risk factor for many noncommunicable diseases like atherosclerosis, metabolic syndrome, cardiovascular disease, insulin resistance and type 2 diabetes, cancer, and obstructive lung disease. On the other hand, regular physical activity has been found to reduce this risk. Many studies of different design were conducted to assess the association between inflammatory mediators as markers of CSSI and regular physical activity. The aim of this review was to present the current level of evidence and understanding of potential mechanisms by which physical activity reduces inflammatory mediators involved in CSSI and the types of physical activity required for the expected effect. We have found that observational studies consistently report a positive association between regular physical activity and lower CSSI, but the design of these studies does not allow to infer a causal relationship. Interventional studies, in contrast, were not consistent about the causal relationship between regular physical activity and lower CSSI. The problem in interpreting these results lies in significant differences between these interventional studies in their design, sample size, study population, and intervention itself (intensity and extent, follow up, weight loss). We can conclude that the scientific community has to invest a significant effort into high-quality interventional trials focused on finding the type, intensity, and extent of physical activity that would produce the most favourable effect on CSSI.
Radiological risk assessment: an overview of the ERICA Integrated Approach and the ERICA Tool use
Authors: Prlić Ivica , Mostečak Ana , Mihić Marija Surić , Veinović Želimir , Pavelić Luka
Published: January 2018

The ERICA project (Environmental Risk from Ionising Contaminants: Assessment and Management) was co-funded by the European Union as part of the 6th Framework Programme (FP EURATOM). The project was carried out between 2004 and 2007 as the collective work of 15 organisations in seven European countries. Two significant outputs of the project are the ERICA Integrated Approach and the ERICA Tool. The ERICA Integrated Approach consists of three elements: assessment, risk characterisation and management. The ERICA Tool is a practical implementation of the assessment component of the ERICA Integrated Approach and has a three-tier structure. The aim of this review paper is to give a concise overview of ERICA project outputs and their structure, updates done since their first release in 2007, as well as to provide a context for their practical application in environmental radiation protection and radiological risk assessments for various engineering scenarios.
On Decay Centrality
Authors: Tsakas Nikolas
Published: January 2018

We establish a relationship between decay centrality and two widely used measures of centrality, namely degree and closeness. We show that for low values of the decay parameter the nodes with maximum decay centrality also have maximum degree, whereas for high values of the decay parameter they also maximize closeness. For intermediate values, we provide sufficient conditions that allow the comparison of decay centrality of different nodes and we show via numerical simulations that in the vast majority of networks, the nodes with maximum decay centrality are characterized by a threshold on the decay parameter below which they belong to the set of nodes with maximum degree and above which they belong to the set of nodes with maximum closeness. We also propose a simple rule of thumb that ensures a nearly optimal choice with very high probability.