bluuebunny/crossref_metadata_2025 huggingface dataset:
Physiotherapy management of acute transverse myelitis in a pediatric patient in a Nigerian hospital: a case report
Authors: Onyekere Chukwuebuka P. , Igwesi-Chidobe Chinonso N.
Published: March 2022

Background

Transverse myelitis is a rare neurological disorder of the spinal cord, caused by inflammation and damage of the myelin sheath of the neurons of the spinal cord across one or more spinal segments. This causes a disruption in the passage of nervous signals leading to motor, sensory, and autonomic dysfunction. This affects the physical and psychological health, as well as the functional status of the patient. This case report presents the physiotherapy evaluation and management of acute transverse myelitis in a pediatric patient.

Case presentation

A 17-year-old Nigerian male diagnosed with acute transverse myelitis was referred to the physiotherapy team for expert management. The patient presented with severe muscle spasms and frequent jerking movements, shocking sensations, hypertonicity, and spasticity (modified Ashworth scale: 1+ on the right, > 2 on the right), and muscle strength of the lower limbs (Oxford muscle grading: 3/5 on the left, 1/5 on the left) with impaired functional status (Functional Independence Measure: 70/126).The patient tolerated and participated in the physiotherapy interventions (cryotherapy, soft tissue mobilization, splinting) and exercises (free active, resistance and functional exercises) in the ward and outpatient clinic, as well as subsequent home programmes (free active, resistance and functional exercises). The patient also received other medical and pharmacological interventions in the ward. After 23 days of therapy, the patient improved in all clinical outcomes, including muscle spasm and hypertonicity, spasticity (modified Ashworth scale: 0 bilaterally), sensation, and muscle strength (Oxford muscle grading: 5/5 bilaterally). The patient’s overall functional status also improved (Functional Independence Measure: 117/126).

Conclusions

Physiotherapy improved the symptoms of acute transverse myelitis in this patient. Randomized controlled trials are required to replicate these findings.
Patient engagement strategies for adults with chronic conditions: an evidence map
Authors: Aboumatar Hanan , Pitts Samantha , Sharma Ritu , Das Asar , Smith Brandon M. , Day Jeff , Holzhauer Katherine , Yang Sejean , Bass Eric B. , Bennett Wendy L.
Published: March 2022

Background

Patient and family engagement (PFE) has been defined as a partnership between patients, families, and health care providers to achieve positive health care outcomes. There is evidence that PFE is critical to improving outcomes. We sought to systematically identify and map the evidence on PFE strategies for adults with chronic conditions and identify areas needing more research.

Methods

We searched PubMed, CINAHL, EMBASE, and Cochrane, January 2015 to September 2021 for systematic reviews on strategies for engaging patients with chronic conditions and their caregivers. From each review, we abstracted search dates, number and type of studies, populations, interventions, and outcomes. PFE strategies were categorized into direct patient care, health system, and community-policy level strategies. We found few systematic reviews on strategies at the health system, and none at the community-policy level. In view of this, we also searched for original studies that focused on PFE strategies at those two levels and reviewed the PFE strategies used and study findings.

Results

We found 131 reviews of direct patient care strategies, 5 reviews of health system strategies, and no reviews of community-policy strategies. Four original studies addressed PFE at the health system or community-policy levels. Most direct patient care reviews focused on self-management support (SMS) (n= 85) and shared decision-making (SDM) (n= 43). Forty-nine reviews reported positive effects, 35 reported potential benefits, 37 reported unclear benefits, and 4 reported no benefits. Health system level strategies mainly involved patients and caregivers serving on advisory councils. PFE strategies with the strongest evidence focused on SMS particularly for patients with diabetes. Many SDM reviews reported potential benefits especially for patients with cancer.

Discussion

Much more evidence exists on the effects of direct patient care strategies on PFE than on the effects of health system or community-policy strategies. Most reviews indicated that direct patient care strategies had positive effects or potential benefits.

A limitation of this evidence map is that due to its focus on reviews, which were plentiful, it did not capture details of individual interventions. Nevertheless, this evidence map should help to focus attention on gaps that require more research in efforts to improve PFE.
Mode-dependent delays for dissipative filtering of stochastic semi-Markovian jump for neural networks
Authors: Aslam Muhammad Shamrooz , Li Qianmu , Hou Jun , Qiulong Hua
Published: March 2022

This work is concerned with the issue of dissipative filtering for stochastic semi-Markovian jump via neural networks where the time-varying delay is based upon another semi-Markov process. Dissipative performance analysis is employed to solve a mode-dependent filtering problem in a unified way. To achieve this task, we implemented the recently proposed notion of extended dissipativity, which gives an inequality equivalent to the well-known $H_{\infty }$

H
∞

, $L_{2}$

L
2

–$L_{\infty }$

L
∞

, and dissipative performances. Different from the existing literature (Arslan et al. in Neural Netw 91:11–21, 2017; Chen et al. in ISA Trans. 101:170–176, 2020) where mostly delay-free filters have been investigated, our filter contains a communication delay. Based upon the delay-dependent conditions, for the analysis of stochastic stability and extended dissipativity for neural networks with time-varying delays, our results are obtained by using a mode-dependent Lyapunov–Krasovskii functional together with a novel integral inequality. Original stochastic filtering conditions are characterized by linear matrix inequalities. A numerical simulation is elaborated to elucidate the feasibility of the proposed design methodology.
Customer engagement design during the COVID 19 pandemic, mutual trust and intelligent automation: a conceptual perspective
Authors: Alfalih Abdullah Abdulmohsen
Published: March 2022

The adoption and use of artificial intelligence, and the application of this concept through the development and implementation of intelligent automation is not considered simply as an option, but rather as an obligation in current times, due to the considerable change caused by the COVID 19 pandemic and responses to it. This study is an attempt to more thoroughly understand and clarify how the adoption of such intelligent automation can work to improve customer engagement in the food and restaurant domain. To attend to this objective, a theoretical framework is developed and tested based on an integrative approach of determinants of customer engagement through artificial intelligence to increase trust levels when intelligent automation is used. This paper will contribute to the construction of a matrix of customer engagement based on the different steps identified in the customer engagement cycle, and build a co-constructive and dynamic model of customer engagement in relation to mutual’ trust and intelligent automation.
Artificial intelligence in diagnosis of knee osteoarthritis and prediction of arthroplasty outcomes: a review
Authors: Lee Lok Sze , Chan Ping Keung , Wen Chunyi , Fung Wing Chiu , Cheung Amy , Chan Vincent Wai Kwan , Cheung Man Hong , Fu Henry , Yan Chun Hoi , Chiu Kwong Yuen
Published: March 2022

Background

Artificial intelligence is an emerging technology with rapid growth and increasing applications in orthopaedics. This study aimed to summarize the existing evidence and recent developments of artificial intelligence in diagnosing knee osteoarthritis and predicting outcomes of total knee arthroplasty.

Methods

PubMed and EMBASE databases were searched for articles published in peer-reviewed journals between January 1, 2010 and May 31, 2021. The terms included: ‘artificial intelligence’, ‘machine learning’, ‘knee’, ‘osteoarthritis’, and ‘arthroplasty’. We selected studies focusing on the use of AI in diagnosis of knee osteoarthritis, prediction of the need for total knee arthroplasty, and prediction of outcomes of total knee arthroplasty. Non-English language articles and articles with no English translation were excluded. A reviewer screened the articles for the relevance to the research questions and strength of evidence.

Results

Machine learning models demonstrated promising results for automatic grading of knee radiographs and predicting the need for total knee arthroplasty. The artificial intelligence algorithms could predict postoperative outcomes regarding patient-reported outcome measures, patient satisfaction and short-term complications. Important weaknesses of current artificial intelligence algorithms included the lack of external validation, the limitations of inherent biases in clinical data, the requirement of large datasets in training, and significant research gaps in the literature.

Conclusions

Artificial intelligence offers a promising solution to improve detection and management of knee osteoarthritis. Further research to overcome the weaknesses of machine learning models may enhance reliability and allow for future use in routine healthcare settings.
A novel heterozygous TPM2 gene mutation (c.456G>C; p.Lys152Asn) in an Iranian family affected by distal arthrogryposis type 1: a case report
Authors: Neissi Mostafa , Sheikh-Hosseini Motahareh , Mohammadi-Asl Javad , Al-Badran Adnan Issa
Published: March 2022

Background

Distal arthrogryposis (DA) is a group of clinically and genetically heterogeneous disorders characterized by congenital contractures of the distal limb joints without a neuromuscular disease. This case study seeks to report an affected son from an Iranian family with a diagnosis of DA1 with a rare causative genetic defect.

Case presentation

Herein, we aimed to figure out the underlying genetic of the subject from an Iranian family with DA1. Whole-exome sequencing (WES) of all known DA1 genes was carried out in the proband of the family. WES identified a novel missense mutation, c.456G>C; p.Lys152Asn, within theTPM2gene, causing a change in one amino acid (Lysine converted to Asparagine). Moreover, this detected variant was confirmed by Sanger sequencing.

Conclusion

Our data expand the mutational spectra ofTPM2gene associated DA1 which is vital for screening and genetic diagnosis of the disease. Also, this detected mutation has not yet been described in patients with the DA1 phenotype.
Detection of an FYCO1 nonsense mutation in an affected patient with autosomal recessive cataract (CTRCT18): a case report
Authors: Al-Badran Raed Abdulelah , Al-Badran Adnan Issa , Mabudi Hadideh , Neissi Mostafa , Mohammadi-Asl Javad
Published: March 2022

Background

Autosomal recessive cataract (CTRCT18) is a rare type of congenital cataract that develops to complete and lifelong childhood blindness. This inherited disorder is one of the major visual health concerns in infants. Genetic studies discovered that various gene mutations resulted in congenital cataracts. This study reports an 8-month-old affected boy from a consanguineous family with a diagnosis of congenital cataract and a causative genetic abnormality.

Case presentation

In this study, we applied whole-exome sequencing (WES) followed by Sanger sequencing to identify probable gene defects in an affected patient with a congenital cataract. We found a homozygous disease-causing FYCO1 gene mutation (c.1387 G > T; p.G463X), located in exon 8 (NM_024513), causing a nonsense mutation that has been resulted in the stop codon. Parents are heterozygous for the detected mutation.

Conclusions

Our findings establish that this detected FYCO1 gene mutation is a pathogenic variant causing autosomal recessive cataract.
The p300 Inhibitor A-485 Exerts Antitumor Activity in Growth Hormone Pituitary Adenoma
Authors: Ji Chenxing , Xu Wen , Ding Hong , Chen Zhengyuan , Shi Chengzhang , Han Jie , Yu Liang , Qiao Nidan , Zhang Yichao , Cao Xiaoyun , Zhou Xiang , Cheng Haixia , Feng Huijin , Luo Cheng , Li Zhiyu , Zhou Bing , Ye Zhao , Zhao Yao
Published: March 2022

Context

Growth hormone pituitary adenoma (GHPA), a major subtype of pituitary adenoma (PA), can lead to progressive somatic disfigurement, multiple complications, and even increased mortality. The efficacy of current treatments is limited; thus, a novel pharmacological treatment is urgently needed. As a histone acetyltransferase (HAT) coactivator, p300 can regulate the transcription of several genes that are crucial for PA tumorigenesis and progression. However, the role of p300 and its catalytic inhibitor in GHPA is still unclear.

Objective

We aimed to identify the expression of p300 in GHPA and in normal pituitary glands.

Methods

The expression of p300 was detected in GHPA and normal pituitary tissues. Genetic knockdown was performed by siRNA. The efficacy of the p300 inhibitor A-485 in the cell cycle, proliferation, apoptosis, and hormone secretion was investigated by flow cytometry, ELISAs, Western blotting, and qRT-PCR. RNA sequencing, bioinformatic analysis, and subsequent validation experiments were performed to reveal the potential biological mechanism of A-485.

Results

High expression of p300 was found in GHPA tissues compared with normal pituitary tissues. Knockdown of p300 inhibited cell proliferation and clone formation. Treatment with A-485 suppressed cell growth and inhibited the secretion of GH in vitro and in vivo. Further mechanistic studies showed that A-485 could downregulate the expression or activity of several oncogenes, such as genes in the Pttg1, c-Myc, cAMP and PI3K/AKT/mTOR signaling pathways, which are crucial for PA tumorigenesis and progression.

Conclusion

Our findings demonstrate that inhibition of HAT p300 by its selective inhibitor A-485 is a promising therapy for GHPA.
Mowing in agri-environmental schemes (AES) and rare species of Vertigo snails: hope for grasslands but a threat to snails
Authors: Lipińska Anna M. , Bielański Wojciech
Published: March 2022

Four Vertigo species are covered by special forms of protection under Annex II of the Habitats Directive. The habitats of these snails are currently rare in Europe. Since typical conservation practices are ineffective for this ecosystem, support mechanisms for measures maintaining biodiversity have been incorporated into agriculture in the form of agri-environmental schemes (AES). However, an inappropriately designed AES may threaten the survival of populations of globally endangered species such as Vertigo moulinsiana (Dupuy) as mowing and swath removal dates coincide with the snails’ activity period in the upper parts of the mown plants, the majority of their population will be removed from the area along with the harvested swath. In addition, mowing instantaneously and radically alters the habitat’s microclimate. The policy of mowing the total area thus leads to unprecedented habitat homogenisation across the landscape, especially when machine mowers are used. In the case of V. moulinsiana, the best approach would be not to mow the whole area but to leave a part unmown where these snails could live unhindered. Instead of machines, traditional mowing could be implemented, which entails cutting at a greater height above the sedge clump level. This would not destroy the tussock structure and would allow the habitat to recreate itself. In combination with the designation of unmown refuges, the effects of this approach could be quite beneficial to the snails.
Hearing improvement among children with cholesteatoma who underwent canal wall up and canal wall down surgical management
Authors: Ahmad Waseem , Akbar Sehrish , Hassan Shazia
Published: March 2022

Objectives: The most frequently used surgical methods for treating cholesteatoma include canal wall up and canal wall down procedures. The objective of the study was to compare the hearing improvement among children with cholesteatoma who underwent canal wall up and canal wall down surgical management.

Methods: The cross-sectional analytical study design was used. The study was conducted at the ENT Department of Nishtar Medical University & Hospital Multan from 15th June to 15th Nov 2020. Forty six patients with cholesteatoma were enrolled in the study after taking informed consent. Inclusion and exclusion criteria were followed. The participants were categorized into two groups. Group-A was treated with canal wall-up surgery while Group-B was treated with canal wall down Mastoidectomy. A 12-month post-operative follow-up and the audiometry assessment were compared with pre-surgical values. Additionally, a COMOT-15 survey was administered to analyze self-perceived hearing functions. The Chi-square test was used for comparative analysis of the surgical outcome and hearing improvement among the two groups. P-value (p value<0.05) was considered statistically significant.

Results: Forty six patients were included in the study with 23 participants in each group. Among 46, 26 were male and 20 were female. The pre and post-operative mean Pure-tone average values were significantly different in (Group-A) who underwent canal wall up Mastoidectomy (p<0.05) than in Group-B, who underwent canal wall down Mastoidectomy. Similarly, hearing sub-section responses of the COMOT-15 survey favored the Canal wall technique. However, the survey showed no significant differences in the mental health status of the two groups (p<0.05).

Conclusion: Our data collected after a one-year follow-up of patients suggests canal wall up as a preferred technique for hearing improvement than canal wall down technique.

doi: https://doi.org/10.12669/pjms.38.4.4933

How to cite this:Ahmad W, Akbar S, Hassan S. Hearing improvement among children with cholesteatoma who underwent canal wall up and canal wall down surgical management. Pak J Med Sci. 2022;38(4):---------. doi: https://doi.org/10.12669/pjms.38.4.4933

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Incidence and assessment of demography-related risk factors associated with pulmonary tuberculosis in Saudi Arabia: A retrospective analysis
Authors: El-Masry Omar S. , . Muzaheed
Published: March 2022

Background & Objectives: Tuberculosis (TB) is a public health challenge and is endemic in many countries including Saudi Arabia. The disease is a major health concern in the Kingdom because of its dynamic population as resident expatriates are mainly from high TB burdened countries and the mass influx of pilgrims every year in peak seasons for Umrah and Hajj. The objective of the current study was to evaluate pulmonary TB incidence rates and conclude the potential high-risk patients to highlight the burdened regions in Saudi Arabia for the health authorities, which could help to establish policies of infection control as necessary.

Methods: We retrospectively investigated the incidence of pulmonary TB data reported by the ministry of health (MOH) in 2018. We analyzed pulmonary TB incidence data by nationality, age, gender, and region using Chi-square test to identify demography-related risk factors associated with pulmonary TB and its significance.

Results: The results indicated that the incidence of pulmonary TB was significantly higher in males than in females in both Saudi and non-Saudi nationals; the number of cases was particularly high in major cities. Also, infections were mainly associated with certain age groups that were different between the Saudi and non-Saudi nationals.

Conclusion: TB control seems to be facing some challenges in several regions of the Kingdom, particularly major cities. National TB Control Program (NTP) needs to continually evaluate official data to spot high risk groups and factors associated with increased incidence. This will help to improve TB control strategies to contain the disease and approaches its eradication.

doi: https://doi.org/10.12669/pjms.38.4.5087

How to cite this:El-Masry OS, Muzaheed. Incidence and assessment of demography-related risk factors associated with pulmonary tuberculosis in Saudi Arabia: A retrospective analysis. Pak J Med Sci. 2022;38(4):---------. doi: https://doi.org/10.12669/pjms.38.4.5087

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Magnitude and pattern of anxiety levels with gender wise predilection of coping strategies amid resident doctors of emergency department
Authors: Zehra Sehrish , Qureshi Farhan Muhammad , Faiz Smaira , Khalid Kanwal
Published: March 2022

Objectives: To screen and assess the severity level of anxiety, its influencing factors along with the gender-wise predilection of coping strategies among resident doctors working in accident and emergency departments.

Methods: A transverse study was conducted amongst 260 resident doctors of accident and emergency department of different teaching hospitals of Karachi from October 2020 until March 2021. A demographic sheet containing questions related to factors, GAD-7 (Generalized Anxiety Disorder) and Brief COPE were used to measure the severity level of anxiety and coping strategies. Data was scored according to the standard scoring procedure for each subscale and for further statistical analysis SPSS Version 21 was used.

Results: Out of all participants, 68.1% were <30 years of age, 63.1% were females while 54.2% were single. The findings of the study showed the prevalence of anxiety within the range of normal (38.1%), mild (35.0%), moderate (16.9%) and severe (10.0%). Gender (p= 0.001), marital status (p= 0.040) and job satisfaction (p= 0.007) among resident doctors were significantly associated with level of anxiety. Deemed to coping strategies, the most frequently were planning (n=145, 90.0%), acceptance (n=141, 87.6%), and religion (n=137, 85.1 %). All coping strategies were mostly opted by females except substance abuse.

Conclusion: More than a half of the resident doctors manifested with mild to severe anxiety disorder, which highlights the need for psychological support programs to minimize anxiety levels and to ensure a healthy environment at workplace for the health practitioners.

doi: https://doi.org/10.12669/pjms.38.4.5105

How to cite this:Zehra S, Qureshi FM, Faiz S, Khalid K. Magnitude and pattern of anxiety levels with gender wise predilection of coping strategies amid resident doctors of emergency department. Pak J Med Sci. 2022;38(4):---------.  doi: https://doi.org/10.12669/pjms.38.4.5105

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Sign patterns associated with some graphs that allow or require diagonalizability
Authors: Das Sunil
Published: March 2022

The problems of characterizing sign pattern matrices that allow or require diagonalizability are mostly open. In this paper, we introduce the concept of essential index for a tree sign pattern matrix and use it to investigate the allow problem on diagonalizability for sign pattern matrices having their graphs as trees. We characterize sign pattern matrices allowing diagonalizability, whose graphs are star or path. We also give a sufficient condition for sign pattern matrices whose graphs are trees to allow diagonalizability. Further, we give a necessary condition for a sign pattern matrix to require diagonalizability and characterize all star sign pattern matrices that require diagonalizability.
Regional differences in initial labour market conditions and dynamics in lifetime income trajectories
Authors: Ecker Kreske , de Luna Xavier , Westerlund Olle
Published: March 2022

We use longitudinal register data from Sweden to study patterns and dynamics in lifetime income trajectories. We examine divergences in these income trajectories by local economic conditions at labour market entry, in combination with other factors such as gender, education level and socio-economic background. We cannot assume that these relationships are constant over the course of individuals’ working lives. Therefore, we use methods from functional data analysis, allowing for a time-varying relationship between income and the explanatory variables. Our results show a large degree of heterogeneity in how lifetime income trajectories develop for different subgroups. We find that, for men, entering the labour market in an urban area is associated with higher cumulative lifetime income, especially later in life. The exception is men with only primary education, for whom those starting their working lives in a large city have lower incomes on average. This divergence increases in size over time. Women who enter into a large urban labour market receive higher lifetime income at all education levels. This relationship is strongest for women with primary education but decreases in strength over time for these women.
Consequences of unrealistic optimism and pessimism for actual behavior: An experimental evidence
Authors: Iyer Dr Subramanian S , S Sai Krishnan , SMR Sai Balaji
Published: March 2022

In this study, we performed experiments to investigate the negative consequences of unrealistic optimism and pessimism. We also attempted to extend the theory of unrealistic optimism and pessimism by investigating how past events running contrary to expectations impact unrealistic optimism and pessimism. We made participants play an insurance decision game pertaining to a gamble for two consecutive rounds while inducing unrealistic optimism and pessimism within the context of the game.
Hα emission from gaseous structures above galactic discs
Authors: Vasiliev Evgenii O. , Drozdov Sergey A. , Shchekinov Yuri A.
Published: March 2022

Extraplanar structures of ionized gas are detected in numerous edge-on galaxies. Whether HII regions or supernovae (SNe) responsible for its ionization is still debated. Here, we consider the

H
α

{\rm{H}}\alpha

emissivity from shells of superbubbles driven by SNe explosions in a stellar cluster located either in the midplane or above the midplane of the disc. We found that these shells form filamentary structures emitting brightly in

H
α

{\rm{H}}\alpha

line at height of

∼
0.6

\sim 0.6

–

1.6

kpc

1.6\hspace{0.33em}{\rm{kpc}}

above the disc depending on cluster location and gas metallicity. The

H
α

{\rm{H}}\alpha

surface brightness ranges within

∼
1

0

−
17

\sim 1{0}^{-17}

–

1

0

−
16

erg

s

−
1

cm

−
2

arcsec

−
2

1{0}^{-16}\hspace{0.33em}{\rm{erg}}\hspace{0.33em}{{\rm{s}}}^{-1}\hspace{0.33em}{{\rm{cm}}}^{-2}\hspace{0.33em}{{\rm{arcsec}}}^{-2}

are close to the values observed in edge-on galaxies. We conclude that the

H
α

{\rm{H}}\alpha

emission of extraplanar structures can be explained by recombination in collisionally ionized gas of unstable shells driven by multiple SNe.
LOOKing for multi-word expressions in American Sign Language
Authors: Hou Lynn
Published: March 2022

Usage-based linguistics postulates that multi-word expressions constitute a substantial part of language structure and use, and are formed through repeated chunking and stored as exemplar wholes. They are also re-used to produce new sequences by means of schematization. While there is extensive research on multi-word expressions in many spoken languages, little is known about the status of multi-word expressions in the mainstream U.S. variety of American Sign Language (ASL). This paper investigates recurring multi-word expressions, or sequences of multiple signs, that involve a high-frequency sign of visual perception glossed as look and the family of ‘look’ signs. The look sign exhibits two broad functions: look/‘vision’ references literal or metaphorical vision and look/‘reaction’ signals a person’s reaction to a visual stimulus. Data analysis reveals that there are recurring sequences in distinct syntactic environments associated with the two functions of look, suggesting that look is in the process of grammaticalization from a verb of visual perception to a stance verb. The sequences demonstrate the emergence of linguistic structure from repeated use through the domain-general cognitive process of chunking in ASL.
Corrosion behavior of low carbon steels and other non-ferrous metals exposed to a real calcareous soil environment
Authors: Pérez Tezozomoc , Domínguez-Aguilar Marco A. , Alamilla Jorge L. , Liu Hongbo , Contreras Antonio , Quej Ake Luis M.
Published: March 2022

The corrosion behavior of four uncoated low carbon steels: X52, X60, X65, and X70, and three non-ferrous metals: copper, bronze, and magnesium, buried in a real calcareous soil, after a year of exposure time was studied. Samples were not cathodically protected on gravimetric testing in field conditions. Severe roughness and color changes occurred in metals and surface evidenced the presence of rust and calcareous deposits. Oxide scale was generated when metals were immersed in calcareous soil for nine months. In field conditions, X52 was the most corrosion resistant and X65 the most susceptible to corrosion. At laboratory level, a real calcareous soil tested by electrochemical methods exhibited the same trend, which was ascribed to difference in microstructure and phase distribution in steels. Corrosion enhanced when X65 was exposed to calcareous soil collected in spring (0.031 mm/year) and rainy summer (0.077 mm/year), as rain enhanced ions mobility and corrosion. Non-ferrous coupons suggested that a passivation process occurred as corrosion rates (CRs) decreased (0.0025–0.0052 mm/year) compared with the results of low carbon steels.
Corruption and International Trade: A Re-assessment with Intra-National Flows
Authors: Esteve-Pérez Silviano , Gil-Pareja Salvador , Llorca-Vivero Rafael , Paniagua Jordi
Published: March 2022

This study re-examines the impact of corruption on international trade accounting for both inter- and intra-national flows in line with the latest advances in the gravity equation literature. Using a wide sample of countries for the period 1995–2017, our results show that the non-inclusion of internal trade flows drastically biases the estimations. Additionally, we find that the negative impact of corruption on trade is reduced, ceteris paribus, in poorer countries. We also find non-linearities, more corrupt countries present a more harmful impact of corruption on trade. Moreover, we perform a general equilibrium analysis to investigate the impact of a given reduction in perceived corruption on a selected group of countries’ economic growth and prices. We find that these effects are far from being negligible, especially when there is a “synchronized” reduction in corruption in most corrupt countries.
A Study of Fibre Attrition in the Processing of Long Fibre Reinforced Thermoplastics
Authors: Bailey R. , Kraft H.
Published: March 2022

A study has been carried out which demonstrates a technique for measuring long fibre lengths. This technique has been used successfully to discuss subtle differences in the fibre length distributions arising in a range of long fibre reinforced thermoplastics. These new materials were processed using a wide range of injection moulding conditions, including such variables as the injection speeds and the preplasticising screw back pressures. This work proposes mechanisms of fibre attrition in the injection moulding process and makes recommendations for the optimisation of fibre lengths in moulded articles. It is shown that alternative polymer matrices in the long glass fibre attrition. It is also demonstrated that this family of long fibre reinforced thermoplastics can be recycled successfully with considerable fibre length advantages over traditional extrusion precompounded short fibre compounds.
Study of the Void Structure of PAN Fiber by Small Angle x-ray Scattering and Spline Function
Authors: Jiang K. , Wang Y. , Jiang Z. , Qian B.
Published: March 2022

The voids in fibers, especially in wet spun fibers are a major factor of fiber structure which greatly affects the fiber properties. A lot of research has shown that the inner voids and surface imperfections were the main causes of strength decreases. Therefore it is very important to determine the void morphology development in fiber processing in order to obtain high quality as-spun fiber.

In this paper we introduce a new method for the determination of void morphology using small angle x-ray scattering with a spline function method in which the average void size, size distribution and the related scattering power as well is obtained.
Micro- and Macromixing in Polymerization Reactors
Authors: Thiele R. , Breme J.
Published: March 2022

The paper deals with the influence of the local mixing state on the product properties in a mass styrene-acrylonitrile copolymerization stirred tank reactor in steady state. Experimental investigations at different stirrer speeds have been carried out in a specially constructed bench scale reactor. The idealized models for microfluid and complete segregation were used to calculate the polymer mass fraction, the weight average polymerization degree and the molecular nonuniformity at the outlet of the reactor. The apparatus operated as an “ideally mixed” continuous stirred tank reactor under all chosed conditions as demonstrated by measurements of the residence time distributions. The results are: the segregation model describes the experimentals at low stirrer speeds and the microfluid model is appropriate at high agitator revolutions. Polymer mass fraction, weight average polymerization degree and molecular nonuniformity as functions of average residence time calculated on the basis of both the idealized models indicate intersection points. A high extent of microfluid must not tend to decrease the molecular nonuniformity. The agitator speed can be limited in such a way that it is just sufficiently high to approximate the residence time distribution of an “ideally mixed” continuous stirred tank reactor in order to avoid dead spots and channelling. Segregation is not dangerous for the reactor performance and the product properties.
Simulation of Compression Molding with Matrix-Fibre Separation and Fibre Orientation for Long Fibre-Reinforced Thermoplastics**
Authors: Hojo H. , Yaguchi H. , Onodera T. , Kim E. G.
Published: March 2022

A model is presented which can be used to predict the flow under consideration of fibre-matrix separation and fibre orientation during sheet-like parts compression molding of long fibre-reinforced thermoplastics for isothermal state. During a molding, fibre content and fibre orientation distributions are calculated from the separation and orientation equations, and the viscosity of composites is expressed as a function of fibre content and fibre orientation. Based on the viscosity, the model was developed using the finite element method, and random and unidirectional reinforced composites are simulated. By comparing the theory with experimental results, the model accurately predicts mold filling patterns for the composite materials.
An Improvement on Design of Sheet Extrusion Dies
Authors: Yang G.-J. , Huang X.-C. , Shen C.-Y. , Chen J.-B.
Published: March 2022

On the basis of the method of representative values and the flow pattern, that is, the position of the isobars parallels to the die orifice (PIPDO), the design of dies for the sheet and annular parisons is improved in the present paper. Since this pattern includes the effects of the sloped manifold and the die design for the circular manifold are independent of flow rate and the polymer viscosity, the distribution system of a die gives better uniformity of flow. In the previous study [1] a defect is found, that is, the calculated position of the path of the island area lags behind actual position. This defect is eliminated, and the modified equation is obtained. Another flow pattern, the pressure loss on all flow path is equal (PLFPE), is introduced. The equivalency of the above two flow patterns is proved theoretically. Although the flow uniformity isn’t perfect in the simplified analytical design of dies proposed in the previous paper, this simplified design is still of advantages. Therefore, its design criterion is put forward in this paper.
Optimization of a Flat Die Including Elongational Viscosity Effects
Authors: Sun Y. , Gupta M.
Published: March 2022

A software package for optimization of polymer extrusion dies is developed. Die geometry is optimized such that a uniform velocity distribution is obtained at the die exit without excessively increasing the pressure drop in the die. The software uses the BFGS optimization algorithm, and employs the adjoint method to obtain the design sensitivities. The optimization software is successfully used to optimize the geometry of a flat die for polymer sheet extrusion such that a uniform velocity distribution is obtained at the die exit, without increasing the pressure drop in the die.
Ultrasonic Vibration Hot Embossing
Authors: Liu S.-J. , Dung Y.-T.
Published: March 2022

Hot embossing has become a popular method for replicating precise micro-features onto large plastic plates. However, a long cycle time of the process due to conventional electric heating or hot oil heating is one of problems that confound the overall success of this technology. This study proposed a novel hot embossing method by using ultrasonic vibration as a heat generator. Experiments were carried out on a 2000-watt ultrasonic welding machine. A 2 mm thick polymethyl methyl acrylic (PMMA) plate was used for embossing microstructures onto its surface. The results in this study suggest that ultrasonic vibration hot embossing can provide an effective way of molding microstructures onto the surface of polymeric plates. Nevertheless, this novel process will need some improvements in the design of the ultrasonic vibration machine in order to make the process feasible.
Generalized temporal transfer matrix method: a systematic approach to solving electromagnetic wave scattering in temporally stratified structures
Authors: Xu Jingwei , Mai Wending , Werner Douglas H.
Published: March 2022

Opening a new door to tailoring electromagnetic (EM) waves, temporal boundaries have attracted the attention of researchers in recent years, which have led to many intriguing applications. However, the current theoretical approaches are far from enough to handle the complicated temporal systems. In this paper, we develop universal matrix formalism, paired with a unique coordinate transformation technique. The approach can effectively deal with temporally stratified structures with complicated material anisotropy and arbitrary incidence angles. This formulation is applied to various practical systems, enabling the solution of these temporal boundary related problems in a simple and elegant fashion, and also facilitating a deep insight into the fundamental physics.
Fabrication of mixed nanoceramic waste with polymeric matrix membranes for water desalting
Authors: Abdallah Heba , Abo-Almaged Hanan H. , Amin Shereen K. , Shalaby Marwa S. , Shaban A. M.
Published: March 2022

Mixed matrix membranes were prepared by blending technique between nanoceramic powder and polyethersulfone. Nanoceramic powder (NC) as a fine powder was produced from ceramic industries. The effect of NC as an additive on the membrane matrix was studied. Increasing in NC% on polymeric blend enhances the membrane mechanical properties, where the tensile strength was 13.92 MPa with elongation of 23.67 mm for prepared blend membrane with NC 1 wt%. The highest salt rejection was about 89.3% with permeate flux of 34.6 L/m2 h for R1 membrane using NS of percentage 4 wt% and nonwoven polyester support. The increase in NS% to 6 wt % leads to an increase in the salt rejection to 94.2% after 1 h operating time. The coating was achieved using the layer by layer technique which was carried out on the membrane surface to improve the salt rejection percentage. The salt rejection was found to reach about 99.8% after such coating process; but for permeate flux, it shows a certain decrease. The flux of membrane before the coating was 23.4 L/m2 h for R2 membrane (1 wt% NC & 6 wt% NS), while after coating the flux was reduced to reach 21.6 L/m2 h.
Relationship between subclasses low-density lipoprotein and carotid plaque
Authors: Pan Zhanhai , Guo Huiwen , Wang Qingqing , Tian Sha , Zhang Xiaoxuan , Li Chengbo , Ma Zheng
Published: March 2022

Backgound

Low-density lipoprotein (LDL) cholesterol can lead to the occurrence of atherosclerotic plaques, but patients with normal LDL still have atherosclerotic plaques in clinical practice. With the proposal of LDL subclass, this experiment investigated the relationship between the LDL content of different subclasses and the stability of carotid plaques.

Methods

Plaque stability was suggested by carotid ultrasound results. 37 patients with stable plaques were classified into one group and 41 patients with unstable plaques were classified into another group. The data of age, glycosylated hemoglobin (Ghb), and homocysteine (Hcy) were collected. The contents of LDL subclasses were measured by LIPOPRINT system. The data of total cholesterol (TC), LDL cholesterol, and triglyceride (TG) were collected. The plaque stability was assessed by carotid artery color Doppler ultrasound and the intima-media thickness (IMT) was measured.

Results

The levels of LDL-1 subclass 19.00 (13.00, 27.50) and LDL-2 subclass (21.62 ± 7.24) in the stable plaque group were higher than those in the unstable plaque group (p < 0.05). The levels of LDL-3 subclass (12.24 ± 4.58), LDL-4 subclass 5.00 (2.00, 9.00), and sd-LDL 0 (0.00, 3.00) in the unstable plaque group were higher than those in the stable plaque group (p < 0.05). LDL-1 subclass (adjusted OR = 0.923 and p < 0.05), and LDL-3 subclass (adjusted OR = 1.176 and p < 0.05) were independent risk factors for plaque stability.

Conclusion

Elevated LDL1 is associated with stable plaques whereas LDL3 was found associated with unstable plaques.
The Torah and the King: Zedekiah’s Edict (Jer 34) and Deuteronomistic Redaction
Authors: Johnson Dylan R.
Published: March 2022

The notion that the Torah represents a supervening »rule of law« that circumscribes the political and legal authority of the king stems from a particular Deuteronomistic scribal circle that worked long after the Davidic monarchy had ended. Using Zedekiah’s edict (Jer 34:8–22) as a case study, this paper examines how Deuteronomistic redactors recast the final normative legal act of an independent Judahite king as his pious application of Pentateuchal law.
The 11Q5 Psalter as a Scribal Product: Standing at the Nexus of Textual Development, Editorial Processes, and Manuscript Production
Authors: Longacre Drew
Published: March 2022

This article demonstrates how pragmatic factors impacted the formation of the 11Q5 (11QPsa) psalter, confirming the essential interdependency between textual development, editorial processes, and physical manuscript production. I enumerate several default modes that guided the compiler and the types of editorial interventions by which he created the 11Q5 psalter. These suggest that the 11Q5 psalter was produced as a revised version of the traditional psalter, expanded and rearranged from an MT-like base text to enhance thematic, lexical, and sometimes formal connections between psalms.
Leveraging dewetting models rather than nucleation models: current crystallographic challenges in interfacial and nanomaterials research
Authors: Ernst Owen C. , Liu Yujia , Boeck Torsten
Published: March 2022

No scientific model has shaped crystallography as much as the classical nucleation theory (CNT). The majority of all growth processes and particle formation processes are attributed to the CNT. However, alternative descriptions exist that may be better suited to explain material formation under certain conditions. One of these alternatives is the dewetting theory (DWT). To describe the possibilities of DWT in more detail, we selected three material systems for three current application areas: Gold particles on silicon as catalysts for nanowire growth, indium particles on molybdenum as precursor material in novel solar cell concepts, and silicon layers on silicon germanium as potential wells in semiconductor quantum computers. Each of these material systems showed particular advantages of DWT over CNT. For example, the properties of surface particles with high atomic mobility could be described more realistically using DWT. Yet, there were clear indications that the DWT is not yet complete and that further research is needed to complete it. In particular, modern crystallographic challenges could serve this purpose, for example the development of semiconductor quantum computers, in order to re-evaluate known models such as the CNT and DWT and adapt them to the latest state of science and technology. For the time being, this article will give an outlook on the advantages of the DWT today and its potential for future research in crystallography.
Prozessketten-Modellierung für textilverstärkte Verbund-Bauteile
Authors: Großmann Knut , Wiemer Hajo
Published: March 2022

Textilverstärkte Verbund-Werkstoffe erlangen auf Grund der funktionsgerecht gestaltbaren Werkstoffeigenschaften für Leichtbaukonzepte zunehmend Bedeutung. Die gezielte und reproduzierbare Einstellung der Werkstoffeigenschaften erweist sich als eine komplexe Aufgabenstellung, da vielfältige Einflüsse aus dem Verhalten des Verbund-Werkstoffs, der Maschinen und Werkzeuge sowie der im Herstellprozess eingestellten technologischen Größen wirken. Diese Veröffentlichungsfolge begründete im Teil 1 [1] die Notwendigkeit neuer, den komplexen Anforderungen genügender Auslegungswerkzeuge und erläuterte den verfolgten Modellierungsansatz. In diesem Beitrag werden der Stand der prozessrelevanten Modellierungsmöglichkeiten in den einzelnen technologischen Bereichen zusammengefasst sowie deren Integration in das übergreifende Prozesskettenmodell des von der DFG geförderten Sonderforschungsbereichs SFB 639 [2] veranschaulicht.*
Komplexitätsreduzierung durch Insourcing
Authors: Dombrowski Uwe , Leichnitz Henning , Sliwonik Pawel
Published: March 2022

Der ständig wachsende Druck des Marktes drängt produzierende Unternehmen zur Erweiterung ihrer Produktspektren. In der scheinbar unkontrollierbaren Vermehrung der Varianten spiegelt sich die wachsende Komplexität wider, mit der Unternehmen heute zunehmend kämpfen. Sie wirkt sich neben den Primärprodukten auch auf deren Verpackungseinheiten aus. Die IAP GmbH hat im Rahmen eines Projekts bei einem Hersteller von Elektronik- und Industriegehäusen mit ihrem strukturierten Ansatz zur Reduzierung von Komplexität – Sensibilisieren, Beherrschen, Bereinigen, Vereinfachen – eine Lösung zur Beherrschung und Vermeidung von Komplexität durch drastische Vereinfachung gefunden: Das Insourcing des bedarfsgerechten Zuschnitts von Versandkartons aus variantenneutralen Kartonagebahnen durch die Beschaffung einer flexiblen Zuschnittanlage entlastet Entwicklung, Planung, Einkauf, Kommissionierung, Lager und Packstellen. Der grundsätzliche Ansatz der IAP GmbH sowie das Vorgehen im Fallbeispiel und die Ergebnisse werden im vorliegenden Artikel dargestellt.