bluuebunny/crossref_metadata_2025 huggingface dataset:
Turnover prevention: The direct and indirect association between organizational job stressors, negative emotions and professional commitment in novice nurses
Authors: ten Hoeve Yvonne , Brouwer Jasperina , Kunnen Saskia
Published: December 2019

Aims

Getting insight in the most crucial organizational job stressors for novice nurses' professional commitment and whether the job stressors are mediated through negative emotions.

Design

The study used an observational cohort design.

Methods

Organizational job stressors were derived from 580 diary entries by 18 novice nurses combined with measures on emotions and commitment. The diaries were collected from September 2013–September 2014.

Results

Path modelling revealed that lack of support from colleagues, negative experiences with patients and confrontations with existential events were most strongly negatively related to professional commitment through negative emotions. Other indirectly and negatively related organizational job stressors to commitment were complexity of care, lack of control and work‐life imbalance; only conflicting job demands, and lack of control related to professional commitment directly.

Conclusion(s)

To enhance professional commitment, it is important to reduce negative emotions in novice nurses by collegial support in dealing with negative experiences with patients, complexity of care and existential events and to prevent lack of control and an imbalance between private life and work. Nurse supervisors and managers can encourage nurses to share negative patient experiences, issues related to complexity of care and existential events.

Impact

Considering the worldwide nursing shortage and early turnover, more understanding is needed about how negative emotions mediate the relationship between organizational negative job stressors and professional commitment and the relative impact of organizational job stressors to professional commitment. The study stresses the importance of a supportive role of supervisors and nurse managers to improve the work environment and hence increase novice nurses' commitment and retention.
Predicting engaging in cosmetic surgery: A test of the role of doing and not doing cognitions
Authors: Richetin Juliette , Osterini Daniela , Conner Mark
Published: December 2019

The decision‐making process underlying cosmetic surgery for esthetic purposes has been rarely investigated. To fill in this gap, we examined the determinants of undergoing plastic surgery among women within a framework that considers that the intentions to undergo and to not undergo surgery are related to different motivational systems that could both contribute to behavior. To do so, we assessed the goals underlying both options and theory of planned behavior constructs (Attitude, Perceived Behavioral Control, Subjective norms) related to undergoing and not undergoing plastic surgery as well as risk perception among a convenience sample of women (N = 265). Results confirmed that undergoing and not undergoing plastic surgery are related to different but not opposite goals. More importantly, both intentions predicted actual behavior but with the intention of not undergoing weighing more than the intention of undergoing plastic surgery. Finally, results supported previous research showing that risk perception does not add to predicting behavior. This contribution, therefore, supports the adoption of a decision‐making framework to provide additional information to individual and social factors that can explain why women are undergoing plastic surgery for esthetic purposes or not.
Novel ultra‐high‐frequency electrocardiogram tool for the description of the ventricular depolarization pattern before and during cardiac resynchronization
Authors: Jurak Pavel , Curila Karol , Leinveber Pavel , Prinzen Frits W. , Viscor Ivo , Plesinger Filip , Smisek Radovan , Prochazkova Radka , Osmancik Pavel , Halamek Josef , Matejkova Magdalena , Lipoldova Jolana , Novak Miroslav , Panovsky Roman , Andrla Petr , Vondra Vlastimil , Stros Petr , Vesela Jana , Herman Dalibor
Published: December 2019

Introduction

The present study introduces a new ultra‐high‐frequency 14‐lead electrocardiogram technique (UHF‐ECG) for mapping ventricular depolarization patterns and calculation of novel dyssynchrony parameters that may improve the selection of patients and application of cardiac resynchronization therapy (CRT).

Methods

Components of the ECG in sixteen frequency bands within the 150 to 1000 Hz range were used to create ventricular depolarization maps. The maximum time difference between the UHF QRS complex centers of mass of leads V1 to V8 was defined as ventricular electrical dyssynchrony (e‐DYS), and the duration at 50% of peak voltage amplitude in each lead was defined as the duration of local depolarization (Vd). Proof of principle measurements was performed in seven patients with left (left bundle branch block) and four patients with right bundle branch block (right bundle branch block) before and during CRT using biventricular and His‐bundle pacing.

Results

The acquired activation maps reflect the activation sequence under the tested conditions. e‐DYS decreased considerably more than QRS duration, during both biventricular pacing (−50% vs −8%) and His‐bundle pacing (−77% vs −13%). While biventricular pacing slightly increased Vd, His‐bundle pacing reduced Vd significantly (+11% vs −36%), indicating the contribution of the fast conduction system. Optimization of biventricular pacing by adjusting VV‐interval showed a decrease of e‐DYS from 102 to 36 ms with only a small Vd increase and QRS duration decrease.

Conclusions

The UHF‐ECG technique provides novel information about electrical activation of the ventricles from a standard ECG electrode setup, potentially improving the selection of patients for CRT and application of CRT.
Using the time‐varying autoregressive model to study dynamic changes in situation perceptions and emotional reactions
Authors: Casini Erica , Richetin Juliette , Preti Emanuele , Bringmann Laura F.
Published: December 2019

Objective

Assuming personality to be a system of intra‐individual processes emerging over time in interaction with the environment, we propose an idiographic approach to investigate potential changes of intra‐individual dynamics in the perception of situations and emotions of individuals varying in personality traits. We compared the semiparametric time‐varying autoregressive model (TV‐AR) that takes into account the non‐stationarity of psychological processes at the individual level, with the standard AR model.

Method

We conducted analyses of individual time series to assess intra‐individual changes in mean levels and inertia on data from two adolescents who completed measures of personality and indicated their situation perceptions and emotions five times a day for 19 days.

Results

For the less honest, emotional, extraverted, and more agreeable adolescent, the TV‐AR model detected reliable changes in the intra‐individual dynamics of situation perceptions and emotions whereas, for the other individual, the standard AR model was more preferred, given the lack of changes in the intra‐individual dynamics.

Conclusions

Psychological processes dynamics in situation perception and emotions may vary from person to person depending on their personality. This work constitutes a first step in demonstrating that an idiographic approach has advantages in identifying changes in individuals' perceptions and reactions to situations.
Isolation, identification, carbon utilization profile and control of Pythium graminicola, the causal agent of chilli damping‐off
Authors: Dubey Manish Kumar , Zehra Andleeb , Aamir Mohd. , Yadav Mukesh , Samal Swarnmala , Upadhyay Ram Sanmukh
Published: December 2019

Postemergence damping‐off of chilli caused by Pythium spp. is a common and serious problem in large chilli growing areas of India under the moist conditions that generally prevails during the sowing period. Therefore, in order to better understand this disease, an isolate belonging to the genus Pythium (Pythiales) was isolated from the infected chilli (Capsicum annuum L.) plant root parts collected from the fields of Chandauli district, Uttar Pradesh, India. Based on the congruence of cultural, morphological, cardinal growth rate and the sequence data analysis, the isolate was identified as Pythium graminicola. The molecular phylogenetic analysis based on ITS‐rDNA sequences clustered the isolate with representative sequences for P. graminicola from GenBank in the Pythium clade. The isolate carbon utilization profiles were characterized using Biolog FF MicroPlate method. The results revealed that the isolate used a wide range of carbon sources, mainly carbohydrates, but also amino acids, suggesting the use of metabolic routes that include glycolysis/gluconeogenesis. Moreover, an in vitro colony growth inhibition assay was performed to determine the influence of chemical (fungicides) and biological (bacteria and fungi) antagonists over the pathogen using the poison plate and dual culture method, respectively. Overall, the results revealed that the presence of aggressive broad range biocontrol agents can be used as an effective environmentally friendly approach for management and control of damping‐off in production systems. The antagonist can serve as a bio‐efficient and eco‐friendly alternative to synthetic fungicides for the development of an effective integrated pest management (IPM) system and obtaining higher yields.
To what extent does smoking affect gingival bleeding response to supragingival plaque? Site‐specific analyses in a population‐based study
Authors: Holde Gro Eirin , Jönsson Birgitta , Oscarson Nils , Müller Hans‐Peter
Published: December 2019

Background and objective

The aim of this study was to investigate the influence of smoking on the site‐specific association between bleeding on gingival probing and supragingival plaque and to assess whether this differs in different regions of the dentition.

Methods

Data from a representative sample of 1911 adults (20‐79 years old) in Northern Norway were analyzed. Periodontal examinations consisted of full‐mouth recordings of periodontal probing depth (PD), bleeding on probing (BOP), and presence of supragingival plaque. Smoking status and background characteristics were self‐reported by questionnaire. The association between plaque and BOP was assessed in several three‐level (subject, tooth, and site) random intercept logistic regression models adjusted for PD, smoking status, socioeconomic factors, and body mass index. In a further model, it was assessed whether the association between supragingival plaque and BOP differed in different parts of the dentition.

Results

For plaque‐free sites, bleeding tendency was lower in smokers, the odds ratio (OR) was 0.773 with a 95% confidence interval of 0.678‐0.881 as compared to non‐smokers (OR: 1; ref., P < .001). The odds of BOP at plaque‐covered sites in non‐smokers were increased twofold (OR: 2.117; 2.059‐2.177). Albeit bleeding tendency was slightly increased in plaque‐covered sites in smokers, it was considerably lower as compared to plaque‐covered sites in non‐smokers (OR: 1.459; 1.282‐1.662, P < .001). Smoking ≥ 20 pack‐years further attenuated the association. In smokers, the odds of BOP were reduced in all parts of the dentition, lower and upper anterior and posterior teeth (= 32.043, P < .001). When restricting the data to younger adults (20‐34 year old), smoking had only a slight effect on the association between plaque and BOP. For plaque‐free and plaque‐covered sites, differences in ORs were not statistically noticeable (P = .221 and P = .235, respectively).

Conclusions

Smoking considerably attenuates the site‐specific association between plaque and BOP with a dose‐dependent effect. The effect of smoking did not differ across tooth types.
Quantitative characterizations of the Sharpey’s fibers of rat molars
Authors: Liang Yongxi , Hu Zhiai , Chang Bei , Liu Xiaohua
Published: December 2019

Background and objective

The Sharpey's fibers of periodontal ligament (PDL) anchor the PDL to alveolar bone and cementum and are essential for the function of PDL. While qualitative analyses of the Sharpey's fibers have been widely explored, a comprehensive quantitative characterization of the Sharpey's fibers is not available. In this work, we selected rat molars as a model and comprehensively characterized the PDL Sharpey's fibers (diameter, density, length, embedding angle, and insertion angle).

Materials and methods

A total of 24 rat mandibular molars, eight maxillary first molars, and their surrounding alveolar bone were harvested, fixed, rendered anorganic and observed under scanning electron microscopy (SEM). The mandibles and maxillae (n = 4) were harvested, processed, sectioned, and stained with Sirius red for histological observation. SEM images were used for quantitative analyses of diameters and densities of the Sharpey's fibers, while Sirius red staining images were used to measure lengths and angles. The Sharpey's fibers were comprehensively characterized in terms of positions (cervical, middle, and apical thirds), PDL fiber groups (alveolar crest, horizontal, oblique, apical, and interradicular groups), sides (cementum and bone sides), and teeth (mandibular first, second, third molars, and maxillary first molar).

Results

Our results showed that the characteristic parameters of the Sharpey's fibers varied in different positions, fiber groups, sides, and teeth. Specifically, the median diameter of the Sharpey's fibers on the bone side was significantly greater than that on the cementum side, while the median density of the Sharpey's fibers on the bone side was significantly lower than that on the cementum side, regardless of the positions and teeth. For the same tooth, the median length of the embedded Sharpey's fibers on the bone side was more than two times greater than that on the cementum side. Among all fiber groups, the alveolar crest group had the maximum length of the Sharpey's fibers on the bone side and the minimal length of the Sharpey's fibers on the cementum side. There is an approximate 5‐15° difference between the embedding angle and the insertion angle in each group. The oblique group had the smallest embedding angles on both the bone and cementum sides.

Conclusion

This study provides a comprehensive and quantitative characterization of the Sharpey's fibers using rat molars as a model. Overall, these parameters varied according to different vertical positions, fiber groups, teeth, and jawbones. The quantitative information of the Sharpey's fibers presented in this work facilitates our understanding of PDL functions and advances the development of biomimetic materials for periodontal tissue regeneration.
Efficient but occasionally imperfect vertical transmission of gut mutualistic protists in a wood‐feeding termite
Authors: Michaud Caroline , Hervé Vincent , Dupont Simon , Dubreuil Géraldine , Bézier Annie M. , Meunier Joël , Brune Andreas , Dedeine Franck
Published: December 2019

Although mutualistic associations between animals and microbial symbionts are widespread in nature, the mechanisms that have promoted their evolutionary persistence remain poorly understood. A vertical mode of symbiont transmission (from parents to offspring) is thought to ensure partner fidelity and stabilization, although the efficiency of vertical transmission has rarely been investigated, especially in cases where hosts harbour a diverse microbial community. Here we evaluated vertical transmission rates of cellulolytic gut oxymonad and parabasalid protists in the wood‐feeding termiteReticulitermes grassei. We sequenced amplicons of the 18S rRNA gene of protists from 24 colonies ofR. grasseicollected in two populations. For each colony, the protist community was characterized from the gut of 14 swarming reproductives and from a pool of 10 worker guts. A total of 98 operational taxonomic units belonging to 13 species‐level taxa were found. The vertical transmission rate was estimated for each protist present in a colony based on its frequency among the reproductives. The results revealed that transmission rates were high, with an average of 0.897 (±0.164) per protist species. Overall, the protist community did not differ between reproductive sexes, suggesting that both the queen and the king could contribute to the gut microbiota of the offspring. A positive relationship between the transmission rate of protists and their prevalence within populations was also detected. However, transmission rates alone do not explain the prevalence of protists. In conclusion, these findings reveal key forces behind a conserved, multispecies mutualism, raising further questions on the roles of horizontal transfer and negative selection in shaping symbiont prevalence.
Cuffed pediatric endotracheal tubes—Outer cuff diameters compared to age‐related airway dimensions
Authors: Fischer Martina , Grass Beate , Kemper Michael , Weiss Markus , Dave Mital H.
Published: December 2019

Background

Reliable sealing of the pediatric airway requires appropriately sized tracheal tube cuffs. The aim of this study was to compare residual cuff diameters of pediatric tracheal tubes with pediatric airway dimensions.

Methods

Cuff diameters of five different brands of locally marketed pediatric cuffed tracheal tubes with internal diameters of 3.0‐7.0 mm were measured at a cuff pressure of 20 cm H2O and compared with cuff diameters indicated by their manufacturers. The latter values were compared to tracheal dimensions using the Motoyama and Khine formulas for cuffed tracheal tube size selection.

Results

There is considerable heterogeneity in cuff diameters among pediatric tracheal tube brands, except for two brands from different manufacturers (Halyard and Parker Medical) which were identically designed. Cuffs made from polyurethane revealed fewer differences (91%‐118%) between measured and manufacturer‐indicated values for outer cuff diameters than did those made from polyvinylchloride (91%‐146%). Particularly in smaller sized tracheal tubes, cuffs did not reach 100% of the tracheal lateral diameter, while others were oversized in larger tracheal tubes, independent of the two formulas used for cuffed tracheal tube size selection. Cuff diameters indicated by the manufacturer corresponded to 86%‐188% of the median and 68%‐157% of the maximum mid‐tracheal lateral diameter of the corresponding upper age range.

Conclusion

Our findings show that many of the cuff diameters of currently marketed tracheal tube brands lack an age‐related anatomical rationale. A proposal for age‐related anatomically based cuff diameters is provided for both recommendations for cuffed tracheal tube size selection in children.
Duration of preoperative clear fluid fasting and peripheral intravenous catheterization in children: A single‐center observational cohort study of 9693 patients
Authors: Galvez Jorge A. , Wu Lezhou , Simpao Allan F. , Tan Jonathan , Muhly Wallis , Masino Aaron , Sutherland Tori , Wasey Jack O. , Nelson Olivia , Lin Elaina , Fiadjoe John E. , Stricker Paul
Published: December 2019

Background

Children routinely undergo inhalational induction of general anesthesia. Intravenous line placement typically occurs after induction of anesthesia and can be challenging, particularly in infants and young children.

Aims

We conducted a retrospective observational study to determine whether there was an association between clear liquid fasting time and the number of peripheral intravenous catheter insertion attempts in anesthetized children. The secondary aim was to identify factors associated with multiple attempts to insert intravenous lines.

Methods

After institutional research board approval, we retrieved a data set of all children between 0 months and 18 years who received general anesthesia at our hospital between January 1, 2016, and September 30, 2017. Data included age, gender, weight, race, ASA status, gestational age, number of peripheral intravenous catheter insertion attempts, any assistive device for insertion, and insertion site. Inclusion criteria were mask induction, ASA status 1 or 2, nonemergency, ambulatory surgical procedures, and placement of a single intravenous line during the anesthetic.

Results

A total of 9693 patients were included in the study. Of which 8869 patients required one insertion attempt and 824 underwent multiple insertion attempts. 50% of patients in the single insertion attempt group had clear liquid fasting time <6.9 hours compared to 51.8% of patients requiring multiple attempts. Logistic regression model adjusted for age, ASA status, gender, and BMI did not find an association between duration of clear liquid fasting time and rate of multiple insertion attempts for intravenous catheters (OR: 0.99, 95% CI: 0.98‐1.01, P = .47).

Conclusion

Clear liquid fasting time was not associated with multiple insertion attempts for intravenous line insertion in children receiving general anesthesia. Factors such as patient age, ethnicity, time of day of induction of anesthesia, and American Society of Anesthesiologists Physical Status classification show a greater association with the risk of multiple intravenous line insertion attempts.
Understanding, treating, and renaming grandiose delusions: A qualitative study
Authors: Isham Louise , Griffith Laura , Boylan Anne‐Marie , Hicks Alice , Wilson Natalie , Byrne Rory , Sheaves Bryony , Bentall Richard P. , Freeman Daniel
Published: December 2019

Background

Grandiose delusions are arguably the most neglected psychotic experience in research.

Objectives

We aimed to discover from patients: whether grandiose delusions have harmful consequences; the psychological mechanisms that maintain them; and what help patients may want from clinical services.

Design

A qualitative interview design was used to explore patients’ experiences of grandiose delusions.

Method

Fifteen patients with past or present experiences of grandiose delusions who were attending psychiatric services were interviewed. Thematic analysis and grounded theory were used to analyse the data.

Results

Participants reported physical, sexual, social, occupational, and emotional harms from grandiose delusions. All patients described the grandiose belief as highly meaningful: it provided a sense of purpose, belonging, or self‐identity, or it made sense of unusual or difficult events. The meaning from the belief was not synonymous with extreme superiority or arrogance. The meaning obtained appeared to be a key driver of the persistence of the beliefs. Other maintenance factors were subjectively anomalous experiences (e.g., voices), symptoms of mania, fantasy elaboration, reasoning biases, and immersive behaviours. Participants described insufficient opportunities to talk about their grandiose beliefs and related experiences and were generally positive about the possibility of a psychological therapy.

Conclusions

We conclude that grandiosity is a psychologically rich experience, with a number of maintenance factors that may be amenable to a targeted psychological intervention. Importantly, the term ‘grandiose delusion’ is an imprecise description of the experience; we suggest ‘delusions of exceptionality’ may be a credible alternative.

Practitioner points

Harm from grandiose delusions can occur across multiple domains (including physical, sexual, social, occupational, and emotional) and practitioners should assess accordingly.

However, grandiose delusions are experienced by patients as highly meaningful: they provide a sense of purpose, belonging, or self‐identity, or make sense of unusual or difficult events.

Possible psychological maintenance mechanisms that could be a target for intervention include the meaning of the belief, anomalous experiences, mania, fantasy elaboration, reasoning biases, and immersive behaviours.

Patients are keen to have the opportunity to access talking therapies for this experience. Taking extra time to talk at times of distress, ‘going the extra mile’, and listening carefully can help to facilitate trust.
Hypofractionated radiotherapy in children with diffuse intrinsic pontine glioma
Authors: Hayashi Akiko , Ito Eiko , Omura Motoko , Aida Noriko , Tanaka Mio , Tanaka Yukichi , Sato Hironobu , Miyagawa Naoyuki , Yokosuka Tomoko , Iwasaki Fuminori , Hamanoue Satoshi , Goto Hiroaki
Published: December 2019

Background

Overall survival (OS) of patients with diffuse intrinsic pontine glioma (DIPG) is poor, with radiation therapy (RT) the only intervention that transiently delays tumor progression. Hypofractionated RT and re‐irradiation at first progression have gained popularity in improving the quality of life of such patients.

Methods

We performed a retrospective review of children with DIPG treated at Kanagawa Children's Medical Center from 2000 to 2018.

Results

A total of 24 cases were reviewed. Median age at diagnosis was 6.3 years (1.6–14.0). Twenty patients received RT only once. Thirteen patients received conventionally fractionated RT, and seven patients received hypofractionated RT as up‐front RT. Severe toxicities were not observed in patients who received hypofractionated RT. Median OS and time to progression were similar between conventionally fractionated and hypofractionated RT groups.(9.7 [95% confidence interval(CI): 7.1‐11.2] versus 11.0[95% CI: 5.2‐13.6] months, P = 0.60; 4.2[95% CI: 1.8‐8.3] versus 7.1 [95% CI:4.5‐8.7] months, P = 0.38). Four patients received re‐irradiation at first progression and all patients showed transient neurological improvement and survival more than a year after diagnosis. A 4‐year‐old boy was re‐irradiated 5‐and‐a‐half months after the first re‐irradiation; following transient neurological improvement. He survived a further 5 months.

Conclusion

Hypofractionated RT for children with newly diagnosed DIPG is well tolerated and feasible from the viewpoint of reducing a patient's burden of treatment. Re‐irradiation at first progression is suggested to be beneficial.
The effects of psychoeducation based on the cognitive‐behavioral approach on premenstrual syndrome symptoms: A randomized controlled trial
Authors: Başoğul Ceyda , Aydın Özkan Semiha , Karaca Türkan
Published: December 2019

Purpose

The present study investigated the effects of psychoeducation based on a cognitive‐behavioral approach on premenstrual syndrome (PMS) symptoms in young adult women.

Design and Methods

The study was performed as a randomized controlled trial. The sample size was identified as 90 (45 intervention group/45 control group) students. The psychoeducation intervention consisted of five sessions performed over a 4‐week period.

Findings

There was a significant difference between the pretest and posttest total mean scores of the intervention group that received psychoeducation (P < .05). There was also a significant difference in depressive thoughts, irritability, and fatigue mean scores between the two groups (P < .05).

Practical Implications

The use of this approach and its inclusion in nursing care interventions is recommended to reduce PMS symptoms in young adult women.
Intensity, moderation, and the pressures of expectation: Calculation and coercion in the street‐level practice of welfare conditionality
Authors: Kaufman James
Published: December 2019

This article offers a street‐level perspective on welfare conditionality as it was practiced in contracted‐out UK activation programs between 2008 and 2015. Drawing on observation and in‐depth interviews, the article illustrates the ways that behavioral conditionality provided street‐level workers with the means to intensify or moderate activation for particular claimants. Responding to arguments about the curtailment of street‐level discretion, the article argues that in the particular context of target‐driven, work‐first, and otherwise highly constrained services, discretion resided in the ability to intensify or moderate conditionality and its coercive potential—in decisions about how, on whom, and to what extent it would be applied. The article argues that attending to this form of discretion provides an alternative frame through which to view the differentiated treatment typically understood as “creaming” and “parking.” In so doing, the article problematizes accounts that draw clear lines between calculative, normative, and dispositional forms of street‐level reason and practice. It shows how advisors' responses to the “street‐level calculus of choice” were articulated in terms of expectation, where attempts at future‐oriented calculation necessarily entailed making other forms of speculative and normative judgement about claimants and their situations. The article thus contributes to an understanding of both the causes and meaning of differentiated treatment in conditional welfare services.
Dynamics of zinc under long‐term application of chemical fertilizers and amendments by maize–wheat cropping sequence in Typic Hapludalfs
Authors: Shambhavi Shweta , Kumar Rakesh , Padbhushan Rajeev , Verma Gayatri , Sharma Surya Prakash , Sharma Sanjay K. , Sharma Raj Paul
Published: December 2019

This present investigation took place on a continuing long‐term fertilizer experiment, initiated in 1972 at the experimental farm of the College of Agriculture CSK HPKV, Palampur, aimed at studying nutrient dynamics of micronutrients, especially Zn, after continuous use of chemical fertilizers and amendments over the previous 36 years in an acid Alfisol under a maize–wheat system. Treatments investigated were as follows: T1: Control; 100% N; 100% NP; 100% NPK (optimal application ‐ 120:26:33(maize)/25(wheat)); 100% NPK + FYM (10 t ha−1 to the maize crop); T6: 100% NPK + lime (900 kg ha−1); T7: 100% NPK + Zn (25 kg ha−1 as ZnSO4); T8: 100% NPK + Hand weeding; T9: 100% NPK (‐S); T10: 150% NPK (super‐optimal application); and T11: 50% NPK (sub‐optimal application). Different forms of zinc in soil were determined through a sequential extraction method. Results revealed that previous applications of high‐analysis fertilizers and amendments caused a marked depletion in the pools of Zn as compared to buffer plots. All pools of Zn as well as crop productivity and Zn uptake were noticeably greater in farmyard manure (FYM)‐amended plots compared with plots not receiving fertilizer. The residual fraction was the dominant form but organically bound and exchangeable forms were found to play major role in nutrient supply, crop productivity and nutrient uptake. Correlation and regression analysis studies showed that organic forms constituted the most important pool contributing towards variation in yield and uptake by maize and wheat crops. Exchangeable and organically bound forms contributed significantly towards the availability of DTPA‐extractable Zn in soil.
Very early‐onset ofCryptococcus neoformansdisease following liver transplantation: Report of two cases and a review of the literature
Authors: Marinelli Tina , Anagnostou Nicholas , Daniel Santhosh , Wigg Alan J. , Teh Joanne
Published: December 2019

Cryptococcosis is the third most common invasive fungal infection following solid organ transplantation, and mortality is high. Most cases occur late and are due to reactivation of latent infection; however, very early reactivation and donor‐derived transmission can occur. Routine screening pre‐transplant and antifungal prophylaxis for cryptococcosis post‐transplant in solid organ transplantation are not standard practice. We present two cases of very early‐onsetCryptococcus neoformansdisease following liver transplantation to highlight the need to consider individualized pre‐transplant screening and be aware that reactivation ofCryptococcosis neoformanscan occur in the immediate post‐transplant period.
Thin film occlusion of an intra‐abdominal vein in cats
Authors: Freund Kristin A. , Wallace Mandy L. , Secrest Scott A. , Lieske Danielle E.
Published: December 2019

Objective

To evaluate the occlusion of an intra‐abdominal vessel as a model of an extrahepatic portosystemic shunt by thin film banding in a controlled setting and to document histologically the perivascular region's response to thin film banding after 8 weeks.

Study design

Experimental study.

Animals

Six purpose‐bred healthy domestic short hair cats.

Methods

Thin film bands were placed around the external iliac vein, with a sham procedure on the contralateral vessel. Closure rates were monitored via computed tomographic angiography (CTA) every 2 weeks for a total of 8 weeks. After 8 weeks, the vessels were resected, if possible, and submitted for histopathologic evaluation.

Results

All cats tolerated the procedure without surgical complications. Eight weeks after surgery, closure was evaluated as complete in one cat, marked in two cats, moderate in one cat, and mild in two cats according to CTA. Histological examination (in three cats) was consistent with chronic, multifocal, granulomatous inflammation with moderate fibrosis and collagen degeneration.

Conclusion

Venous occlusion was inconsistent and often incomplete 8 weeks after thin film banding of the external iliac vein despite the presence of moderate to abundant perivascular fibrous tissue.

Clinical significance

Vascular occlusion by thin film banding in cats is mainly incomplete after 2 months. This study supports the theory that high level of residual shunting may be expected in some cats after thin film banding.
Hypertension and sympathetic nervous system overactivity rely on the vascular tone of pial vessels of the rostral ventrolateral medulla in spontaneously hypertensive rats
Authors: Malheiros‐Lima Milene R. , Antunes Vagner R. , Takakura Ana C. , Moreira Thiago S.
Published: December 2019

New Findings

What is the central question of this study?

Is purinergic signalling in the pial vessels involved in the control of vascular tone in the ventral surface of the brainstem, affecting high blood pressure and sympathetic overactivity in spontaneously hypertensive rats?

What is the main finding and its importance?

The regulation of vascular tone in the ventral surface of the brainstem is tailored to support neuronal functions, arterial pressure and sympathetic activity. This adds one more piece in the complex puzzle to understand the central mechanisms underlying the genesis of hypertension.

Evidence suggests the rostral ventrolateral medulla (RVLM) region is chronically hypoperfused and hypoxic in spontaneously hypertensive rats (SHR), which can facilitate ATP release throughout the brainstem. Thus, we hypothesized that purinergic signalling plays a key role in the increased vascular tone in the RVLM region, which in turn could be responsible for the high sympathetic tone and blood pressure in the SHR. The application of an antagonist of P2 receptors, pyridoxalphosphate‐6‐azophenyl‐2′,4′‐disulfonic acid (10 µm), or of P2Y1a receptors, MRS2179 (100 µm), on the surface of RVLM pial vessels of SHR produced an increase in the diameter of blood vessels (PPADS: 31 ± 1.4 µm or MRS2179: 32 ± 0.78 µm vs. saline: 27 ± 1.2 µm), an effect not observed in normotensive Wistar rats. In addition, the antagonism of P2 receptors was able to evoke a significant decrease in the arterial pressure, heart rate and splanchnic nerve activity in SHR, but not in Wistar rats. Our data show that SHR have higher vascular tone of pial vessels in the RVLM region when compared to the normotensive Wistar rats, a mechanism that relies on purinergic signalling through P2 receptors, suggesting a possible association with higher activity of sympathoexcitatory neurones, and sustained increases in blood pressure.
Investigation on Vibration Response for Misaligned Rotor-Bearing-Flexible Disc Coupling System—Theory and Experiment
Authors: Tuckmantel F. W. S. , Castro H. F. , Cavalca K. L.
Published: December 2019

Modeling of the dynamic behavior of the rotating system when subject to misaligned shafts is an interesting subject, aiming either the selection of appropriate couplings from early stages of project or the monitoring and model-based diagnosis of such machines. This research is focused on the dynamics of the system when angular misalignment is induced. The methodology to take into account this fault is based on the structural analysis of the flexible coupling, with the consequent use of cyclic restoring forces and moments exerted by this component on the coupled shafts. Structural analysis of metallic disc coupling is conducted by means of the finite element method, in which the flexible disc component is modeled using thin shell formulation. Once misalignments are applied, the cyclic nature of coupling efforts is captured by the application of consecutive shaft spin angles. Steady-state response is simulated and then displacements spectrum are analyzed in order to highlight harmonic components rising due to misalignment. Test rig measurements are performed, and the theoretical model is discussed in terms of locus, frequency response function (FRF), orbit shape, and spectrum information. Disc coupling is regarded, as limited literature in vibration spectrums is available for this type of coupling.
Effects of Operating Conditions on the Heat Management of a Microscale Fuel Cell
Authors: Sun Liyong , Hollinger Adam S. , Zhou Jun
Published: December 2019

Higher energy densities and the potential for nearly instantaneous recharging make microscale fuel cells very attractive as power sources for portable technology in comparison with standard battery technology. Heat management is very important to the microscale fuel cells because of the generation of waste heat. Waste heat generated in polymer electrolyte membrane fuel cells includes oxygen reduction reaction in the cathode catalyst, hydrogen oxidation reaction in the anode catalyst, and Ohmic heating in the membrane. A novel microscale fuel cell design is presented here that utilizes a half-membrane electrode assembly. An ANSYS Fluent model is presented to investigate the effects of operating conditions on the heat management of this microscale fuel cell. Five inlet fuel temperatures are 22°C, 40°C, 50°C, 60°C, and 70°C. Two fuel flow rate are 0.3 mL/min and 2 mL/min. The fuel cell is simulated under natural convection and forced convection. The simulations predict thermal profiles throughout this microscale fuel cell design. The exit temperature of fuel stream, oxygen stream and nitrogen stream are obtained to determine the rate of heat removal. Simulation results show that the fuel stream dominates heat removal at room temperature. As inlet fuel temperature increases, the majority of heat removal occurs via convection with the ambient air by the exposed current collector surfaces. The top and bottom current collector removes almost the same amount of heat. The model also shows that the heat transfer through the oxygen channel and nitrogen channel is minimal over the range of inlet fuel temperatures. Increasing fuel flow rate and ambient air flow both increase the heat removal by the exposed current collector surfaces. Ultimately, these simulations can be used to determine design points for best performance and durability in a single-channel microscale fuel cell.
Fluid Flow and Heat Transfer Characteristics of Micro Oscillating Heat Pipes With and Without Expanding Channels
Authors: Sun Qin , Qu Jian , Yuan Jianping , Wang Hai , Thompson Scott M.
Published: December 2019

The oscillating heat pipe is considered a promising candidate for high-efficiency and compact thermal control for next-generation electronics. In this paper, the visualized flow and heat transfer characteristics of two silicon-based micro oscillating heat pipes (micro-OHPs) with expanding and straight channels, respectively, were experimentally investigated. The overall size of these two micro-OHPs are both 28 mm × 23 mm × 1.025 mm and have thirty rectangular cross-section channels. The hydraulic diameter of parallel direct channel is 332.4 μm, while they are about 364.4 and 287.0 μm at the two ends of expanding channel, respectively. R141b was used as the working fluid with the volumetric filling ratio of 50%. Inside these two micro-devices, the fluid oscillating motion, including unidirectional movement and intermittent stopovers, was observed at the quasi-steady oscillation state, accompanied by bubbly flow, slug flow and annular/semi-annular flow in microchannels. The micro-OHP with expanding channels possessed better thermal performance and could achieve ephemeral circulation flow, while poorer heat transfer performance occurred for the micro-OHP with straight channels due to more localized slug/plug oscillations and intermittent stopovers. The oscillating amplitudes of liquid slugs are presented to estimate the flow behavior of working fluid inside micro-OHPs. The introduction of expanding channels in a micro-OHP is beneficial for realizing the more robust oscillating motion of liquid slugs with larger oscillating amplitudes for heat transfer enhancement.
Topological Phonon Polaritons for Thermal Radiation Control
Authors: Wang B. X. , Zhao C. Y.
Published: December 2019

Topological phonon polaritons (TPhPs) are highly localized edge modes that can achieve a strong confinement of electromagnetic waves and are topologically protected to be immune to impurities and disorder. In this paper, we theoretically study the topological phonon polaritons (TPhPs) in one-dimensional (1D) dimerized silicon carbide (SiC) nanoparticle (NP) chains, as an extension of the celebrated Su-Schrieffer-Heeger (SSH) model. We analytically calculate the band structure and complex Zak phase for such chains by taking all near-field and far-field interactions into account. It is found that the 1D dimerized chain supports nontrivial topological states as long as the dimeriza-tion parameter β > 0.5 and the long-range interactions are weak, although the system is non-Hermitian. By analyzing the distribution of eigenmodes and their participation ratios (PRs), we comprehensively study the effects of disorder on the band structure and midgap modes. We reveal that such TPhPs are very robust under high-degree disorders and even enhanced by the disorder. Through a finite-size scaling analysis, we show this enhancement can be attributed to Anderson localization scheme. These topological phonon polaritonic states provide an efficient interface for thermal radiation control in the mid-infrared.
Numerical Study on Flow and Heat and Mass Transfer in Pulsating Heat Pipe
Authors: Liu Jian-Hong , Shang Fu-Min , Efimov Nikolay
Published: December 2019

Numerical simulation was performed to establishing a two-dimensional pulsating heat pipe model, to investigate the flow and heat transfer characteristics in the pulsating heat pipe by using the Mixture and Euler models, which were unsteady models of vapor-liquid two-phase, based on the control-volume numerical procedure utilizing the semi-implicit method. Through comparing and analyzing the volume fraction and velocity magnitude of gas phase to decide which model was more suitable for numerical simulation of the pulsating heat pipe in heat and mass transfer research. It was showed there had gas phase forming in stable circulation flow in the heating section, the adiabatic section using the Mixture and Euler models respectively, and they were all in a fluctuating state at 10s, besides, the pulsating heat pipe had been starting up at 1s and stabilizing at 5s, it was all found that small bubbles in the heat pipe coalescing into large bubbles and gradually forming into liquid plugs and gas columns from the contours of volume fraction of the gas phase; through comparing the contours of gas phase velocity, it could be seen that there had further stably oscillating flow and relatively stabler gas-liquid two-phase running speed in the pulsating heat pipe used the Mixture model, the result was consistent with the conclusion of the paper[11] extremely, from this it could conclude that the Mixture model could be better simulate the vaporization-condensation process in the pulsating heat pipe, which could provide an effective theoretical support for further understanding and studying the phase change heat and mass transfer mechanism of the pulsating heat pipe.
Evaluation of Existing Frictional Pressure Drop Correlations During Condensation of R410A in Four Horizontal Tubes
Authors: Shen Kunrong , Sun Zhichuan , Li Wei , Ma Xiang , He Yan , Lin Yuansheng , Ke Zhiwu , Ke Hanbing
Published: December 2019

Results are presented here from an experimental investigation on tube side condensation characteristics that took place in four tested tubes — 1EHT-1, 1EHT-2, 4LB and a smooth tube. The equivalent outer diameter of the tubes was 9.52 mm and the inner diameter was 8.32 mm. Condensation tests were conducted using refrigerant R410A at a saturation temperature of 318K, over a mass flow range of 150–450 kgm−2s−1, with inlet and outlet vapor quality of 0.8 and 0.2, respectively. Pressure drop data of the four tested tubes were collected to evaluate five identified prediction correlations based on the separated flow model and the homogeneous flow model. For 1EHT-2 and the smooth tube, all the listed correlations manage to present predictions with the Mean Absolute Relative Deviation (MARD) less than 30%, while they underestimate the frictional pressure drop of the 4LB tube with MARD exceeding 40% averagely. Regarding the experimental data, it is found that the Muller-Steinhagen and Heck correlation presents the most accurate and stable prediction for the 4 tested tubes. The listed homogeneous flow correlations can provide acceptable predictions with MARD ranging from 25% to 40% under a few conditions, but their average predictive accuracies are inferior to that of the separated flow correlations. Consequently, the separated flow approach performs better than the homogeneous flow model in the prediction of frictional pressure drop for our experimental data.
Study on Forced Convective Heat Transfer of FC-72 in Vertical Small Tubes
Authors: Li Yantao , Ji Yulong , Fukuda Katsuya , Liu Qiusheng , Ma Hongbin
Published: December 2019

In this paper, the forced convective heat transfer of FC-72 was experimentally investigated for various of parameters like velocity, inlet temperature, tube size, and exponential period of heat generation rate. Circular tubes with different inner diameters (1, 1.8 and 2.8 mm) and heated lengths (30–50 mm) were used in this study. The experiment data suggest that the single-phase heat transfer coefficient increases with increasing flow velocity as well as decreasing tube diameter and ratio of heated length to inner diameter. The experiment data were nondimensionalized to study the effect of Reynolds number (Red) on forced convection heat transfer. The results indicate that the relation between Nusselt numbers (Nud) and Red for d = 2.8 mm show the same trend as the conventional correlations. However, the Nud for d = 1 and 1. 8 mm depend on Red in a different manner. The conventional heat transfer correlations are not adequate for prediction of forced convective heat transfer in mini channels. The heat transfer correlations for FC-72 in vertical small tubes with diameters of 1, 1.8 and 2.8 mm were developed separately based on the experiment data. The differences between experimental and predicted Nud are within ±15%.
Investigation on Thermal Conductivity and Viscosity of Thin Water Film by Molecular Dynamics Simulation
Authors: Jin Lu , Zhou Leping
Published: December 2019

This work provides a molecular dynamics simulation of the thermal conductivity and viscosity of thin water film. The results show that the average normal thermal conductivity and viscosity of thin water film is about an order of magnitude lower than those of bulk water, and they increase nonlinearly with the increase of thin film thickness. However, the viscosities at different sub-layers of a thin water film are apparently different. The density profiles at different positions of the thin water films are given to indicate their influence on the normal thermal conductivity and viscosity. The large increase of the viscosity and substantial decrease of the normal thermal conductivity in the near wall region of the substrate is influenced by the structural transition of thin water film because of its high density, which has prominent impact on the mean free path at the nanoscale. It provides a viable guidance for the mechanism study on the heat and mass transfer of an evaporating thin liquid film near the triple line.