bluuebunny/crossref_metadata_2025 huggingface dataset:
Allergen‐specific IgG show distinct patterns in persistent and transient food allergy
Authors: McKendry Richard T. , Kwok Matthew , Hemmings Oliver , James Louisa K. , Santos Alexandra F.
Published: May 2021

Background

Immediate food‐allergic reactions are IgE‐mediated, but many individuals with detectable allergen‐specific IgE do not react to the food. Allergen‐specific IgG may interfere with allergen‐IgE interaction and/or through intracellular inhibitory signalling to suppress mast cell and basophil response to food allergens. We aimed to understand the role of allergen‐specific IgG in food allergy and natural tolerance.

Methods

IgG and IgG isotypes specific to peanut, cow's milk and egg were measured using ImmunoCAP and ELISA respectively in samples of children with suspected food allergies. Expression of IgE and IgG and their receptors and expression of activation markers following allergen stimulation were measured on basophils and mast cells by flow cytometry, with and without blockade of FcγRIIα or FcγRIIβ receptors.

Results

The levels of peanut‐specific IgG, IgG1, IgG2, IgG3 and IgG4 in ELISA were higher in peanut‐allergic than in non–peanut‐allergic children. No difference in allergen‐specific IgG isotypes was observed between allergic and non‐allergic children to milk or egg, except for milk‐specific IgG4 that was higher in non–cow's milk‐allergic than in cow's milk‐allergic children. Basophils and LAD2 cells expressed IgG receptors, but IgG and IgA were not detected on the surface of either cell type and blocking FcγRIIα or FcγRIIβ did not modify basophil or mast cell activation in response to allergen in allergic or tolerant children.

Conclusion

Allergen‐specific IgG patterns were distinct in persistent (peanut) versus transient (milk and egg) food allergies. We found no evidence that FcγRIIα or FcγRIIβ receptors affect allergen‐induced activation of mast cells and basophils in food allergy or natural tolerance.
Guns or Butter… or Elections? Understanding intertemporal and distributive dimensions of policy choice through the examination of budgetary tradeoffs at the local level
Authors: McGowan Mary Jo , Pope JoEllen V. , Kropf Martha E. , Mohr Zachary
Published: May 2021

The level of spending for public services is known to be influenced by spending on other services. This interdependency is known in the literature in public budgeting and finance as budgetary tradeoffs. While it is well known that spending in one area affects spending in other areas, the factors that influence budgetary tradeoff decisions are not well understood, and specifically how intertemporal evaluation of funding influences budgetary tradeoffs is not currently addressed in the public budgeting and finance literature. Building on Jacob's theory of intertemporal policy choice, we develop a tradeoff model to test the key predictions of intertemporal policy choice theory. Using data from counties in North Carolina, we find that partisanship and time horizon generally influence budgetary tradeoffs in ways that are consistent with intertemporal policy choice. This research informs the budgetary tradeoff choices that are made at the local level, and it specifically informs the unique case of election administration spending. Our findings lend theoretical support to assertions that election administration is underfunded in the United States because the budgetary tradeoff models suggest that election administration suffers from not having a natural constituency to advocate for it in county governments and because the outcomes from funding or underfunding are only observed intermittently.
CTP synthase is essential for early endosperm development by regulating nuclei spacing
Authors: Yoon Jinmi , Cho Lae‐Hyeon , Kim Sung‐Ryul , Tun Win , Peng Xin , Pasriga Richa , Moon Sunok , Hong Woo‐Jong , Ji Hyeonso , Jung Ki‐Hong , Jeon Jong‐Seong , An Gynheung
Published: May 2021

Cereal grain endosperms are an important source of human nutrition. Nuclear division in early endosperm development plays a major role in determining seed size; however, this development is not well understood. We identified the rice mutant endospermless 2 (enl2), which shows defects in the early stages of endosperm development. These phenotypes arise from mutations in OsCTPS1 that encodes a cytidine triphosphate synthase (CTPS). Both wild‐type and mutant endosperms were normal at 8 h after pollination (HAP). In contrast, at 24 HAP, enl2 endosperm had approximately 10–16 clumped nuclei while wild‐type nuclei had increased in number and migrated to the endosperm periphery. Staining of microtubules in endosperm at 24 HAP revealed that wild‐type nuclei were evenly distributed by microtubules while the enl2‐2 nuclei were tightly packed due to their reduction in microtubule association. In addition, OsCTPS1 interacts with tubulins; thus, these observations suggest that OsCTPS1 may be involved in microtubule formation. OsCTPS1 transiently formed macromolecular structures in the endosperm during early developmental stages, further supporting the idea that OsCTPS1 may function as a structural component during endosperm development. Finally, overexpression of OsCTPS1 increased seed weight by promoting endosperm nuclear division, suggesting that this trait could be used to increase grain yield.
Early application of non‐invasive ventilation for children with pulmonary edema after drowning
Authors: Şık Nihan , Şenol Hüseyin Bahadır , Çağlar Aykut , Yılmaz Durgül , Duman Murat
Published: May 2021

Background

The present study aimed to assess the efficacy of non‐invasive ventilation (NIV) on the clinical course, oxygenation, need for invasive mechanical ventilation (IMV), and outcomes for children with pulmonary edema after drowning.

Methods

We conducted a retrospective chart review. Children who were referred to the pediatric emergency department due to drowning‐related pulmonary edema and underwent NIV between May 2014 and October 2020 were included. Demographics, vital signs, clinical findings, and results of laboratory and radiologic investigations were recorded. Patients were divided into six groups using the Szpilman classification system. The need for IMV, the need for pediatric intensive care unit admission, and the length of NIV treatment and stay in the pediatric intensive care unit were recorded for each patient.

Results

Twenty‐five patients were enrolled. According to the Szpilman classification, 13 (52.0%) patients were evaluated as grade 3 and 12 (48.0%) as grade 4. All patients were treated with bi‐level positive airway pressure in the spontaneous / timed mode. A significant increase in oxygen saturation (SpO₂) and SpO₂/fraction of inspired oxygen ratios was observed from the beginning of NIV treatment and this increase was also observed for the second and fourth hours. There was a decrease in respiratory rate at the fourth hour of NIV treatment. No patient subsequently deteriorated to require IMV.

Conclusions

We have reported a favorable clinical course of drowning patients who underwent early use of NIV in the pediatric emergency department. Management of drowning patients with pulmonary edema by NIV with close follow‐up can be successfully applied in selected cases.
Factors enabling systematized national school health services in Japan
Authors: Shizume Erika , Tomokawa Sachi , Miyake Kimihiro , Asakura Takashi
Published: May 2021

Background

Japan has provided nationwide school health services since 1872. However, the system used and the factors enabling this provision have not been fully and systematically explored. This study aimed to provide an overview of the system and identify enabling factors for the provision of school health services in Japan, to support successful implementation in developing countries.

Methods

We reviewed research papers and related documents and identified factors likely to support successful provision of school health services in developing countries.

Results

The following six key factors were identified that support systematized, nationwide school health service provision in Japan: (i) existence of a legal basis for school health services provision, (ii) partnership between the education and health sectors, (iii) a systematized supervision system at all administrative levels, (iv) clear definition of essential services and stakeholders’ responsibilities, (v) utilization of skilled human resources for school health services at school level, and (vi) regular assessment of children’s health issues.

Conclusion

Five factors were proposed as essential for successful provision of school health services in developing countries: (i) formulation of national school health policies and guidelines with clear definitions of essential health services and stakeholders’ responsibilities, (ii) strengthening partnerships within and between health and education sectors at all administrative levels, (iii) building cooperation between school and health professionals and at the community and school levels, (iv) establishing sustainable development of personnel for school health in the education sector, and (v) developing systems for collecting children’s health data, assessing their health issues, and monitoring and evaluating the implementation.
Feasibility of Immunoadsorption plasmapheresis in an infant for ABO‐incompatible solid organ transplant—A reality
Authors: Gaur Saumil , Paul Partha Pratim , Motamarri Mounika , Tulla Shaik Raham
Published: May 2021

Background

Immunoadsorption (IA) plasmapheresis is standard modality for pretransplant desensitization in ABO‐incompatible solid organ transplants though technically challenging when considered for an infant or a child less than 10 kg due to non‐availability of pediatric immunoadsorption (IA) columns. The major challenge is to maintain hemodynamic stability considering the large extracorporeal circuit volume meant for adults. To our best knowledge after extensive search in acclaimed global medical journals, this is the first successful attempt in an underweight (6 kg) infant of less than 1 year of age using adult size IA Column thus making it a reality.

Case characteristics

We report an 8‐month‐old male infant (A positive) of 6 kg with decompensated liver disease secondary to extrahepatic biliary atresia requiring urgent live donor liver transplantation with AB positive donor with significantly elevated pretransplant anti‐B IgG/ IgM antibody titers >1:1024. Baby underwent multiple sessions of anti‐B immunoadsorption plasmapheresis to lower anti‐B IgM / IgG titers using available adult anti‐B immunoadsorption column. Postprocedure, the antibody titers reduced to 1:8 (anti‐IgG) 1:16 (anti‐IgM) followed by successful ABO‐incompatible live donor liver transplant (LDLT).

Outcome

Anti‐B titers remained in normal range in the immediate and post‐transplant period with satisfactory liver functions and no rejection.

Conclusion

Immunoadsorption plasmapheresis for ABO‐incompatible solid organ transplantation in infants gives desirable results and can be offered to small sized infants using currently available adult sized IA columns when conducted with adequate technical expertise.
How to Explain Major Policy Change Towards Sustainability? Bringing Together the Multiple Streams Framework and the Multilevel Perspective on Socio‐Technical Transitions to Explore the German “Energiewende”
Authors: Derwort Pim , Jager Nicolas , Newig Jens
Published: May 2021

Most efforts at explaining major policy transformation apply a single lens to study specific cases. Recent contributions have called for a more plural use of theories to facilitate the production of valuable new perspectives and research agendas. The German energy transition is a good example of such a transformative change. This article takes up the call for cross‐fertilization of theories, using two complementary lenses to explain the German energy transition: (i) applying the multiple streams framework (MSF) demonstrates how political factors and public opinion have opened a “policy window” for reform from a political dimension. (ii) The multilevel perspective on sustainability transitions (MLP) sheds more light on the importance technological innovation for transformation processes. Exemplified through the German energy transition, we highlight limitations of both lenses, as well as the value of using multiple lenses to analyze specific cases of major policy change. The MSF highlights the role of agency and power relations. The MLP demonstrates how niche‐technologies uproot the incumbent regime. Employing both lenses together offers insights as to how major policy change goes beyond single instances of decision‐making but is the product of a larger trajectory of path‐dependence that emerges from the interplay of socio‐technical and political dynamics.
Development of the Dementia Caregiver Positive Feeling Scale 21‐item version (DCPFS‐21) in Japan to recognise positive feelings about caregiving for people with dementia
Authors: Fuju Taiga , Yamagami Tetsuya , Yamaguchi Haruyasu , Yamazaki Tsuneo
Published: May 2021

Background

This study aimed to develop and validate the Dementia Caregiver Positive Feeling Scale 21‐item version (DCPFS‐21) in Japan.

Methods

We selected and generated 27 items based on the preliminary 25‐item version of the DCPFS. Next, the DCPFS‐21 was developed and validated through two phases. In Phase 1, we obtained data from 147 caregivers of people with dementia by using the 27‐item version, examined the construct validity and internal consistency of the scale and then selected 21 items (DCPFS‐21). In Phase 2, we compared the scores of 30 caregivers of people with dementia on the DCPFS‐21 with the standard scales. Four weeks after the first examination, we re‐examined the intra‐rater reliability.

Results

In Phase 1, via factor analysis, we reduced the 27 items to 21 items (DCPFS‐21). Moreover, the DCPFS‐21 was grouped into four subscales, namely, meaning in caregiving, caregiving mastery, positive emotion on caregiving and support from others. This classification agreed with the following factors extracted from the pilot study. The DCPFS‐21 showed good internal consistency (Cronbach's α = 0.92). In Phase 2, the DCPFS‐21 correlated with the Caregiving Gratification Scale by 0.54 (P < 0.01). The DCPFS‐21 also showed good intra‐rater reliability (1.1: ρ = 0.62).

Conclusion

We developed and validated the DCPFS‐21, which measures the positive feelings of family caregivers of people with dementia, in Japan.
High‐throughput sequencing reveals differential expression of miRNAs in yak and cattleyak epididymis
Authors: Wang Cailian , Hussain Solangi Tajmal , Wang Hongmei , Yang Liuyueling , Adjei Michael , Ahmed Siraj , Shahzad Khuram , Zhao Wangsheng , Lang Xia
Published: May 2021

Cattleyaks (CY) are interspecific hybrids between cattle (Bos taurus) and yak (Bos gruniens, YK) exhibiting the same prominent adaptability and higher performances than YK. The main problem of this crossbreeding is that the males are sterile. Different series of events of spermatogenesis coordinate to regulate gene expressing, involving microRNAs (miRNAs). As non‐coding ribonucleic acids (ncRNAs), miRNAs predominantly facilitate the regulation of gene expression at post‐transcriptional stages and play important roles in the acquisition and maintenance of male fertility in reproduction. The function of miRNA in the male reproductive system extends from the testis into the epididymis, regulating gene expression and contributing to regional gene expression variations. RNA sequencing on biological replicates, we described differentially expressed miRNAs profiles for tissue from epididymis of YK and CY. In the present study, High‐throughput sequencing analysis showed that 55 differentially expressed (DE) miRNAs were identified in the epididymis of YK and CY. Among these, 43 DE miRNAs were upregulated while the remaining 12 DE miRNAs were downregulated between epididymis of YK and CY. In addition, we identified that the top most important DE miRNAs, bta‐miR‐449c, bta‐miR‐539, bta‐ miR‐136, bta‐miR‐504, bta‐miR‐31 and bta‐miR‐222 were involved in the process of sperm maturation in epididymis CY. It was identified that the bta‐miR‐449c and bta‐miR‐222 may play major roles in the process of sperm maturation, sperm quality, sperm count, sperm production and male infertility of CY. Furthermore, GO and KEGG analyses were performed to classify the functions of target genes for DE miRNAs. In addition, RT‐qPCR validation of the DE miRNAs and its targeted genes revealed that putative miRNAs are involved in the male CY infertility by altering the gene expression. Present findings may not only increase our understanding of the molecular mechanisms regulated by the miRNAs in epididymis, but also provide a valuable information to understand the male infertility mechanism of CY.
Cardiovascular risks of children with primary snoring: A 5‐year follow‐up study
Authors: Au Chun Ting , Chan Kate Ching‐Ching , Chook Ping , Wing Yun Kwok , Li Albert Martin
Published: May 2021

Background and objective

This study aimed to investigate if childhood primary snoring (PS) was associated with adverse cardiovascular outcomes at 5‐year follow‐up.

Methods

This was a prospective matched cohort study. Subjects were recruited from a hospital‐based cohort established from years 2006 to 2012 and they were aged 6–18 years at baseline. Each subject with PS was gender, age and BMI z‐score matched with a control who had normal sleep study (obstructive apnoea–hypopnoea index [OAHI] < 1/h) and without habitual snoring (<3 nights/week) at baseline. All subjects underwent measurements of flow‐mediated dilation (FMD) and carotid intima‐media thickness (cIMT) and sleep study at baseline and follow‐up visits. Twenty‐four hour ambulatory blood pressure (ABP) was also recorded at follow‐up.

Results

Fifty‐five case–control pairs were recruited and the length of follow‐up was 5.1 ± 1.3 years. At follow‐up visit, subjects with PS at baseline had significantly lower FMD (−0.34% [−0.59 to −0.10]), greater cIMT (+0.01 mm [+0.001 to +0.013]), higher wake systolic blood pressure (SBP) (+2.6 mm Hg [+0.02 to +5.1]), sleep SBP (+3.0 mm Hg [+0.3 to +5.6]), sleep diastolic blood pressure (+2.2 mm Hg [+0.04 to +4.4]) and sleep mean arterial pressure (+2.2 mm Hg [+0.1 to +4.2]) compared to matched controls in the fully adjusted model for variables including change in OAHI and parental history of cardiovascular diseases.

Conclusion

Childhood PS is associated with poorer endothelial function, greater cIMT and higher ABP at 5‐year follow‐up irrespective of change in obstructive sleep apnoea severity.
A Two‐Stage Data‐Driven Spatiotemporal Analysis to Predict Failure Risk of Urban Sewer Systems Leveraging Machine Learning Algorithms
Authors: Fontecha John E. , Agarwal Puneet , Torres María N. , Mukherjee Sayanti , Walteros Jose L. , Rodríguez Juan P.
Published: May 2021

Risk‐informed asset management is key to maintaining optimal performance and efficiency of urban sewer systems. Although sewer system failures are spatiotemporal in nature, previous studies analyzed failure risk from a unidimensional aspect (either spatial or temporal), not accounting for bidimensional spatiotemporal complexities. This is owing to the insufficiency of good‐quality data, which ultimately leads to under‐/overestimation of failure risk. Here, we propose a generalized methodology/framework to facilitate a robust spatiotemporal analysis of urban sewer system failure risk, overcoming the intrinsic challenges of data imperfections—e.g., missing data, outliers, and imbalanced information. The framework includes a two‐stage data‐driven modeling technique that efficiently models the highly right‐skewed sewer system failure data to predict the failure risk, leveraging a bidimensional space‐time approach. We implemented our analysis for Bogotá, the capital city of Colombia. We train, test, and validate a battery of machine learning algorithms—logistic regression, decision trees, random forests, and XGBoost—and select the best model in terms of goodness‐of‐fit and predictive accuracy. Finally, we illustrate the applicability of the framework in planning/scheduling sewer system maintenance operations using state‐of‐the‐art optimization techniques. Our proposed framework can help stakeholders to analyze the failure‐risk models' performance under different discrimination thresholds, and provide managerial insights on the model's adequate spatial resolution and appropriateness of decentralized management for sewer system maintenance.
The Role of Regulatory Agencies in Agenda‐Setting Processes: Insights from the Italian Response to the COVID‐19 Infodemic
Authors: Di Mascio Fabrizio , Natalini Alessandro , Barbieri Michele , Selva Donatella
Published: May 2021

International organizations such as the WHO have worked to raise awareness of the massive infodemic that accompanied the COVID‐19 outbreak and made it hard for people to find trustworthy sources of information and reliable guidance for their decisions. Our contribution focuses on the Italian case, where the Communications Regulatory Authority (AGCOM) was able to act as first mover in its field so as to strategically frame the problem of disinformation in the absence of a pre‐existing policy intervention. An emerging body of research shows that the activity of formally independent regulators is not necessarily limited to the implementation of delegated regulatory competencies. We discuss the implications of the activity of independent regulators for the fight against disinformation during the COVID‐19 pandemic. We find that as a political actor in its own right, the Italian media regulator claimed control over sectoral expertise in order to shape the crucial first steps of the response to the infodemic.
Tacrolimus exposure windows responsible for Listeria monocytogenes infection susceptibility
Authors: Miller‐Handley Hilary , Erickson John J. , Gregory Emily J. , Prasanphanich Nina Salinger , Shao Tzu‐Yu , Way Sing Sing
Published: May 2021

Tacrolimus is widely used to prevent graft rejection after allogeneic transplantation by suppressing T cells in a non‐antigen‐specific fashion. Global T‐cell suppression makes transplant recipients more susceptible to infection, especially infection by opportunistic intracellular pathogens. Infection followed by secondary challenge with the opportunistic intracellular bacterial pathogen, Listeria monocytogenes, was used to probe when tacrolimus most significantly impacts antimicrobial host defense. Tacrolimus‐treated mice showed no difference in innate susceptibility following primary infection, whereas susceptibility to secondary challenge was significantly increased. Modifying the timing of tacrolimus initiation with respect to primary infection compared with secondary challenge showed significantly reduced susceptibility in tacrolimus‐treated mice where tacrolimus was discontinued prior to secondary challenge. Thus, tacrolimus overrides protection against secondary infection primed by primary infection (and presumably live attenuated vaccines), with the most critical window for tacrolimus‐induced infection susceptibility being exposure immediately prior to secondary challenge. These results have important implications for strategies designed to boost antimicrobial T‐cell‐mediated immunity in transplant recipients.
Bacterial protease activity as a biomarker to assess the risk of non‐healing in chronic wounds: Results from a multicentre prospective cohort clinical trial
Authors: Serena Thomas E. , Bayliff Simon W. , Brosnan Patrick J. , DiMarco Daniel T. , Doner Bryan A. , Guthrie David A. , Patel Keyur D. , Sabo Matthew J. , Samies John H. , Carter Marissa J.
Published: May 2021

Millions worldwide suffer from chronic wounds challenging clinicians and burdening healthcare systems. Bacteria impede wound healing; however, the diagnosis of excessive bacterial burden or infection is elusive. Clinical signs and symptoms of infection are inaccurate and unreliable. This trial evaluated a novel, point‐of‐care, lateral flow diagnostic designed to detect virulence factors released by the most common bacteria found in chronic wounds. A multicentre prospective cohort clinical trial examined the efficacy of a diagnostic test in detecting bacterial proteases taken from swab samples of chronic venous, arterial, pressure and mixed aetiology chronic wounds. Two hundred and sixty six wounds were included in the analysis of the study. The wounds were tested at the start of the study after which investigators were permitted to use whatever dressings they desired for the next 12 weeks. Healing status at 12 weeks was assessed. The presence of elevated bacterial protease activity decreased the probability of wound healing at 12 weeks. In contrast, a greater proportion of wounds were healed at 12 weeks if they had little or no bacterial protease activity at study start. In addition, the presence of elevated bacterial protease activity increased the time it takes for a wound to heal and increased the risk that a wound would not heal, when compared to the absence of bacterial protease activity. The results of this clinical trial indicate that bacterial protease activity, as detected by this novel diagnostic test, is a valid clinical marker for chronicity in wounds. The diagnostic test offers a tool for clinicians to detect clinically significant bacteria in real time and manage bacteria load before the clinical signs and symptoms of infection are evident.
Effectiveness of exercise interventions to prevent shoulder injuries in athletes: a systematic review protocol
Authors: Swart Johannes Jacobus Wessel , Olivier Benita
Published: May 2021

Objective:

This review will evaluate the effectiveness of exercise intervention versus no intervention or alternate intervention to prevent shoulder injuries in athletes.

Introduction:

Injury-prevention research has proven the effectiveness of exercise in preventing sports injuries in general and in the lower limb specifically. However, the results have been extrapolated to sport-related shoulder injuries from limited evidence. Similar reviews have been faced with insufficient high-quality evidence and limited studies due to restrictive target populations, resulting in reduced generalizability.

Inclusion criteria:

Peer-reviewed randomized controlled trials, with adequate control arms, investigating shoulder-injury events after exercise intervention in athletes, both training or competing in sports, will be included. Studies with substitute end points for injury events and non-self-propelled athletes, or vehicle-assisted athletes, will be excluded.

Methods:

A comprehensive search of multiple databases will be used to find relevant studies. The databases will be searched from inception to April 2021, with no language restrictions imposed. Keywords and derivatives of “sport,” “exercise intervention,” “prevention,” “shoulder injury,” and “randomized controlled trials” will be used.

Sources will include Academic Search Ultimate (EBSCO), CINAHL Plus (EBSCO), Cochrane Central Register of Controlled Trials (Wiley), MasterFILE Premier (EBSCO), MEDLINE (PubMed), Physiotherapy Evidence Database (PEDro), ProQuest Health and Medical Complete and Nursing and Allied Health Source (ProQuest Complete), ScienceDirect (Elsevier), Scopus (Elsevier), SPORTDiscus (EBSCO), and Web of Science (Clarivate Analytics). Data appraisal, extraction, and synthesis will follow JBI guidance for systematic reviews of effectiveness.

Systematic review registration number:

PROSPERO CRD42020204141
Damping Characteristics of Fluidic Pressure-Fed Mechanism for Positioning Applications
Authors: Chun Heebum , Kim Jungsub , Kim Hyo-Young , Lee ChaBum
Published: May 2021

This paper represents a novel approach capable of in-process damping parameter control for nanopositioning systems by implementing a fluidic pressure-fed mechanism (FPFM). The designed internal fluidic channels inside the nanopositioning stage fabricated by a metal additive manufacturing process can be filled with various fluids such as air, water, and oil and pneumatically or hydraulically pressurized. The damping was experimentally characterized with respect to fluids and corresponding pressure level (80 psi, which was the maximum safe operating pressure in the current laboratory setting) through a free-vibration test, hammering test, and sine input sweeping test in open-loop and closed-loop positioning control conditions. As a result, the FPFM revealed the following characteristics: (1) damping increases when the internal fluidic channels filled with fluids and pressure level at 80 psi, (2) the dynamic system showed the highest damping when the water exists in internal channels, and (3) the existence of fluids and certain pressure in the fluidic channel does not have a negative influence on the motion quality and positioning control while the nanopositioning system is in operating. Additionally, the tracking error was reduced by FPFM. It is expected that the FPFM method will be utilized for vibration and noise control applications for high precision dynamic systems.
Mechanical Impact Effects of Fluid Hammer Effects on Drag Reduction of Coiled Tubing
Authors: Liu Yongsheng , Qin Xing , Sun Yuchen , Dou Zijun , Zhang Jiansong , Chen Guoqiang
Published: May 2021

Aiming at the oscillation drag reduction tool that improves the extension limit of coiled tubing downhole operations, the fluid hammer equation of the oscillation drag reducer is established based on the fluid hammer effect. The fluid hammer equation is solved by the asymptotic method, and the distribution of fluid pressure and flow velocity in coiled tubing with oscillation drag reducers is obtained. At the same time, the axial force and radial force of the coiled tubing caused by the fluid hammer oscillator are calculated according to the momentum theorem. The radial force will change the normal contact force of the coiled tubing, which has a great influence on frictional drag. The results show that the fluid flowrate and pressure decrease stepwise from the oscillator position to the wellhead position, and the fluid flowrate and pressure will change abruptly during each valve opening and closing time. When the fluid passes through the oscillator, the unit mass fluid will generate an instantaneous axial tension due to the change in the fluid velocity, thereby converting the static friction into dynamic friction, which is conducive to the extend limit of coiled tubing.
Investigation of Tire Rotating Modeling Techniques Using Computational Fluid Dynamics
Authors: Fu Gen , Untaroiu Alexandrina
Published: May 2021

Fuel efficiency becomes very important for new vehicles. Therefore, improving the aerodynamics of tires has started to receive increasing interest. While the experimental approaches are time consuming and costly, numerical methods have been employed to investigate the air flow around tires. Rotating boundary and contact patch are important challenges in the modeling of tire aerodynamics. Therefore, majority of the current modelling approaches are simplified by neglecting the tire deformation and contact patch. In this study, a baseline CFD model is created for a tire with contact patch. To generate mesh efficiently, a hybrid mesh, which combines hex elements and polyhedral elements, is used. Then, three modeling approaches (rotating wall, multiple reference frame and sliding mesh) are compared for the modeling of tire rotation. Additionally, three different tire designs are investigated, including smooth tire, grooved tire and grooved tire with open rim. The predicted results of the baseline model agree well with the measured data. Additionally, the hybrid mesh show to be efficient and to generate accurate results. The CFD model tends to over predict the drag of a rotating tire with contact patch. Sliding mesh approach generated more accurate predictions than the rotating wall and multiple reference frame approaches. For different tire designs, tire with open rim has the highest drag. It is believed that the methodology presented in this study will help in designing new tires with high aerodynamic performance.
Vortex Pump as Turbine for Energy Recovery in Viscous Fluid Flows With Reynolds Number Effect
Authors: Li Wenguang
Published: May 2021

A vortex pump with a specific speed of 76 was studied in its turbine mode by using fluent 6.3 based on the steady, three-dimensional, incompressible, Reynolds time-averaged Navier–Stokes equations, standard k-ε turbulence model, and nonequilibrium wall function in multiple reference frame system. The performance and flow structure of six liquids with different densities and viscosities were characterized, and the hydraulic, volumetric, and mechanical losses were discomposed. The correction factors of flow rate, head, shaft-power, efficiency, and disk friction power in turbine mode were correlated with impeller Reynolds number at three operational points. The conversion factors of flow rate, head, efficiency from the pump mode to the turbine mode were expressed with Reynolds number and compared with the counterparts of centrifugal pumps in the literature. It was indicated that the vortex pump can produce power as a turbine but becomes inefficient with increasing viscosity or decreasing impeller Reynolds number, especially as the number is smaller than 104 due to increased hydraulic, volumetric, and mechanical power losses. A vortex structure with radial, axial, and meridian vortices occurs in the impeller at different flow rates and viscosities. The incidence at blade leading edge and deviation angle at the blade trailing edge depend largely on flow rate and viscosity. The impeller should be modified to improve its hydraulic performance under highly viscous fluid flow conditions. The entropy generation rate method cannot demonstrate the change in hydraulic loss with viscosity when the Reynolds number is below 104.
Use of Perforation and Mathematical Modeling to Increase Solar-Based Steam Distillation System Efficiency
Authors: Afzal Arslan , Munir Anjum , Amjad Waseem , Alvarado Jorge L. , Umair Muhammad , Azam Muhammad , Anjum Muhammad Naveed
Published: May 2021

Solar distillation system has recently been explored and used for the extraction of essential oil from different agricultural herbs. The efficiency of conventional distillation systems is low, and most are driven by hot gases. On the other hand, the solar-driven distillation system has higher efficiency and is based on renewable energy. The modified solar distillation system comprises a Scheffler reflector “concentrator,” newly design steam receiver, distillation still, steam condenser, florentine flask, and biomass-based boiler. A perforated circular pan added at the still bottom and pattern of steam flow and temperature distribution was examined using the computational fluid dynamics (CFD) technique. The CFD simulation results showed that homogeneity in the steam distribution in the distillation still is required to get maximum essential oil extraction efficiency. The energy dissemination at different parts of the newly design solar distillation system was estimated using mathematical modeling. The results of different experiments showed that the yield of essential oils from fresh Rosemary and Cumin was 0.17% w/w and 1.11% w/w, respectively. The efficiency of the modified solar distillation system with a perforated pan and steam receiver was found to be 8% higher than the previous system.
Multifractality and Universality of Thermal Fluctuations in Terrestrial and Microgravity Pool Boiling
Authors: Saini Ankit , Srinivasan Vinod
Published: May 2021

Nucleation site interaction in pool boiling is well known to cause intermittent bubble growth and departure. Such interactions can cause long-term temporal correlations in spatio-temporal fluctuations of temperature and heat flux and may affect the conditions leading to the onset of boiling crisis. In this study, we check for the presence of such long-term correlations. A multifractal analysis is carried out on heat flux fluctuations recorded in pool boiling experiments under terrestrial and microgravity conditions. The Hurst exponent is shown to progressively decrease as the wall temperature is increased, attaining a value close to 0.5 near the onset of boiling crisis. This trend persists for multiple pressures and levels of bulk subcooling and may serve as an indicator of proximity to the boiling crisis. Similar experiments performed with an identical setup under terrestrial gravity conditions are shown to exhibit similar trends.
Previously Uncharacterized Mycoplasma Isolates from an Investigation of Canine Pneumonia
Authors: Armstrong D. , Tully J. G. , Yu B. , Morton V. , Friedman M. H. , Steger L.
Published: May 2021

Mycoplasmas recovered from the respiratory tract and genitourinary system of dogs, with and without respiratory infection, have been characterized by biological and immunological methods. Some of the isolates were indentified as being similar to the three species of canine mycoplasmas described earlier under the designation
Mycoplasma spumans, M. canis
, and
M. maculosum
. Other mycoplasmas placed in three groups (A, C, and D) were found to be clearly distinct from the three classified species. Group A strains fermented glucose but not mannose and were serologically distinct from other canine mycoplasmas recovered in this study. These strains were subsequently found to be biologically and serologically related to a previously reported, but unclassified, canine mycoplasma. Group D strains differed in some biological properties but were serologically related. These were found to be nonfermenting mycoplasmas representing isolations from the throat and bladder of dogs. They were serologically distinct from other canine mycoplasmas and were apparently unrelated to other known mycoplasma serotypes. Group C mycoplasmas were recovered only from the lungs of dogs. Within the group, they differ in some immunological properties but appear to be serologically distinct from other canine strains. They can also be separated from other dog strains in their ability to ferment glucose and mannose. Group B strains were found to have biological properties similar to
M. canis
strains but seemed to be only partially related to this serotype when examined in several serological techniques. It is suggested that these strains might represent antigenic variants of
M. canis
.
Enzymatic Adenylylation of Streptomycin and Spectinomycin by R-Factor-Resistant
Escherichia coli
Authors: Benveniste R. , Yamada T. , Davies J.
Published: May 2021

A resistance (R) factor- containing strain of
Escherichia coli
which is known to inactivate streptomycin by adenylylation has been shown to be spectinomycin resistant. An osmotic shockate of this strain catalyzes the formation of the biologically inactive spectinomycin adenylate, in which the adenylyl residue is probably attached to a
d
-
threo
methylamino alcohol moiety of spectinomycin. Both the streptomycin and spectinomycin adenylylating activities show the same temperature inactivation profile, and both are present in a protein fraction purified for the streptomycin inactivating enzyme. Mutants obtained from this strain which were sensitive to either spectinomycin or streptomycin were shown to lack both enzymatic activities when tested in vitro. Revertants of these mutants selected for recovery of either streptomycin resistance or spectinomycin resistance regain both activities. Therefore, we conclude that the inactivation of the two drugs is catalyzed by the same enzyme. Examination of a number of R factor-carrying strains has shown that those strains which are resistant to streptomycin and spectinomycin contain the adenylylating enzyme, whereas strains resistant to streptomycin but sensitive to spectinomycin inactivate streptomycin by phosphorylation.
Hybridization by Deoxycholate Treatment or by Biological Degradation of Bacterial Endotoxins Extracted from Smooth and Rough Strains
Authors: Chedid L. , Parant M. , Parant F. , Peroux F. , Perez J. J.
Published: May 2021

An endotoxin extracted with phenol-water from a rough microorganism (
Salmonella typhi
strain R
2
) was hybridized with an endotoxin obtained by the Boivin technique from a smooth strain (
S. enteritidis
Danysz) when they were mixed in the presence of sodium deoxycholate. These two toxic antigens could also be hybridized by incubation in citrated serum. With this new composite molecule, the presence of the hydrophilic side chains on the smooth moiety influenced the electrophoretic migration of the R antigen and greatly hindered the reactivity of the R sites with their specific antibodies.
A
Chlamydia
from the Peritoneal Cavity of Mice
Authors: Gerloff Robert K. , Watson Rex O.
Published: May 2021

During continuous intraperitoneal passage of liver and spleen suspension in normal stock mice, a syndrome developed which involved ascites and certain other visceral changes but seldom clinical illness and never fatality. From these mice, a chlamydia was established in yolk sacs of chick embryos and in tissue cultures. This agent readily infects mice when inoculated intranasally but is without effect intracerebrally. It has very low pathogenicity for guinea pigs and is resistant to sodium sulfadiazine. These characteristics, together with results of serum neutralization tests, indicate that the agent is different from the Nigg and DeBurgh strains of mouse pneumonitis.
Purification and Characterization of Two Proteins from Culture Filtrates of
Mycobacterium tuberculosis
H
37
Ra Strain
Authors: Daniel Thomas M. , Ferguson Lavenia E.
Published: May 2021

Two proteins have been purified from culture filtrates of
Mycobacterium tuberculosis
, H
37
Ra strain by a procedure combining gel filtration, diethylaminoethyl (DEAE)-cellulose chromatography, and zone electrophoresis. The two proteins are similar in molecular weight but differ slightly in charge. The faster migrating protein, designated a
1
, is not antigenic. The slower migrating protein, designated a
2
, is antigenic both with respect to antisera and as a skin-testing antigen.
Mechanisms of Pathogenesis in
Listeria monocytogenes
Infection IV. Hepatic Carbohydrate Metabolism and Function in Experimental Listeriosis
Authors: McCallum R. E. , Sword C. P.
Published: May 2021

Previous reports have shown alterations in carbohydrate metabolism in mice infected with
Listeria monocytogenes
. This study was undertaken to elucidate mechanisms involved in these changes. Female CD-1 mice were injected intraperitoneally with 10
6
L. monocytogenes
strain A4413. Animals were fasted 12 hr prior to infection, and pooled tissue from several mice was observed at intervals after infection. Blood glucose, liver glucose, and liver glycogen decreased within 10 hr after infection. Sustained treatment with gluconeogenic precursors, including glucose-6-phosphate, fructose-1, 6-biphosphate, phosphoenolpyruvate, α-glycerophosphate, pyruvate, and amino acids, did not restore and maintain glucose and glycogen at normal levels and did not affect survival. Administration of hydrocortisone induced restoration of liver glycogen early in the infection but did not maintain normal levels as the infection progressed. Activities of succinic dehydrogenase and cytochrome oxidase in liver homogenates from infected mice were elevated as early as 10 hr after infection. Liver function tests using rose bengal sodium-
131
I showed no significant differences in plasma clearance or liver uptake between normal and infected mice except in terminal infections (60 hr after infection).
Intestinal Strangulation in
Escherichia coli
-Monocontaminated Gnotobiotic Rats
Authors: Yale Charles E. , Vivek Alapakkam R.
Published: May 2021

The natural course of ischemic and hemorrhagic intestinal strangulation in previously germ-free rats individually monocontaminated with one of five separate strains of
Escherichia coli
was investigated. In addition, the effect of intraintestinal homologous heparinized blood upon the course of ischemic intestinal strangulation in
E. coli
-monocontaminated rats was studied. It was found that (i)
E. coli
could be an important lethal factor in ischemic and hemorrhagic intestinal strangulation, (ii) hemorrhagic was more deadly than ischemic strangulation, (iii) intra-intestinal blood did not augment the action of the
E. coli
in these experiments, and (iv) some strains of
E. coli
were more toxic than others in the presence of intestinal strangulation.
Mutation of
Listeria monocytogenes
After Prolonged In Vivo Survival in Diffusion Chambers
Authors: Osebold John W. , Outteridge P. M. , Pearson L. D.
Published: May 2021

Listeria monocytogenes
remained viable when confined in diffusion chambers in the peritoneal cavities of mice. Bacterial survival was associated with mutations.
Antibody Response to Bacterial Antigens: Characteristics of Antibody Response to Somatic Antigens of
Salmonella typhimurium
Authors: Fukazawa Y. , Shinoda T. , Yomoda T. , Tsuchiya T.
Published: May 2021

The character of the antibody response in the rabbit to
Salmonella typhimurium
somatic (O) antigen was similar to the response to each of several serotypes of
Shigella flexneri
O antigens, namely a predominance of production of immunoglobulin M (IgM) antibody. Lipopolysaccharide protein (LPSP) and lipopolysaccharide (LPS) fractions of
Salmonella
O antigen differed significantly in both quantitative and qualitative aspects of their immunogenicity. LPSP elicited high levels of agglutinins and also induced the production of a significant amount of immunoglobulin G (IgG) antibody at a late period. LPS antigen elicited low levels of agglutinins which were exclusively IgM antibody. These results suggested that the chemical nature of the antigen is one important factor in the determination of the character of the antibody response. Further, it is suggested that the protein moiety of the O antigen complex is a carrier active in allowing induction of early IgM and of late IgG antibodies; in contrast, the lipid moiety may compete with this action of the carrier protein, thereby suppressing IgG antibody in the primary stage of the antibody-forming process.
Oral Immunization Against Experimental Salmonellosis I. Development of Temperature-Sensitive Mutant Vaccines
Authors: Fahey K. J. , Cooper G. N.
Published: May 2021

Mutant strains of
Salmonella enteritidis
were selected for their inability to proliferate at 37 C; when exposed to this temperature, these organisms formed tangled masses of long filaments in liquid media, presumably as a result of their inability to form cross septa. The mutants were also incapable of synthesizing flagella protein. A study of the biological charateristics of the mutants indicated that in most respects they resembled the parent strain of
S. enteritidis
; however, they were avirulent for mice, presumably because of the restriction of growth imposed by the body temperature of the animal. Preliminary studies have suggested that these mutants are highly effective in inducing protection against severe challenge infections of
S. enteritidis
; of especial interest is the fact that, when given orally, the mutants conferred a substantial degree of protection against oral infection with the virulent strain.
Neuraminidase of
Pasteurella multocida
Authors: Scharmann Wolfgang , Drzeniek Rudolf , Blobel Hans
Published: May 2021

We found that 102 of 104 strains of
Pasteurella multocida
and 3 of 5 strains of
P. hemolytica
produced neuraminidase.
The Impact of Experiential Learning in Host-Pathogen Research on Medical Students’ Interests and Attitudes towards Microbiology and Immunology
Authors: Cervantes Jorge , Hong Bo-Young
Published: May 2021

There is a shortage of residents in the infectious diseases (IDs) specialty due to a lack of interest in this field. If the choice of an ID subspecialty is linked to medical school experiences, then how we teach microbiology and immunology could be a factor in the declining interest in the field.
Competence-Associated Peptide BriC Alters Fatty Acid Biosynthesis in Streptococcus pneumoniae
Authors: Aggarwal Surya D. , Gullett Jessica M. , Fedder Tara , Safi J. Pedro F. , Rock Charles O. , Hiller N. Luisa
Published: May 2021

Adaptation of bacteria to their host environment is a key component of colonization and pathogenesis. As an essential component of bacterial membranes, fatty acid composition contributes to host adaptation.