bluuebunny/crossref_metadata_2025 huggingface dataset:
Blood thiamine (vitaminB1), ascorbic acid (vitamin C), and cortisol concentrations in healthy and ill neonatal foals
Authors: Wong David M. , Young Lauren , Dembek Katarzyna A.
Published: May 2021

Background

Sepsis is common in foals and several treatments are used to facilitate recovery. Evidence in people suggests an association between low blood concentrations of thiamine, ascorbic acid, and cortisol and sepsis, with further evidence suggesting that administration of hydrocortisone, thiamine, and ascorbic acid may improve outcome. No information is available with regard to these treatments in foals.

Hypothesis/Objectives

To compare blood concentrations of thiamine, ascorbic acid, and cortisol in healthy and ill foals.

Animals

Fifteen healthy and 27 ill (septic and sick‐nonseptic [SNS]) foals were evaluated at admission. Fewer healthy and ill foals were available for sampling at 72 and 120 hours.

Methods

Prospective study. Blood was collected from healthy foals at 12 (n = 15), 72 (n = 11), and 120 (n = 9) hours of age and from ill foals <48 hours old at admission (n = 27), 72 (n = 8), and 120 (n = 8) hours after presentation. Thiamine, ascorbic acid, and cortisol concentrations were measured in blood samples and compared between groups of foals.

Results

Blood concentrations of thiamine were significantly lower in septic compared to healthy foals at 72 (median, 1.72 ng/mL;P= .02) and 120 (median, 2.0 ng/mL;P = .04) hours after admission; blood concentrations of ascorbic acid also were significantly lower in septic compared to healthy foals at 72 (median, 4.4 μg/mL;P = .02) and 120 hours (median, 4.8 μg/mL;P = .03). Blood concentrations of ascorbic acid were lower in SNS compared to healthy foals at 72 (median, 6.9 μg/mL;P = .03) and 120 (median, 6.4 μg/mL;P = .04) hours after admission. Serum cortisol concentrations were significantly higher at admission in septic (median, 4.23 μg/dL) compared to SNS (median, 1.8 μg/dL;P = .01) and healthy (median, 2.2 μg/dL;P = .002) foals.

Conclusions and Clinical Importance

A potential association exists between illness in foals and lower blood concentrations of thiamine and ascorbic acid during hospitalization. Additional studies are needed to examine a larger population of foals and determine the clinical impact of low vitamin concentrations, if any, on morbidity and mortality.
Recent research progress on the role of ulinastatin in chronic kidney disease
Authors: Wei Xuejiao , Zhu Xiaoyu , Jiang Lili , Long Mengtuan , Du Yujun
Published: May 2021

With the continuous improvement in living standards, lifestyle changes and ageing of the population, the prevalence of chronic kidney disease (CKD) has increased significantly, and its prevention and treatment have become important public health issues worldwide. Renal fibrosis is the main pathological basis of CKD progression to end‐stage renal disease. Preventing the progression of renal fibrosis has always been the focus of clinical and scientific research. Ulinastatin is a serine protease inhibitor that is found in human blood and urine and inhibits the inflammatory response, regulates immunity and improves the microcirculation. It is widely used in patients with sepsis and septic shock in clinical practice. Recent studies have shown that ulinastatin can also play an important anti‐fibrotic and organ protective role and can provide a new therapeutic hope for CKD patients. This review mainly introduced the research progress of UTI in inflammation, oxidative stress, apoptosis, acute kidney injury and renal fibrosis. By investigating the role of ulinastatin in CKD, we can determine the possible mechanisms for its renal protection and improvement of renal fibrosis, so as to provide new ideas for the treatment of CKD.
Light fuels while nitrogen suppresses symbiotic nitrogen fixation hotspots in neotropical canopy gap seedlings
Authors: McCulloch Lindsay A. , Porder Stephen
Published: May 2021

Mature neotropical lowland forests have relatively lower symbiotic nitrogen fixation (SNF) rates compared with secondary forests. Canopy gap formation may create transient SNF hotspots in mature forests that increase overall SNF rates in these ecosystems, as canopy gaps are pervasive across the landscape and increasing in frequency. However, what environmental conditions are driving SNF upregulation in canopy gaps is unknown.

In a field experiment to test these potential environmental controls on SNF, we grew 540 neotropical nitrogen‐fixing legume seedlings (Pentaclethra macroloba, Zygia longifolia, and Stryphnodendron microstachyum) under manipulated light and soil nitrogen availability in canopy gaps and intact forests at La Selva Biological Station, Costa Rica.

Seedling biomass, nodule biomass, and SNF (g N seedling−1 h−1) were 4‐, 17‐ and 42‐fold higher, respectively, in canopy gaps than in the intact forest. Nitrogen additions decreased SNF, but light had a stronger positive effect. Upregulation of SNF in canopy gaps was driven by increased plant growth and not a disproportionate increased SNF allocation.

These data provide evidence that canopy gap SNF hotspots are driven, in part, by light availability, demonstrating a potential driver of SNF spatial heterogeneity. This further suggests that canopy gap dynamics are important for understanding the biogeochemistry of neotropical forests.
Linguistic meanings as cognitive instructions
Authors: Knowlton Tyler , Hunter Tim , Odic Darko , Wellwood Alexis , Halberda Justin , Pietroski Paul , Lidz Jeffrey
Published: May 2021

Natural languages like English connect pronunciations with meanings. Linguistic pronunciations can be described in ways that relate them to our motor system (e.g., to the movement of our lips and tongue). But how do linguistic meanings relate to our nonlinguistic cognitive systems? As a case study, we defend an explicit proposal about the meaning of most by comparing it to the closely related more: whereas more expresses a comparison between two independent subsets, most expresses a subset–superset comparison. Six experiments with adults and children demonstrate that these subtle differences between their meanings influence how participants organize and interrogate their visual world. In otherwise identical situations, changing the word from most to more affects preferences for picture–sentence matching (experiments 1–2), scene creation (experiments 3–4), memory for visual features (experiment 5), and accuracy on speeded truth judgments (experiment 6). These effects support the idea that the meanings of more and most are mental representations that provide detailed instructions to conceptual systems.
The utility of native ureter in the management of ureteral complications in children after renal transplantation
Authors: Serrell Emily C. , Su Ruthie , O'Kelly Fardod , Semanik Michael , Farhat Walid A.
Published: May 2021

Background

Ureteral complications after renal transplantation in children are a major source of morbidity. Management is complex and variable.

Methods

With IRB approval, health records were retrospectively reviewed of patients who: were <18 years, underwent kidney transplant between 1997 and 2017, had at least 2 years of follow‐up, and underwent interventions due to post‐transplant ureteral complications.

Results

Of 136 patients, seventeen (13%) required ureteral intervention due to stricture (n = 3), reflux (n = 12), or both (n = 2). Transplant occurred at median 10.5 years (3.1–14.7). Reconstruction occurred at median 10 months (7–15) after transplant. Pre‐existing bladder pathology was present in 6 (35%) patients. Four of five patients with strictures had at least one endoscopic balloon dilation. Ultimate management included reimplantation, ureteroureterostomy of native to transplant ureter, pyeloureterostomy to native ureter, multiple endoscopic interventions followed by a Boari flap, or multiple failed endoscopic interventions. Fourteen patients with VUR underwent reimplantation (n = 5), ureteroureterostomy of native to transplant ureter (n = 4), pyeloureterostomy to native ureter (n = 4), and one underwent endoscopic injection with Deflux of the transplant ureter. Only one patient had a non‐functioning graft due to ureteral complication. All patients were alive at follow‐up (median 17 years [12–19]).

Conclusions

Transplant ureteral reflux and stricture are significant complications following pediatric renal transplantation and may require surgical management. In our population, reflux or stricture requiring ureteral reconstruction occurred in 10% and 4%, respectively. Endoscopic interventions were rarely successful. Native ureters were used for ureteral reconstruction in more than two thirds of patients should be considered in management of ureteral complications.
Does CSR Reduce Idiosyncratic Risk? Roles of Operational Efficiency and AI Innovation
Authors: Li Guo , Li Na , Sethi Suresh P.
Published: May 2021

In the context of Industry 4.0, corporate social responsibility (CSR) plays an increasingly important role in firm risk management. To mitigate risk and improve operational productivity, artificial intelligence (AI), a key disruptive technology, has been increasingly employed in many industries. In this study, we examine the relationship between CSR and idiosyncratic risk (IR) as moderated by AI innovation and operational efficiency based on data from 1614 firms in China during the period from 2010 to 2017. The empirical results show that CSR can negatively affect IR, while beyond a certain level, it acts in the opposite direction, exhibiting a U‐shaped relationship. In particular, operational efficiency shifts the turning point of the U‐shaped curve to the right, implying that firms with high operational efficiency can obtain a higher optimal benefit by improving their CSR. Furthermore, AI innovation flattens the U‐shaped curve, thereby weakening CSR's positive impact on IR. This result indicates that AI innovation is not always beneficial. As AI innovation can have some substitution effect on CSR, enterprises should focus on either CSR or AI innovation as their main differentiation strategy to maximize the utilization of resources. We further instrument CSR using the social expenditure ratio of the province where the firm is headquartered to address a potential endogeneity concern. Finally, we provide several prominent managerial implications for enterprises, governments, and investors.
Does the Sharing Economy Technology Disrupt Incumbents? Exploring the Influences of Mobile Digital Freight Matching Platforms on Road Freight Logistics Firms
Authors: Zhou Zenan , Wan Xiang
Published: May 2021

In this paper, we study the disruptive power of the mobile digital sharing economy to the road freight logistics industry. New information technologies, such as the mobile internet, mobile payment methods, and GPS, have enabled platforms to match freight shippers’ demand with carriers’ supply by utilizing the convenience and mobility of smartphones. We empirically study the influence of the emergence of mobile digital freight matching platforms in the U.S. on the profitability and stock performance of two types of incumbent road freight logistics companies: freight arrangement companies (freight forwarders and brokers) and trucking companies (freight carriers). Since the mobile digital freight matching platforms mainly match small and mid‐sized trucking companies with shipping demand, we expect the platforms to introduce interference (direct) competition to traditional freight arrangement companies and exploitation (indirect) competition to large trucking companies, which potentially raises operational challenges for both types of incumbents. We use Difference‐in‐Differences (DID) analyses to study the incumbents’ profitability and the event study method to evaluate their stock performance. We find that after the advent of the mobile digital freight matching platforms in the U.S., the profitability of the traditional freight arrangement companies counter‐intuitively remained unchanged. In contrast, the profitability of the large trucking companies increased. Furthermore, we examine the changes in sales and costs behind these profitability changes. Our dynamic analyses suggest a time lag of the influence of the mobile digital freight matching platforms. Besides, we find that the stock value of the traditional freight arrangement companies received a significant negative shock, whereas the stock value of the large trucking companies showed no significant reaction. This study contributes to understanding the disruptive power of an emerging technology innovation of sharing economy to firm performances in an increasingly competitive and innovative business environment.
The hydrophobicity of mutations targeting D1:Val219 modifies formate and diuron binding in the quinone‐Fe‐acceptor complex of Photosystem II
Authors: Forsman Jack A. , Eaton‐Rye Julian J.
Published: May 2021

The D1:Val219 residue of Photosystem II in the cyanobacteriumSynechocystissp. PCC 6803 was mutated to alanine or isoleucine, creating the V219A and V219I mutants, respectively. Oxygen evolution was slowed in these mutants, while chlorophyllafluorescence induction assays indicated slowed electron transfer. As previously observed [Erickson J.M., Rahire, M., Rochaix, J.‐D. and Mets. L. (1985)Science, 228, 204–207], the V219I mutant was resistant to 3,4‐dichloro‐1,1‐dimethyl urea (DCMU); however, the V219A strain displayed no DCMU resistance. Additionally, the V219A strain was less sensitive to the addition of formate than the control, while the V219I strain was more sensitive to formate. Both mutant strains were susceptible to photodamage and required protein synthesis for recovery. We hypothesize that the sensitivity to DCMU and the extent of bicarbonate‐reversible formate‐induced inhibition, as well as the capacity for recovery in cells following photodamage, are influenced by the hydrophobicity of the environment associated with the Val219 residue in D1.
Return to work after coronary artery bypass grafting and aortic valve replacement surgery: A scoping review
Authors: Mortensen Michael , Sandvik Reidun K. N. M. , Svendsen Øyvind S. , Haaverstad Rune , Moi Asgjerd L.
Published: May 2021

Background

Coronary artery bypass grafting surgery and aortic valve replacement surgery are essential treatment options for people suffering from angina pectoris or aortic valve disease. Surgery aims to prolong life expectancy, improve quality of life, and facilitate participation in society for the individuals afflicted. The aim of this review was to explore the literature on work participation in patients following coronary artery bypass grafting or aortic valve replacement surgery, and to identify demographic and clinical characteristics associated with returning to work.

Methods

A scoping review framework of Arksey and O'Malley was chosen. Four electronic databases: Medline, CINAHL, Embase, and Google Scholar were searched for studies in English, Swedish, Danish or Norwegian between January 1988 and January 2020. A blinded selection of articles was performed. The data were then charted and summarized by descriptive numerical analyses and categorized into themes.

Results

Forty‐five out of 432 articles were included in the final full‐text analysis. Absence from work following coronary artery bypass graft grafting or aortic valve replacement surgery lasted on average 30 weeks, whereas 34% of the patients never returned to work. Being female, suffering from pre‐existing depression, having limited secondary education, or low income were associated with decreased return to work rates. Previous employment was a decisive factor for returning to work after surgery. Data on return to work after aortic valve replacement were scarce.

Conclusions

A significant number of patients never return to work following coronary artery bypass grafting or aortic valve surgery, and the time interval until work return is longer than expected. Failure to resume work represents a threat to the patients’ finances and quality of life. Nurses are in a unique position to assess work‐related issues and have an active part in the multi‐disciplinary facilitation of tailored occupational counselling after cardiac surgery.
Environmental Precedent: Foregrounding the Environmental Consequences of Law in Sociology
Authors: Shtob Daniel , Fox Besek Jordan
Published: May 2021

The central premise of environmental sociology is that social and environmental processes influence one another in fundamental ways. Here we build upon that insight and develop the concept of “environmental precedent” to better incorporate the full range of environmentally consequential law ‐ even law that is not “environmental” per se ‐ in sociological analysis. Environmental precedent refers to the environmental consequences of legal processes, consequences that become the new, enduring, dynamic material reality for future legal processes. Unlike legal precedent, which may be amended to suit immediate needs through judicial or legislative action, environmental precedent can have interpretive and material consequences that may be impossible for any social process to predict, amend, or reverse. To demonstrate the concept’s usefulness, we illustrate the varied, dialectical environmental and legal relationships that exist in three case studies; the Flint water crisis, the federal passage of a suite of environmental laws in the early 1970s, and how some preconditions to the catastrophic effects of Hurricane Katrina came to pass in New Orleans. In addition to foregrounding the benefits to sociology of a sharper understanding of environmental legal theory and practice, our aim is to encourage collaboration between social scientists, environmental lawyers, and legal scholars.
Allograft recognition by recipient's natural killer cells: Molecular mechanisms and role in transplant rejection
Authors: Hamada Sarah , Dubois Valérie , Koenig Alice , Thaunat Olivier
Published: May 2021

The current transplant immunology dogma defends that allograft rejection is initiated by recipient's adaptive immune system. In this prevalent model, innate immune cells in general, and natural killer (NK) cells in particular, are merely considered as downstream effectors which participate in the destruction of the graft only upon recruitment by adaptive effectors: alloreactive T cells or donor‐specific antibodies (DSA). Challenging this vision, recent data demonstrated that recipients' NK cells are capable of a form of allorecognition because they can sense the absence of self HLA class I molecules on the surface of graft endothelial cells. Missing‐self triggers mTORC1‐dependent activation of NK cells, which in turn promote the development of graft microvascular inflammation and detrimentally impact graft survival. The fact that some patients develop chronic vascular rejection in absence of DSA or genetically‐predicted missing self suggests that other molecular mechanisms could underly NK cell allorecognition. This review provides an overview of these proven and putative molecular mechanisms and discusses future research directions in this emerging field in organ transplant immunology.
HLA‐G expression correlates with histological grade but not with prognosis in colorectal carcinoma
Authors: Kaprio Tuomas , Sariola Hannu , Linder Nina , Lundin Johan , Kere Juha , Haglund Caj , Wedenoja Satu
Published: May 2021

Trophoblast‐specific expression of HLA‐G induces immune tolerance for the developing fetus. Pathological HLA‐G expression later in life might contribute to immune escape of various cancers. We studied the still controversial role of HLA‐G in colorectal carcinoma (CRC) using the MEM‐G/1 antibody and a tissue microarray series of CRC tumors (n = 317). HLA‐G expression appeared in 20% of the tumors and showed high intratumoral heterogeneity. HLA‐G positivity was associated with better differentiation (p = 0.002) and non‐mucinous histology (p = 0.008). However, HLA‐G expression alone showed no prognostic value: 5‐years disease‐specific survival among patients with HLA‐G expression was 68.9% (95% CI: 62.7%–75.0%) compared to 74.8% (95% CI: 63.2%–86.3%) among those without expression. These results support a modulatory role of HLA‐G in CRC.
Starch granule initiation in Arabidopsis thaliana chloroplasts
Authors: Mérida Angel , Fettke Joerg
Published: May 2021

The initiation of starch granule formation and the mechanism controlling the number of granules per plastid have been some of the most elusive aspects of starch metabolism. This review covers the advances made in the study of these processes. The analyses presented herein depict a scenario in which starch synthase isoform 4 (SS4) provides the elongating activity necessary for the initiation of starch granule formation. However, this protein does not act alone; other polypeptides are required for the initiation of an appropriate number of starch granules per chloroplast. The functions of this group of polypeptides include providing suitable substrates (maltooligosaccharides) to SS4, the localization of the starch initiation machinery to the thylakoid membranes, and facilitating the correct folding of SS4. The number of starch granules per chloroplast is tightly regulated and depends on the developmental stage of the leaves and their metabolic status. Plastidial phosphorylase (PHS1) and other enzymes play an essential role in this process since they are necessary for the synthesis of the substrates used by the initiation machinery. The mechanism of starch granule formation initiation in Arabidopsis seems to be generalizable to other plants and also to the synthesis of long‐term storage starch. The latter, however, shows specific features due to the presence of more isoforms, the absence of constantly recurring starch synthesis and degradation, and the metabolic characteristics of the storage sink organs.
Therapeutic relationships in speech-language pathology: a scoping review protocol
Authors: Hansen Hilke , Erfmann Kerstin , Göldner Julia , Schlüter Rieke , Zimmermann Franziska
Published: May 2021

Objective:

The purpose of this scoping review is to provide an overview of empirical research regarding the therapeutic relationship between speech-language pathologists and their clients of all ages and clinical areas.

Introduction:

The influence of a positive relationship between professionals and clients on the process and outcome of interventions is well documented for many health professions. However, research in speech-language pathology predominantly focuses on the outcome of specific treatment methods and techniques. The number of empirical research studies on the therapeutic relationship within this research area is increasing. At present, existing research has not been summarized and compared.

Inclusion criteria:

The review will include all empirical research that addresses the therapeutic relationship between speech-language pathologists and their clients of all ages and clinical areas. Since speech-language pathologists often collaborate intensively with caregivers of their clients, such as parents or partners, these groups will also be included.

Methods:

Systematic searches will be conducted across seven research databases (ASHAWire, CINAHL, ERIC, Fachportal Pädagogik, LIVIVO, MEDLINE [PubMed], and PsycINFO) and four unpublished/gray literature databases (evidenssst, ndldt, OpenGrey, and SSOAR). Data will be extracted by two independent reviewers for author(s), year of publication, country of origin, research questions, participants, terminology and theoretical foundations, research design, and focus. Central findings concerning the therapeutic relationship on the input-, process-, outcome, and output-level of speech-language interventions will be analyzed. Results will be presented as a narrative summary.
Physical sequelae of growing into adolescence with perinatally acquired HIV: a scoping review protocol
Authors: Comley-White Nicolette , Potterton Joanne , Ntsiea Veronica
Published: May 2021

Objective:

This scoping review aims to identify and describe the physical sequelae experienced by adolescents with perinatally acquired HIV.

Introduction:

Perinatally acquired HIV is a prevalent condition affecting adolescents. It results in neurocognitive dysfunction and mental health challenges. Data show that some of the physical challenges facing this population include stunted growth and delayed puberty; however, other physical challenges remain largely unknown.

Inclusion criteria:

This review will consider studies that include adolescents aged 10 to 19 years, with perinatally (vertically) acquired HIV. Adolescents from any geographic area, of any ethnicity or socioeconomic background will be considered. The concepts included will be all physical sequelae of perinatally acquired HIV. Studies of any research design, including quantitative, qualitative, and mixed methods, as well as systematic reviews, will be considered.

Methods:

This review will utilize a three-step search strategy. There will be an initial search of MEDLINE (PubMed), followed by a full search of MEDLINE (PubMed), PEDro, CINAHL (EBSCO), Scopus (Elsevier), ScienceDirect (Elsevier), and Google Scholar. Gray literature will be searched using CDC Stacks and OpenGrey. Lastly, the reference lists of all articles will be checked for additional studies. Titles and abstracts will be screened by two independent reviewers against the inclusion criteria, and a third reviewer will resolve any discrepancies. Results will be charted on a data extraction tool and presented with a table, diagrammatic representation, and a descriptive narrative.
Patient-reported outcome measures in the emergency department: a scoping review protocol
Authors: Poulsen Ninna Rysholt , Schougaard Liv Marit Valen , Søvsø Morten Breinholt , Leutscher Peter Derek Christian , Pedersen Mona Kyndi
Published: May 2021

Objective:

The objective of this scoping review is to identify and characterize validated patient-reported outcome measures used to assess adult patients’ health status in the emergency department to support clinical decision-making and to develop individual care and treatment plans.

Introduction:

In recent years, the workload in emergency departments has increased and patient management is characterized by a fast pace. The accelerated approach may lead to unintentional negligence by health care professionals of patient-reported signs and symptoms in the emergency department. Thus, use of patient-reported outcome measures in the emergency department may improve health care professionals’ attention to the needs and health status of patients.

Inclusion criteria:

Studies assessing adult patients’ health status in the emergency department using patient-reported outcome measures will be considered. The patient-reported outcome measures should be self-reported, assisted by a proxy, or administered through interviews. Only studies reporting on the measurement properties of patient-reported outcome measures will be included. Moreover, health-related information retrieved using patient-reported outcome measures should be applicable at an individual patient level.

Methods:

A systematic literature search will be performed primarily in the databases MEDLINE, Embase, CINAHL, and PsycINFO. Both published and unpublished sources of information will be considered. Studies published from 2000 onwards in Danish, Swedish, Norwegian, German, and English will be included. Using the JBI methodology for scoping reviews, two reviewers will independently perform the study selection and data extraction. The results will be presented in a tabular form together with a narrative summary.
On State-Space Modeling and Signal Localization in Dynamical Systems
Authors: Ray Asok
Published: May 2021

This letter focuses on two topics in engineering analysis, which are (1) degree-of-freedom (DOF) in modeling of dynamical systems and (2) simultaneous time and frequency localization of signals. These issues are explained from the perspectives of decision and control by making use of concepts from applied mathematics and theoretical physics. Specifically, a new definition is proposed to clarify the notion of “DOF,” which is consistent with the dimension of the state space of the dynamical system model. Relevant examples are presented on (finite-dimensional) vector spaces over the real field R and/or the complex field C.
The Design and Control of a Rigid-Flexible Coupling Positioning Stage for Enhanced Settling Performance
Authors: Peng Hao , Yang Zhijun , Xue Wenchao , Huang Ruirui , Huang Yi
Published: May 2021

Traditional high-speed precision motion stage (HSPMS) design pursues high-stiffness structure to achieve fast response. However, such structure leads to high-frequency disturbance near dead zone of friction, which causes poor performance in controlling HSPMS. To this end, this paper proposes the active disturbance rejection control (ADRC)-based mechanical design to reduce the bandwidth of friction disturbance and improve the control performance of HSPMS. It is proved that the low-frequency disturbance can be more effectively tackled by the extended state observer (ESO) in the frame of ADRC. In particular, rigid-flexible coupling (RFC) positioning stage is presented for converting the high-frequency friction disturbance into the low-frequency elastic deformation disturbance by flexure hinges. The experimental tests are carried out for both traditional stage and RFC stage. It is clearly shown that compared with traditional design, the control performance of RFC stage is remarkably promoted.
Influence of Fin Parameters on Melting and Solidification Characteristics of a Conical Shell and Tube Latent Heat Storage Unit
Authors: Kalapala Lokesh , Devanuri Jaya Krishna
Published: May 2021

Augmenting meting and solidification rates of latent heat storage unit (LHSU) is very much essential for its efficient operation. By the effective utilization of natural convection, rate of heat transfer can be enhanced and the conical shell is beneficent in this regard. Using fins further improves the charging and discharging rates. Hence, the current study is focused on analyzing melting and solidification characteristics of a conical shell and tube LHSU along with the effect of fin parameters viz., fin diameter and number of fins. Numerical analysis is chosen for this purpose and the performance is compared via melting/solidification times, energy stored, energy/exergy efficiencies. Initially, the performance of unfinned conical shell is compared with the cylindrical shell without fins and then the effect of fin parameters is presented. For melting process conical shell is found to be superior to cylindrical shell. 34.46% reduction in melting time is noted by using conical shell and rate of energy stored is also higher for conical shell. Increase in fin diameter caused an increase in melting time when 20 number of fins are used, whereas melting time got decreased with the increase in fin diameter when five number of fins are used. Hence, when a greater number of fins are used, lesser diameter is preferred for melting. For discharging process, conical shell took 60% more time than cylindrical shell. Even after using fins, solidification time is not drastically reduced in comparison with cylindrical shell.
Effect of Zirconium Oxide Reinforcement on Microstructural, Electrochemical, and Mechanical Properties of TiNi Alloy Produced via Powder Metallurgy Route
Authors: Abbas Raza S. , Imran Khan M. , Ramzan Abdul Karim M. , Ali Rashid , Umair Naseer M. , Zameer Abbas S. , Ahmad Mairaj
Published: May 2021

Equiatomic TiNi alloy composites, reinforced with 0, 5, 10, and 15 vol% ZrO2, were synthesized using conventional sintering approach. Equiatomic TiNi pre-alloyed powder and ZrO2 powder were mixed in planetary ball mill for 6 h followed by cold compaction and pressure-less sintering, respectively. The sintered density was found to vary inversely with the addition of ZrO2 content. The X-ray diffraction (XRD) spectra have shown the formation of multiple-phases which were resulted from the decomposition of the B19′ and B2 phases of the equiatomic TiNi alloy due to the addition of ZrO2 and higher diffusion rate of Ni than that of Ti in the alloy composite. An increase in hardness was noted due to the addition of ZrO2, measured by micro and nanoindentation techniques. Potentiodynamic polarization scan revealed a 10% decrease in the corrosion rate of the composite containing 10 vol% ZrO2. Electrochemical impedance spectroscopy (EIS) results indicated an increase in passive layer resistance (Rcoat) due to the increase in charge transfer resistance (Rct) caused by the reduced leaching of ions from the surface.
Two-Dimensional Numerical Analysis of Gas Diffusion-Induced Cassie to Wenzel State Transition
Authors: Mayer Michael D. , Kadoko Jonah , Hodes Marc
Published: May 2021

We develop a two-dimensional model for the transient diffusion of gas from the cavities in ridge-type structured surfaces to a quiescent liquid suspended above them in the Cassie state to predict the location of the liquid vapor-interface (meniscus) as a function of time. The transient diffusion equation is numerically solved by a Chebyshev collocation (spectral) method coupled to the Young–Laplace equation and the ideal gas law. We capture the effects of variable meniscus curvature and, subsequently, when applicable, movement of triple contact lines. Results are presented for the evolution of the dissolved gas concentration field in the liquid and, when applicable, the time it takes for a meniscus to depin and that for longevity, i.e., the onset of the Cassie to Wenzel state transition. Two configurations are examined; viz., one where an impermeable membrane pressurizes the liquid above the ridges and one where hydrostatic pressure is considered and the top of the liquid is exposed to noncondensible gas.
Anisotropy and the Onset of the Thermoconvective Instability in a Vertical Porous Layer
Authors: Barletta A. , Celli M.
Published: May 2021

The thermoconvective instability of the parallel vertical flow in a fluid saturated porous layer bounded by parallel open boundaries is studied. The open boundaries are assumed to be kept at constant uniform pressure while their temperatures are uniform and different, thus forcing a horizontal temperature gradient across the layer. The anisotropic permeability of the porous layer is accounted for by assuming the principal axes to be oriented along the directions perpendicular and parallel to the layer boundaries. A linear stability analysis based on the Fourier normal modes of perturbation is carried out by testing the effect of the inclination of the normal mode wavevector to the vertical. The neutral stability curves and the critical Rayleigh number for the onset of the instability are evaluated by solving numerically the stability eigenvalue problem.
Dynamic Processes of Nanobubbles: Growth, Collapse, and Coalescence
Authors: Choi Heejun , Li Calvin , Peterson G. P.
Published: May 2021

Nanobubbles are typically classified as gas/vapor phase cavities in an aqueous solution with a characteristic length of approximately 100 nanometers (nm). The theoretical lifetime of these nanobubbles has been estimated to be less than ∼1 μs at a diameter of 100 nm based upon the Young-Laplace pressure, but experimental observations have been reported that indicate that they may exist for many hours, or even days. These nanobubbles can be generated by a number of different methods, such as solvent exchange, pressure and/or temperature variations, chemical reactions, or through the electron beam radiolysis of water. The imaging methods utilized to observe these nanobubbles have evolved from low temporal resolution/high spatial resolution, using atomic force microscopy (AFM); or low spatial resolution/high temporal resolution, using optical microscopy (X-rays); or finally, high spatial/high temporal resolution using more recent electron microscopy techniques. A review of the various methods utilized in the nucleation of nanobubbles and the different imaging technologies utilized, along with a summary of the most recent experimental and theoretical investigations of the dynamic behavior and processes of these nanobubbles, including nanobubble growth, nanobubble collapse, and nanobubble coalescence, are presented, discussed and summarized.
Multiplication of
Mycobacterium tuberculosis
Within Normal and “Immune” Mouse Macrophages Cultivated With and Without Streptomycin
Authors: Patterson Ronald J. , Youmans Guy P.
Published: May 2021

Acquired cellular immunity to infection with
Mycobacterium tuberculosis
is believed to reside in the capacity of mononuclear phagocytes of immunized animals to inhibit intracellular multiplication of the parasite. However, in macrophage tissue culture systems, it has been customary to employ streptomycin in the medium for the purpose of restricting extracellular, but not intracellular, growth of
M. tuberculosis.
In contrast, our data show that small amounts of streptomycin markedly inhibit intracellular as well as extracellular growth of
M. tuberculosis
in normal mouse peritoneal macrophages, and that the degree of this inhibition is directly proportional to the concentration of streptomycin used. In the absence of streptomycin, virulent tubercle bacilli grew as rapidly in “immune” macrophages as in normal macrophages. “Immune” macrophages, however, were slightly more resistant to destruction by the intracellularly multiplying mycobacteria. In the presence of streptomycin, however, intracellular mycobacterial growth was inhibited more in “immune” macrophages than in normal macrophages, and this effect also was directly proportional to the concentration of streptomycin used. Virulent mycobacteria grew somewhat more slowly within mouse peritoneal macrophages obtained after induction of a peritoneal exudate with glycogen than in noninduced cells. The rate of multiplication, though, was the same within normal and “immune” induced peritoneal cells except in the presence of streptomycin. As with noninduced macrophages, this drug inhibited the intracellular multiplication of virulent tubercle bacilli more effectively within “immune” induced than within normal induced cells. It would appear, therefore, that the greater inhibition of intracellular multiplication of virulent tubercle bacilli in “immune” macrophages in tissue culture noted by a number of investigators in the past may have been an artifact created by the use of streptomycin in the tissue culture medium.
Effect of Hypertonic Sucrose Upon the Immune Bactericidal Reaction
Authors: Muschel Louis H. , Larsen Linda J.
Published: May 2021

This study was performed to determine the mechanism whereby hypertonic sucrose inhibits the immune bactericidal reaction. Other investigators had postulated that the initial attack of complement (C) on the cell wall was followed with lysozyme-containing whole serum by an enzymatic reaction upon the peptidoglycan substrate resulting in cell death. In the absence of serum lysozyme, secondary lethal changes might occur from damage to the cell's inner membrane as a result of osmotic forces in the presence of a defective cell wall. Hypertonic sucrose giving rise to plasmolysis and protection of the inner membrane was presumed to differentially inhibit the immune response mediated by lysozyme-free serum. The experimental results observed in this investigation have indicated, however, that the inhibitory effect of sucrose upon the bactericidal reaction may be explained simply by its anticomplementary effect and not by any effect on the bacterial cell. This view was supported by the following observations: (i) the comparability of the inhibitory effect of sucrose upon the immune hemolytic and bactericidal reactions, (ii) the comparable percentage loss in bactericidal activity of whole serum and lysozyme-free serum resulting from hypertonic sucrose, (iii) bactericidal antibody titrations were relatively unaffected and C titrations markedly inhibited by sucrose, (iv) the inhibitory effect of sucrose on the bactericidal reaction was unaffected by prior growth of the organism in the presence of sucrose, (v) the kinetics of the bactericidal reactivity of lysozyme-free serum in hypertonic sucrose, compared with whole serum, did not reveal a prolonged lag phase with lysozyme-free serum, but simply diminished reactivity at all times. These observations are compatible with the view that the C attack upon the outer surface of gram-negative bacteria, which plays a part in the cell's permeability control, may account for cell death. In this regard, the immune bactericidal reaction is quite comparable to the lysis of red cells or nucleated cells by C despite the lack of overt lysis in bacteria, probably because of their underlying supporting structures.
Inhibition of the Synthesis of Wax D Peptidoglycolipid of
Mycobacterium tuberculosis
by
d
-Cycloserine
Authors: David Hugo L. , Goldman Dexter S. , Takayama Kuni
Published: May 2021

The antibiotic
d
-cycloserine inhibits the synthesis of the wax D peptidoglycolipid in cells of the H37Ra strain of
Mycobacterium tuberculosis
. This inhibition occurs at a lower concentration of the drug than that required for the inhibition of growth. The inhibition is completely reversed by
d
-alanine. An arabino-galactan-galactosamine-(diaminopimelic acid)-mycolate accumulates in H37Ra cells exposed to the antibiotic. The chemical and functional group analyses of this lipid suggests it to be a possible precursor to the synthesis of wax D.
Plaque Formation by
Chlamydia
in L Cells
Authors: Banks Joyce , Eddie B. , Schachter Julius , Meyer K. F.
Published: May 2021

Chlamydiae were found capable of producing plaques in several cell lines. Mouse fibroblast cells, L-929, proved the most sensitive to infection and yielded plaques of the highest clarity. Assay of chlamydial infectivity by plaque titration was at least as sensitive as egg
ld
50
determination. Among chlamydial isolates of avian, mammalian, and human origin, only slow-growing trachoma-inclusion-conjunctivitis agents did not produce plaques. The plaque assay is highly sensitive, reproducible, and offers a potential tool for investigations requiring accurate measurement of small changes in chlamydial infectivity.
Protection of Mice Against Bacterial Infection by Interferon Inducers
Authors: Pindak Frank F.
Published: May 2021

Antibacterial effect of known interferon inducers was investigated. Intraperitoneal injection of statolon or pyran markedly enhanced the survival of mice challenged with
Klebsiella pneumoniae
. The sparing effect of these two interferon inducers resembled that of bacterial endotoxin. Significant protection was obtained when the inducers were administered 24 hr before challenge. Treatments given 6 hr before or at the time of infection were ineffective. The persistence of increased resistance of treated animals to encephalomyocarditis virus strain MM, inoculated 5 days after challenge with
K. pneumoniae
, indicated that the bacterial infection did not adversely influence the induction or effectiveness of interferon.
Conditions Affecting the Viability of Spheroplasts in Urine
Authors: Gnarpe Håkan , Edebo Lars
Published: May 2021

Penicillin-induced spheroplasts from
Escherichia coli
and
Proteus vulgaris
, which at neutral
p
H had little resistance to osmotic lysis, retained viability in media of low osmolality at
p
H 5.0 to 5.5. In the presence of 1,000 IU of penicillin per ml (
p
H 5.0) in liquid media,
E. coli
remained in rod form without conspicuous growth. On hypotonic agar media at
p
H 5.2 with 1,000 IU of penicillin per ml, the bacteria grew out as L-type colonies. These findings are discussed in relation to penicillin therapy.
Microbial skin flora of selected cancer patients and hospital personnel
Authors: McBride M E , Duncan W C , Bodey G P , McBride C M
Published: May 2021

The bacterial flora of the skin from five anatomical sites on 10 leukemia patients, 10 patients with malignant melanoma, and a control group of 10 medical personnel was examined quantitatively and qualitatively. This was done to determine whether malignant disease results in changes in skin flora and to establish carrier rates of gram-negative bacteria on the skin of personnel in hospital environments. Gram-negative bacteria were isolated more frequently (74 isolates from 100 cultures) from the skin of leukemia patients than from either patients with malignant melanoma (8 isolates from 100 cultures) or the medical personnel (9 isolates from 100 cultures). Klebsiella pneumoniae and Pseudomonas aeruginosa were isolated exclusively from leukemia patients. Relative proportions of gram-negative bacteria in total populations were determined. The axilla was the only site with a uniformly high proportion of gram-negative bacteria. From all other sites cultured, gram-negative populations were low (1 to 5 bacteria/cm2 of skin), although a high proportion of gram-negative populations occurred randomly throughout all subject groups. It was concluded that leukemia patients tend to carry gram-negative bacteria on the skin. The factors permitting colonization of skin by gram-negative bacteria are discussed.
Preparation and testing of vaccines prepared from the envelopes of Venezuelan, eastern, and western equine encephalomyelitis viruses
Authors: Pedersen C E
Published: May 2021

Envelope components were separated from Venezuelan, Eastern, and Western equine encephalomyelitis viruses after treatment of the virions with detergent. Vaccines prepared from the envelope component were capable of stimulating mice to produce humoral antibodies. Protective efficacy studies were performed using mono-, di-, and trivalent vaccine combinations. These elicited varying degrees of homologous protection, and Eastern and Venezuelan equine encephalomyelitis envelope products appeared to confer protection to mice challenged with Western equine encephalomyelitis virus.
Evaluation of the rapid decarboxylase and dihydrolase test for the differentiation of nonfermentative bacteria
Authors: Oberhofer T R , Rowen J W , Higbee J W , Johns R W
Published: May 2021

A rapid medium for the detection of lysine and ornithine decarboxylase and arginine dihydrolase activity of 439 strains of gram-negative, nonfermenting bacteria was evaluated and compared with Moeller decarboxylase medium. Results were obtained in 4 to 24 h using the rapid medium, whereas Moeller medium often required extended (3 to 7 days) incubation. There was 100% agreement in the lysine tests with both media and almost 100% agreement in the ornithine tests. There was 91% agreement in the arginine tests, with the significance of discrepant results discussed. The sensitivity, specificity, and quick results obtained by the rapid test make it a suitable substitute for Moeller medium for the identication of gram-negative, nonfermenting bacteria.
Comparison of a microneutralization test in cell culture and virus neutralization test in embryonated eggs for determining infectious bronchitis virus antibodies
Authors: Wooley R E , Brown J , Davis R B , Blue J L , Lukert P D
Published: May 2021

A microneutralization test (MNT) system utilizing cytopathic effect end points was effective in determing neutralization indexes for infectious bronchitis virus antibodies. The system is reproducible within 1 index unit at the 95% level of probability. Comparison of the MNT to tests in eggs resulted in a positive correlation (B =0.81), which was significant (P greater than 0.01). The quantitative dose-response relationship of the MNT is linear (P greater than 0.005), with the 95% prediction limits fitting between one 10-fold dilution.
Phage Typing Set for Group C
1
and C
2
Salmonellae
Authors: Gershman M.
Published: May 2021

Fifteen common serotypes representative of group C
1
and C
2
Salmonella
were characterized using a single set of phages.
Effectiveness of palladium chloride for the isolation of anaerobes
Authors: Owens D R , Rolfe R D , Hentges D J
Published: May 2021

Because of the increased price of palladium chloride, we investigated the effectiveness of the addition of this ingredient to the culture medium used for the recovery of anaerobes. With our system, the addition of palladium chloride did not consistently improve the recovery rate of bacteria from guinea pig intestinal contents and human fecal material.