scholarly journals Spontaneous Polarization Calculations in Wurtzite II-Oxides, III-Nitrides, and SiC Polytypes through Net Dipole Moments and the Effects of Nanoscale Layering

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1956
Author(s):  
William Troy ◽  
Mitra Dutta ◽  
Michael Stroscio

Herein, the spontaneous polarization in crystals with hexagonal symmetry are calculated as a function of the number of monolayers composing a nanostructure by adding the dipole moments for consecutive units of the nanostructure. It is shown that in the limit of a large numbers of monolayers that the spontaneous polarization saturates to the expected bulk value of the spontaneous polarization. These results are relevant to understanding the role of the built-in spontaneous polarizations in a variety of nanostructures since these built-in polarizations are generally quite large, on the order of 1 × 108 to 1 × 1010 V/m. Using these formulations, we come to the prediction that small nanolayered structures are theoretically capable of having larger spontaneous polarizations than their bulk counterparts due to how the dipole moments of the anions and cations within a wurtzite lattice cancel out with one another more in larger structures.

Author(s):  
Thomas T.F. Huang ◽  
Patricia G. Calarco

The stage specific appearance of a retravirus, termed the Intracisternal A particle (IAP) is a normal feature of early preimplantation development. To date, all feral and laboratory strains of Mus musculus and even Asian species such as Mus cervicolor and Mus pahari express the particles during the 2-8 cell stages. IAP form by budding into the endoplasmic reticulum and appear singly or as groups of donut-shaped particles within the cisternae (fig. 1). IAP are also produced in large numbers in several neoplastic cells such as certain plasmacytomas and rhabdomyosarcomas. The role of IAP, either in normal development or in neoplastic behavior, is unknown.


Author(s):  
Vivek Charu ◽  
Paul B. Rosenberg ◽  
Lon S. Schneider ◽  
Lea T. Drye ◽  
Lisa Rein ◽  
...  

AbstractPhysicians and patients may choose a certain treatment only if it is predicted to have a large effect for the profile of that patient. We consider randomized controlled trials in which the clinical goal is to identify as many patients as possible that can highly benefit from the treatment. This is challenging with large numbers of covariate profiles, first, because the theoretical, exact method is not feasible, and, second, because usual model-based methods typically give incorrect results. Better, more recent methods use a two-stage approach, where a first stage estimates a working model to produce a scalar predictor of the treatment effect for each covariate profile; and a second stage estimates empirically a high-benefit group based on the first-stage predictor. The problem with these methods is that each of the two stages is usually agnostic about the role of the other one in addressing the clinical goal. We propose a method that characterizes highly benefited patients by linking model estimation directly to the particular clinical goal. It is shown that the new method has the following two key properties in comparison with existing approaches: first, the meaning of the solution with regard to the clinical goal is the same, and second, the value of the solution is the best that can be achieved when using the working model as a predictor, even if that model is incorrect. In the Citalopram for Agitation in Alzheimer’s Disease (CitAD) randomized controlled trial, the new method identifies substantially larger groups of highly benefited patients, many of whom are missed by the standard method.


2021 ◽  
Vol 104 (8) ◽  
pp. 1389-1392

To summarize the recent trials and studies of the role of beta-blocker on the treatment for cancer patients treated with anthracycline to decrease morbidity and mortality rate. Good management of cancer will result in large numbers of cancer survivors. On the other hand, cancer therapy also has side effects, one of which is cardiotoxicity. Cardiotoxicity could reduce therapy effectiveness, hence, increase disease progression and mortality rate. Anthracyclines is one of the chemotherapy agents with cardiotoxicity as a side effect. Beta-blocker has the ability to reduce cardiotoxicity due to anthracyclines usage. Keywords: Beta-blocker; Cardiotoxicity; Anthracyclines


1990 ◽  
Vol 36 (12) ◽  
pp. 859-863 ◽  
Author(s):  
James A. Novitsky

The role of protozoan grazing in controlling bacterial populations was examined in four microbial habitats in Halifax Harbor, Canada: the water column, setting particles, the sediment–water interface, and the sediment. Large numbers of protozoans were found in all habitats although most (>56%) were small (<5 μm) flagellates. Protozoans larger than 10 μm were rarely observed; protozoans >20 μm were never observed. Protozoans were also observed to a depth of 9 cm below the sediment surface although efforts to culture viable protozoa failed except for the top 1 cm. The use of the metabolic inhibitor cycloheximide with and without colchicine to selectively inhibit eucaryotic metabolism was shown to severely affect procaryotic metabolism in sediment (and presumably particle and water) samples. Using fluorescently labelled bacteria as food, and under optimum conditions, up to 42% of the Protozoa population exhibited active grazing within 7 h. Using protozoan and bacterial community sizes and doubling times, it was calculated that each protozoan in Halifax Harbor would have to consume 13–118 bacteria per hour for the enumerated nanoplanktonic (<20 μm) Protozoa to be the sole control of the size of the bacterial community. Key words: marine, Protozoa, bacterivory, particles, bacteria.


Author(s):  
Golfo Alexopoulos

This chapter discusses the role of the Gulag medical-sanitation department. Their task was not necessarily to keep prisoners healthy, but to maximize exploitation and minimize “labor losses.” The Gulag routinely reported health data under the heading “illness and lost labor.” Inmate health was only relevant as it impacted production. The Stalinist leadership established quotas on illnesses and deaths, and would not tolerate large numbers of non-working prisoners. The Stalinist leadership called this “labor therapy,” and believed in work as the key to convalescence. Although sickness, emaciation, and disability were widespread, Gulag officials concealed their existence. In the Gulag, illness was widespread, yet it remained largely untreated, concealed, and even criminalized.


Author(s):  
Joan Lynch ◽  
Yenna Salamonson ◽  
Paul Glew ◽  
Lucie M. Ramjan

AbstractIn nursing, expectations of honesty and integrity are clearly stipulated throughout professional standards and codes of conduct, thus the concept of academic integrity has even more impetus in preparing students for graduate practice. However, a disparity between policy and practice misses the opportunity to instil the principles of academic integrity, and at its core honesty, a pivotal trait in the nursing profession. This study draws upon the experience of the nursing faculty to explore how academic integrity policy of deterrence operate in nursing education.While participants deplored cheating behaviours, they expressed frustration in having to ‘police’ large numbers of students who had little awareness of the academic standards to meet policy requirements. In addition, they were cynical because of a perceived lack of severity in sanctions for students who repeatedly breached integrity. Participants expressed a moral obligation as educators to meet student learning needs and preferred to engage with students in a more meaningful way to uphold academic integrity. The ambivalence to detect and report breaches in integrity undermines the effectiveness of policy. Therefore, faculty must recognise the importance of their role in detecting and escalating cases of dishonesty and execute deterrence in a more consistent way. To do this, greater support at an institutional level, such as smaller class sizes, inclusion in decision making around sanctions and recognition of additional workload, will enable faculty to uphold policy. Although policing was not their preferred approach, the role of faculty in detecting and reporting cases of misconduct is crucial to increase the certainty of students getting caught, which is essential if policy is to be effective in deterring dishonest behaviour.


Author(s):  
Alastair H. C. Sommerville

SynopsisThe ecological role of native willows is described in terms of the diverse structure of the species involved, the wide range of plant communities they form and the large numbers of invertebrates associated with them. The conservation importance of the genusSalixis discussed along with comments on the necessary management to retain willow habitats.


1965 ◽  
Vol 122 (1) ◽  
pp. 99-116 ◽  
Author(s):  
Charles G. Cochrane ◽  
Emil R. Unanue ◽  
Frank J. Dixon

In acute nephrotoxic nephritis, polymorphonuclear leukocytes (polymorphs) accumulated in large numbers in the glomeruli in the first 12 hours. The endothelial cells were dislodged by the polymorphs which then came to lie immediately adjacent to the glomerular basement membranes. Ultrastructural changes in neither polymorphs nor basement membranes were observed. Depletion of polymorphs in both rats and rabbits prevented the development of proteinuria. This occurred when doses of nephrotoxic globulin were employed that produced proteinurias of as much as 1800 mg/kg/24 hours in intact rabbits, or enough to yield near maximal immediate proteinuria in intact rats. In addition, measurable glomerular damage was frequently averted until the onset of the secondary stage of NTN. Controls indicated that the polymorph depleted animals exhibited minimal non-specific changes in the blood, that the ability of their vascular beds to react to stimuli was not affected, and that deposition of nephrotoxic antibody and C' in the glomeruli was not inhibited. Elimination of polymorphs from the circulation was only partially effective in preventing glomerular damage when large doses of nephrotoxic globulin were used. This indicated that under these circumstances, a polymorph independent glomerular injury may also take place in first stage nephrotoxic nephritis. An indirect role of C', i.e., the accumulation of polymorphs, in bringing about glomerular injury in first stage nephrotoxic nephritis was apparent. When rabbit nephrotoxic globulin was injected into rats depleted of C', or when duck nephrotoxic globulin that fixed C' poorly was injected into normal rats, C' failed to bind with the antibody along glomerular basement membranes and polymorphs did not accumulate.


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