Results 71 to 80 of about 73,803 (304)

Essential norms of some singular integral operators [PDF]

open access: yesArchiv der Mathematik, 1999
Let \(S\) be a singular integral operator on the unit circle \(T\). The author calculates the essential norm \(\|S_{a,b}\|_e\) in \(L^2(T)\) of the singular integral operator \(S_{a,b}=aP+bQ\), where \(P=\frac 12 (I+S), Q=\frac 12 (I-S)\) are projections in \(L^2(T)\) and \(a,b \in L^\infty(T)\). Theorem. Let \(a,b \in L^\infty (T)\). Then \[ \|S_{a,b}\
openaire   +2 more sources

Exercise Interventions in Children, Adolescents and Young Adults With Paediatric Bone Tumours—A Systematic Review

open access: yesPediatric Blood &Cancer, EarlyView.
ABSTRACT Bone tumours present significant challenges for affected patients, as multimodal therapy often leads to prolonged physical limitations. This is particularly critical during childhood and adolescence, as it can negatively impact physiological development and psychosocial resilience.
Jennifer Queisser   +5 more
wiley   +1 more source

On the Norm of Certain Weighted Composition Operators on the Hardy Space

open access: yesAbstract and Applied Analysis, 2009
We obtain a representation for the norm of certain compact weighted composition operator 𝐶𝜓,𝜑 on the Hardy space 𝐻2, whenever 𝜑(𝑧)=𝑎𝑧+𝑏 and 𝜓(𝑧)=𝑎𝑧−𝑏. We also estimate the norm and essential norm of a class of noncompact weighted composition operators ...
M. Haji Shaabani, B. Khani Robati
doaj   +1 more source

The essential norm of multiplication operators on $L_p(��)$

open access: yes, 2022
We show that the formula for the essential norm of a multiplication operator on $L_p$, for ...
openaire   +2 more sources

DELP Treatment on Vision and Retinal Microcirculation in Patients With Acute Ischemic Stroke: Report of Five Cases and Literature Review

open access: yesTherapeutic Apheresis and Dialysis, EarlyView.
ABSTRACT Background The delipid extracorporeal lipoprotein filter from plasma (DELP) treatment can effectively reduce blood lipid, increase blood flow, and improve neurological deficits in patients with acute ischemic stroke (AIS). However, its effect on vision and retinal microcirculation in stroke patients has never been reported.
Ning Li   +9 more
wiley   +1 more source

Norm and Essential Norm of Composition Followed by Differentiation from Logarithmic Bloch Spaces to Hμ∞

open access: yesAbstract and Applied Analysis, 2014
In this note we express the norm of composition followed by differentiation DCφ from the logarithmic Bloch and the little logarithmic Bloch spaces to the weighted space Hμ∞ on the unit disk and give an upper and a lower bound for the essential norm of ...
Shanli Ye
doaj   +1 more source

A Comparative Study of Cerebral Oxygenation During Exercise in Hemodialysis and Peritoneal Dialysis Patients

open access: yesTherapeutic Apheresis and Dialysis, EarlyView.
ABSTRACT Introduction Cognitive impairment and exercise intolerance are common in dialysis patients. Cerebral perfusion and oxygenation play a major role in both cognitive function and exercise execution; HD session per se aggravates cerebral ischemia in this population. This study aimed to compare cerebral oxygenation and perfusion at rest and in mild
Marieta P. Theodorakopoulou   +10 more
wiley   +1 more source

Revealing the structure of land plant photosystem II: the journey from negative‐stain EM to cryo‐EM

open access: yesFEBS Letters, EarlyView.
Advances in cryo‐EM have revealed the detailed structure of Photosystem II, a key protein complex driving photosynthesis. This review traces the journey from early low‐resolution images to high‐resolution models, highlighting how these discoveries deepen our understanding of light harvesting and energy conversion in plants.
Roman Kouřil
wiley   +1 more source

Boundedness and essential norm of an integral-type operator on a Hilbert–Bergman-type spaces

open access: yesJournal of Inequalities and Applications, 2019
Let D ${\mathbb {D}} $ be the open unit disk of the complex plane C ${\mathbb {C}} $ and H(D) $H({\mathbb {D}} )$ be the space of all analytic functions on D ${\mathbb {D}} $.
Stevo Stević, Zhi-Jie Jiang
doaj   +1 more source

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