Immersions into manifolds without conjugate points

Many differential geometric concepts such as (isometric) immersion, stability, etc., realized in Euclidean spaces proved to be also realized in manifolds without conjugate points while other concepts are found to be strictly associated with Euclidean spaces. In fact, this thesis may be considered as a trial for finding out to what extent geometric phenomena in Euclidean spaces are still l valid in manifolds without conjugate points. In the introduction, we have quoted the necessary background material for the following chapters. Specially, we have concentrated on the geometry of submanifolds. The interesting problem of rigidity of submanifolds lies in three different categories : finite rigidity, continuous rigidity and infinitesimal rigidity. These three types of rigidity have been studied in hyperbolic spaces in chapter I, sections 1 and 2. K. Nomizu, B. Snmyth (1969) and S. Braidi, C.C. Hsuing (1970) studied some geometric properties of immersed submanifolds in Euclidean sphere essentially the behaviour of the second fundamental form and the Gauss map. In chapter II (sections 1, 2) we have carried out similar study for immersed submanifolds in hyperbolic spaces which shows some deviations from the corresponding one in Euclidean sphere. Since B.Y. Chen's paper (1973) which established the geometric concept of stability of submanifolds in Euclidean spaces, other geometers tried to extend this concept to non-Euclidean spaces. In chapter II (section 3) we share this development through studying stability of surfaces in hyperbolic 3-dimensional space. The most interesting part of our thesis is the last chapter which deals with tight and taut (convex-minimal) immersions in manifolds without conjugate points. Some geometric concepts such as (spherical) two-piece property, h-two-piece property, total (absolute) curvature,... e t c . , have been introduced. Relations between the above concepts have been adopted. We expect for this part to receive more attention in the future to discover more results and to generalize other Euclidean concepts which we did not touch

Функциональное печенье, обогащенное порошком картофельной кожуры: физические, химические, реологические и антиоксидантные свойства

This research aimed to replace wheat flour with potato peel powder (PPP) at different levels (3, 5, 7, 10, 30, and 50%). An effect of PPP on physical, chemical, rheological, and antioxidant properties of biscuit samples was investigated. The results show that the PPP sample had a significantly higher content of total sugar, protein and ash, and a lower content of moisture (15.68g/100g dry weight, 15.32 g/100g dry weight, 9.11%, 8.35%, respectively) compared with the wheat flour sample. Also, a higher total phenolic content and antioxidant activity (71.12 mg Gallic acid equivalent / 100g dry weight and 68.39%, respectively) was observed in the PPP sample. The highest percentage of PPP addition (50%) exerted the greatest significant effect on the content of total sugar, protein, moisture, ash, total phenols, and antioxidant activity compared with the control sample and other biscuit samples leading to their increase to 50.90 g/100g dry weight, 12.74 g/100g dry weight, 5.56%, 2.39%, 41.71 mg Gallic acid equivalent / 100g dry weight, 59.72%, respectively. A decrease in the L*, a*, b*, C*, h and BI values, and an increase in ∆E values were observed with replacing wheat flour with PPP. The 3% and 5% replacement rates contributed to improving most organoleptic characteristics (general acceptability, color, taste) compared to the samples with the highest studied percentages (30% and 50%). Although the highest percentages of PPP addition led to lower scores for sensory characteristics, all studied samples were acceptable from the sensory point of view, except the samples with the 50% replacement rate in terms of their taste and color.Цель этой работы состоит в описании и исследовании ранее неизвестного явления самосегментации молочного сгустка в сыродельной ванне открытого типа. На основе анализа кинетики гелеобразования определено, что самосегметация геля начинается вблизи гель-точки, развивается в течение нескольких десятков секунд и закрепляется по мере уплотнения геля. Сегменты в молочном сгустке не имеют определённой правильной формы, их средний размер вариабелен в пределах от 5 до 50 см. Форма и размеры сегментов не повторяются и не коррелируют с видом вырабатываемого сыра. Смещение сегментов молочного сгустка в сыродельной ванне относительно друг друга по высоте составляет от 0,5 до 2 мм. Ширина граничного слоя между сегментами сгустка увеличивается в процессе вторичной фазы гелеобразования от 3 до 10 мм. В результате проведенных экспериментальных исследований показано, что самосегментация молочного геля вызывается термогравитационной конвекцией, образующей циркуляционные ячейки Бенара. Предложено описание возможного механизма самосегментации молочного геля в сыродельных ваннах открытого типа. Отмечена действенная роль жировых шариков в механизме самосегментации молочного сгустка. Высказано предположение, что самосегментация молочного сгустка в сыродельной ванне может вызвать некоторые органолептические дефекты в готовом сыре, в частности неравномерность текстуры и неравномерность цвета

Lithium treatment in cluster headache, review of literature

ABSTRACT -Background: The pain, which is involved in Cluster Headache (CH), is excruciating and is probably one of the most painful conditions known to humans. In the early 70es it was found out that lithium could be used in treating this rare condition. Ekbom produced his first report of using lithium successfully to treat five cases of CH and this was followed later by other studies, which showed the effectiveness of lithium in this condition. Objective: In this article we reviewed the evidence for using lithium in CH. We discuss some issues including the duration, the dosage of lithium required and the short and longterm side effects, which are likely to occur. We also included the mechanism of action of lithium in treating this condition. Methodology: We searched the Medline database from 1950 to date. We included all studies done in English, which were related to the use of lithium in cluster headache. We excluded all studies which were not in English and which included other types of headache. Results and conclusions: We concluded that lithium is effective in both chronic and episodic forms of cluster Headache

FGFR3 – a Central Player in Bladder Cancer Pathogenesis?

The identification of mutations in FGFR3 in bladder tumors in 1999 led to major interest in this receptor and during the subsequent 20 years much has been learnt about the mutational profiles found in bladder cancer, the phenotypes associated with these and the potential of this mutated protein as a target for therapy. Based on mutational and expression data, it is estimated that >80% of non-muscle-invasive bladder cancers (NMIBC) and ∼40% of muscle-invasive bladder cancers (MIBC) have upregulated FGFR3 signalling, and these frequencies are likely to be even higher if alternative splicing of the receptor, expression of ligands and changes in regulatory mechanisms are taken into account. Major efforts by the pharmaceutical industry have led to development of a range of agents targeting FGFR3 and other FGF receptors. Several of these have entered clinical trials, and some have presented very encouraging early results in advanced bladder cancer. Recent reviews have summarised the drugs and related clinical trials in this area. This review will summarise what is known about the effects of FGFR3 and its mutant forms in normal urothelium and bladder tumors, will suggest when and how this protein contributes to urothelial cancer pathogenesis and will highlight areas that may benefit from further study

Biogenic Synthesis of Zinc Oxide Nanoparticles Using <i>Citrullus colocynthis</i> for Potential Biomedical Applications

Green nanoparticle synthesis is considered the most efficient and safe nanoparticle synthesis method, both economically and environmentally. The current research was focused on synthesizing zinc oxide nanoparticles (ZnONPs) from fruit and leaf extracts of Citrullus colocynthis. Four solvents (n-hexane, methanol, ethyl acetate, and aqueous) were used to prepare the extracts from both plant parts by maceration and extraction. Zinc acetate was used to synthesize the nanoparticles (NPs), and color change indicated the synthesis of ZnONPs. X-ray diffraction, UV spectroscopy, and scanning electron microscopy were used to study the ZnONPs. UV–visible spectroscopy revealed an absorbance peak in the 350–400 nm range. XRD patterns revealed the face-centered cubic structure of the ZnONPs. SEM confirmed a spherical morphology and a size range between 64 and 82 nm. Phytochemical assays confirmed that the complete flavonoid, phenolic, and alkaloid concentrations were higher in unrefined solvent extracts than in nanoparticles. Nanoparticles of C. colocynthis fruit aqueous extracts showed stronger antioxidant activity compared with the crude extracts. Strong antifungal activity was exhibited by the leaves, crude extracts, and nanoparticles of the n-hexane solvent. In a protein kinase inhibition assay, the maximum bald zone was revealed by nanoparticles of ethyl acetate extracts from leaves. The crude extracts and nanoparticles of leaves showed high cytotoxic activities of the n-hexane solvent, with LC50 values of 42.08 and 46.35, respectively. Potential antidiabetic activity was shown by the n-hexane (93.42%) and aqueous (82.54%) nanoparticles of the fruit. The bioactivity of the plant showed that it is a good candidate for therapeutic use. The biosynthesized ZnONPs showed promising antimicrobial, cytotoxic, antidiabetic, and antioxidant properties. Additionally, the in vivo assessment of a nano-directed drug delivery system for future therapeutic use can be conducted based on this study

Genome Editing Technology: A New Frontier for the Treatment and Prevention of Cardiovascular Diseases

Over the past 2 decades, genome-editing technique has proven to be a robust editing method that revolutionizes the field of biomedicine. At the genetic level, it can be efficiently utilized to generate various disease-resistance models to elucidate the mechanism of human diseases. It also develops an outstanding tool and enables the generation of genetically modified organisms for the treatment and prevention of various diseases. The versatile and novel clustered regularly interspaced short palindromic repeats (CRISPR/Cas9) system mitigates the challenges of various genome editing techniques such as zinc-finger nucleases, and transcription activator-like effector nucleases. For this reason, it has become a ground-breaking technology potentially employed to manipulate the desired gene of interest. Interestingly, this system has been broadly utilized due to its tremendous applications for treating and preventing tumors and various rare disorders; however, its applications for treating cardiovascular diseases (CVDs) remain in infancy. More recently, 2 newly developed genome editing techniques, such as base editing and prime editing, have further broadened the accuracy range to treat CVDs under consideration. Furthermore, recently emerged CRISPR tools have been potentially applied in vivo and in vitro to treat CVDs. To the best of our knowledge, we strongly enlightened the applications of the CRISPR/Cas9 system that opened a new window in the field of cardiovascular research and, in detail, discussed the challenges and limitations of CVDs. 2023 Elsevier Inc.The authors appreciated the researchers supporting Project Number: (RSPD2023R725), King Saud University, Riyadh, Saud Arabia.Scopu