Laura Neimane, Liene Zamure, Vadims Klimecs, Aleksandrs Grišuļonoks, Andrejs Skaģers and Andrejs Ivanovs
Sinus lift surgery elevation is a procedure that requires radiological maxillary sinus evaluation and procedure planning. The condition of the maxillary sinus before and after sinus lift surgery was assessed. Sixty-five sinuses of 49 patients were included in the study. Preoperative and postoperative cone beam computed tomography (CBCT) scans were performed. The sinuses were analysed radiologically for pathological changes: mucosal thickening, ostia obstruction and accessory opening. The presence of concha bullosa in nasal cavity and septa in the maxillary sinus were recorded. The sinus volume also was measured before and after surgery. Thickened mucosa was found more often in postoperative scans than in preoperative scans (63.1% and 67.7%, respectively). Concha bullosa was found in 30 preoperative scans and in 33 postoperative scans. A correlation between mucosal thickening and ostia obstruction was found. The mean sinus volume decreased after surgery and the changes were statistically significant. In conclusion, changes of the maxillarysinus and nasal cavity can be detected with CBCT. Sinus lift surgery does not excacerebate the existing conditions of the maxillary sinus; however, there is a tendency for pathological features to increase after surgery. Sinus lift surgery is a safe surgery with regard to the maxillary sinus if performed with care.
The aim of this paper is to introduce a new class of hyper-modules that may be called (M, N)-hypermodules over (R, S)-hyperrings. Then, we investigate some properties of this new class of hyperstructures. Since the main tools in the theory of hyperstructures are the fundamental relations, we give some results about them with respect to the fundamental relations.
Ieva Kalere, Ieva Strēle, Mārtiņš Miglinieks, Ilze Repša, Santa Pildava, Mihails Romanovs, Valdis Pīrāgs and Ilze Konrāde
The most common autoimmune disorders with clinically opposite manifestations are hypothyroidism in Hashimoto’s thyroiditis and hyperthyroidism in Graves’ disease. The healthcare burden of thyroid disease is substantial, resulting in substantial health care costs. The aim of the present analysis is to assess the use of thyroid medications in Latvia from 2011 to 2014 by age and gender. Our study used reimbursed medication prescriptions data, collected by the National Health Service of Latvia. The main indicator was the number of prevalent users of thyroid medications each year from 2011 to 2014, stratified by age and gender. From 2011 to 2014, the number of thyroxine users per 100 000 revealed a statistically significant increase in all age and gender groups, except in 0- to 9-year-old girls. The number of Thiamazole users among men increased in the age group from 40 to 89 years and in women age groups above 49 years. Increasing sales of both thyroid hormones and antithyroid medications are also observed in Estonia and Lithuania, indicating that growing thyroid morbidity is an issue in the whole region. The substantial increase in number of patients highlights the necessity for national guidelines on the use of thyroid function tests and standards of medical care.
Liliya Kraleva, Vincent Rijmen and Nikolai L. Manev
In this paper we study two-round key-alternating block ciphers with round function f (x)= x(2t+1)2s, where t, s are positive integers. An algorithm to compute the distribution weight in respect to input and output masks is described. Also, in the case t = 1 the correlation distributions depending on input and output masks are completely determined for arbitrary pairs of masks.
Fully homomorphic encryption (FHE) has been among the most popular research topics of the last decade. While the bootstrapping-based, public key cryptosystems that follow Gentry’s original design are getting more and more efficient, their performance is still far from being practical. This leads to several attempts to construct symmetric FHE schemes that would not be as inefficient as their public key counterparts. Unfortunately, most such schemes were also based on (randomized) linear transformations, and shown to be completely insecure. One such broken scheme was the Matrix Operation for Randomization and Encryption (MORE). In a recent paper, Hariss, Noura and Samhat propose Enhanced MORE, which is supposed to improve over MORE’s weaknesses. We analyze Enhanced MORE, discuss why it does not improve over MORE, and show that it is even less secure by presenting a highly efficient ciphertext-only decryption attack. We implement the attack and confirm its correctness.
The most commonly used methods for solving classical (historical) ciphers are based on global optimization (meta-heuristic methods). Despite the fact that global optimization is a well-studied problem, in the case of classical ciphers, there are still many open questions such as the construction of fitness functions or efficient transformation of the cryptanalysis (breaking attempt) to an optimization problem. Therefore the transformation of a cryptanalytical task to an optimization problem and the choice of a suitable fitness function form an important part of the topic. In this paper, we focus on the simple columnar transposition in depth. Our main contribution is a detailed analysis and comparison of different fitness functions, fitness landscape analysis and solving experiments.
In this paper we introduce a new cryptographic system which is based on the idea of encryption due to [McEliece, R. J. A public-key cryptosystem based on algebraic coding theory, DSN Progress Report. 44, 1978, 114–116]. We use the McEliece encryption system with a new linear error-correcting code, which was constructed in [Hannusch, C.—Lakatos, P.: Construction of self-dual binary 22k, 22k−1, 2k-codes, Algebra and Discrete Math. 21 (2016), no. 1, 59–68]. We show how encryption and decryption work within this cryptosystem and we give the parameters for key generation. Further, we explain why this cryptosystem is a promising post-quantum candidate.
Anda Kadiša, Zaiga Nora-Krūkle, Simons Švirskis, Pēteris Studers, Irute Girkontaite, Aivars Lejnieks and Modra Murovska
Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes erosive changes and ankylosis of joints and may cause internal injuries. Osteoarthritis (OA) is a degenerative process of the articular cartilage. However, inflammatory mediators may play a pivotal role in the initiation and perpetuation of the OA process. It is necessary to continue to study possible factors that may promote the development of the disease. The goal of this study was to evaluate the frequency and activity stage of parvovirus B19 (B19V) and persistent human herpes virus (HHV)-6 and HHV-7 infection in RA and OA patients, and healthy persons, in relation to cytokine levels and presence or absence of viral infections. RA patients with active B19V infection had the highest levels of tumour necrosis factor alpha (TNF-α), which may contribute to the development of RA. In the case of OA, the TNF-α level was higher in patients with active persistent B19V infection, suggesting that B19V reactivation affects also OA. Interleukin (IL)-6, IL-10 and metalloproteinase (MMP)-9 levels were higher in RA patients with latent HHV-6/-7 infection in comparison with active HHV-6/-7 infection, whereas in OA patients levels of all studied cytokines were very variable, ranging from low to high but without significant differences. This suggests that also latent HHV-6 and -7 viral infections can promote development of RA.
Let R be a principal ideal domain with quotient field K, and L = K(α), where α is a root of a monic irreducible polynomial F (x) ∈ R[x]. Let ℤL be the integral closure of R in L. In this paper, for every prime p of R, we give a new efficient version of Dedekind’s criterion in R, i.e., necessary and sufficient conditions on F (x) to have p not dividing the index [ℤL: R[α]], for every prime p of R. Some computational examples are given for R = ℤ.
Monta Madelāne, Angelika Krūmiņa, Raimonds Sīmanis, Ģirts Šķenders, Andrejs Ivanovs, Gunta Stūre and Ludmila Vīksna
Immune activation in human immunodeficiency virus (HIV) infection is driven by microbial translocation and in HIV patients is one of the contributors to faster progression of liver disease along with increased cell apoptosis. The aim of the study was to compare microbial translocation and apoptosis markers in HIV monoinfected and HIV/hepatitis C virus (HCV) coinfected patients, depending on HIV immune status and antiretroviral treatment (ART). We analysed data for 78 HIV monoinfected and 105 HIV/HCV coinfected patients from the Rīga East University Hospital. Lipopolysaccharide (LPS), endotoxin core antibodies (EndoCAb), cytokeratin 18 (CK18) and cyto-chrome c (Cyt-c) levels were measured. No significant difference in LPS, EndoCAb, Cyt-c levels between HIV and HIV/HCV patients was found. The CK18 level was higher in the HIV/HCV group. Correlation between CD4+ cell count and EndoCAb antibodies was found in HCV positive patients. There was a significant effect of ART on markers for EndoCAb IgA and EndoCAb IgM antibodies in the HIV monoinfected group. Correlation between CD4+ cell count and EndoCAb antibodies and LPS was found in HIV/HCV patients on ART. Coinfection with HCV can lead to more pronounced response in EndoCAb antibody production and higher levels of cell apoptosis markers, despite similar LPS levels. ART has a positive effect on immune activation.