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Choice of the Acetabular Component Placement in Dysplastic Hip Patients

Abstract

Total hip arthroplasty (THA) in patients with hip dysplasia is a challenging surgical operation. Many orthopedic surgeons concur that the anatomical placement of the acetabular components of endoprostheses (AC-EPs) during THA yields the best result. However, there are advocates of the high rotation center of the hip joint after replacement surgery. In our study, we compared the outcomes of THA based on the placement of acetabular cups to identify the most favorable site for AC-EPs in patients with varying grades of dysplastic osteoarthritis. Our study included 88 patients with dysplastic hip osteoarthritis who underwent 106 THAs during a three-year period using cementless fixation endoprostheses. Functional results were assessed by Merle d’Aubigne and Postel’s method and by instrumental gait analysis (IGA). Gait deviation index was calculated based on IGA to compare results in different acetabular component placement groups. Functional assessment of patients by Merle d’Aubigne and Postel’s grading method and IGA showed no significant difference in results due to the placement of the acetabular component. Most complications were found in the severe dysplasia patients group with the anatomical placement of the AC-EP. The appropriate location of cementless acetabular cups during THA in dysplastic hips depends on the grade of dysplasia, expected elongation of the leg, and the potential for adequate bone coverage for the AC-EP. In cases of severe dysplasia, the placement of the AC-EP in the secondary socket can provide a good functional outcome and reduce the risk of complications.

Open access
Clinical and Sociodemographic Characteristics in First-Episode Psychosis Patients in a Rural Region of Latvia

Abstract

The first psychosis is a crucial point for further development of mental disorders. Previous evidence has demonstrated that psychotic disorders, including schizophrenia, are associated with a large number of years living with the disability. It is a global aim to improve prognosis of psychotic disorders, especially in rural regions, where mental health care possibly is not so easily accessible for patients. The aim of this study was to investigate clinical and sociodemographic determinants in association with patient and illness related factors to improve knowledge and understanding of first time psychosis patients in a rural region. This is a descriptive, cohort-based study of all consecutive first episode psychosis (F20, F23, ICD 10) patients admitted in the Daugavpils Psychoneurological Hospital (DPNH) between January 2016 and December 2017. Of the 94 first-time patients hospitalised in DPNH with symptoms of psychosis, 69 met the inclusion criteria. Our results showed that median age of patients was 33 years (IQR 27.5–42.0), median duration of untreated illness (DUI) was 30 months (IQR 11.0–60.0), and median duration of untreated psychosis (DUP) was 8 weeks (IQR 4.0–48.0). The results showed that 55.1% of first psychosis patients had not seen any health care specialist before being admitted to the psychiatric hospital. We found statistically significant differences between some sociodemographic aspects in DUI/DUP. Patients who lived with relatives had the longest DUI — 36 months, compared with 12 months for those who had established their own family. Unemployed patients had longer DUI — 36 months, compared with 12 months for employed patients. Similar findings were shown for associations with DUP. To our knowledge this study adds several important findings that help to better understand first psychosis patients.

Open access
Clinical Characterisation of Rota Virus Infection Associated with Most Commonly Circulating Genotypes in Children Hospitalised in Children’s University Hospital: A Cross-Sectional Study in Latvia

Abstract

In developed and developing countries, most cases of acute gastroenteritis in children are caused by viruses, and rotaviruses are known as the leading cause. The aim of our study was to estimate the main circulating serotypes of rotavirus before the introduction of routine immunisation in Latvia, and to search for their possible correlation with clinical symptoms and circulating genotypes. A cross-sectional study was carried out among children who had been hospitalised in the Children’s Clinical University Hospital from April 2013 to December 2015. Genotyping was done for 462 stool samples. Among G/P combinations, the most predominant genotypes were G4P[8] (61.3%), G9P[8] (12.4%) and G2P[4] (10.0%) in children of age < 5 years, G4P[8] (45.5%), G2P[4] (18.2%), G9P[8], G3P[8], and G1P[8] (9.1%) in children of age > 5 years. There was a statistically significant correlation (p < 0.05) between clinical signs (vomiting, dehydration, chronic diseases) and G1P[8] and G8P[8] genotypes. Infants infected with genotype G4P[4] had a statistically significant negative correlation with severity of acute gastroenteritis episodes (p < 0.05). We detected nine different rotavirus G genotypes, and two different P genotypes. G4P[8], G9P[8], and G2P[8] were predominant. We observed correlation between the dominant genotypes and clinical manifestations of rotavirus infection.

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Cone Beam Computed Tomography Evaluation of Maxillary Sinus Before and After Sinus Floor Elevation

Abstract

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.

Open access
Construction of (M, N)-hypermodule over (R, S)-hyperring

Abstract

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.

Open access
Consumption of Thyroid Medications as an Indicator of Increase of Thyroid Morbidity in Latvia from 2011 to 2014

Abstract

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.

Open access
Correlation Distribution Analysis of a Two-Round Key-Alternating Block Cipher

Abstract

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.

Open access
Cryptanalysis of Enhanced More

Abstract

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.

Open access
Cryptanalysis of the Columnar Transposition Using Meta-Heuristics

Abstract

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.

Open access
A Cryptographic System Based on a New Class of Binary Error-Correcting Codes

Abstract

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 22 k, 22 k−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.

Open access