Attachment of hybridizable oligonucleotides to a silica support and its application for selective extraction of unmodified and antisense oligonucleotides from serum samples

The main aim of the present study was the synthesis of an oligonucleotide-based material with high chemical stability, repeatability and specificity to complementary oligonucleotides. The oligonucleotides were attached to a silica gel surface modified with amino acids during one-step synthesis. The amount of the oligonucleotides immobilized on the support surface had an impact on adsorption effectiveness, due to steric interference. The adsorption capacity corresponds to 4.7 μg of complementary oligonucleotide per 1 mg of material, which reflects 50% of immobilized oligonucleotides. The presented results contain comprehensive studies on hybridization and release of fully complementary, partially complementary, non-complementary and antisense oligonucleotides from the newly synthesized adsorbent. The salt concentration and time period were the most influential parameters in the case of adsorption, while high temperature and low salt content were indispensable for effective desorption. Selectivity studies revealed that the adsorption percentage increases with the decreasing number of base mismatches. Consequently, the desorption of low complementarity oligonucleotides was always greater in comparison with the fully complementary sequence. Furthermore, it was shown that oligonucleotide-based materials may be successfully used for the extraction of antisense oligonucleotides and their metabolites from serum samples with recoveries ranging between 65 and 73%.

The main aim of the present study was the synthesis of an oligonucleotide-based material with high chemical stability, repeatability and specificity to complementary oligonucleotides.     

Validation of temperature methods for the estimation of pre-appearance interval in carrion insects

The pre-appearance interval (PAI) is an interval preceding appearance of an insect taxon on a cadaver. It decreases with an increase in temperature in several forensically-relevant insects. Therefore, forensic entomologists developed temperature methods for the estimation of PAI. In the current study these methods were tested in the case of adult and larval Necrodes littoralis (Coleoptera: Silphidae), adult and larval Creophilus maxillosus (Coleoptera: Staphylinidae), adult Necrobia rufipes (Coleoptera: Cleridae), adult Saprinus semistriatus (Coleoptera: Histeridae) and adult Stearibia nigriceps (Diptera: Piophilidae). Moreover, factors affecting accuracy of estimation and techniques for the approximation and correction of predictor temperature were studied using results of a multi-year pig carcass study. It was demonstrated that temperature methods outperform conventional methods. The accuracy of estimation was strongly related to the quality of the temperature model for PAI and the quality of temperature data used for the estimation. Models for larval stage performed better than models for adult stage. Mean temperature for the average seasonal PAI was a good initial approximation of predictor temperature. Moreover, iterative estimation of PAI was found to effectively correct predictor temperature, although some pitfalls were identified in this respect. Implications for the estimation of PAI are discussed.     

The influence of hydromorphological modifications of the littoral zone in lakes on macrophytes

The study aimed at determining the influence of hydromorphological modifications of the littoral zone in lakes on the occurrence and quantitative diversity of macrophytes. The field research was carried out at the peak of the growing season (June – September) between 2006 and 2009. Altogether, 457 transects were studied, located in 5 lakes. Studies on the hydromorphology were performed with the method of Lake Habitat Survey (LHS), and on macrophytes — with the method of transects. The studied sites were divided into 3 groups of different intensity of morphological transformations. The identified groups constituted the starting point for the analysis of influence exerted by transformations on macrophytes. The obtained results indicate that hydromorphological modifications of lakes are an important ecological factor affecting the occurrence and quantitative diversity of macrophytes. The transformations recorded in the studied reservoirs resulted mostly from recreational exploitation. They were responsible for mechanical elimination of dominant species, which led to an increased number of taxa, synanthropization and an average level of hemeroby as well as a decrease in the total vegetation cover. Helophytes were the most negatively affected group by the transformations, which reduce their contribution in the vegetation cover, whereas macroscopic filamentous algae and elodeids were positively affected.     

High-Performance Face Milling of 42CrMo4 Steel: Influence of Entering Angle on the Measured Surface Roughness,Cutting Force and Vibration Amplitude

High feed Milling is a new milling method, which allows to apply high feed rates and increase machining efficiency. The method utilizes face cutters with a very small entering angle, of about 10°–20°. Thus, the cut layer cross-section is different than in traditional milling. In order to examine the high feed milling (HFM), experimental tests were conducted, preceded by an analysis of cutting zones when milling with an HF face cutter. The face milling tests of 42CrMo4 steel with the use of an HF cutter characterized by an entering angle, dependent on axial depth of cut a_p and insert radius r values, as well as with a conventional face cutter with the entering angle of 45° were performed. The study focused on analyzing the vibration amplitude, cutting force components in the workpiece coordinate system, and surface roughness. The experimental tests proved, that when milling with constant cut layer thickness, the high feed cutter allowed to obtain twice the cutting volume in comparison with the conventional face cutter. However, higher machining efficiency resulted in an increase in cutting force components. Furthermore, the results indicate significantly higher surface roughness and higher vibration amplitudes when milling with the HF cutter.     

Foundation Piles—A New Feature for Concrete 3D Printers

Foundation piles that are made by concrete 3D printers constitute a new alternative way of founding buildings constructed using incremental technology. We are currently observing very rapid development of incremental technology for the construction industry. The systems that are used for 3D printing with the application of construction materials make it possible to form permanent formwork for strip foundations, construct load-bearing walls and partition walls, and prefabricate elements, such as stairs, lintels, and ceilings. 3D printing systems do not offer soil reinforcement by making piles. The paper presents the possibility of making concrete foundation piles in laboratory conditions using a concrete 3D printer. The paper shows the tools and procedure for pile pumping. An experiment for measuring pile bearing capacity is described and an example of a pile deployment model under a foundation is described. The results of the tests and analytical calculations have shown that the displacement piles demonstrate less settlement when compared to the analysed shallow foundation. The authors indicate that it is possible to replace the shallow foundation with a series of piles combined with a printed wall without locally widening it. This type of foundation can be used for the foundation of low-rise buildings, such as detached houses. Estimated calculations have shown that the possibility of making foundation piles by a 3D printer will reduce the cost of making foundations by shortening the time of execution of works and reducing the consumption of construction materials.     

Initial prevalence of anal human papilloma virus infection in liver transplant recipients

Although liver transplant recipients are at increased risk of human papilloma virus (HPV)‐related anal cancer, limited data are available regarding the initial prevalence of anal HPV infection in this population. Anal swabs collected from 50 liver transplant recipients within the first three postoperative weeks were subjected to real‐time polymerase chain reaction for detection of the four HPV genotypes: 6, 11, 16, and 18. Predictors of any, low‐risk, and high‐risk anal HPV infection were evaluated. Overall, the prevalence of any anal HPV infection was 18.0%, with the corresponding rates for high‐ and low‐risk HPV genotypes being 8.0% and 10.0%, respectively. Infection with any type of anal HPV was higher in patients with hepatitis B virus (HBV) infection (P = 0.027), ≥3 sexual partners (P = 0.031), and alcoholic liver disease (P = 0.063). HBV infection was the only factor significantly associated with high‐risk HPV infection (P = 0.038). Male sex (P = 0.050), age ≥52 years (P = 0.016), ≥30 sexual partners (P = 0.003), age at first intercourse ≤18 years (P = 0.045), and time since first intercourse ≥38 years (P = 0.012) were identified as predictors of low‐risk HPV infection. These results indicate that HPV vaccination of liver transplant candidates and screening for anal HPV infection in high‐risk groups should be considered.     

Constrictive pericarditis as complication of viral respiratory infection

A 24 year-old man with 3-months medical history of recurrent respiratory infections and pericardial effusion, despite treatment with nonsteroid anti-inflammatory drugs, was admitted to the hospital with dyspnea on exertion. On admission he presented the symptoms of right heart insufficiency. Computed tomography of the chest demonstrated a thickened pericardium. Echocardiographic examination and right heart catheterisation established the diagnosis of constrictive pericarditis. Serologic tests suggested viral aetiology. The patient was referred to cardiothoracic surgery, partial pericardiectomy was performed with marked haemodynamic improvement.     

Young convalescent COVID‐19 pneumonia with extensive pneumomediastinum emphysema: Case report

The development of the SARS‐CoV‐2 pandemic caused a common appearance of severe pulmonary complications, rarely seen as a result of the other infections. These are pneumothorax, pneumomediastinum, emphysematous bullae, cavitary lung lesions, or subcutaneous emphysema. Their formation is influenced by both—the natural course of the disease and the treatment strategy adopted.     

Letter: Is Central Nervous System Involvement in Hodgkin's Disease Really Very Rare?

Sir, Central nervous system (CNS) involvement in Hodgkin's disease (HD) seems to be more common than previously realized. 2 In the period 1988-1993, among 38 children, we have seen two cases of CNS involvement in HD, while during the period 1969-1987 we have not recognised such cases at all among 125 children.