Possible Role of Accessory Proteins in the Viral Replication for the 20I/501Y.V1 (B.1.1.7) SARS CoV-2 Variant

The emergence of new severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) has been a global concern. The B.1.1.7 variant of SARS CoV-2 is reported to cause higher transmission. The study investigates the replication cycle and transcriptional pattern of the B.1.1.7 to hypothesis the possible role of different genes in viral replication. It was observed that the B.1.1.7 variant required a longer maturation time. The transcriptional response demonstrated higher expression of ORF6 and ORF8 compared to nucleocapsid transcript till the eclipse period which might influence higher viral replication. The number of infectious viruses titer is higher in the B.1.1.7, despite a lesser copy number than B.1, indicating higher transmissibility. The experimental evidence published linked ORF6 and ORF8 to play important role in replication and we also observed their higher expression. This leads us to hypothesis the possible role of ORF6 and ORF8 in B.1.1.7 higher replication which causes higher transmission.

Nanocomposites based on apatitic tricalcium phosphate and autofibrin

Nanocomposites based on apatitic tricalcium phosphate in an autofibrin matrix were obtained by precipitation at a Ca/P ratio of 1.50, pH 9 and a maturation time from 30 min to 7–14 days. The resorbability of nanocomposites was determined by the composition of calcium phosphates, which, during long-term maturation, formed as the calcium-deficient hydroxyapatite with a Ca/P ratio of 1.66, whereas biopolymer matrix favored the formation of more soluble calcium phosphates with a Ca/P ratio of 1.53–1.59. It was found that the fibrin clot stabilized, along with apatitic tricalcium phosphate, the phase of amorphous calcium phosphate, which after 800 °C was transformed into resorbable α-tricalcium phosphate. Citrated plasma inhibited the conversion of apatitic tricalcium phosphate into stoichiometric hydroxyapatite, which also facilitated the formation of resorbable β-tricalcium phosphate after 800 °C. The combined effect of the maturation time and the biopolymer matrix determined the composition, physicochemical and morphological properties of nanocomposites and the possibililty to control its extent of resorption

Sol-gel system evolution control for the synthesis of gas-sensitive nanomaterials based on semiconductor oxides

The article analyzes conditions for the occurrence of spinodal decomposition in sol-gel systems based on semiconductor oxide precursors, resulting in labyrinthine structures. Such materials are promising for use in chemoresistive gas sensors with increased sensory response. It is shown that system evolution towards these structures is possible due to sol cooling, or increased its maturation time.

Zagreb clay improved with various binders

The paper presents the results of laboratory testing of clay samples from two localities in the city of Zagreb, mixed with fly ash, slag and cement. Under laboratory conditions, composite samples of clay mixtures with binders were prepared, where the binders are added to the clay in ratios of 5 %, 10 % and 20 %, and tested at different maturation time intervals of 7, 14 and 28 days. The influence of different type and amount of binder and age of the composite sample on moisture and uniaxial compressive strength was examined and analysed. The obtained results show that the utilization of cement, fly ash and slag can improve the physical and mechanical properties of Zagreb clay, depending on the amount of binder and the maturation time of the composite.

A Comparative Study between Radiocephalic and Brachiocephalic Arteriovenous Fistula in End Stage Renal Disease

Background: Chronic Kidney Disease (CKD) is a major health issue all over the world. Patients with deteriorating renal function and end-stage renal disease require vascular access for hemodialysis. Studies suggest that Arterio-Venous fistula (AVF) constructed judiciously using autologous conduit give the best outcome in this regard. Objective of the study was to compare the outcomes of Radiocephalic and Brachiocephalic AVF in end stage renal disease (ESRD). Methods: It was a quasi-experimental study carried out at the Department of Vascular Surgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka. The study was conducted from June 2019 to May 2020. Patients suffering from ESRD underwent AVF creation surgery for hemodialysis access. A total of 60 (Sixty) patients were included in this study. The patients were divided into two groups; Group I included 30 patients who underwent Radiocephalic AVF operation and Group II included 30 patients who had Brachiocephalic AVF operation. Results: In Group I, (Radiocephalic AVF) 60% were male and 40% were female. On the other hand, in Group II (Brachiocephalic AVF) 73.3% were male and 26.7% were female. Calculated volume flow (Q max) was significantly higher in Group II compared with Group I (769.11±101.54 ml/min vs 626.37±55.81) ml/min) with the difference being statistically significant (P=0.001). Maturation time was significantly less in Group II compared with Group I )37.78±1.93 vs 43.33±2.12 days) with the difference between the two group being statistically significant (P=0.001). Complication was more in Group I than Group II (16.7% vs 3.3%). Conclusion: The present study shows that Brachiocephalic AVF gives significantly better outcome in terms of shorter maturation time and less complications compared with Radio-Cephalic AVF. Color Doppler study is an essential tool for preoperative vessel evaluation which guides the selection of suitable AVF construction site. Cardiovasc j 2021; 14(1): 44-49

Balloon angioplasty: A promising adjunct to arteriovenous fistula creation compared with hydrostatic dilatation in small-caliber cephalic veins

Background To maintain the patency and longevity of arteriovenous fistula, the availability of a venous segment with adequate diameter is important. In Indian population, many chronic kidney disease patients have poor caliber veins. The study aimed to evaluate the efficacy of hydrostatic dilatation versus Primary balloon angioplasty of small caliber cephalic veins of (≤2.5 mm) preoperatively in terms of patency rate and maturation time of arteriovenous fistula. Methods Patients ( n = 80) with an end-stage renal disease requiring arteriovenous access surgery for hemodialysis with small caliber cephalic veins were randomized into two groups, i.e., hydrostatic dilatation and primary balloon angioplasty, each with 40 patients. All patients underwent a thorough clinical examination as well as duplex ultrasound vein mapping of both upper extremities. Patients were followed up for six months and primary patency, maturation time, and complications were noted. Results Immediate technical success with good palpable thrill was achieved in 97.5% of patients in the primary balloon angioplasty group and 87.5% in the hydrostatic dilatation group. The fistula maturation time in the primary balloon angioplasty group was 34.41 days and 46.18 days in the hydrostatic dilatation group. In the primary balloon angioplasty group, the primary patency of the fistula was 97.5% and 87.5% in the hydrostatic dilatation group, at six months. The arteriovenous fistula functioning rate was 77.5% in the hydrostatic dilatation group as compared to 92.5% in the primary balloon angioplasty group at six months. The incidence of surgical site infection was 5% in the primary balloon angioplasty group as compared to 10% in the hydrostatic dilatation group. Conclusion Primary balloon angioplasty of small caliber cephalic veins (≤2.5 mm) performed prior to arteriovenous fistula creation for hemodialysis is a beneficial procedure.

NaNuTrap, a technique for in vivo cell nucleus labelling using nanobodies

In vivo cell labelling is challenging in fast developmental processes because many cell types differentiate more quickly than the maturation time of fluorescent proteins making visualization of these tissues impossible with standard techniques. Here we present a nanobody-based method, Nanobody Nuclear Trap (NaNuTrap), which works with the existing Gal4/UAS system in Drosophila and allows for early in vivo cell nuclei labelling independent of the fluorescent protein's maturation time. This restores the utility of fluorescent proteins that have longer maturation times, such as those used in two-photon imaging, for live imaging of fast or very early developmental processes. We also present a more general application of this system, whereby NaNuTrap can convert cytoplasmic GFP expressed in any existing transgenic fly line into a nuclear label. This nuclear re-localization of the fluorescent signal can improve the utility of the GFP label, for example in cell counting, as well as resulting in a general increase in intensity of the live fluorescent signal. We demonstrate these capabilities of NaNuTrap by effectively tracking subsets of cells during the fast movements associated with gastrulation.

Improvement of Water Resistance of Vegetable Proteins by the Use of Synthetic Origin Additives: Trials with Resins and Metal Ions

The adhesives industry is increasingly interested in products coming from natural and renewable resources. The aim of the present work was to improve the water resistance of soy-based proteins by using synthetic and formaldehyde-free additives. These include polyamide-amine epichlorohydrin (PAE), different types of isocyanates, and combinations of these cross-linkers between them and with other agents, including metal ions. In addition, the effect of both curing temperature and maturation time was assessed. Performances were evaluated by means of shear strength tests, solubility tests, and spectroscopic analysis. The obtained results showed that while isocyanates reacted completely but with water instead of proteins, tests with PAE were generally successful. In fact, the insoluble residue as well as the shear strength in wet conditions dramatically increased after PAE addition. Moreover, the wet performances of protein/PAE formulations appreciably increased gluing at 60 °C instead of room temperature. Furthermore, the maturation time had a positive effect on the formulations where metal ions were added, both for solubility and wet shear strength. Actually, for the very long conditioning time of 3 months, a significant and substantial increase of wet shear strength was observed for the series protein/PAE/aluminum.