Intermediate veins in swine (Sus scrofa domestica) kidney: authors’ own anatomical classification

Background: The use of domestic swine as an experimental animal is increasing steadily. Swine organs are the best animal model for urological experiments. The aim of the study was to evaluate the course and size of intermediate veins in a swine kidney. The research results were compared with the results obtained from studies on venous vascularisation of human kidneys. The knowledge of the above-mentioned vessels is important both in human and veterinary medicine and will enable researchers to compare and notice differences between human and swine organs. Materials and methods: The study was conducted on 94 kidneys, 47 right ones and 47 left ones, taken from adult domestic swines (Sus scrofa domestica). The kidneys were prepared and corrosion casts were made. Results: The average lumen diameter of secondary intermediate veins was 7.96 mm. The average diameter of the primary intermediate veins directly inserted in the renal vein (type A) and primary intermediate veins inserted in the secondary intermediate veins (type B) amounted to 6.7 mm and 4.75 mm, respectively. The average length of primary intermediate veins of type A was 21.91 mm. Secondary intermediate veins were shorter — on average 19.83 mm. Primary intermediate veins of type B were on average 12.91 mm long. Conclusions: Intermediate veins are formed in the area of vascular anastomoses on the level of renal papillae. The following veins can be distinguished: primary intermediate veins of type A and type B, as well as secondary intermediate veins. Secondary intermediate veins and primary intermediate veins of type A run only on the ventral side of the renal pelvis. Only the primary intermediate veins of type B can run on the dorsal side. From the anatomy point of view, intermediate veins of swine kidneys are very similar to equivalent vessels in human kidneys as regards their run and anastomoses.

Manufacturing of Composite Castings by the Method of Fused Models Reinforced with Carbon Fibers Based on the Aluminum Matrix

The paper presents an attempt to produce aluminum matrix composites reinforced with short carbon fibers by precision casting in a chamber with a pressure lower than atmospheric pressure. The composite casting process was preceded by tests related to the preparation of the reinforcement. This is related to the specificity of the precision casting process, in which the mold for shaping the castings is fired at a temperature of 720°C before pouring. Before the mold burns, the reinforcement must be inside, while the carbon fiber decomposes in the atmosphere at 396°C. In the experiment, the reinforcement in the form was secured with flake graphite and quartz sand. The performed firing procedure turned out to be effective. The obtained composite castings were evaluated in terms of the degree of alloy saturation and the displacement of carbon fibers. As a result of the conducted tests, it was found that as a result of unfavorable arrangement of fibers in the CF preform, the flow of metal may be blocked and porosity may appear in the casting

The Optical Gravitational Lensing Experiment. Monitoring of QSO 2237+0305

We present results from 2 years of monitoring of Huchra's lens (QSO 2237+0305) with the 1.3 m Warsaw telescope on Las Campanas, Chile. Photometry in the V band was done using a newly developed method for image subtraction. Reliable subtraction without Fourier division removes all complexities associated with the presence of a bright lensing galaxy. With positions of lensed images adopted from HST measurements it is relatively easy to fit the variable part of the flux in this system, as opposed to modeling of the underlying galaxy. For the first time we observed smooth light variation over a period of a few months, which can be naturally attributed to microlensing. We also describe automated software capable of real time analysis of the images of QSO 2237+0305. It is expected that starting from the next observing season in 1999 an alert system will be implemented for high amplification events (HAE) in this object. Time sampling and photometric accuracy achieved should be sufficient for early detection of caustic crossings.Comment: 8 pages (including 4 figures and table), latex, emulateapj, submitted to ApJ, revised version - minor change

One pot ‘click’ reactions: tandem enantioselective biocatalytic epoxide ring opening and [3+2] azide alkyne cycloaddition

Halohydrin dehalogenase (HheC) can perform enantioselective azidolysis of aromatic epoxides to 1,2-azido alcohols which are subsequently ligated to alkynes producing chiral hydroxy triazoles in a one-pot procedure with excellent enantiomeric excess.

What is the value of water contact angle on silicon?

Silicon is a widely applied material and the wetting of silicon surface is an important phenomenon. However, contradictions in the literature appear considering the value of the water contact angle (WCA). The purpose of this study is to present a holistic experimental and theoretical approach to the WCA determination. To do this, we checked the chemical composition of the silicon (1,0,0) surface by using the X-ray photoelectron spectroscopy (XPS) method, and next this surface was purified using different cleaning methods. As it was proved that airborne hydrocarbons change a solid wetting properties the WCA values were measured in hydrocarbons atmosphere. Next, molecular dynamics (MD) simulations were performed to determine the mechanism of wetting in this atmosphere and to propose the force field parameters for silica wetting simulation. It is concluded that the best method of surface cleaning is the solvent-reinforced de Gennes method, and the WCA value of silicon covered by SiO2 layer is equal to 20.7° (at room temperature). MD simulation results show that the mechanism of pure silicon wetting is similar to that reported for graphene, and the mechanism of silicon covered by SiO2 layer wetting is similar to this observed recently for a MOF