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A chimeric protein containing most of the hepatitis B virus preS2 region (amino acid residues 1–48) upstream to, and colinear with the amino-terminus of bluetongue virus VP7 protein (preS2VP7) was expressed by a recombinant Autographa californica nuclear polyhedrosis virus (AcNPV). The chimeric protein formed BTV core-like particles (CLPs) in Spodoptera frugiperda cells only when the cells were coinfected with this recombinant virus and a recombinant baculovirus that expresses unmodified VP7 and VP3 of BTV. The ratio of preS2VP7 incorporated into CLPs was influenced by the relative multiplicities of infection of the two viruses. Immunoelectron microscopy of the chimeric particles indicated that the preS2 epitope was exposed on the surface of the CLPs. When insect cells were coinfected with the preS2 VP7 recombinant virus and a baculovirus vector that synthesized only the VP3 protein, no CLPs were identified. 相似文献
4.
Dmitry Permin Olga Postnikova Stanislav Balabanov Alexander Belyaev Vitaliy Koshkin Oleg Timofeev Jiang Li 《Materials》2023,16(1)
This study looked at optimizing the composition of precursors for yttria nanopowder glycine–nitrate self-propagating high-temperature synthesis (SHS). Based on thermodynamic studies, six different precursor compositions were selected, including with excesses of either oxidant or fuel. The powders from the precursors of all selected compositions were highly dispersed and had specific surface areas ranging from 22 to 57 m2/g. They were consolidated by hot pressing (HP) with lithium–fluoride sintering additive and subsequent hot isostatic pressing (HIP). The 1 mm thick HPed ceramics had transmittance in the range of 74.5% to 80.1% @ 1μm, which was limited by optical inhomogeneity due to incomplete evaporation of the sintering additive. Two-stage HIP significantly improves optical homogeneity of the ceramics. It was shown that an excess of oxidizer in the precursor decreases the powders’ agglomeration degree, which forms large pore clusters in the ceramics. 相似文献
5.
Al-Bahry SN Al-Mashani BM Al-Ansari AS Elshafie AE Mahmoud IY 《Asian Pacific journal of tropical medicine》2013,6(9):718-722
ObjectiveTo screen for Escherichia coli (E. coli) resistant to tetracycline, followed by identification of tet efflux genes by polymerase chain reaction (PCR). In addition, detection of tetracycline residues in chicken livers and kidneys were conducted using high performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS-MS).MethodsStrains of E. coli were isolated from samples of chicken colon and screened for tetracycline resistance. Tetracycline genes conferring resistance (Tcr) were detected by polymerase chain reaction (PCR). Most of the isolates were resistant to tetracycline (97.9%).ResultsPCR analysis indicated that Tcr E. coli R-plasmids contained tet(A), tet(B) and a combination of both efflux genes. None of the isolates contained other efflux tet genes tet (C, D, E and Y). High performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS-MS), a sensitive technique, was used to detect residues of chlortetracycline (CTC), oxytetracycline (OTC), doxycycline (DC) in chicken livers and kidneys. The samples containing tetracycline residues were at 0.13-0.65 pg/μL levels.ConclusionsTetracycline and other antibiotics are commonly used in the poultry and meat production industry for prevention of microbial infections. Multiple antibiotic resistant bacteria in Oman have increased to alarming levels, threatening public health, domestic and may have adverse effect on environment. 相似文献
6.
Ilgar Aghalarov Torsten Herzog Waldemar Uhl Orlin Belyaev 《HPB : the official journal of the International Hepato Pancreato Biliary Association》2018,20(7):676-683
Background
Double-loop (DL) reconstruction after pancreaticoduodenectomy (PD), diverting pancreatic from biliary secretions, has been reported to reduce rates and severity of postoperative pancreatic fistula (POPF) compared to single loop (SL) reconstruction at the price of prolonged operative duration. This study investigated the feasibility of a new reconstruction method combining the advantages of DL with the simplicity of SL in patients with high-risk pancreas.Methods
A modified single-loop (mSL) reconstruction was used in patients undergoing PD with a soft pancreatic remnant and a pancreatic duct smaller than 3 mm (n = 50). The loop between the pancreatic and the biliary anastomoses was left longer and a side-to-side jejunojejunal anastomosis was performed between them at the lowest point to promote isolated flow of pancreatic and biliary secretions. Rate and severity of POPF, mortality, duration of surgery, and POPF-associated morbidity were compared to those of 50 matched patients with SL and 25 patients with DL reconstruction.Results
Duration of surgery was 57 min longer for DL, but equal for mSL and SL. The POPF rate did not differ between the three groups. The severity of POPF was more pronounced in the SL group (62% grade C: p = 0.011). Mortality and major morbidity were lower and hospital stay shorter in the mSL and DL groups compared to the SL group.Conclusions
The new mSL reconstruction was safer than conventional SL and faster to perform than DL reconstruction in patients with a high-risk pancreas. It did not influence the rate of POPF, but reduced its severity, leading to less major morbidity and mortality. 相似文献7.
Ruslan I. Belyaev Alexander N. Kuznetsov Natalya E. Prilepskaya 《Journal of anatomy》2021,238(1):113-130
In this paper, we develop and validate an osteometry-based mechanistic approach to calculation of available range of motion (aROM) in presacral intervertebral joints in sagittal bending (SB), lateral bending (LB), and axial rotation (AR). Our basic assumption was the existence of a mechanistic interrelation between the geometry of zygapophysial articular facets and aROM. Trigonometric formulae are developed for aROM calculation, of which the general principle is that the angle of rotation is given by the ratio of the arc length of motion to the radius of this arc. We tested a number of alternative formulae against available in vitro data to identify the most suitable geometric ratios and coefficients for accurate calculation. aROM values calculated with the developed formulae show significant correlation with in vitro data in SB, LB, and AR (Pearson r = 0.900) in the reference mammals (man, sheep, pig, cow). It was found that separate formulae for different zygapophysial facet types (radial (Rf), tangential (Tf), radial with a lock (RfL)) give significantly greater accuracy in aROM calculation than the formulae for the presacral spine as a whole and greater accuracy than the separate formulae for different spine regions (cervical, thoracic, lumbar). The advantage of the facet-specific formulae over the region-specific ones shows that the facet type is a more reliable indicator of the spine mobility than the presence or absence of ribs. The greatest gain in calculation accuracy with the facet-specific formulae is characteristic in AR aROM. The most important theoretical outcome is that the evolutionary differentiation of the zygapophysial facets in mammals, that is the emergence of Tf joints in the rib cage area of the spine, was more likely associated with the development of AR rather than with SB mobility and, hence, with cornering rather than with forward galloping. The AR aROM can be calculated with the formulae common for man, sheep, pig, and cow. However, the SB aROM of the human spine is best calculated with different coefficient values in the formulae than those for studied artiodactyls. The most suitable coefficient values indicate that the zygapophysial articular facets tend to slide past each other to a greater extent in the human thoracolumbar spine rather than in artiodactyls. Due to this, artiodactyls retain relatively greater facet overlap in extremely flexed and extremely extended spine positions, which may be more crucial for their quadrupedal gallop than for human bipedal locomotion. The SB, LB, and AR aROMs are quite separate in respect of the formulae structure in the cervical region (radial facet type). However, throughout the thoracolumbar spine (tangential and radial with lock facets), the formulae for LB and AR are basically similar differing in coefficient values only. This means that, in the thoracolumbar spine, the greater the LB aROM, the greater the AR aROM, and vice versa. The approach developed promises a wide osteological screening of extant and extinct mammals to study the sex, age, geographical variations, and disorders. 相似文献
8.
Orlin Belyaev MD Sonja RosenkranzJohanna Munding MD Torsten Herzog Ansgar M. Chromik Andrea Tannapfel Waldemar Uhl 《The Journal of surgical research》2013
Background
Hard pancreas is welcome by surgeons performing resective pancreatic surgery, because it is believed to offer better suture holding capacity (SHC), thus decreasing the risk for a postoperative leak. However, neither the actual SHC of pancreatic tissue in humans nor its determinants have been studied.Methods
We directly measured SHC for polydioxanone 5–0 suture and tissue hardness at the pancreatic isthmus in 53 human pancreata using a dynamometer and a durometer. A histologic score based on fibrosis grade, fat content, pancreatic duct size, and signs of chronic pancreatitis was calculated for every sample. We tested the hypothesis that SHC of the pancreas was proportional to tissue hardness, and evaluated the role of different possible histomorphologic determinants of SHC.Results
Suture-holding capacity correlated perfectly with tissue hardness (r = 0.98; P < 0.001; 95% confidence interval, 0.96–0.99). The histologic score showed a stronger correlation with both parameters than any single histologic parameter. The SHC of transductal sutures was significantly higher than that of pure transparenchymal sutures. The SHC and hardness were significantly lower in patients who developed a clinically relevant pancreatic fistula postoperatively.Conclusions
A mixture of histomorphologic features of human pancreas determines its tissue hardness and SHC. Involvement of the main pancreatic duct in the suture line appears to increase the mechanical strength of the pancreatic anastomosis. 相似文献9.