The detection of influenza A virions with a nanoribbon detector (NR detector) has been demonstrated. Chips for the detector have been fabricated based on silicon-on-insulator nanoribbon structures ...(SOI nanoribbon chip), using a complementary metal-oxide-semiconductor (CMOS)-compatible technology-by means of gas-phase etching and standard optical photolithography. The surface of the SOI nanoribbon chip contains a matrix of 10 nanoribbon (NR) sensor elements. SOI nanoribbon chips of n-type conductance have been used for this study. For biospecific detection of target particles, antibodies against influenza virus have been covalently immobilized onto NRs. Influenza A virus detection was performed by real-time registration of the source-drain current through the NRs. The detection of the target viral particles was carried out in buffer solutions at the target particles concentration within the range from 10
to 10
viral particles per milliliter (VP/mL). The lowest detectable concentration of the target viral particles was 6 × 10
M (corresponding to 10
VP/mL). The use of solutions containing ~10
to 10
VP/mL resulted in saturation of the sensor surface with the target virions. In the saturation mode, detection was impossible.
Plasmonic enhancement of the luminescence of fl uorescein isothiocyanate and human immunoglobulin conjugates near silver nanoparticles was investigated as functions of the nanoparticle-conjugate ...distance and the excitation polarization. The maximum luminescence enhancement of 7.4 was achieved for p-polarized excitation and nanoparticle-conjugate distance 3.3 nm. The luminescence enhancement factor increased experimentally for p-polarized excitation and decreased for s-polarized excitation as compared with unpolarized excitation.
The stationary and oscillatory regimes of thermal convection in a binary liquid mixture flowing in narrow connected channels under the action of positive and negative thermodiffusion have been ...studied. It is established that specific oscillatory flows develop in the case of positive thermodiffusion at a small supercriticality. A mechanism explaining the observed phenomena is proposed and confirmed by the results of numerical calculations. It is shown that connected channels can be used in technological processes for the separation of components in binary liquid mixtures.
Herein, we report the development of a highly sensitive nanotechnology-based system—silicon-on-insulator nanowire biosensor for the revelation of microRNAs (miRNAs), associated with the development ...of glioma in the human. In this system, a sensor chip, bearing an array of silicon nanowire structures, is employed. The sensor chip is fabricated using a top-down technology. In our experiments reported herein, we demonstrated the detection of DNA oligonucleotide (oDNA), which represents a synthetic analogue of microRNA-363 associated with the development of glioma. To provide biospecific detection of the target oligonucleotides, the surface of the nanowire structures is modified with oligonucleotide probes; the latter are complementary to the target ones. The concentration limit of the target oligonucleotide detection, attained using our nanowire biosensor, is at the level of DL~10−17 M. The revelation of the elevated level of glioma-associated miRNA in plasma is also demonstrated.
To assess the diagnostic performance of urine telomerase activity (TA) in detecting bladder cancer (BCa) using the modified Telomeric Repeat Amplification Protocol (TRAP) and the Real Time Telomeric ...Repeat Amplification Protocol with double Polymerase Chain Reaction (RT-TRAP-2PCR).
In this case-control study, matching urine (in the pre- and post-surgical period) and tissue samples from 68 patients with BCa were assessed for TA. As a control, 45 urine samples were examined from non-BCa patients. TA levels were measured using TRAP and RT-TRAP-2 PCR methods.
Preoperative urinary TA was elevated in 64 (94.1%) of the 68 BCa patients. Urine TA was undetectable in 44 control patients, while TA was detected in one patient with histologically verified cystitis. Sensitivity for BCa detection of 94.1% and specificity of 97.8% were observed for urinary TA, while tissue TA had 100% sensitivity and 97.8% specificity. Both urine and tissue TA levels were not significantly higher in patients with muscle-invasive disease compared to those with non-muscle invasive BCa (
> 0.05). Urine and tissue TA levels were not associated with higher tumor grade, stage, and number of tumors (
> 0.05). However, the association was found between higher urinary and tissue TA levels with tumor size ≥ 3 cm (
= 0.02 and
= 0.01, respectively). During the first postoperative year, 17 BCa patients experienced disease recurrence, and urinary TA was present in 14 (82.4%) of these patients. The sensitivity and specificity of urinary TA levels for BCa recurrence in patients with non-muscle invasive bladder cancer (NMIBC) during follow-up were 82% and 94.4%, respectively.
This pilot study demonstrates a high diagnostic performance of urinary and tissue TA levels measured by a new RT-TRAP-2PCR method for detecting and monitoring BCa. Additionally, the association was found between higher urinary and tissue TA levels with tumor size ≥ 3 cm; however, higher TA levels failed for significant correlation with advanced tumor stage and grade. Our study could serve as a benchmark for the evaluation of novel biomarkers using the RT-TRAP-2PCR method.
This paper presents the results of a study of the formation of the structure and properties of the 40Au–25.4Pd–34.6Cu alloy (wt %) in the course of its atomic ordering. A number of literature sources ...have been analyzed, and possible reasons for the deviation between experimental data of different authors are discussed here. Earlier field ionic microscopy (FIM) results have been confirmed: ordered
В
2-phase nuclei in a matrix with an
L
1
0
-superstructure were observed in this alloy after prolonged annealings. It has been shown that the kinetic of atomic ordering is abruptly accelerated in a field of external tensile stresses. The results of this work demonstrate the possibility to control the structure in the course of “disorder ↔ order” transitions and can be used for the creation of new approaches to the treatment of orderable alloys.
Bacteriophage capsids constitute icosahedral shells of exceptional stability that protect the viral genome. Many capsids display on their surface decoration proteins whose structure and function ...remain largely unknown. The decoration protein pb10 of phage T5 binds at the centre of the 120 hexamers formed by the major capsid protein. Here we determined the 3D structure of pb10 and investigated its capsid-binding properties using NMR, SAXS, cryoEM and SPR. Pb10 consists of an α-helical capsid-binding domain and an Ig-like domain exposed to the solvent. It binds to the T5 capsid with a remarkably high affinity and its binding kinetics is characterized by a very slow dissociation rate. We propose that the conformational exchange events observed in the capsid-binding domain enable rearrangements upon binding that contribute to the quasi-irreversibility of the pb10-capsid interaction. Moreover we show that pb10 binding is a highly cooperative process, which favours immediate rebinding of newly dissociated pb10 to the 120 hexamers of the capsid protein. In extreme conditions, pb10 protects the phage from releasing its genome. We conclude that pb10 may function to reinforce the capsid thus favouring phage survival in harsh environments.
PDF
