Single DNA molecule detection using nanopipettes and nanoparticles

Single DNA molecules labeled with nanoparticles can be detected by blockades of ionic current as they are translocated through a nanopipette tip formed by a pulled glass capillary. The nanopipette detection technique can provide not only tools for detection and identification of single DNA and protein molecules but also deeper insight and understanding of stochastic interactions of various biomolecules with their environment.     

Small-diameter (2 mm) laparoscopy in the evaluation of liver disease

We report the case of a pathological mediopatellar plica found in the right knee of a 15-month-old infant girl. Flexion contracture of the knee was found to be 40 degrees. An arthroscopic view showed a large and thick voluminous mediopatellar plica. It was trapped between the patella and the medial femoral condyle and it was in tight contact with the medial facet of the patella at 40 degrees flexion in the knee, blocking further extension. A longitudinal groove was noted on the articular surface of the medial femoral condyle that looked as if it had another trochlea on arthroscopic view. The mediopatellar plica came into contact with the groove at 60 degrees flexion in the knee and it fitted precisely into the groove at further flexion. The pathological plica was resected arthroscopically, which resulted in approximately 10 degrees improvement in extension of the knee. Histological examination found hypertrophy and chronic nonspecific inflammation of the synovium. The patient was helped with range-of-motion exercise and quadriceps-strengthening exercise. At 27 months follow-up, the knee had gained full extension. This article reports that a pathological mediopatellar plica may develop in infants.     

A time‐dependent multiphysics,multiphase modeling framework for carbon nanotube synthesis using chemical vapor deposition

A time‐dependent multiphysics, multiphase model is proposed and fully developed here to describe carbon nanotubes (CNTs) fabrication using chemical vapor deposition (CVD). The fully integrated model accounts for chemical reaction as well as fluid, heat, and mass transport phenomena. The feed components for the CVD process are methane (CH₄), as the primary carbon source, and hydrogen (H₂). Numerous simulations are performed for a wide range of fabrication temperatures (973.15–1273.15 K) as well as different CH₄ (500–1000 sccm) and H₂ (250–750 sccm) flow rates. The effect of temperature, total flow rate, and feed mixture ratio on CNTs growth rate as well as the effect of amorphous carbon formation on the final product are calculated and compared with experimental results. The outcomes from this study provide a fundamental understanding and basis for the design of an efficient CNT fabrication process that is capable of producing a high yield of CNTs, with a minimum amount of amorphous carbon. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

Effect of solar chimney inclination angle on space flow pattern and ventilation rate

The solar chimney is a simple and practical idea that is applied to enhance space natural ventilation. The chimney could be vertical or inclined. The chimney inclination angle is an important parameter that greatly affects space flow pattern and ventilation rate.In the present study, the effect of chimney inclination angle on air change per hour and indoor flow pattern was numerically and analytically investigated. A numerical simulation using Ansys, a FEM-based code, was used to predict flow pattern. Then the results were compared with published experimental measurements. A FORTRAN program was developed to iteratively solve the mathematical model that was obtained through an overall energy balance on the solar chimney.The analytical results showed that an optimum air flow rate value was achieved when the chimney inclination is between 45° and 70° for latitude of 28.4°. The numerically predicted flow pattern inside the space supports this finding. Moreover, in the present study a correlation to predict the air change per hour was developed. The correlation was tested within a solar intensity greater than or equal to 500 W/m², and chimney width from 0.1 m to 0.35 m for different inclination angles with acceptable values.     

Architecture (and the other 99%): Open-Source Architecture and Design Commons

Under the current commercial practice model, can architecture ever really be cutting-edge or egalitarian in its aims? If only 2 per cent of the world's buildings are designed by architects for 1 per cent of the richest clients, is it possible to design for a wide cross section of the population let alone be truly subversive? Alastair Parvin of architecture studio 00 (zero zero) and co-founder of the Wiki-House puts the case forward for a whole new model of open-source practice.     

A chromium complex under water oxidation: A conversion mechanism and a comprehensive hypothesis

Water splitting toward hydrogen production is a promising method to store energy, but water oxidation is a bottleneck for water splitting. First-row transition metal complexes have been extensively used for water-oxidation reaction. However, only one chromium complex has been applied for water-oxidation reaction until now. Thus, the reinvestigation of water-oxidation reaction by this chromium complex in detail is interesting. Herein, water-oxidation reaction by the chromium complex with diphenoxy N,N′-ethylenebis(salicylimine) (SALEN) ligand is reinvestigated using scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction studies, X-ray photoelectron spectroscopy, thermal gravimetric analysis, elemental analysis, Fourier-transform infrared spectroscopy, and electrochemical methods. All the experiments showed that the chromium complex is neither a catalyst nor a precatalyst for water-oxidation reaction. During OER, a relationship between first-row transition metal complexes and the related metal oxides has been proposed.     

Effects of GPTMS concentration and powder to liquid ratio on the flowability and biodegradation behaviors of 45S5 bioglass/tragacanth bioactive composite pastes

Injectable composite pastes were prepared using melt-derived 45S5 bioactive glass and tragacanth crosslinked by (3-glycidyloxypropyl)trimethoxysilane (GPTMS). The effect of powder to liquid ratio (P:L = 1.0:2.0–1.0:2.5) and GPTMS/tragacanth ratio (0.0–1.5) on the injectability, swelling behavior, rheology, bioactivity, and cellular behavior of the pastes was investigated. Based on the results, the apparent stability and consistency of the pastes increased upon crosslinking by GPTMS. Due to the increased interactions between tragacanth and glass, a hysteresis loop with larger area was formed in the presence of GPTMS. With increase of GPTMS:tragacanth ratio from 0 to 1.5, the swelling percent dropped from 24.65 to 16.25% after 24 h and the degradation percent also went down from 27.89 to 9.11% after 21 days in the simulated body fluid. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed a drop in the optical density of MG63 osteoblasts up to 30.07% after exposure to the GPTMS-crosslinked composite pastes for 3 days. However, the number of viable cells gradually increased in the presence of the pastes and the cell morphology remained unchanged over time. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47604.     

Microstructure and Optical Bandgap of Cobalt Selenide Nanofilms

Semiconductors - The purpose of this research is to explore the properties of CoSe nanostructured thin films on glass substrates prepared by a chemical solution deposition method. Special attention...     

Benders Decomposition Algorithms for Two Variants of the Single Allocation Hub Location Problem

Networks and Spatial Economics - The hub location problem (HLP) is a special type of the facility location problem with numerous applications in the airline industry, postal services, and computer...