Intelligent Chiral Sensing Based on Supramolecular and Interfacial Concepts

Of the known intelligently-operating systems, the majority can undoubtedly be classed as being of biological origin. One of the notable differences between biological and artificial systems is the important fact that biological materials consist mostly of chiral molecules. While most biochemical processes routinely discriminate chiral molecules, differentiation between chiral molecules in artificial systems is currently one of the challenging subjects in the field of molecular recognition. Therefore, one of the important challenges for intelligent man-made sensors is to prepare a sensing system that can discriminate chiral molecules. Because intermolecular interactions and detection at surfaces are respectively parts of supramolecular chemistry and interfacial science, chiral sensing based on supramolecular and interfacial concepts is a significant topic. In this review, we briefly summarize recent advances in these fields, including supramolecular hosts for color detection on chiral sensing, indicator-displacement assays, kinetic resolution in supramolecular reactions with analyses by mass spectrometry, use of chiral shape-defined polymers, such as dynamic helical polymers, molecular imprinting, thin films on surfaces of devices such as QCM, functional electrodes, FET, and SPR, the combined technique of magnetic resonance imaging and immunoassay, and chiral detection using scanning tunneling microscopy and cantilever technology. In addition, we will discuss novel concepts in recent research including the use of achiral reagents for chiral sensing with NMR, and mechanical control of chiral sensing. The importance of integration of chiral sensing systems with rapidly developing nanotechnology and nanomaterials is also emphasized

Development of Digested Sludge-Assimilating and Biohydrogen-Yielding Microflorae

Digested sludge (DS) is a waste product of anaerobic digestion that is produced during the biodegradation of excess sludge. It cannot be used as a substrate for further biogas production owing to its recalcitrant nature. In the present study, we used a heat treatment technique to convert DABYS microflora (DABYS = digested sludge-assimilating and biogas-yielding soil microflora), which degraded DS and produced methane gas, to a microflora that could produce hydrogen gas from DS. Heat treatment at 80 and 100 °C inactivated the methanogens that consume hydrogen for methane production but did not affect the thermotolerant bacteria. We developed three microflorae (DABYS-A80, DABYS-A100, and DABYS-80B) to exclusively produce hydrogen gas. They included representatives from the anaerobic eubacterial families Clostridiaceae and Enterobacteriaceae. Pseudomonas sp. was also present in DABYS-A80 and DABYS-A100. It is thought that bacteria in the Enterobacteriaceae family or Pseudomonas genus survive heat treatment because they are embedded in microgranules. Enzymatic analysis suggested that the microflorae hydrolyzed DS using cellulase, chitinase, and protease. Under optimum culture conditions, DABYS-A80, -A100, and B-100 produced gas yields of 8.0, 7.1, and 2.6 mL, respectively, from 1.0 g of dried DS

Variable temperature characterization of N,N′-Bis(n-pentyl)terrylene-3,4:11,12-tetracarboxylic diimide thin film transistor

International audienceOrganic thin film transistors (OTFT) based on N,N′-Bis(n-pentyl)terrylene-3,4:11,12-tetracarboxylic diimide (TTCDI-5C) with Al or Au top-contact electrodes were deposited on SiO2 (200 nm)/p-Si (0 0 1) substrates. Carrier mobility was examined as a function of temperature in the range from 50 to 310 K. Two distinct carrier transfer behaviours were observed: temperature independent behaviour below 150 K and thermally activated behaviour above 150 K. Activation energies presented values of 85–130 meV depending on the metal electrodes (Au, Al), which can be attributed to the carrier traps at the interface and the energy-level offset between the lowest unoccupied molecular orbital (LUMO) and the work functions of the respective metals

Difficult Cutting Property of NiTi Alloy and Its Mechanism

This paper describes the difficult machinability of nickel titanium alloy (NiTi alloy) and its mechanism. As a result of examining the difficult cutting machinability via a turning experiment, NiTi alloy cutting showed larger cutting force, higher cutting temperature, and severe tool wear with plastic deformation of the tool compared to Ti-6Al-4V. In addition, the discharged chips were tangled with the jaw chuck and the cutting tool. As a result of investigating the cause of these difficult machining properties by orthogonal cutting, it was found that the progression of severe flank wear is affected by the elastic recovery due to the super elasticity of the material. The verification of the results according to the shear plane theory suggest that the large deformation resistance of the material is the cause of the increase in cutting temperature. Furthermore, because the cutting temperature exceeds the shape memory transformation temperature, the generated chips are shape memory processed. It was also found that because the generated chips are super elastic, chips are not easily broken and they are lengthened, and are easily entangled with a cutting tool and a jaw chuck

Growth and electrical properties of N,N[sup ʹ]-bis(n-pentyl)terrylene- 3,4:11,12-tetracarboximide thin films

International audienceA n-type semiconductor molecule N,N′-bis(n-pentyl)terrylene-3,4:11,12-tetracarboximide (TTCDI-5C) was synthesized. Theoretical calculations predict several advantages in electrical properties, including large adiabatic electron affinity and small reorganization energy. The molecule was deposited on SiO2surfaces and the structure of the resultant thin film was studied. Grain size and thin film crystallinity improve as the temperature increases. Top-contact organic field effect transistors (OFETs) using TTCDI-5C as the semiconductor layer were fabricated using SiO2 as the gate dielectric. Values of charge carrier mobility up to 7.24×10−2cm2V−1s−1 and current on/off ratios higher than 104 were obtained, demonstrating the potential of TTCD-5C for use in OFETs

Effect of Surface Treatment of Multi-Directionally Forged (MDF) Titanium Implant on Bone Response

Multi-directional forging (MDFing) of titanium drastically improved its mechanical properties due to the evolution of an ultrafine-grained structure. Forging strain was repeatedly applied while changing the forging axis during MDFing. Of note is the decreased elastic modulus of MDFed titanium (MDF-Ti) as compared to conventional coarse-grained pure Ti (Ti). In the present study, we evaluated bone’s response toward surface-treated MDF-Ti after implantation into the extraction sockets of rat maxillary molars. As surface treatments, acid (Acid, sulfuric acid at 120 °C for 75 s), alkali without post-heat (Alkali, NaOH at 60 °C for 24 h), and alkali with post-heat (Alkali-heat, subsequent heating at 600 °C for 1 h) treatments were employed. The presence of minute nanoscale dimples in the microscale dimples to form regular fractal structures on MDF-Ti surfaces was observed after Acid treatments. Structures of sponge-like porous networks after Alkali treatments and submicron fiber networks after Alkali-heat treatment were produced on the surfaces of both Ti and MDF-Ti. Surface-treated specimens were superhydrophilic. More crystal deposition was clearly observed on each surface-treated specimen after immersion in simulated body fluid for both Ti and MDF-Ti. The bone-to-implant contact (BIC) ratios of the Acid and Alkali-heat specimens were significantly higher than those of the untreated control (p < 0.05). Moreover, Acid and Alkali-heat treatment for MDF-Ti caused significantly greater BICs than that for Ti (p < 0.05). In conclusion, Acid or Alkali-heat treatment of MDF-Ti is useful for improving bone response

Evaluation of the delta-shaped anastomosis in laparoscopic distal gastrectomy: midterm results of a comparison with Roux-en-Y anastomosis

Various methods of reconstruction after laparoscopic distal gastrectomy (LDG) have been developed and published, whereas only a limited number of reports are available on the utility of the delta-shaped anastomosis (Delta). This study compared Delta and Roux-en-Y anastomoses (RY), with the aim to clarify the utility of Delta. Stage 1 gastric cancer patients who had undergone LDG with Delta (group D, n = 68) and those who had undergone LDG with RY (group RY, n = 60) were compared in terms of operative outcomes, postoperative clinical symptoms, gastrointestinal fiberscopic findings, and changes in body weight. Both the operative and anastomotic times were significantly shorter in group D (230 and 13 min, respectively) than in group RY (258 and 38 min, respectively) (p < 0.001). Among the complications observed at the anastomotic site, obstruction was seen in one group D patient and two group RY patients but was relieved with conservative management. Postoperative clinical symptoms were reported for 26.4 % of the group D patients but had decreased to 5.9 % 1 year later. Group RY yielded similar results. Upper gastrointestinal fiberscopy performed 1 year postoperatively showed no intergroup differences in the incidence of gastritis or residual retention and a significantly more frequent occurrence of bile reflux in group D. Postoperative weight changes did not differ between the two groups. Delta reconstruction after LDG is a safe and effective procedure that is totally laparoscopic, less time consuming, and associated with a favorable postoperative course and a better quality of life