Wacker type and π-allyl type oxidations of propylene controlled by fuel cell system in the gas phase

Oxidation of propylene applying the (C₃H₆, Pd/H₃PO₄/Pt, O₂) fuel cell system in the gas phase produced acrolein and acrylic acid, the -allyl type oxidation products. However, addition of H₂PdCl₄ or HCl to the electrolyte reduced the -allyl oxidation, but enhanced Wacker type oxidation producing acetone. Direction to either Wacker type or -allyl type oxidation can easily be controlled electrochemically by applying the fuel cell system in the gas phase.     

The changes of transesterification level in PET/PEN blends with the addition of PET–PEN copolymer

The extent of transesterification in poly(ethylene terephthalate) (PET)/poly(ethylene‐2,6‐naphthalate) (PEN) blends with the addition of PET–PEN copolymers was examined by DSC and ¹H‐NMR measurements to evaluate the factor affecting the reaction level at a given temperature and time. Both block (P(ET‐block‐EN)) and random (P(ET‐ran‐EN)) copolymers were used as the copolymers. At a given treatment temperature and time, the level was increased by the addition of P(ET‐block‐EN) into PET/PEN blends. On the other hand, a reverse change was observed when P(ET‐ran‐EN) was mixed with PET/PEN blends. During the treatment, an inhomogeneous phase of the blends changed into the homogeneous one; however, the change showed little effect on the reaction level. The effects of molecular weight on the reaction level were also examined. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Overall numerical simulation of extrusion blow molding process

This paper focuses on the overall numerical simulation of the parison formation and inflation process of extrusion blow molding. The competing effects due to swell and drawdown in the parison formation process were analyzed by a Lagrangian Eulerian (LE) finite element method (FEM) using an automatic remeshing technique. The parison extruded through an annular die was modeled as an axisymmetric unsteady nonisothermal flow with free surfaces and its viscoelastic properties were described by a K‐BKZ integral constitutive equation. An unsteady die‐swell simulation was performed to predict the time course of the extrudate parison shape under the influence of gravity and the parison controller. In addition, an unsteady large deformation analysis of the parison inflation process was also carried out using a three‐dimensional membrane FEM for viscoelastic material. The inflation sequence for the parison molded into a complex‐shaped mold cavity was analyzed. The numerical results were verified using experimental data from each of the sub‐processes. The greatest advantage of the overall simulation is that the variation in the parison dimension caused by the swell and drawdown effect can be incorporated into the inflation analysis, and consequently, the accuracy of the numerical prediction can be enhanced. The overall simulation technique provides a rational means to assist the mold design and the determination of the optimal process conditions.     

给水质量对超纯水制备的影响

超纯水的制备通常只以电阻率来进行水质监控.这种制备方法需要若干步骤.以本地用水为纯化水源时,必须在最终精制之前对其进行预处理. 纯化的初始步骤包括DI（去离子技术）或者RO（反渗透）/EDI（连续电流去离子技术）联用.尽管通过这两种技术都能获得电阻率较高的超纯水,但是当更能精确地监控超纯水质量的TOC（有机碳总量）也被列入考查指标的时候,不同制备技术得到的超纯水之间水质的差异就明显了.由于TOC偏高,选用去去离子技术（DI）进行预处理需要更加严谨的维护和操作.而且,树脂再生之后使用,容易导致有机物脱落进入离子交换精制介质甚至后面的过滤器,进而影响、削弱整个系统的效率、可靠性和使用寿命.     

Temperature distribution in a workpiece during cylindrical plunge grinding

In cylindrical plunge grinding, a large amount of heat flows into the workpiece continuously, accumulates and remains even after the process, which causes dimensional error. Therefore it is necessary to investigate the temperature distribution in the workpiece during grinding and analyze the influence of grinding heat on the dimension. Such an investigation has not been done enough, because the technology to measure the temperature distribution in the rotating workpiece has not matured. Considering such background, an in-process measuring system has been developed, which makes it possible to detect the temperature distribution in a wide range from the outer surface to the inside of the rotating workpiece. The system consists of small temperature sensors which are embedded into the workpiece, a micro computer attached on the workpiece which acquires the data from the sensors and transmits to a personal computer by a wireless communication device. Furthermore the contact type thermocouple which enables to measure the rotating surface temperature is added to the system. Measurement experiments revealed that the grinding heat conducts from the workpiece surface toward the center, accumulates, and remains in the workpiece even after the process. Heat conduction simulation was also performed. Good agreement was achieved between the simulated temperatures and experimental measurements.     

Characteristics of MSCs in Synovial Fluid and Mode of Action of Intra-Articular Injections of Synovial MSCs in Knee Osteoarthritis

We have been studying mesenchymal stem cells (MSCs) in synovial fluid and the intra-articular injection of synovial MSCs in osteoarthritis (OA) knees. Here, mainly based on our own findings, we overview the characteristics of endogenous MSCs in the synovial fluid of OA knees and their mode of action when injected exogenously into OA knees. Many MSCs similar to synovial MSCs were detected in the synovial fluid of human OA knees, and their number correlated with the radiological OA grade. Our suspended synovium culture model demonstrated the release of MSCs from the synovium through a medium into a non-contacting culture dish. In OA knees, endogenous MSCs possibly mobilize in a similar manner from the synovium through the synovial fluid and act protectively. However, the number of mobilized MSCs is limited; therefore, OA progresses in its natural course. Synovial MSC injections inhibited the progression of cartilage degeneration in a rat OA model. Injected synovial MSCs migrated into the synovium, maintained their MSC properties, and increased the gene expressions of TSG-6, PRG-4, and BMP-2. Exogenous synovial MSCs can promote anti-inflammation, lubrication, and cartilage matrix synthesis in OA knees. Based on our findings, we have initiated a human clinical study of synovial MSC injections in OA knees.     

CRISPR-Cas9–Mediated TIM3 Knockout in Human Natural Killer Cells Enhances Growth Inhibitory Effects on Human Glioma Cells

Glioblastoma (GBM) is the most common and aggressive primary malignant brain tumor in adults. Natural Killer (NK) cells are potent cytotoxic effector cells against tumor cells inducing GBM cells; therefore, NK cell based- immunotherapy might be a promising target in GBM. T cell immunoglobulin mucin family member 3 (TIM3), a receptor expressed on NK cells, has been suggested as a marker of dysfunctional NK cells. We established TIM3 knockout in NK cells, using the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9). Electroporating of TIM3 exon 2- or exon 5-targeting guide RNA- Cas9 protein complexes (RNPs) inhibited TIM3 expression on NK cells with varying efficacy. T7 endonuclease I mutation detection assays showed that both RNPs disrupted the intended genome sites. The expression of other checkpoint receptors, i.e., programmed cell death 1 (PD1), Lymphocyte-activation gene 3 (LAG3), T cell immunoreceptor with Ig and ITIM domains (TIGIT), and TACTILE (CD96) were unchanged on the TIM3 knockout NK cells. Real time cell growth assays revealed that TIM3 knockout enhanced NK cell–mediated growth inhibition of GBM cells. These results demonstrated that TIM3 knockout enhanced human NK cell mediated cytotoxicity on GBM cells. Future, CRISPR-Cas9 mediated TIM3 knockout in NK cells may prove to be a promising immunotherapeutic alternative in patient with GBM.     

Synthesis and Photobehavior of a New Dehydrobenzoannulene-Based HOF with Fluorine Atoms: From Solution to Single Crystals Observation

Hydrogen-bonded organic frameworks (HOFs) are the focus of intense scientific research due their potential applications in science and technology. Here, we report on the synthesis, characterization, and photobehavior of a new HOF (T12F-1(124TCB)) based on a dehydrobenzoannulene derivative containing fluorine atoms (T12F-COOH). This HOF exhibits a 2D porous sheet, which is hexagonally networked via H-bonds between the carboxylic groups, and has an interlayers distance (4.3 Å) that is longer than that of a typical π–π interaction. The presence of the fluorine atoms in the DBA molecular units largely increases the emission quantum yield in DMF (0.33, T12F-COOH) when compared to the parent compound (0.02, T12-COOH). The time-resolved dynamics of T12F-COOH in DMF is governed by the emission from a locally excited state (S1, ~0.4 ns), a charge-transfer state (S1(CT), ~2 ns), and a room temperature emissive triplet state (T1, ~20 ns), in addition to a non-emissive triplet structure with a charge-transfer character (T1(CT), τ = 0.75 µs). We also report on the results using T12F-ester. Interestingly, FLIM experiments on single crystals unravel that the emission lifetimes of the crystalline HOF are almost twice those of the amorphous ones or the solid T12F-ester sample. This shows the relevance of the H-bonds in the photodynamics of the HOF and provides a strong basis for further development and study of HOFs based on DBAs for potential applications in photonics.     

Asymmetric forming of aluminum sheets by synchronous spinning

Asymmetric conventional metal spinning was performed in this study to break through the limitation of ordinary axisymmetric spinning. A synchronous spinning machine was developed for this purpose; in this case, the mandrel motion, mandrel feed, and roller feed were synchronized by pulse control. Trial spinning experiments were carried out on a 1-mm-thick aluminum sheet to obtain an asymmetric truncated-elliptical-cone-shaped product. The roller path was traced using a control software by taking into account the errors caused by the step pulse control. Asymmetric sheet metal forming was successfully carried out by using the developed synchronous spinning method. The characteristics of asymmetric spinning were discussed by comparing the shape of the product, strain distributions, and force components with those obtained in the case of axisymmetric spinning.     

Influence of aldehydes in make-up oils on antioxidation properties

The addition of more antioxidant to aged oils is not always effective in preventing autoxidation. To investigate this phenomenon, a solution of antioxidant and model oxide in hexadecane was examined by means of the induction period method. Aldehydes were found to be the most active species for reducing the antioxidation properties of zinc dialkyldithiophosphate (ZDTP), 2,6-di(tert. butyl)-4-methylphenol (DBPC), and N-phenyl-1-naphtylamine (PNA). Carboxylic acids, ethers, alcohols, and ketones to some extent reduced the induction period with these antioxidants. Esters showed almost no influence on reducing their antioxidant properties. Reaction of ZDTP with aldehyde was studied by means of ³¹P-NMR analysis. It was found that (a) aldehydes accelerate conversion of ZDTP, and thereby reduce its antioxidant performance. (b) Conversion of ZDTP in the presence of aldehydes under oxygen at 130° in hexadecane and no reaction was observed under nitrogen at the same temperature. Active intermediates derived by the autoxidation of aldehyde were suspected. (c) Reaction of peroxycarboxylic acid with ZDTP took place smoothly at 0°C under nitrogen to give bis(dialkylthiorophosphoro)disulphide and the corresponding carboxylic acid. Reaction of hydroperoxide with ZDTP took place at room temperature to give oxo-hexa(dialkylphosphorothiorothionato)-tetrazinc. Two mechanisms for decomposition of ZDTP promoted by aldehydes, namely hydroperoxide and peroxycarboxylic acid mechanisms, are proposed. Reaction of peroxycarboxylic acid with DBPC or PNA barely took place at room temperature: for these antioxidants, the peroxycarboxylic acid mechanism would be excluded. Radical species derived by the autoxidation of aldehydes were considered as active intermediates. It is considered that classification of the types of oxides that exist in used oils in the key to optimising the effect of re-added antioxidants.