Search

The paper was conducted to solve the low machining accuracy of eccentric parts and thin-walled parts on tomato harvester, reduce the machining steps of thin-walled parts and eccentric parts, and promote the machining accuracy and labor productivity, a special fixture was designed. High concentricity machining was applied based on adjusting the fixture, and manufacturing workpiece didn’t need to dismount, thus the concentricity and machining accuracy of manufacturing workpiece can be achieved. It’s beneficial to improve productivity and production quality.

The chemical compositions of Manihot esculenta crantz(M. utilissima Pohl)stalks were investigated, the contents of phenolic hydroxyl group and UV spectra of lignin were determined by ultraviolet-visible spectrophotometer. The result showed that the chemical compositions of Manihot esculenta crantz(M. utilissima Pohl)stalks were as follows: ashes 4.97%, cold water extraction 12.04%, hot water extraction 12.57%, 1% sodium hydroxide solution extraction 34.16%, benzene-alcohol solution extraction 4.20%, nitric acid-alcohol cellulose 35.86%, holo-cellulose 72.62%, pentosan 19.20%, acid-soluble lignin 2.51%, acid-insoluble lignin 26.10%, organic solvent-soluble lignin 1.07%, pectin content is 0.02%; it can be used as a non-wood renewable source of natural products.Phenolic hydroxyl content of organic solvent-soluble lignin and acid-insoluble lignin are 1.245 mmol·g-1 and 0.261mmol·g-1 respectively; the maximum absorption wavelength of organic solvent-soluble lignin and acid-soluble lignin in the UV region is near to 205 nm and 280 nm, but shifts to long wavelength or short wavelength with the nature of the different solvents.

Cellulose crystalline and FTIR spectra of Artocarpus heterophyllus Lam wood and its main chemical compositions were analyzed.The result showed that the FTIR spectra of original wood samples from Artocarpus heterophyllus Lam wood present the same basic structure of all wood samples, the FTIR spectra of extracted wood samples were compared with the original wood sample, some of their absorption peaks of the band shifted to long or short wave, the wood and the solvent had little chemical reaction in the extracting process. FTIR spectra crystalline index of nitric acid-ethanol cellulose from Artocarpus heterophyllus Lam wood is NO′KI1 0.984, O′KI2 1.59, X-ray diffraction crystalline index of nitric acid-ethanol cellulose from Artocarpus heterophyllus Lam wood is 0.794.

In this paper, the feasibility of preparing activated carbon from corncob furfural residue with ZnCl2 by microwave irradiation was studied. The effect of the ratio by weight of ZnCl2 to corncob furfural residue, ZnCl2 solution soaking time, microwave irradiation time and the pH value of ZnCl2 solution on the quality of activated carbon was investigated. On the condition that the microwave power is 800 W and ZnCl2 solution mass concentration is 50%, the best technological parameter on preparing activated carbon with ZnCl2 by microwave irradiation is obtained: at the ratio of 3.5:1 by weight of ZnCl2 to corncob furfural residue, microwave irradiation time is 20 min, ZnCl2 solution soaking time is 12 h, the pH value of ZnCl2 solution is 2, the activated carbon yield reached 33.1% and the decolorizing capacity for methylene blue is 202.5 mg/g, the product is used in treating Cr6+ solution(pH value 4.0, concentration 50 mg/L), its adsorption capacity of Cr6+ is 7.583 mg/g.

Abstract: Objective: The obesity hormone, leptin, has been found to participate in the development and proliferation of normal and malignant tissues. The aim of this study was to evaluate the role of leptin in human colorectal cancer. Methods: Serum leptin levels were measured via ABC-ELLSA in 30 colorectal cancers and 24 normal controls. Leptin concentration in colorectal cancer was analyzed in terms of selected clinicopathological features and some oncogenes. Results: The mean concentration of leptin was significantly higher for colorectal cancers(3.54±1.46 ng/ml) than normal controls(2.27±0.99 ng/ml), no gender difference was observed in this study. Leptin expression in poorly differentiated tumors was obviously lower than those in moderately and well differentiated tumors. There were no statistically significant correlations between leptin and the serum CEA and CA199 in colorectal cancers (P>0.05), and between leptin and the expressions of K-RAS, P53, APC, DCC genes in tumor tissues (P>0.05). Conclusion: Leptin is overexpressed in human colorectal cancer, which is related to the differentiation degrees of the tumor. There is no correlation between leptin expression and changes of oncogenes in colorectal cancers.

Abstract: Objective: To assess the anal sphincter function after intersphincteric resection for low rectal cancer by questionnaire and vectorial manometry. Methods: Twenty five patients underwent intersphincteric resection, the controls contained 25 patients of rectal cancer who underwent low anterior resection and 25 healthy people. The therapeutic responses were evaluated using the Vaizey and Wexner scoring systems and vectorial manometry. Results: The Vaizey and Wexner scores after intersphincteric resection were significantly higher than those of low anterior resection controls at one month, but had no significant difference one year after. On the other hand, the indexes of vectorial manometry still had significant difference one year later. The indexes after intersphincteric resection could not reach the normal level. Conclusion: The anal sphincter function after intersphincteric resection is lower than that after low anterior resection in short term, although the long-term results can be accepted, it still can not reach the normal level.

β-sialon bonded corundum-based sliding gate plate was developed from raw materials of Al, metallic silicon and alumina through nitriding-reaction process. It was found that the effects of β-sialon content on the physical properties are significant and the mechanical properties of developed sliding gate plate are strongly related to the Z-value. The materials with Z value of 2 and 20wt% β-sialon, exhibit the highest hot modulus of rupture and cold crushing strength. It was also found that sialon bonded corundum-based material has good oxidation resistance because a protective layer is formed during oxidation process.

Not Available

Glutamatergic and GABAergic synaptic transmission controls excitation and inhibition of postsynaptic neurons, whereas activity of ion channels modulates neuronal intrinsic excitability. However, it is unclear how excessive neuronal excitation affects intrinsic inhibition to regain homeostatic stability under physiological or pathophysiological conditions. Here, we report that a seizure-like sustained depolarization can induce short-term inhibition of hippocampal CA3 neurons via a mechanism of membrane shunting. This depolarization-induced shunting inhibition (DShI) mediates a non-synaptic, but neuronal intrinsic, short-term plasticity that is able to suppress action potential generation and postsynaptic responses by activated ionotropic receptors. We demonstrate that the TRESK channel significantly contributes to DShI. Disruption of DShI by genetic knockout of TRESK exacerbates the sensitivity and severity of epileptic seizures of mice, whereas overexpression of TRESK attenuates seizures. In summary, these results uncover a type of homeostatic intrinsic plasticity and its underlying mechanism. TRESK might represent a therapeutic target for antiepileptic drugs.