聚焦超声辐射高血脂大鼠涌泉穴对血脂水平的影响

目的研究聚焦超声辐射涌泉穴对血脂的影响.方法采用高脂饲料喂养建立高血脂大鼠模型,通过聚焦超声辐射高血脂模型大鼠涌泉穴,测定大鼠血清总胆固醇(tota cholesterol, TC)、甘油三脂 (triacylglycerol, TG)、高密度脂蛋白胆固醇(high density lipoprotein, HDL-c)和低密度脂蛋白胆固醇(low density lipoprotein, LDL-c)等指标.结果检测血清TC、TG、HDL-C、LDL-C水平,聚焦超声辐照涌泉穴可明显降低高血脂模型大鼠血清TC、TG(P＜0.05),而超声治疗组和针刺组无明显差异.结论聚焦超声辐射高血脂大鼠的涌泉穴位,可明显降低TC、TG,有调节血脂的作用.     

Stable and efficient immobilization technique of aldolase under consecutive microwave irradiation at low temperature

To establish a stable and efficient immobilization technique under microwave irradiation, a focused microwave reaction system was used, where the temperature was set appropriately in the microwave system and cooling module to produce consecutive microwave irradiation. 2-Deoxy-D-ribose-5-phosphate aldolase (DERA) was rapidly and efficiently immobilized in mesocellular siliceous foams (MCFs) under microwave irradiation. When the output power in the microwave system was set to 30 W, after 3 min, 88.4% of the enzyme protein was coupled to the wall of the support pores and the specific activity of the immobilized enzyme was 2.24 U mg⁻¹, 149.2% higher than that of the free enzyme and 157.0% higher than that of the non-microwave-assisted immobilized enzyme. In catalysis, microwave-assisted immobilized DERA tolerated a wider range of both pH and temperature than other DERA preparations. The thermal and storage stabilities were also significantly improved. This focused; microwave-assisted immobilization technique has proven to be simple, stable and highly efficient. This technique could also be applied to other enzyme immobilizations.     

In vivo regional levels of PGE and thromboxane in mouse brain: Effect of decapitation,focused microwave fixation,and indomethacin

A focused microwave fixation technique was tested for use in determining basal PGE and thromboxane B₂ levels of mouse brain. Focused microwave irradiation (3.5 Kw/0.4 sec) to the head of C3H mice produced basal values of PGE and TXB₂ which were five-fold less than those in animals killed by decapitation. Indomethacin (10 mg/kg) pretreatment blocked the decapitation rise in PGE and TXB₂ levels and gave values similar to focused microwave irradiation. Indomethacin pretreatment combined with microwave fixation did not reduce PG levels more tham microwave treatment alone. When microwave fixation was used, there was no difference in regional (cerebral cortex, whole cerebellum, midbrain, hypothalamus) levels of either PGE or TXB₂. However, PGE levels were significantly higher than TXB₂ in all regions. After decapitation there was a greater increase in TXB₂ than PGE. The cerebellum produced less PGE and TXB₂ after decapitation compared to the other regions. Our results confirm the usefulness of the focused microwave irradiation technique for examining $\text{in vivo}$ basal prostaglandin levels in mouse brain.     

In Vivo Stimulation of D1 Receptors Increases the Phosphorylation of Proteins in the Striatum

In vivo changes in levels of DARPP-32 [dopamine (DA)- and cyclic AMP-regulated phosphoprotein, Mr = 32,000] protein phosphorylation in response to DA agonists in the rat striatum were measured using a novel assay that combines the benefits of rapid quenching of enzyme activity by focused microwave irradiation with a back-phosphorylation assay. The basal level of phospho-DARPP-32 was 5.6% of total DARPP-32. Injections of L-3,4-dihydroxyphenylalanine (100 mg/kg) increased this level to 44.4%. This effect was not as great if focused microwave irradiation was not used. The D1-specific agonist SKF 38393 (10 mg/kg) increased the level of phospho-DARPP-32 to 36.4%. A further modification of the back-phosphorylation assay was used to detect other phosphoproteins that appear to be regulated by DA. These results establish an assay for in vivo studies of postsynaptic responses involving second messengers in the DA system and provide direct in vivo evidence for the hypothesis that stimulation of D1 receptors increases the phosphorylation of DARPP-32, as well as several other proteins.     

Enzymatic synthesis of cetyl oleate in a solvent-free medium using microwave irradiation and physicochemical evaluation

Abstract

A cosmetic ester, cetyl oleate was synthesized using microwave irradiated system. The esterification reaction was carried using Candida antarctica lipase B in a solvent-free media. The influence of various reaction parameters was studied, and the efficiency of Fermase CALB^TM10000 was compared with other enzymes. Equilibrium conversion of 97.5% was obtained within 20?min at 60?°C temperature, 1:2 oleic acid to cetyl alcohol molar ratio and 4% w/w dose of lipase. A comparative study showed that microwave irradiation is a much more efficient method than ultrasound irradiation and conventional heating. Fermase CALB^TM10000 was reusable over 6 enzymatic cycles as its stability improved under microwave system. Physicochemical parameters of cetyl oleate were tested in order to analyze its suitability for further cosmetic use.     

Quantitative neuropeptidomics of microwave-irradiated mouse brain and pituitary

In neuropeptidomics, the degradation of a small fraction of abundant proteins overwhelms the low signals from neuropeptides, and many neuropeptides cannot be detected by mass spectrometry without extensive purification. Protein degradation was prevented when mice were sacrificed with focused microwave irradiation, permitting the detection of hypothalamic neuropeptides by mass spectrometry. Here we report an alternative and very simple method utilizing an ordinary microwave oven to inhibit enzymatic degradation. We used this technique to identify brain and pituitary neuropeptides. Quantitative analysis using mass spectrometry in combination with stable isotopic labeling was performed to determine the effect of microwave irradiation on relative levels of neuropeptides and protein degradation fragments. Microwave irradiation greatly reduced the levels of degradation fragments of proteins. In contrast, neuropeptide levels were increased about 2-3 times in hypothalamus by the microwave irradiation but not increased in pituitary. In a second experiment, three brain regions (hypothalamus, hippocampus, and striatum) from microwave-irradiated mice were analyzed. Altogether 41 neuropeptides or fragments of secretory pathway proteins were identified after microwave treatment; some of these are novel. These peptides were derived from 15 proteins: proopiomelanocortin, proSAAS, proenkephalin, preprotachykinins A and B, provasopressin, prooxytocin, melanin-concentrating hormone, proneurotensin, chromogranins A and B, secretogranin II, prohormone convertases 1 and 2, and peptidyl amidating monooxygenase. Although some protein degradation fragments were still found after microwave irradiation, these appear to result from protein breakdown during the extraction and not to an enzymatic reaction during the postmortem period. Two of the protein fragments corresponded to novel protein forms: VAP-33 with a 7-residue N-terminal extension and beta tubulin with a glutathione on the Cys near the N terminus. In conclusion, microwave irradiation with an ordinary microwave oven effectively inhibits enzymatic postmortem protein degradation, increases the recovery of neuropeptides, and makes it possible to conduct neuropeptidomic studies with mouse brain tissues.     

Direct conversion of cellulose to 1-(furan-2-yl)-2-hydroxyethanone in zinc chloride solution under microwave irradiation

Conversion of cellulose to 1-(furan-2-yl)-2-hydroxyethanone has been demonstrated in concentrated zinc chloride solution under microwave irradiation. Compared with the conventional oil-bath heating mode, microwave irradiation significantly reduced the reaction time and increased the yield of 1-(furan-2-yl)-2-hydroxyethanone. A typical degradation reaction with cellulose produced 1-(furan-2-yl)-2-hydroxyethanone in 12.0% molar yield in ZnCl₂ solution (ZnCl₂–H₂O ratio = 2.25:1, w/w) with microwave irradiation at 600 W for 5 minutes at 135 °C.     

ELEVATION IN RAT BRAIN HISTAMINE CONTENT AFTER FOCUSED MICROWAVE IRRADIATION1

Abstract— —Microwave irradiation focused on the head of small rodents is now widely used as a means of more accurately measuring acetylcholine, choline, cyclic AMP, and several other important brain constituents. Because of its probable neurotransmitter role and rapid turnover, a similar approach was taken to study brain histamine. Histamine was measured by a modified radio-enzymatic method and was found to be nearly tripled in brains from microwave treated rats, compared to decapitation controls (124 vs 42 ng/g). Possible explanations include a microwave-induced inactivation of histamine breakdown, a microwave-induced redistribution of previously unmeasured histamine, and microwave-induced histidine decarboxylation. Brain histamine remained unchanged up to 30 min after decapitation and microwave heated brains from decapitated rats also had elevated histamine levels, indicating that brain histamine levels in decapitated rats do not represent the remainder of a rapidly depleting pool. No evidence for previously unmeasured histamine was found. Furthermore, microwave irradiation did not enhance the formation of [³H]histamine after intraventricular [³H]histidine administration, indicating a lack of microwave-induced histidine decarboxylation. It is concluded that the elevation in rat brain histamine after focused microwave irradiation is probably not artifactual, although the mechanism responsible for this phenomenon remains obscure.     

The differential response of the skin in young and old rats to a combination of X-rays and 'wet' or 'dry' hyperthermia

The left hind feet of groups of female rats aged 7, 14 and 52 weeks were irradiated at three dose levels of X-rays (20, 25 or 30 Gy). Hyperthermia (42.5 degrees C for 1 h) was carried out immediately following irradiation using either 'wet' or 'dry' heat, achieved by immersion in either water or fluorocarbon liquid. The results demonstrated that 'wet' heat produced a consistently greater enhancement of the irradiation damage than 'dry' heat. The thermal enhancement ratio for irradiation plus 'wet' heat was approximately 1.5 and for irradiation plus 'dry' heat it was in the range 1.17 to 1.39. Immersion of the feet in fluorocarbon liquid at 37 degrees C did not significantly modify the irradiation response of the skin. The lower thermal enhancement ratios obtained using immersion in fluorocarbon liquid at 42.5 degrees C are close to those obtained in large animal studies and also similar to the limited amount of data from clinical studies where microwave or ultrasound heating techniques were used. It has been demonstrated that there are large age-related differences in the response of the rat foot skin to irradiation alone. It has also been shown in the present study, using rats of the same age, that the response to irradiation plus hyperthermia was less age dependent. This finding may reflect the differing methods by which damage occurs in tissue after irradiation or hyperthermia.     

Microwave assisted extraction of ursolic acid and oleanolic acid from Ocimum sanctum

Present study deals with the microwave assisted extraction (MAE) of ursolic acid (UA) and oleanolic acid (OA) from Ocimum sanctum leaves. UA and OA have been reported to possess significant medicinal properties. Various experimental parameters such as selection of solvent, solvent composition, irradiation time, microwave power, solid to solvent ratio, preleaching time and number of cycles were investigated to optimize the extraction process. Under optimum conditions of irradiation time (3 min), microwave power (272 W), solid to solvent ratio (1:30), preleaching time (10 min), maximum UA and OA has been extracted in one extraction cycle with ethanol: water (80:20) as a solvent. Maximum 86.76 and 89.64% of UA and OA was extracted under above mentioned optimized experimental conditions. MAE was also compared with the batch and ultrasound assisted extraction (UAE) method. As compared to batch and UAE, higher extraction yield of these important phytochemicals have been obtained through MAE in only 3 min.     

微波辐射对肾小管上皮细胞的影响以及金雀异黄素对其保护作用

目的：观察微波辐照对人近端肾小管上皮细胞（HKC）的影响及金雀异黄素对其的保护作用。方法：HKC分为对照组、微波辐照组、金雀异黄素组（n=6）。金雀异黄素组在辐照前2 h用含30μmol/L金雀异黄素的DMEM培养基进行预培养。辐照后24 h留取上清进行乳酸脱氢酶（LDH）、β-N-乙酰氨基葡萄糖苷酶（NAG）活性及丙二醛（MDA）、超氧化物歧化酶（SOD）活性检测。Hoechst 33258染色观察细胞凋亡情况。结果：与对照组比较,微波辐照组上清NAG、LDH活性明显增加（P < 0.01）,金雀异黄素预处理组则较微波辐照组明显下降（P < 0.01）;微波辐照组上清活性也较对照组明显增加（P < 0.01）。Hoechst 33258染色显示,微波辐照可导致较多量的细胞凋亡,而应用金雀异黄素预处理后细胞凋亡的比例均大大减少。微波辐照可大大提高HKC细胞中的MDA含量,SOD活性降低（P< 0.01）,应用金雀异黄素预处理后MDA的含量无明显降低,SOD的活性明显增大（P < 0.01）。结论：微波辐照可导致人近端肾小管上皮细胞出现功能损伤,金雀异黄素对其具有一定的保护作用,可能与其减轻氧化应激损伤、减少细胞凋亡有关。     

微波处理对嗜碱和嗜盐海洋放线菌分离效果的影响

【目的】研究微波处理对于分离嗜碱和嗜盐海洋放线菌的效果。【方法】用微波处理7份海泥样品,梯度稀释后涂布于3种分离培养基,分离具有嗜碱和嗜盐特性的海洋放线菌。【结果】微波处理后的7份样品中,4份样品中嗜碱海洋稀有放线菌和3份样品的嗜盐海洋稀有放线菌数量极显著提高;7份样品中的嗜碱、嗜盐海洋小单孢菌属、游动放线菌属、诺卡氏菌属等稀有放线菌数量均有显著增加,不同样品中新分离到链孢菌属、小双孢菌属、链孢囊菌属及其他未鉴定的海洋稀有放线菌,分离到属的数量提高了1-4个。【结论】微波处理不仅显著提高嗜碱和嗜盐海洋放线菌的分离数量,而且明显增加了海洋稀有放线菌的分离种类。     

Destruction of Bacillus licheniformis spores by microwave irradiation

Aims:  To investigate the sporicidal mechanisms of microwave irradiation on Bacillus licheniformis spores.
Methods and Results:  We measured spore viability and the release of DNA and proteins, and performed transmission electron microscopy (TEM). A microwave oven (0·5 kW) was modified to output power at 2·0 kW, which allowed a shorter sterilization cycle. A 2·0 kW microwave treatment at the boiling temperature for 1 min did not kill all spores, but killed most spores. The spore inactivation rate was faster than that of boiling and 0·5 kW microwave oven. In contrast to boiling and 0·5 kW microwave treatments, the 2·0 kW microwave resulted in significant leakage of proteins and DNA from spores due to injury to the spore structure. TEM revealed that 2·0 kW microwave irradiation affected spore cortex hydrolysis and swelling, and ruptured the spore coat and inner membrane.
Conclusions:  These results suggest that 2·0 kW microwave irradiation ruptures the spore coat and inner membrane, and is significantly different from boiling.
Significance and Impact of the Study:  This study provides information on the sporicidal mechanisms of microwave irradiation on B. licheniformis spores.     

微波和电场对蒙古裸腹溞存活、生长和生殖的影响

研究了微波和电场对蒙古裸腹溞存活、生长和生殖的影响.结果表明: 35 s以上的2 450 MHz的微波辐照对蒙古裸腹溞的致死效应明显.短时间(<25 s)微波处理显著提高了蒙古裸腹溞的每窝产幼量及一生产幼量,其中10 s微波处理组一生产幼量最高.微波处理使蒙古裸腹溞的寿命显著延长(总寿命15.8～18 d).短时间的微波处理对幼溞的发育无显著影响,但对成溞的生长具有一定的抑制作用.脉冲电场可大幅提高蒙古裸腹溞的一生产幼量, 其中29 kV·cm^-1的脉冲电场效果最佳; 高压静电场对蒙古裸腹溞的繁殖无显著影响.高压静电场和脉冲电场对幼溞的发育均无显著影响,高压静电场对成溞的生长影响不明显,而脉冲电场则对成溞的生长具有一定的抑制作用,且电压越高,抑制作用越明显.     

The effect of microwave irradiation on enzymatic hydrolysis of rice straw

A series of experiments involving microwave irradiation were carried out to evaluate the effect of microwave irradiation on enzymatic hydrolysis of rice straw. Compared with microwave irradiation free hydrolysis, rice straw pretreated by combining microwave irradiation with alkali could increase the initial hydrolysis rate but the hydrolysis yield remained unchanged. When the enzyme solution was treated by microwave irradiation, the initial hydrolysis rate increased slightly, but the yield was decreased remarkably. Its optimal hydrolysis conditions were temperature (45 degrees C), pH (4.8) and enzyme loading (20 mg g(-1) substrate), which was determined by an orthogonal experiment. When intermittent microwave irradiation was used, initial hydrolysis rate was greatly accelerated but the yield was decreased slightly. Its optimal hydrolysis conditions were temperature (50 degrees C), pH (4.8) and enzyme loading (20 mg g(-1) substrate), which was determined by another orthogonal experiment.     

Salt-assisted acid hydrolysis of chitosan to oligomers under microwave irradiation

The effect of inorganic salts such as sodium chloride on the hydrolysis of chitosan in a microwave field was investigated. While it is known that microwave heating is a convenient way to obtain a wide range of products of different molecular weights only by changing the reaction time and/or the radiation power, the addition of some inorganic salts was shown to effectively accelerate the degradation of chitosan under microwave irradiation. The molecular weight of the degraded chitosan obtained by microwave irradiation was considerably lower than that obtained by traditional heating. Moreover, the molecular weight of degraded chitosan obtained by microwave irradiation assisted under the conditions of added salt was considerably lower than that obtained by microwave irradiation without added salt. Furthermore, the effect of ionic strength of the added salts was not linked with the change of molecular weight. FTIR spectral analyses demonstrated that a significantly shorter time was required to obtain a satisfactory molecular weight by the microwave irradiation-assisted inorganic salt method than by microwave irradiation without inorganic salts and conventional technology.     

Synthesis of nucleotide-activated disaccharides with recombinant β3-galactosidase C from Bacillus circulans

Nucleotide-activated di- and oligosaccharides represent a novel class of glycoconjugates. They are components of human milk with still unknown biological function. Synthetic access to a wide range of nucleotide di- and oligosaccharides would also facilitate their utilization as donor substrates or inhibitors of Leloir-glycosyltransferases. We here present for the first time the synthesis of β1-3-linked nucleotide activated disaccharides by recombinant β3-galactosidase C from Bacillus circulans. UDP-Glc, UDP-GlcNAc, and UDP-GalNAc reacted as acceptor substrates in the transglycosylation reaction with p-nitrophenyl-β-galactoside as donor substrate. In an attempt to optimise the transglycosylation reaction, focused microwave irradiation was investigated. In comparison to conventional thermal heating product compositions and product yields were affected by microwave irradiation and depended on the used acceptor substrate. Microwave irradiation was advantageous for syntheses with UDP-GlcNAc as preferred acceptor substrate of β3-galactosidase C. The β1,3 linked UDP-disaccharide was the main product with minor fractions of UDP-tri- and UDP-tetrasaccharide. In summary, access to important UDP-disaccharides such as UDP-LacNAc type 1 and UDP-Thomsen-Friedenreich(T)-antigen was accomplished for further studies of their role as donor substrates or inhibitors of glycosyltransferases.     

微波辐射对桃蚜生长发育和繁殖的影响

【目的】研究筛选对桃蚜Myzus persicae有致死作用的安全微波频率和照射时长,以为探究新型物理防蚜技术,弥补化学防治上的缺陷提供参考依据。【方法】在暗箱中,应用微波发射仪分别发射1375, 2 750, 5 500和11 000 MHz 4个不同频率的微波照射桃蚜1日龄无翅成蚜,每个频率的照射时长分别为15, 30, 60和120 s;照射后在人工气候箱中饲养,分别于照射后8, 24, 48和72 h观察其生长发育及繁殖状况,统计桃蚜死亡率、繁殖力(累计产蚜量)及子代有翅蚜率。【结果】4个不同频率的微波分别在4个不同照射时长下,对桃蚜1日龄无翅成蚜的死亡率、繁殖力和子代翅型分化都有不同程度的影响。照射后72 h, 5 500 MHz微波照射时间为15 s时对桃蚜1日龄无翅成蚜的致死作用最强,死亡率达到55.00%,在照射时间为30和120 s时可抑制子代桃蚜向有翅蚜的分化。2 750 MHz微波照射30和60 s时促进桃蚜1日龄成蚜繁殖,照射30 s时繁殖力最强,而照射15和120 s时却表现为抑制繁殖,且2 750 MHz微波照射30 s能抑制子代桃蚜向有翅蚜分化。【结论】微波辐射能够影响桃蚜1日龄成蚜的存活、繁殖和子代翅型分化。本研究初步筛选出了对桃蚜1日龄无翅成蚜有致死作用的微波频率和照射时长。     

Microwave facilitation of domperidone antagonism of apomorphine-induced stereotypic climbing in mice

The dopaminergic agonist apomorphine produced dose-dependent stereotypic climbing behavior in mice housed in cages with vertical bars. This drug effect was competitively inhibited by systemic pretreatment with the centrally acting dopaminergic antagonist haloperidol but not by microwave irradiation (2.45 GHz, 20 mW/cm2, CW, 10 min) nor by systemic pretreatment with domperidone, a dopaminergic antagonist that only poorly penetrates the blood-brain barrier (BBB). Yet when mice were systemically pretreated with domperidone and then subjected to microwave irradiation (as above), the apomorphine effect was significantly reduced. Microwave irradiation also facilitated antagonism of the apomorphine effect by low and otherwise ineffective systemic pretreatment doses of haloperidol. Apomorphine-induced stereotypic climbing behavior was also reduced by domperidone administered intracerebrally, which bypassed the BBB. Exposure of intracerebral domperidone-pretreated animals to microwave irradiation failed to increase the degree of antagonism. These findings indicate that microwave irradiation can facilitate central effects of domperidone, a drug which acts mainly in the periphery. One possible explanation for these findings is that microwave irradiation alters the permeability of the BBB and increases the entry of domperidone to central sites of action.     

Chemical modifications of bile acids under high-intensity ultrasound or microwave irradiation

High-intensity ultrasound (HIU) and microwave (MW) irradiation, having emerged as effective promoters of organic reactions, were exploited for the synthesis of bile acids derivatives. Esterification, amidation, hydrolysis, oxidation, and reduction were investigated. Compared to conventional methods, both techniques proved much more efficient, increasing product yields and dramatically cutting down reaction times. Scaled-up studies are now under way.