The thermal effect of urethral warming during cryosurgery

The heating effect of urethral warming during cryosurgery has been investigated theoretically, via heat transfer simulations. Two warmer configurations have been considered: (i). the clinically available urethral warmer, which has a configuration of a counter flow fluid heat exchanger; (ii). a newly designed urethral warmer, based on a temperature controlled electrical heater, termed a "cryoheater". A dramatic effect of thermal resistance to heat transfer through the heat exchanger wall has been identified, which is absent in the cryoheater. It follows that the cryoheater is expected to be more efficient in generating an unfrozen region around the urethra. It is shown that the conventional heat exchanger may fail to prevent freezing around the urethra in a significant number of prostate cases, depending on the layout of cryoprobes around the urethra. On the other hand, clinical reports exist which suggest that the heat exchanger improves in many cases the outcome of cryosurgery, in terms of long term complications. It is speculated in the current report that the cryoheater can further improve the outcome of cryosurgery, by providing protection from freezing in a wider range of cases. It is suggested that a future study be conducted to examine the correlation between the layout of cryoprobes and surgical outcome.     

Evaluation of the ethanol intake on the Calomys callosus seminal vesicle structure

The effects of chronic alcohol ingestion on the structure of the glandular epithelium of the seminal vesicle of the rodent Calomys callosus were analyzed in 24 adult animals aged 3 months divided into three experimental groups. The control group received a solid diet and tap water, the alcoholic group received the same solid diet and ethanol P.A. diluted 20% in water (v/v) for 4 months. The abstinent group received the same liquid diet of the alcoholic one for the same period and after that the alcoholic diet was changed by water for a period of 3 months. After treatment, all animals were anesthetized, weighed and sacrificed. At the end of treatment, mean body weight did not differ between animal groups. The glandular epithelial cells of the alcoholic and abstinent groups showed atrophy and ultrastructural alterations such as the presence of altered nuclei, intense dilatation of the cisterns of the granular endoplasmic reticulum, intense digestive vacuoles and lipid droplets. Ethanol ingestion provokes marked lesions on the epithelium of the seminal vesicle probably interfering on the glandular secretion.     

Chronic ethanol exposure increases microtubule content in PC12 cells

Background  

Chronic ethanol exposure has been shown to result in changes in neuronal cyto-architecture such as aberrant sprouting and alteration of neurite outgrowth. In PC12 cells, chronic ethanol treatment produces an increase in Nerve Growth Factor (NGF)-induced neurite outgrowth that appears to require the epsilon, but not delta, isoform of Protein Kinase C (PKC). Neurites contain a core of microtubules that are formed from polymerization of free-tubulin. Therefore, it would be expected that an increase in neurite outgrowth would correlate with an increase in microtubule content. We examined the effect of chronic ethanol exposure on microtubule content in PC12 cells and the role of PKC epsilon and delta in ethanol's effect on microtubule levels.     

乙醇在电感耦合等离子体质谱中的增强效应研究

本文报道了乙醇在ＩＣＰ－ＭＳ中的溶剂效应。详细研究了入射功率和载气流量等条件与乙醇溶剂效应的相关性。并与甘油和铥的基体效应进行了比较。结果表明：乙醇对被分析元素信号有显著影响。     

Motion of coarse drops of binary concentrated solutions in a nonuniformly heated ternary gaseous mixture: A theory

For coarse drops of binary concentrated solutions with the double phase transition that move in a ternary gaseous mixture via thermophoresis, a theory including thermal diffusion effects is elaborated. The drops consist of water with ethanol dissolved in it. Numerical estimates are made and plots are constructed for the rate of thermophoresis of drops with radii 5, 10, and 15 μm at different ethanol concentrations with and without allowance for volume thermal diffusion.     

基于UHPLC-QE-MS的CCI模型大鼠的血清代谢组学研究

采用超高效液相色谱-四级杆静电场轨道阱质谱（UHPLC-QE-MS）非靶向代谢组学方法,观察CCI模型大鼠血清内源性代谢物的变化,筛选出慢性坐骨神经痛大鼠血清差异性代谢物,分析慢性疼痛对差异性代谢物的影响。将12只SPF级SD雄性大鼠随机均分为正常组和坐骨神经慢性压迫损伤（CCI）组,每组6只。CCI组建立大鼠左侧坐骨神经慢性压迫损伤模型,正常组除不结扎坐骨神经,其余步骤一样。14天后腹主动脉采血, 分离血清,对大鼠血清中的代谢物进行代谢组学检测。利用UHPLC-QE-MS技术并结合PCA(主成分分析)筛选差异代谢物,利用MetabolicAnalyst5.0进行差异代谢物的富集分析。富集分析结果表明,与正常对照组相比,CCI模型大鼠血清有机酸、有机杂环化合物、脂肪酰基、碳水化合物、核酸、有机氮化合物、碳氢化合物等9类代谢物具有统计学差异。结果表明：基于UHPLC-QE-MS的血清代谢组学方法能够有效区分正常组和CCI组,筛选出的差异代谢物有助于慢性疼痛的机制及药物靶点研究。     

Ethanol-induced fatty liver in the rat examined by in vivo 1H chemical shift selective magnetic resonance imaging and localized spectroscopic methods.

In vivo 1H magnetic resonance imaging (MRI), chemical shift selective imaging (CSI), and localized (VOSY) 1H magnetic resonance spectroscopy (MRS) were used to study fatty infiltration in the livers of rats chronically fed an ethanol-containing all-liquid DeCarli-Lieber diet. Conventional total proton MRI showed a somewhat hyperintense liver for ethanol-fed rats, compared with pair-fed controls. CSI showed a dramatic increase in the fat signal intensity for ethanol-treated rats that was fairly homogeneous throughout the liver. However, CSI also showed a substantial decrease in the water signal intensity for the ethanol-treated rats compared to pair-fed control rats. 1H VOSY MR spectra also showed a 5.5-fold increase in the methylene resonance (1.3 ppm) of fat and a 50-70% decrease in the water resonance (4.8 ppm). Relative in vivo proton T1 and T2 relaxation times for the water resonance separate from the fat resonance, determined from modified VOSY experiments, were found to tend to increase and decrease, respectively, for ethanol-treated rat livers compared with controls. The decrease in hepatic water signal intensity could be accounted for by the decrease in T2 and decrease in water density due to the presence of accumulated hepatic fat (approximately 25 mg/g wet weight of liver). When ethanol was withdrawn from the chronically treated rats, fatty infiltration was observed by both CSI and VOSY spectra to revert toward control values with a half-life of 2-4 days. By day 16, however, the signal intensity for hepatic fat was still significantly higher than control levels. In vitro 1H MRS studies of chloroform-methanol extracts confirmed the 5.5-fold increase in total hepatic fat induced by the chronic ethanol treatment, and showed further that triacylglycerols were increased 7.7-fold, cholesterol was increased fourfold, and phospholipids were increased 3.3-fold, compared with liver extracts from pair-fed control rats.     

2-Naphthol-phosphatidylethanolamine: A fluorescent phospholipid analogue for excited-state proton transfer studies in membranes

The fluorescence properties of the phospholipid derivative,N-[1-(2-naphthol)]-phosphatidylethanolamine (NAPH-PE), have been studied by steady-state and time-resolved fluorescence techniques. The new probe is a naphthol adduct of phosphatidylethanolamine. The emission spectrum of the fluorescent phospholipid depends on the pH and on the proton acceptor concentration as expected for a typical two-state excited-state proton transfer reaction. In ethanol solutions at an apparent pH of 6.7 and in the presence of acetate anion (0.14M), a biexponential decay is obtained from global analysis of the data. The lifetimes, ₁=3.9 ns and ₂=6.2 ns. are constant across the spectral region 350–460 nm. The decay-associated spectra and the species-associated spectra reproduce well the profiles reported for a two-state excited-state proton transfer reaction. The fluorescent phospholipid has been incorporated into dimyristoyllecithin and dipalmitoyllecithin vesicles. Although lower proton transfer is found, the reaction appears to be dependent on the gel-to-liquid-crystalline phase transition of the lipid membrane. In addition, the steady-state anisotropy of NAPH-PE measured as a function of temperature trace the phase transition of the two vesicle systems. Thus, it is shown that the physical state of the bilayer affects a reaction which takes place at the membrane surface. In the presence of acetate ions (0.3M), global analysis, performed in terms of fluorescence decay parameters, recovers preexponential coefficients that are consistent with an excited-state proton transfer reaction. The short lifetime drops from 3.9 to 0.44 ns without significant changes of the longer-lifetime component.     

Repeated-Binge Ethanol Intoxication Leads to Lower Choline-Containing Compound Signals in Adult Rats: An In Vivo Marker of Ethanol-Induced Neurochemical Abnormalities

Ethanol is the most commonly abused intoxicating substance among young and middle-aged adults, and ranks highly as a cause of disability and mortality. A pattern of heavy consumption, called binge drinking, leads to various psychiatric disorders. However, to the best of our knowledge, assessments of the influence of short-term binge ethanol (SBE) intoxication on cerebral metabolite changes in human and rat models are scarce. We used in vivo ¹H magnetic resonance spectroscopy (¹H-MRS) to quantitatively assess neurochemical responses in hippocampus in a rat model of SBE intoxication. Seven SBE-exposed rats received an initial dose of 5.0-g/kg ethanol (30 %-w/v solution) through gavage and additional doses of 2.0-g/kg ethanol (25 %-w/v solution), every 8 hour for 4 days. Six rats in sham control group (CNTL) received an equivalent volume of distilled water at comparable times. Sixty minutes after last gavage session, in vivo ¹H-MRS scans were obtained from all rats using a 4.7 Tesla animal scanner. For neurochemical analysis, a single voxel was positioned in the hippocampal region and spectra were fitted for the quantification of 17 cerebral neurochemical signals. In hippocampus, the concentration of total choline-containing compound signals (tCho: [glycerophosphocholine] + [phosphocholine]) was significantly lower in SBE-exposed rats than in CNTL rats. Moreover, gamma-aminobutyric acid (GABA)/total creatine (tCr: creatine + phosphocreatine), tCho/tCr, and tCho/total N-acetyl-aspartate (tNAA: N-acetyl-aspartate + N-acetyl-aspartyl-glutamate) ratios were significantly lower in SBE-exposed rats than CNTL rats. We determined that tCho, GABA, and tNAA signals were highly sensitive to short-term binge ethanol intoxication, which provides insights into neurochemical alterations associated with ethanol abuse.     

电感耦合等离子体质谱中有机试剂的基体效应研究

研究了乙醇、丙醇、丙三醇、乙酸、乙二胺和三乙醇胺等与水互溶的有机试剂对不同质量和电离曜闰元素质谱信号的影响。在优化的工作条件下,溶液中加入少量的乙醇、丙醇、丙三醇、乙酸、乙二胺或三乙醇胺对电离能在９～１１ｅＶ的元素的信号有不同程度的增强,附加乙二胺或三乙醇胺对Ｈｇ信号的增强效应显著大于乙醇、丙醇和丙三醇等试剂;探讨了乙二胺和三乙醇胺对Ｈｇ的信号增强机理。利用乙二胺或三乙醇胺对Ｈｇ的信号增强的特性,     

Capacitive technique for measuring the component concentration in drops of binary solutions

A capacitive technique for measuring the component concentration in drops of binary mixtures consisting of liquids with different permittivities is described. Test results for the technique are presented, and the component concentration in drops of ethanol, methanol, and acetone aqueous solutions vaporizing in an air flow is measured.     

Organization of membrane-associated proteins in lipid bilayers

Lateral organization of proteins in biomembranes is vitally important to membrane functions such as signal transduction, endocytosis, and membrane trafficking. One of the major goals in current biomembrane science is to reveal the microscopic mechanism of membrane-associated protein organization in biomembranes. Here, we investigate the structural organization of membrane-associated proteins in lipid bilayers by combining self-consistent field theory with density functional theory. The present study can simultaneously take into account the entropy effect of lipids, depletion effect of membrane-associated proteins due to the presence of lipid headgroups as well as the effect of interfacial interaction. By varying the volume fraction of lipids, we examine various effects on protein organization, and reveal that a close-packed crystal structure appears at low lipid volume fractions due to interfacial energy and weak depletion effect, whereas a chain structure with branches occurs at high lipid volume fractions mainly due to strong depletion. The present results may provide some theoretical insight into further experiments on organization of membrane proteins.     

7 T 下脂肪对基于 NOE 的磁共振对比成像的影响

核 Overhauser 增强(NOE)效应在高场下的化学交换饱和转移中会造成 Z 谱高场位置的负背景信号,有望成为一种新的磁共振成像(MRI)对比机制．然而,研究指出, NOE信号的发生区域与主要的脂肪信号的频率位置有重叠,因此 MRI 中观察到的 NOE 信号有可能混合了脂肪信号．该文通过鸡蛋的模型实验,初步分析了脂肪含量较高的组织内脂肪信号对 NOE 效应的影响,并通过健康大鼠鼠脑及颅内肿瘤大鼠鼠脑实验,分析了脂肪对脑部 NOE 对比成像及基于 NOE 对比成像的疾病诊断的影响．结果表明,脂肪含量较高的组织内脂肪信号会引起伪 NOE 效应,并影响 NOE对比图像的准确性．
     

The effects of lipid A on gamma-irradiated human peripheral blood lymphocytes in vitro

The modulatory effects of lipid A (diphosphoryl lipid A (DLA) and monophosphoryl lipid A (MLA)) on apoptosis induction and DNA structure damage (single and double-strand breaks (SSBs and DSBs, respectively)) in peripheral human blood lymphocytes are studied for ⁶⁰Co gamma-irradiation. It is shown that in the presence of these agents the amount of apoptotic cells increases compared with the irradiated control samples. The effect is most strongly pronounced for DLA. In its presence, a significant increase is observed in the number of radiation-induced DNA SSBs and DSBs. Possible mechanisms are discussed of the modifying influence of the used agents on radiation-induced cell reactions     

Fermentation of Saccharomyces cerevisiae in a 7.5 L ultrasound-enhanced fermenter: Effect of sonication conditions on ethanol production,intracellular Ca2+ concentration and key regulating enzyme activity in glycolysis

In this study, the effect of sonication on the fermentation process of a single-celled fungus was examined. During the experiment, Saccharomyces cerevisiae (S. cerevisiae) was used as the starting strain for ethanol fermentation (batch fermentation) in a 7.5 L automated fermentation tank. The fermentation tank connected with a six-frequency ultrasonic equipment. Non-sonication treatment was set up as the control. Sonication treatment with power density of 280 W/L and 48 h of treatment time were set up as trial groups for investigating the influence of different ultrasound frequency including 20, 23, 25, 28, 33 and 40 kHz on the changes in dry cell-weight, glucose consumption rate, and ethanol yield. The results showed that the dry cell-weight, glucose consumption rate, and ethanol content reached the best results under the ultrasonic condition of 28 kHz ultrasound frequency in comparison with other ultrasound frequency. The dry cell-weight and ethanol content of the 28 kHz ultrasonic treatment group increased by 17.30% and 30.79%, respectively in comparison with the control group The residual sugar content dropped to a lower level within 24 h, which was consistent with the change in ethanol production. Besides, the results found that the glucose consumption rate increased compared to the control. It indicated that ultrasound accelerated glucose consumption contributed to increase the rate of ethanol output. In order to explore the mechanism of sonication enhanced the content of ethanol output by S. cerevisiae, the morphology, permeability of S. cerevisiae and key enzyme activities of ethanol synthesis were investigated before and after sonication treatment. The results showed that after sonication treatment, the extracellular nucleic acid protein content and intracellular Ca²⁺ concentration increased significantly. The morphology of S. cerevisiae was observed by SEM and found that the surface of the strain had wrinkles and depressions after ultrasonic treatment. furthermore after sonication treatment, the activities of three key enzymes which catalyze three irreversible reactions in glycolysis metabolism, namely, hexokinase, phosphofructokinase and pyruvate kinase increased by 59.02%, 109.05% and 87.27%, respectively. In a word, low-intensity ultrasound enhance the rate of ethanol output by S. cerevisiae might due to enhancing the growth and cell permeability of strains, and increasing the activities of three key enzymes of ethanol biosynthesis.     

Derivative Spectroscopy in Conjunction with Thin Layer Chromatography Applied for Determination of Mixtures of Amino Acids in Baby Food.

The preparative thin layer chromatography using silica gel and solvent systems n. butanol : acetic acid: water (4:1:1 V/V) and 96% ethanol : water (70 : 30 v/v) were used to separate the amino acids mixture into groups that can be eluted and one or two of amino acids can be determined by derivative spectroscopy. This was done for determining histidine in presence of cystine, arginine in presence of lysine and ornithine, tryptophan in presence of tyrosine and phenylalanin, and methionine in presence of aspartic acid. The proposed method is applied for determination of these amino acids in baby food, Neslac, Dialac and Nestogen. The statistical analysis of the results were found to be good and in agreement with the ion exchange chromatographic method.     

Self-concentration and large-scale coherence in bacterial dynamics

Suspensions of aerobic bacteria often develop flows from the interplay of chemotaxis and buoyancy. We find in sessile drops that flows related to those in the Boycott effect of sedimentation carry bioconvective plumes down the slanted meniscus and concentrate cells at the drop edge, while in pendant drops such self-concentration occurs at the bottom. On scales much larger than a cell, concentrated regions in both geometries exhibit transient, reconstituting, high-speed jets straddled by vortex streets. A mechanism for large-scale coherence is proposed based on hydrodynamic interactions between swimming cells.     

Energy analysis of possible channels for decomposition of a charged drop into two parts

Based on numerical analysis of the mathematical expression for potential energy of an isolated charged spheroidal drop and two approximate spheroidal daughter drops, mechanisms for decomposition of a multiply charged drop in two nearly equal parts were studied taking into account the electrostatic interaction of the daughter drops. It was shown that, as the distance between the daughter drops increased, both the probability of spontaneous decomposition of a multiply charged drop in two daughter drops and the decomposition symmetry degree increase at the moment of breaking the connection between the daughter drops.     

Vesicles and red blood cells in flow: From individual dynamics to rheology

The rheology of suspensions of soft particles, such as red blood cells, is a long-standing problem in science and engineering due to the complex interplay between deformable microstructure and the macroscale flow. The major challenge stems from the free-boundary nature of the particle interface. Lipid bilayer membranes that envelop cells and vesicles are particularly complex interfaces because of their unusual mechanics: the molecularly thin membrane is a highly-flexible incompressible fluid sheet. As a result, particles made of closed lipid bilayers (red cells and vesicles) can exhibit richer dynamics than would capsules and drops. We overview the key experimental observations and recent advances in the theoretical modeling of the vesicles and red blood cells in flow. To cite this article: P.M. Vlahovska et al., C. R. Physique 10 (2009).     

Liposome destruction by hydrodynamic cavitation in comparison to chemical,physical and mechanical treatments

Liposomes are widely applied in research, diagnostics, medicine and in industry. In this study we show for the first time the effect of hydrodynamic cavitation on liposome stability and compare it to the effect of well described chemical, physical and mechanical treatments. Fluorescein loaded giant 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) lipid vesicles were treated with hydrodynamic cavitation as promising method in inactivation of biological samples. Hydrodynamic treatment was compared to various chemical, physical and mechanical stressors such as ionic strength and osmolarity agents (glucose, Na⁺, Ca²⁺, and Fe³⁺), free radicals, shear stresses (pipetting, vortex mixing, rotational shear stress), high pressure, electroporation, centrifugation, surface active agents (Triton X-100, ethanol), microwave irradiation, heating, freezing-thawing, ultrasound (ultrasonic bath, sonotrode). The fluorescence intensity of individual fluorescein loaded lipid vesicles was measured with confocal laser microscopy. The distribution of lipid vesicle size, vesicle fluorescence intensity, and the number of fluorescein loaded vesicles was determined before and after treatment with different stressors. The different environmental stressors were ranked in order of their relative effect on liposome fluorescein release. Of all tested chemical, physical and mechanical treatments for stability of lipid vesicles, the most detrimental effect on vesicles stability had hydrodynamic cavitation, vortex mixing with glass beads and ultrasound. Here we showed, for the first time that hydrodynamic cavitation was among the most effective physico-chemical treatments in destroying lipid vesicles. This work provides a benchmark for lipid vesicle robustness to a variety of different physico-chemical and mechanical parameters important in lipid vesicle preparation and application.