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1.
An 8-m thick Cuprophane hollow-fibre membrane not only had a higher ultrafiltration coefficient than an 11-m thick membrane but was more permeable and selective for ethanol dialysis and extract removal from beer. Transmembrane pressures above 40 Pa did not affect alcohol removal but did prevent further extract removal and therefore improved the final beer quality. To achieve selective removal of alcohol, beer flow rates must be above the critical velocities but remain below values which would require too great a membrane area.  相似文献   

2.
Summary The closed form solution to a distributed parameter mathematical model of a countercurrent flow dialyser is presented. The model consisting of a bundle of hollow fibres in a shell accounts for axial convection and radial diffusion. The proposed model relates the fractional removal of a solute to mass transfer parameters such as Sherwood number, length Peclet number and system geometry. Excellent agreement with experimental beer dialysis data is demonstrated for the removal of alcohol using 8-lm thick 200-lm diameter cuprophane hollow-fibre membrane fibres. Potentially, this model could be very helpful in designing new processes involving dialysis. For example, removal efficiency better than 90% is achievable in systems operating with a Sherwood number of 2.0, length Peclet number of 5 · 105, unit tube-side/shell-side volumetric flow and length-to-diameter ratio of 5000. Results were obtained in this work from only the first eigenvalue and the case of no solute in the incoming dialysate stream.  相似文献   

3.
采用10 Kev低能N~+注入啤酒酵母,经筛选获得一菌株Lz37,再用150 MPa超高压处理菌株Lz37,经双乙酰平板筛选获得一菌株Gy3,其凝聚性很强,适合于在小麦汁中发酵啤酒,其发酵度为66%~68%,双乙酰含量低于口味阈值,遗传稳定性良好。将Gy3酵母定为全小麦啤酒生产应用酵母,命名为商啤3号(Sp-03)。SP-03啤酒酵母菌株的各项生理及生产性能都较优良,特别是在全小麦芽啤酒的酿造中适用性较强,经过对发酵工艺等的调整,用其酿制的啤酒口感纯正、淡爽、柔和。  相似文献   

4.
A fast, robust and sensitive LC–MS–MS method for the determination of zearalenone (ZON) and its metabolites α-zearalenol (α-ZOL) and β-zearalenol (β-ZOL) in beer samples is described. Sample preparation was performed by direct RP-18 solid-phase extraction of undiluted beer samples followed by selective determination of analytes by LC–MS–MS applying an atmospheric pressure chemical ionization (APCI) interface. Using the negative ion mode limits of determination of 0.03–0.06 μg l−1 beer and limits of quantification of 0.07–0.15 μg l−1 beer were achieved, which was distinctly more sensitive than in the positive ion mode. Twenty-three beer samples from different countries, produced from different grains and under different brewing conditions, were investigated by this method, but only in one sample could β-ZOL and ZON be detected. Independently of the type of beer, relative standard deviations between 2.1% and 3.3%, a linear working range of 0.15 μg l−1 to 500 μg l−1 beer and recovery rates around 100% could be achieved when zearalanone (ZAN) was used as internal standard.  相似文献   

5.
摘要 目的:探讨高通量血液透析对糖尿病肾病(DN)血液透析患者心脏功能及结构的影响,并分析预后的影响因素。方法:选取2017年5月~2018年11月期间我院收治的DN血液透析患者(n=172),上述DN血液透析患者中普通透析治疗者60例(普通透析组)、高通量血液透析治疗者112例(高通量透析组)。普通透析组采用低通量透析治疗,高通量透析组采用高通量透析治疗,比较两组患者心脏功能及结构以及预后情况,采用单因素、多因素Logistic回归分析预后的影响因素。结果:高通量透析组治疗6个月后左心房内径(LAD)、左心室舒张末内径(LVDd)、左心室心肌重量指数(LVMI)低于治疗前和普通透析组(P<0.05),高通量透析组治疗6个月后左心室射血分数( LVEF )高于治疗前和普通透析组(P<0.05)。高通量透析组的生存率高于普通透析组(P<0.05)。存活组年龄、上机前舒张压、上机前收缩压、血磷、全段甲状旁腺激素(iPTH)均低于死亡组(P<0.05),存活组透析频率、白蛋白、血红蛋白均高于死亡组(P<0.05),两组性别、血钙比较无差异(P>0.05)。多因素Logistic回归分析结果显示,上机前舒张压高、上机前收缩压高、血磷高、iPTH高、透析频率少、白蛋白低、血红蛋白低均是DN血液透析患者死亡的危险因素(P<0.05)。结论:高通量血液透析能减轻DN患者血液透析所引起的心脏功能及结构损伤,改善患者预后。影响DN血液透析患者预后的因素较多,其中上机前舒张压、上机前收缩压、血磷、iPTH越高,白蛋白、血红蛋白越低,透析频率越少,患者的死亡风险越大。  相似文献   

6.

Background

End-stage renal disease (ESRD) confers a large health-care burden for the United States, and the morbidity associated with vascular access failure has stimulated research into detection of vascular access stenosis and low flow prior to thrombosis. We present data investigating the possibility of using differential pressure (ΔP) monitoring to estimate access flow (Q) for dialysis access monitoring, with the goal of utilizing micro-electro-mechanical systems (MEMS) pressure sensors integrated within the shaft of dialysis needles.

Methods

A model of the arteriovenous graft fluid circuit was used to study the relationship between Q and the ΔP between two dialysis needles placed 2.5–20.0 cm apart. Tubing was varied to simulate grafts with inner diameters of 4.76–7.95 mm. Data were compared with values from two steady-flow models. These results, and those from computational fluid dynamics (CFD) modeling of ΔP as a function of needle position, were used to devise and test a method of estimating Q using ΔP and variable dialysis pump speeds (variable flow) that diminishes dependence on geometric factors and fluid characteristics.

Results

In the fluid circuit model, ΔP increased with increasing volume flow rate and with increasing needle-separation distance. A nonlinear model closely predicts this ΔP-Q relationship (R2 > 0.98) for all graft diameters and needle-separation distances tested. CFD modeling suggested turbulent needle effects are greatest within 1 cm of the needle tip. Utilizing linear, quadratic and combined variable flow algorithms, dialysis access flow was estimated using geometry-independent models and an experimental dialysis system with the pressure sensors separated from the dialysis needle tip by distances ranging from 1 to 5 cm. Real-time ΔP waveform data were also observed during the mock dialysis treatment, which may be useful in detecting low or reversed flow within the access.

Conclusion

With further experimentation and needle design, this geometry-independent approach may prove to be a useful access flow monitoring method.  相似文献   

7.
Beer is a natural product and is a multicomponent system that has both positive and negative consumer properties. Organoleptical off-flavors of beer are difficult to eliminate. Yeasts are the main active component of the system. The relationship between beer quality and yeast usage is well known. New industrial strains for brewery are continuously developed. An industrial yeast Saccharomyces cerevisiae strain was obtained and showed high technological properties, including efficient fermentation, a reduced production of sulfur hydrate, and a high diacetyl reduction rate. The advantages made it possible to develop new brands of beer and nonalcoholic products. The commercial use of the strain was patented. The strain was deposited in the Russian Collection of Industrial Microorganisms.  相似文献   

8.
LCA of an Italian lager beer   总被引:1,自引:1,他引:0  
Background, Aim and Scope  The increasing concern about environment protection and a broader awareness of the sustainable development issues cause more and more attention to be given to the environmental impacts of products through the different phases of their life cycle. Foods are definitely among the products whose overall environmental performance can be effectively investigated resorting to LCA. A LCA case study was performed in order to detect and quantify the environmental impacts deriving from the life cycle of a lager beer produced by an Italian small brewery, investigating and comparing two packaging options: beer in 20 L returnable stainless steel kegs and beer in 33 cL one way glass bottles. Materials and Methods  The investigated system included: production and acquisition of materials and energy, brewing process, packaging, transports, beer consumption and waste disposal. Data for the study were mostly collected from the Theresianer Brewery and completed on the basis of literature information. Data uncertainty was treated with a Monte Carlo analysis. Life Cycle Inventories were constructed for 1 L of beer in bottle and 1 L of beer in keg using the LCA software SimaPro and then assessed at the endpoint level according to the Eco-Indicator’99 method. Results  Inorganic emissions, land use and fossil fuel consumptions resulted to be the most critical environmental issues of both beer life cycles. Beer in keg turned out to cause a lower environmental load along its life cycle than bottled beer; this was mainly due to the higher emissions and the higher energy consumptions allocated to the glass bottles. Moreover, beer consumption phase, glass bottle production and barley cultivation were found to be the critical stages of the beer life cycle. Discussion  The brewing process did not result as a critical stage and therefore the company dimension may not be a crucial element for the overall impact quantification. On the contrary, beer consumption may have a significant impact mainly due to the consumer displacement. Conclusions  The analysis pointed out the relevance of the beer consumption phase and of the packaging choice within the beer life cycle and allowed to detect the other critical stages of the life cycle. It is worth to notice that producers and consumers can be active and responsible actors in pursuing the collective goal of the environmental sustainability. Recommendations and Perspectives  In order to improve the environmental performance of the beer life cycle, producers should set up marketing strategies in favour of reusable packaging and consumers should prefer draught beer and reduce car use. As beer consumption phase, bottle production and recycling and barley cultivation were found to be very significant stages of the life cycle of the beer, deepening the analysis of these aspects in similar studies is suggested. ESS-Submission Editor: Dr. Rolf Frischknecht (frischknecht@ecoinvent.org)  相似文献   

9.
Numerous studies have focused on the metabolic contributions of glucose and other substrates in isolated tissue preparations by examining the effects of eliminating glucose from the physiologic perfusate or bath solution. To date, however, an effective method of glucose removal from the blood supply to selected tissue in the whole animal model has not been available. We have developed a method for blood glucose removal by continuous flow dialysis. This method was used to generate isolated coronary hypoglycemia for an investigation of myocardial metabolic substrate selection during hypoperfusion in open-chest, anesthetized dogs. Arterial blood was passed through the dialysis system against an isotonic and physiologic dialysate solution prior to controlled coronary perfusion. During normal perfusion pressure (100 mmHg), with a coronary blood flow of 32 ± 4 ml/min, arterial blood glucose was reduced from 3.26 ± 0.31 to 0.54 ± 0.14 mM. When blood flow was reduced to 12 ± 3 ml/min with lower perfusion pressure (40 mmHg), dialysis reduced arterial glucose from 3.53 ± 0.36 to 0.15 ± 0.03 mM. We conclude that this is an effective method for producing regional hypoglycemia.  相似文献   

10.
The standard twin-coil Kolff artificial kidney has been redesigned to a single-pass system employing cold dialysis, bath-heated and recirculated within the coil. With considerably reduced bath requirements, a comparable dialysis is achieved in spite of a lower bath-to-blood urea gradient. Coil pressure is monitored by a simplified high-and-low pressure control system linked to a specially designed roller blood pump. The re-use of priming blood and disposable coils have proved economical and feasible. A considerable reduction in bacterial growth has been achieved. The Kolff system retains its capacity in the management of acute renal failure and has proved efficient in twice-weekly six-hour chronic hemodialyses.  相似文献   

11.
Isolated internodes of Chara corallina and Nitella flexilis have been used to determine the concentration of one passively permeating solute in the presence of non-permeating solutes. The technique was based on the fact that the shape of the peaks of the biphasic responses of cell turgor (as measured in a conventional way using the cell pressure probe) depended on the concentration and composition of the solution and on the permeability and reflection coefficients of the solutes. Peak sizes were proportional to the concentration of the permeating solute applied to the cell. Thus, using the selective properties of the cell membrane as the sensing element and changes of turgor pressure as the physical signal, plant cells have been used as a new type of biosensor based on osmotic principles. Upon applying osmotic solutions, the responses of cell turgor (P) exactly followed the P(t) curves predicted from the theory based on the linear force/flow relations of irreversible thermodynamics. The complete agreement between theory and experiment was demonstrated by comparing measured curves with those obtained by either numerically solving the differential equations for volume (water) and solute flow or by using an explicit solution of the equations. The explicit solution neglected the solvent drag which was shown to be negligible to a very good approximation. Different kinds of local beers (regular and de-alcoholized) were used as test solutions to apply the system for measuring concentrations of ethanol. The results showed a very good agreement between alcohol concentrations measured by the sensor technique and those obtained from conventional techniques (enzymatic determination using alcohol dehydrogenase or from measurement of the density and refraction index of beer). However, with beer as the test solution, the characean internodes did show irreversible changes of the transport properties of the membranes leading to a shift in the responses when cells were treated for longer than 1 h with diluted beer. The accuracy and sensitivity of the osmotic biosensor technique as well as its possible applications are discussed.  相似文献   

12.
啤酒酵母是啤酒酿造的灵魂,可以直接影响啤酒品质。在啤酒酿造过程中,由于啤酒酵母被多次传代和保藏,造成优良菌种发酵性能衰退等问题,导致发酵不彻底,影响最后啤酒的风味质量。为此以8株Lager型啤酒酵母为出发菌株,通过平板分离纯化获得80株分离菌株,再经过三角瓶发酵初筛和复筛、发酵罐中试发酵实验最终获得了8株发酵性能优良的啤酒酵母。其中,6株酵母可应用于酿造双乙酰含量低于0.1 mg/L的啤酒;3株酵母发酵度高于70%,适合酿造干啤酒;1株酵母发酵度低于50%,适合酿造低醇啤酒。在风味方面:1株酵母酿造的啤酒醇酯比为3.3,啤酒酯香味较突出;另1株酵母酿造的啤酒醇酯比为4.5,啤酒高级醇含量较高。8株经过选育的啤酒酵母发酵特征明显,便于精酿啤酒厂实际应用。  相似文献   

13.
Commercially available beer, which is a dilute solution containing components of yeast, malt, and hop used in the manufacture of the beer, was used as a model system to demonstrate the potential of foam fractionation beyond the primary foaming stage. Most of the components present in the beer concentrated in the initial foam, but they drained differentially in the subsequent collapsed foam collected over a period of 30 min. This resulted in further enrichment, in particular, of components which were present in low concentration in the original beer, Preferential drainage from foam, hence, might provide a novel way of fractionating further the proteins concentrated initially in the liquid films of foam. (c) 1994 John Wiley & Sons, Inc.  相似文献   

14.
刘俊伟  邓爱民  宋丹丹  李红梅  郭燕燕 《生物磁学》2013,(27):5330-5332,5288
目的:探讨分析糖尿病肾病腹膜透析患者血管内皮功能的变化。方法:将来我院行腹膜透析的糖尿病肾病患者56例作为观察组,非糖尿病肾病患者64例作为对照组,测量血压及血容量,采用血流介导的肱动脉扩张法测定血流介导的血管扩张。结果:观察组患者的收缩压、脉压、细胞外液均明显高于对照组,血管扩张则显著低于对照组(P〈0.05);血管扩张与身高、体重、收缩压、细胞外液均呈负相关(P〈0.05);细胞外液、有无糖尿病肾病是血管扩张的独立预测因素。结论:糖尿病肾病腹膜透析患者具有严重的内皮功能不全,其中细胞外液、有无糖尿病肾病是血管扩张的独立预测因素。  相似文献   

15.
啤酒中风味物质双乙酰含量的测定   总被引:5,自引:0,他引:5  
采用Turbotherm Vap40自动定氮仪进行啤酒的蒸馏操作以测定啤酒中双乙酰含量,测定结果与国标法进行了对照,结论是Turbotherm Vap40自动定氮仪可以替代国标法中的双乙酰蒸馏装置进行啤酒中双乙酰含量的测定。  相似文献   

16.
Specific isolates of lactic acid bacteria (LAB) can grow in the harsh beer environment, thus posing a threat to brew quality and the economic success of breweries worldwide. Plasmid-localized genes, such as horA, horC, and hitA, have been suggested to confer hop tolerance, a trait required for LAB survival in beer. The presence and expression of these genes among LAB, however, do not universally correlate with the ability to grow in beer. Genome sequencing of the virulent beer spoilage organism Lactobacillus brevis BSO 464 revealed the presence of eight plasmids, with plasmids 1, 2, and 3 containing horA, horC, and hitA, respectively. To investigate the roles that these and the other five plasmids play in L. brevis BSO 464 growth in beer, plasmid curing with novobiocin was used to derive 10 plasmid variants. Multiplex PCRs were utilized to determine the presence or absence of each plasmid, and how plasmid loss affected hop tolerance and growth in degassed (noncarbonated) beer was assessed. Loss of three of the eight plasmids was found to affect hop tolerance and growth in beer. Loss of plasmid 2 (horC and 28 other genes) had the most dramatic effect, with loss of plasmid 4 (120 genes) and plasmid 8 (47 genes) having significant, but smaller, impacts. These results support the contention that genes on mobile genetic elements are essential for bacterial growth in beer and that beer spoilage ability is not dependent solely on the three previously described hop tolerance genes or on the chromosome of a beer spoilage LAB isolate.  相似文献   

17.

Purpose

Global beer consumption is growing steadily and has recently reached 187.37 billion litres per year. The UK ranked 8th in the world, with 4.5 billion litres of beer produced annually. This paper considers life cycle environmental impacts and costs of beer production and consumption in the UK which are currently unknown. The analysis is carried out for two functional units: (i) production and consumption of 1 l of beer at home and (ii) annual production and consumption of beer in the UK. The system boundary is from cradle to grave.

Methods

Life cycle impacts have been estimated following the guidelines in ISO 14040/44; the methodology for life cycle costing is congruent with the LCA approach. Primary data have been obtained from a beer manufacturer; secondary data are sourced from the CCaLC, Ecoinvent and GaBi databases. GaBi 4.3 has been used for LCA modelling and the environmental impacts have been estimated according to the CML 2001 method.

Results and discussion

Depending on the type of packaging (glass bottles, aluminium and steel cans), 1 l of beer requires for example 10.3–17.5 MJ of primary energy and 41.2–41.8 l of water, emits 510–842 g of CO2 eq. and has the life cycle costs of 12.72–14.37 pence. Extrapolating the results to the annual consumption of beer in the UK translates to a primary energy demand of over 49,600 TJ (0.56 % of UK primary energy consumption), water consumption of 1.85 bn hl (5.3 % of UK demand), emissions of 2.16 mt CO2 eq. (0.85 % of UK emissions) and the life cycle costs of £553 million (3.2 % of UK beer market value). Production of raw materials is the main hotspot, contributing from 47 to 63 % to the impacts and 67 % to the life cycle costs. The packaging adds 19 to 46 % to the impacts and 13 % to the costs.

Conclusions

Beer in steel cans has the lowest impacts for five out of 12 impact categories considered: primary energy demand, depletion of abiotic resources, acidification, marine and freshwater toxicity. Bottled beer is the worst option for nine impact categories, including global warming and primary energy demand, but it has the lowest human toxicity potential. Beer in aluminium cans is the best option for ozone layer depletion and photochemical smog but has the highest human and marine toxicity potentials.
  相似文献   

18.
A continuous multistage column bioreactor with fluidised beds and continuous gas-lift bioreactor system with immobilised yeast Saccharomyces cerevisiae was developed for the first step of wort fermentation. The system of gas-lift reactor with yeast entrapped in calcium pectate beads was stable for 5 weeks by the optimal residence time of 12.75h and produced beer with a composition and flavour profile similar to that of beer produced by batch fermentation. Concentration of diacetyl was less than 0.1mg/l.  相似文献   

19.
Moderate alcohol consumption has shown to induce benefits on host specific (cell-mediated and humoral) immune system, but there is scarce literature regarding first-line immune responses. The aim of this study was to investigate differences in non-specific immunity after alcohol abstention and moderate beer consumption in healthy adults. After a 30 day-alcohol abstemious period, 57 healthy volunteers were submitted to a daily moderate consumption of beer (330 mL for women and 660 mL for men, respectively) during the following 30 days. White blood cell counts and phagocytic and oxidative burst activity were evaluated at three points: a) basal, b) abstemious, c) after moderate consumption of beer. Absolute values of leukocytes, neutrophils, lymphocytes and basophiles (x10(9)/L) increased significantly in women from point b to point c (6.34 +/- 1.26 vs. 7.27 +/- 1.97, 3.43 +/- 0.88 vs. 4.13 +/- 1.53, 2.14 +/- 0.50 vs. 2.38 +/- 0.63, and 0.05 +/- 0.02 vs. 0.06 +/- 0.03, respectively; p < 0.05) as well as basophils in men (0.05 +/- 0.03 vs. 0.06 +/- 0.03). A significant increase of oxidative burst capacity was also observed after the moderate consumption of beer in both women (33.90 +/- 19.00 vs. 48.86 +/- 21.83) and men (27.39 +/- 18.13 vs. 39.25 +/- 24.53). In healthy adults, after 30 days of moderate beer consumption the parameter describing the non-specific immunity improved when compared to the basal situation. For several of these parameters, the response is more enhanced in women.  相似文献   

20.
Analytical procedures for the determination of deoxynivalenol (DON) in bread and beer, using enzyme immunoassay (EIA) and HPLC methods, were developed. For determination of DON by EIA, aqueous raw extracts of bread or degassed beer were extracted by liquid-liquid partitioning with ethyl acetate, the organic solvent evaporated, and the residue redissolved in phosphate buffered saline (PBS) for analysis. For determination by HPLC (UV detection at 218 nm), DON in bread extracts or beer was purified on immunoaffinity chromatographic columns. In bread, detection limits for DON of 15 µg/kg (EIA) and 7 µg/kg (HPLC) were achieved, with mean recoveries of 81%. In beer, the detection limit for DON was 2 µg/l both in EIA and HPLC, with recoveries of 91–93%. Both methods showed good agreement of the results for naturally contaminated sample materials, with r2=0.993 for bread and r2=0.823 for beer, respectively.  相似文献   

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