Multiple episodes of induced secretion of human growth hormone from recombinant AtT-20 cells

Recombinant AtT-20 cells expressing human growth hormone (hGH) secreted the hormone at a constant, basal rate of 0.3–0.5 ng/10⁵ cells-hour when exposed to medium without secretagogues. When triggered with 8 bromo-cyclic AMP, cells secreted hGH at an initial rate of 1.7 ng/10⁵ cells-hour while intracellular hGH declined sharply. Upon extended exposure to secretagogue, secretion decreased gradually to the basal rate and intracellular hGH stabilized at a value 40% the initial. In cells switched from secretion to growth medium, the total rate of hGH accumulation intracellularly and in medium was 2.2 times that observed with cells never exposed to secretagogue; however, only a fraction of the hormone was stored intracellularly and the rest was secreted. When cells were exposed alternately to growth and secretion medium, induced cells secreted at rates at least two times higher than uninduced controls during the first five cycles. The induced response deteriorated with time, however, in parallel with outgrowth of attached cells by foci of round cells, and by the eighth cycle induced secretion did not occur. Operational modifications that may improve the performance of cycling schemes are discussed.     

Stanford A型主动脉夹层孙氏手术患者术后血流感染的影响因素及术前PCT、IL-6、D-D的预测价值研究

摘要 目的：分析Stanford A型主动脉夹层（AD）孙氏手术患者术后血流感染（BSI）的影响因素,并探讨术前血清降钙素原（PCT）、白细胞介素-6（IL-6）、D-二聚体（D-D）对术后发生BSI的预测价值。方法：选取2019年1月～2022年1月贵州医科大学附属医院收治的236例接受孙氏手术的Stanford A型AD患者,根据术后是否BSI分为BSI组和非BSI组。收集患者基础资料和实验室指标,采用多因素Logistic回归分析Stanford A型AD孙氏手术患者术后发生BSI的影响因素,采用受试者工作特征（ROC）曲线分析血清PCT、IL-6、D-D水平对Stanford A型AD孙氏手术患者术后发生BSI的预测价值。结果：BSI组年龄≥60岁、糖尿病史、机械通气、气管切开、人工瓣膜植入比例和术后24 h引流量、血清C反应蛋白、PCT、IL-6、D-D水平高于非BSI组,手术时间、心包纵隔管保留时间长于非BSI组（P＜0.05）。多因素Logistic回归分析显示,年龄≥60岁、糖尿病史、机械通气、气管切开、术后24 h引流量上升,血清PCT、IL-6、D-D水平上升为Stanford A型AD孙氏手术患者术后发生BSI的危险因素（P＜0.05）。ROC曲线分析显示,血清PCT、IL-6、D-D三项联合预测的Stanford A型AD孙氏手术患者术后发生BSI的曲线下面积大于单独预测。结论：年龄、糖尿病史、机械通气、气管切开、术后24 h引流量、血清PCT、IL-6、D-D水平是Stanford A型AD孙氏手术患者术后发生BSI的影响因素,术前血清PCT、IL-6、D-D水平可作为Stanford A型AD孙氏手术患者术后发生BSI的辅助预测指标。     

Degradation of quinoline by immobilized Comamonas acidovorans in a three-phase airlift reactor

Quinolie degradation by Comamonas acidovorans was studied in a continuously operated three-phase airlift reactor. Porous glass beads were applied as support matrix for cell imobilization by colonization. Under steady-state conditions (S approximately 0), cell attachment was poor at low dilution rates but imporved considerably with increasing dilution rate. Conversion of quinoline was investigated below and above the washout for suspended culture (D(crit) = mu(max) = 0.42 h(-1)). With immobilized cells the reactor could be operated at D > mu(max), and complete conversion of quinoline was achieved as long as the specific quinoline feed rate D*S(0)/X did not exceed the maximum specific degradation rate (r(S, max)). The biofilm thickness was about 100 mum, and its efficiency was about 54% compared to suspended organisms. If quinoline overloads were supplied to the reactor, quinoline, as overloads were supplied to the reactor, quinoline, as well as its pathway intermediates, appeared in the reactor and conversion was low. Hence, the immobilized microorganisms remained viable and active. They could survive quinoline overloads. If the quinoline feed rate was reduced agains, complete conversion was reestablished. (c) 1995 John Wiley & Sons, Inc.     

Periodic operation of immobilized live cell bioreactor for the production of candicidin

A lumped model for cell growth and secondary metabolite production in an immobilized live cell bioreactor has been developed. This model is applied here to simulate the performance of an immobilized bioreactor under steady-state conditions and under conditions of periodically varying concentration of a growth-limiting substrate. The results of the simulation study were experimentally verified in the case of the production of the antibiotic candicidin by Streptomyces griseus in an immobilized bioreactor with forced periodic operation. The results of the studies suggest that periodically operated immobilized live cell bioreactors can provide a potent alternative for the production of non-growth-associated biochemicals, as compared to free cell fermentations, pulsed fermentations with process cycle regeneration, and nonregenerated bioreactors. This work has demonstrated that by frequent pulsing of the growth limiting nutrient, stable extended production can be obtained at high specific cellular productivities.     

Glucose uptake of Cytophaga johnsonae studied in batch and chemostat culture

The influence of different physiological states on the glucose uptake and mineralization by Cytophaga johnsonae, a freshwater isolate, was examined in batch and chemostat cultures. At different growth rates under glucose limitation in chemostat cultures, different uptake patterns for ¹⁴C labeled glucose were observed. In batch culture and at high growth rates the glucose uptake potential showed a higher maximum velocity and a much lower substrate affinity than at lower growth rates. These findings and the results of short-term labeling patterns could be explained by two different glucose uptake mechanisms which enable the strain to grow efficiently both at high and low substrate concentrations. Substrate specificity studies showed that a structural change of the C-2 atom of the glucose molecule was tolerated by both systems. The consequences of these results for the ecophysiological classification of the Cytophaga group and for the operation of continuous cultures are discussed.     

Evolution of specialized microbial cooperation in dynamic fluids

Here, we study the evolution of specialization using realistic computer simulations of bacteria that secrete two public goods in a dynamic fluid. Through this first‐principles approach, we find physical factors such as diffusion, flow patterns and decay rates are as influential as fitness economics in governing the evolution of community structure, to the extent that when mechanical factors are taken into account, (a) generalist communities can resist becoming specialists despite the invasion fitness of specialization; (b) generalist and specialists can both resist cheaters despite the invasion fitness of free‐riding; and (c) multiple community structures can coexist despite the opposing force of competitive exclusion. Our results emphasize the role of spatial assortment and physical forces on niche partitioning and the evolution of diverse community structures.     

复方丹参滴丸联合沙库巴曲缬沙坦对老年心肌梗死患者PCI术后炎性反应、心室重塑和心肌灌注的影响

摘要 目的：探讨复方丹参滴丸联合沙库巴曲缬沙坦对老年心肌梗死患者经皮冠状动脉介入术（percutaneous coronary intervention,PCI）术后炎性反应、心室重塑和心肌灌注的影响。方法：采用随机数字表法将本院2017年3月至2020年2月间收治的行PCI治疗的68例老年心肌梗死为研究对象,分为对照组（34例）和观察组（34例）。两组均行常规药物治疗,在此基础上予以对照组沙库巴曲缬沙坦治疗,予以观察组复方丹参滴丸联合沙库巴曲缬沙坦治疗。比较两组治疗前后血浆中超敏C反应蛋白（high-sensitivity creactive protein,hs-CRP)、肿瘤坏死因子-α（Tumor necrosis factor-α,TNF-α）、白细胞介素-8（interleukin-8,IL-8）、N末端脑钠肽前体（N-terminal-pro-brain-natriuretic-peptide,NT-proBNP）、左室舒张末期前后径（left ventricular end-diastolic diamete,LVEDD）、左室射血分数（left ventricular ejection fraction,LVEF）、左室质量指数（left ventricular mass index,LVMI）以及治疗后TIMI血流分级。结果：两组血浆hs-CRP、TNF-α、IL-8和NT-proBNP水平以及LVEDD和LVMI水平较治疗前明显降低,LVEF水平明显增加（P<0.05）。观察组治疗后血浆hs-CRP、TNF-α、IL-8和NT-proBNP水平以及LVEDD和LVMI水平明显低于对照组,LVEF水平明显高于对照组（P<0.05）。两组术后20 minTIMI血流分级均明显好转,观察组术后20 min时TIMI血流分级明显优于对照组（P<0.05）。两组不良反应总发生率比较无明显差异（P>0.05）。结论：复方丹参滴丸联合沙库巴曲缬沙坦能够明显降低老年心肌梗死患者PCI术后炎性反应,抑制心室重塑,改善心肌灌注,安全性较高。     

医学生实习中外科基本操作常犯错误及对策分析

目的：探讨医学生临床实习中在基本操作上常犯的错误,并对此提出建议和纠正措施,旨在进一步提高临床带教水平及临床教学质量。方法i总结我院临床医学专业实习生进行常见的外科临床基本操作考核成绩的情况,对错误类型等进行统计并提出合理的解决措施。结果：共考察学生90名,其中外科换药方法欠佳者22人（24．4％）,消毒铺巾存在问题24人（26．6％）,缝合存在问题32人（35．5％）,打结存在问题38（42．2％）人,拆线存在问题19（21．1％）人。结论：加强医学生外科实习期间的无菌观念培养及强化手术基本操作是临床教学的重要环节。     

不同剂量地佐辛用于腹腔镜妇科手术超前镇痛的效果观察

目的：观察不同剂量地佐辛用于腹腔镜妇科手术超前镇痛的效果。方法：将90例ASAI．II级、年龄18~60岁拟行腹腔镜妇科手术的患者随机分成3组,每组30例,A组给予地佐辛0．1mg／kg开皮前15rain静脉注射;B组给予地佐辛0．15mg／kg开皮前15min静脉注射;C组给予地佐辛0．2mg／kg开皮前15min静脉注射,采用VAS评分评估术后镇痛效果并观察术后辅助镇痛药物的使用和不良反应的发生情况。结果：B、c组术后2、4、6、8h的VAS评分明显低于A组（P〈0．05）;C组术后2、4h的Ramsay评分明显高于A、B组（P〈0.05）;A组术后辅助镇痛药的使用率明显高于B组和C组（P／0．05）;3组不良反应的发生率比较均无统计学差异（P〉0．05）。结论：开皮前15rain静注地佐辛0．15mg／kg用于腹腔镜妇科手术镇痛效果好,且不增加不良反应的发生率。     

Combining model structure identification and hybrid modelling for photo-production process predictive simulation and optimisation

Integrating physical knowledge and machine learning is a critical aspect of developing industrially focused digital twins for monitoring, optimisation, and design of microalgal and cyanobacterial photo-production processes. However, identifying the correct model structure to quantify the complex biological mechanism poses a severe challenge for the construction of kinetic models, while the lack of data due to the time-consuming experiments greatly impedes applications of most data-driven models. This study proposes the use of an innovative hybrid modelling approach that consists of a simple kinetic model to govern the overall process dynamic trajectory and a data-driven model to estimate mismatch between the kinetic equations and the real process. An advanced automatic model structure identification strategy is adopted to simultaneously identify the most physically probable kinetic model structure and minimum number of data-driven model parameters that can accurately represent multiple data sets over a broad spectrum of process operating conditions. Through this hybrid modelling and automatic structure identification framework, a highly accurate mathematical model was constructed to simulate and optimise an algal lutein production process. Performance of this hybrid model for long-term predictive modelling, optimisation, and online self-calibration is demonstrated and thoroughly discussed, indicating its significant potential for future industrial application.