• 【Tamarix ramosissima的水热处理和酶促水解: 作为生物精炼概念中的转化方法的过程评估。】 复制标题 收藏 收藏
    DOI:10.1016/j.biortech.2012.08.143 复制DOI
    作者列表:Xiao LP,Shi ZJ,Xu F,Sun RC
    BACKGROUND & AIMS: :The present work investigated the effects of hydrothermal treatment (HTT) of Tamarix ramosissima by determination of sugar and inhibitor formation in the liquid fraction, and chemical and morphological changes of the pretreated solid material coupled with an evaluation of enzymatic hydrolysis. HTT was carried out in a batch reactor system at a maximal temperature (TMAX 180-240 °C) and evaluated for severities logRo ranging from 2.40 to 4.17. The liquid fractions were analyzed by HPLC, GPC, and GC-MS. The morphology and composition of the solid residues were characterized using an array of techniques, such as SEM, XRD, BET surface area, and CP/MAS (13)C NMR. Using a variety of tools, we have developed a better understanding of how HTT process affects biomass structure and cellulose properties that impact on its digestibility. These results provided new insights into the factors limiting enzymatic digestibility and mechanism of biomass deconstruction during hydrothermal process.
    背景与目标: : 目前的工作通过测定液体馏分中的糖和抑制剂的形成以及预处理固体材料的化学和形态变化以及酶水解的评估,研究了Tamarix ramosissima的水热处理 (HTT) 的影响。在间歇反应器系统中在最高温度 (TMAX 180-240 °C) 下进行HTT,并评估范围为2.40至4.17的严重度。通过HPLC,GPC和gc-ms分析液体级分。使用一系列技术 (例如SEM,XRD,BET表面积和CP/MAS (13)C NMR) 表征了固体残基的形态和组成。使用各种工具,我们对HTT过程如何影响生物质结构和纤维素特性 (影响其消化率) 有了更好的了解。这些结果为水热过程中限制酶消化率的因素和生物质解构的机理提供了新的见解。
  • 【使用厌氧-好氧工艺从垃圾填埋场渗滤液中去除生物氮: 通过原始渗滤液中的有机物和微生物的细胞内存储聚合物进行脱氮。】 复制标题 收藏 收藏
    DOI:10.1016/j.biortech.2012.10.063 复制DOI
    作者列表:Zhu R,Wang S,Li J,Wang K,Miao L,Ma B,Peng Y
    BACKGROUND & AIMS: :A system which combined ASBR with pulsed SBR (PSBR) was introduced to enhance COD and nitrogen removal from the real landfill leachate. ASBR was used to degrade the organics from raw leachate mainly. Three equal feeds mode was applied in PSBR operation. The results obtained from the joint operation period (157 days) show that the COD removal rate of ASBR was 83-88% under the specific loading rate of 0.43-0.62 gCOD gVSS(-1) day(-1). PSBR's operation can be divided into four phases according to the different influent NH(4)(+)-N which increased to 800-1000 mg L(-1) finally, and total nitrogen (TN) removal rate of more than 90% with the effluent TN of less than 40 mg L(-1) was obtained. PHB and glycogen can act as electron donor for endogenous denitritation orderly with the hypothetical function from DNGAOs. Consequently, the system achieved COD and TN removal rate of 89.61-96.73% and 97.03-98.87%, respectively, without any extra carbon source addition.
    背景与目标: : 引入了一种将ASBR与脉冲SBR (PSBR) 相结合的系统,以提高实际垃圾渗滤液中COD和氮的去除。ASBR主要用于降解原渗滤液中的有机物。PSBR操作中采用了三等馈模式。联合运行期 (157天) 获得的结果表明,在0.43-0.62 gCOD gVSS(-1) 天 (-1) 的比载率下,ASBR的COD去除率为83-88%。PSBR的操作可根据不同的进水NH(4)(+)-N分为四个阶段,最后增加到800-1000 mg L(-1),当出水TN小于40 mg L(-1) 时,总氮 (TN) 去除率大于90%。PHB和糖原可以作为内源性脱氮的电子供体,具有DNGAOs的假设功能。因此,该系统在不添加任何额外碳源的情况下,分别实现了89.61-96.73% 和97.03-98.87% 的COD和TN去除率。
  • 【提出了一种用有限元方法模拟无骨水泥中骨向内生长过程的方法。】 复制标题 收藏 收藏
    DOI:10.1016/j.medengphy.2012.10.010 复制DOI
    作者列表:Tarala M,Janssen D,Verdonschot N
    BACKGROUND & AIMS: :In cementless total hip arthroplasty, long-term implant stability is achieved by bone ingrowth. The strength of the new bond gradually increases in time, due to bone maturation and progression of ingrowth. In finite element simulations, osseointegration generally is implemented as an instant change in the mechanical behavior of the implant-bone interface, although this is a simplified interpretation of the bone ingrowth process. The aim of the present study was to build on previous bone ingrowth simulations and propose a new methodology to simulate bone ingrowth as a time-dependent process. We developed an algorithm to calculate the strength of the local implant-bone bond based of the magnitude of interface micromotions and gaps in time. Our algorithm was subsequently tested in multiple hip reconstructions in which the bone quality and implant-bone contact area were varied. The results of the simulations showed that in the ideal situation (good bone quality and no interface gaps), 91% of implant area could achieve ingrowth, while in the worst case only 17% of implant area showed ingrowth. The initial contact area had a significant effect on ingrowth, overruling the effect of variations in bone quality. The progression of ingrowth had a stabilizing effect on adjacent regions, especially in the high contact area cases. Further development and validation of the presented algorithm requires more information on the nature of the relation between the ingrowth rate and the magnitude of micromotions and gap.
    背景与目标: : 在无骨水泥全髋关节置换术中,植入物的长期稳定性是通过骨向内生长来实现的。由于骨骼的成熟和向内生长的进展,新键的强度随时间逐渐增加。在有限元模拟中,骨整合通常是作为植入物-骨界面的机械行为的即时变化来实现的,尽管这是对骨向内生长过程的简化解释。本研究的目的是在以前的骨向内生长模拟的基础上,提出一种新的方法来模拟骨向内生长,这是一个与时间有关的过程。我们开发了一种算法,可以根据界面微动的大小和时间间隙来计算局部植入物-骨键的强度。随后,我们的算法在多次髋关节重建中进行了测试,其中骨质量和植入物-骨接触面积发生了变化。模拟结果表明,在理想情况下 (良好的骨质量和无界面间隙),植入物区域的91% 可以实现向内生长,而在最坏的情况下,只有17% 的植入物区域显示向内生长。初始接触面积对向内生长有显着影响,从而推翻了骨质量变化的影响。向内生长的进程对相邻区域具有稳定作用,尤其是在高接触面积的情况下。提出的算法的进一步开发和验证需要更多有关向内生长速率与微动和间隙大小之间关系的性质的信息。
  • 【通过Dirichlet过程进行贝叶斯单体型推断。】 复制标题 收藏 收藏
    DOI:10.1089/cmb.2006.0102 复制DOI
    作者列表:Xing EP,Jordan MI,Sharan R
    BACKGROUND & AIMS: :The problem of inferring haplotypes from genotypes of single nucleotide polymorphisms (SNPs) is essential for the understanding of genetic variation within and among populations, with important applications to the genetic analysis of disease propensities and other complex traits. The problem can be formulated as a mixture model, where the mixture components correspond to the pool of haplotypes in the population. The size of this pool is unknown; indeed, knowing the size of the pool would correspond to knowing something significant about the genome and its history. Thus methods for fitting the genotype mixture must crucially address the problem of estimating a mixture with an unknown number of mixture components. In this paper we present a Bayesian approach to this problem based on a nonparametric prior known as the Dirichlet process. The model also incorporates a likelihood that captures statistical errors in the haplotype/genotype relationship trading off these errors against the size of the pool of haplotypes. We describe an algorithm based on Markov chain Monte Carlo for posterior inference in our model. The overall result is a flexible Bayesian method, referred to as DP-Haplotyper, that is reminiscent of parsimony methods in its preference for small haplotype pools. We further generalize the model to treat pedigree relationships (e.g., trios) between the population's genotypes. We apply DP-Haplotyper to the analysis of both simulated and real genotype data, and compare to extant methods.
    背景与目标: : 从单核苷酸多态性 (snp) 的基因型推断单倍型的问题对于理解种群内部和种群之间的遗传变异至关重要,对于疾病倾向和其他复杂性状的遗传分析具有重要应用。可以将问题表述为混合模型,其中混合成分对应于种群中的单倍型库。这个池的大小是未知的; 实际上,知道池的大小将对应于了解基因组及其历史的重要信息。因此,用于拟合基因型混合物的方法必须至关重要地解决估计具有未知数量的混合物成分的混合物的问题。在本文中,我们基于称为Dirichlet过程的非参数先验,提出了一种解决此问题的贝叶斯方法。该模型还结合了一种可能性,该可能性捕获了单倍型/基因型关系中的统计误差,将这些误差与单倍型池的大小进行了权衡。我们在模型中描述了一种基于马尔可夫链蒙特卡罗的后验推理算法。总体结果是一种灵活的贝叶斯方法,称为DP-Haplotyper,它使人想起了对小型单体型池的偏爱。我们进一步推广了该模型,以处理人群基因型之间的血统关系 (例如三重奏)。我们将DP-Haplotyper应用于模拟和真实基因型数据的分析,并与现有方法进行比较。
  • 【庇护程序对精神卫生的影响: 挪威无人陪伴的未成年难民的纵向研究。】 复制标题 收藏 收藏
    DOI:10.1136/bmjopen-2016-015157 复制DOI
    作者列表:Jakobsen M,Meyer DeMott MA,Wentzel-Larsen T,Heir T
    BACKGROUND & AIMS: OBJECTIVES:To examine the mental health of unaccompanied refugee minors prospectively during the asylum-seeking process, with a focus on specific stages in the asylum process, such as age assessment, placement in a supportive or non-supportive facility and final decision on the asylum applications. DESIGN:This was a2½ year follow-up study of unaccompanied minors (UM) seeking asylum in Norway. Data were collected within three weeks (n=138) and at 4 months (n=101), 15 months (n=84) and 26 months (n=69) after arrival. SETTING:Initially in an observation and orientation centre for unaccompanied asylum-seeking adolescents, and subsequently wherever the UM were located in other refugee facilities in Norway. PARTICIPANTS:Male UM from Afghanistan, Somalia, Algeria and Iran. MAIN OUTCOME MEASURES:Mental health symptoms assessed by Hopkins Symptom Checklist-25 and Harvard Trauma Questionnaire. RESULTS:At the group level, the young asylum seekers reported high levels of psychological distress on arrival and symptom levels that stayed relatively unchanged over time. According to age-assessment procedures, 56% of the population were not recognised as minors. Subsequent placement in a low-support facility was associated with higher levels of psychological distress in the follow-up period. Those who were placed in a reception centre for adults had higher levels of psychological distress symptoms both after 15 months and 26 months compared with the remaining participants who were placed in reception centres for youth. Refusal of asylum was highly associated with higher levels of psychological distress. CONCLUSION:Mental health trajectory of young asylum seekers appears to be negatively affected by low support and refusal of asylum.
    背景与目标:
  • 【对不可逆过程的新见解: 根治性前列腺切除术后膀胱尿道吻合口狭窄组织的mRNA和miRNA组合分析。】 复制标题 收藏 收藏
    DOI:10.1007/s00345-017-2060-2 复制DOI
    作者列表:Worst TS,Daskalova K,Steidler A,Berner-Leischner K,Röth R,Niesler B,Weis CA,Kriegmair MC,Erben P,Pfalzgraf D
    BACKGROUND & AIMS: PURPOSE:Until recently, tissue fibrosis-ultimately leading to permanent scaring-has been considered an irreversible process. However, recent findings indicate that it may be reversible after all. Vesicourethral anastomotic stenosis (VUAS) as fibrous narrowing is a frequent complication after radical prostatectomy with high recurrence rates and requires invasive treatment. The pathophysiology is poorly understood. Therefore, a combined mRNA and miRNA transcription profiling in tissue from VUAS was performed using nCounter technology. METHODS:To assess tissue morphology and fiber composition, histochemical staining was performed. RNA expression of healthy and fibrotic tissue of twelve patients was analyzed using the human miRNA panel v3 and mRNA PanCancer pathway panel on the nCounter gene1 system and qRT-PCR. Differential expression data analysis was performed using the nSolver software implementing the R-based advanced pathway analysis tool. miRWalk2.0 was used for miRNA target prediction. RESULTS:More linearized tissue architecture, increased collagens, and decreased elastic fibers were observed in VUAS samples. 23 miRNAs and 118 protein coding genes were differentially expressed (p < 0.01) in fibrotic tissue. miRNA target prediction and overlap analysis indicated an interaction of the strongest deregulated miRNAs with 29 deregulated mRNAs. Pathway analysis revealed alterations in DNA repair, cell cycle regulation, and TGF-beta signaling. qRT-PCR confirmed differential expression of top deregulated miRNAs and mRNAs. CONCLUSIONS:In VUAS tissue, severe alterations on mRNA and miRNA level are found. These consistent changes give insights into the pathogenesis of VUAS after radical prostatectomy and point to future options for transcriptomics-based risk stratification and targeted therapies.
    背景与目标:
  • 【MIEX的适用性 (®) 从NOM水中去除有机物的DOC工艺。】 复制标题 收藏 收藏
    DOI:10.1007/s11356-012-1334-x 复制DOI
    作者列表:Karpinska AM,Boaventura RA,Vilar VJ,Bilyk A,Molczan M
    BACKGROUND & AIMS: :The aim of this study was to evaluate applicability of ion exchange process for organics removal from Douro River surface water at the intake of Lever water treatment plant using magnetized ion exchange resin MIEX®. Qualitative analysis of the natural organic matter present in the surface water and prediction of its amenability to removal in conventional coagulation process were assessed. Results obtained in MIEX®DOC process kinetic batch experiments allowed determination of ion exchange efficiency in dissolved organic carbon (DOC), UV absorbing organics, and true color removal. The data were compared with the efficiencies of the conventional unit processes for organics removal at Lever WTP. MIEX®DOC process revealed to be more efficient in DOC removal than conventional treatment achieving the efficiencies in the range of 61-91 %, lowering disinfection by-products formation potential of the water. DOC removal efficiency at Lever WTP depends largely on the raw water quality and ranges from 28 % for water of moderated quality to 89 % of significantly deteriorated quality. In this work, MIEX®DOC process was also used as a reference method for the determination of contribution of anionic fraction to dissolved organic matter and selectivity of the unit processes at Lever WTP for its removal.
    背景与目标: : 这项研究的目的是评估使用磁化离子交换树脂MIEX在Lever水处理厂进水口从杜罗河地表水中去除有机物的离子交换工艺的适用性®。评估了地表水中存在的天然有机物的定性分析,并预测了其在常规混凝过程中的去除能力。在MIEX中获得的结果®DOC过程动力学批处理实验可以确定溶解有机碳 (DOC) 中的离子交换效率,吸收紫外线的有机物和真正的颜色去除。将数据与常规单元工艺在杠杆WTP去除有机物的效率进行了比较。米克斯®DOC工艺显示在DOC去除方面比常规处理更有效,实现了61-91% 范围内的效率,降低了水的消毒副产物形成潜力。杠杆WTP处的DOC去除效率在很大程度上取决于原水的质量,并且范围从对具有温和质量的水的28% 到具有显著劣化质量的89%。在这项工作中,米克斯®DOC工艺也被用作参考方法,用于确定阴离子级分对溶解有机物的贡献以及Lever WTP去除其单元工艺的选择性。
  • 【医疗决策过程与家庭: 乳腺癌患者及其丈夫的案例。】 复制标题 收藏 收藏
    DOI:10.1111/j.1467-8519.2008.00650.x 复制DOI
    作者列表:Gilbar R,Gilbar O
    BACKGROUND & AIMS: OBJECTIVES:The objectives of the study were (1) to assess similarities and differences between breast cancer patients and their husbands in terms of doctor-patient/spouse relationships and shared decision making; and (2) to investigate the association between breast cancer patients and husbands in terms of preference of type of doctor, doctor-patient relationship, and shared decision making regarding medical treatment. METHOD:Fifty-seven women with breast cancer, and their husbands, completed questionnaires measuring doctor-patient/spouse relationships (paternalism, autonomy), and decision making regarding medical treatment. RESULTS:Patients believe they have a key role in the medical decision-making process (93%) and that the participation of their husbands, and their agreement with the decision, is important (84% and 89%, respectively). Both breast cancer patients and their husbands prefer a shared decision-making process to paternalistic or autonomy-based approaches. CONCLUSION:In contrast to legal and bioethical approaches, which focus on the patient as the primary decision maker, this study reflects a practical recognition of the role of the breast cancer patient's husband in the decision-making process. It also reflects a relational rather than an individualistic perception of patient autonomy.
    背景与目标:
  • 【酿酒过程中的诱变活性: 与芦丁和槲皮素水平的相关性。】 复制标题 收藏 收藏
    DOI:10.1093/mutage/5.4.393 复制DOI
    作者列表:Rueff J,Laires A,Gaspar J,Rodrigues A
    BACKGROUND & AIMS: :Mutagenic activity was monitored during the time course of the vinification process of a Portuguese red wine using the Ames assay. Dependence upon faecalase treatment for detection of mutagenicity was evaluated concurrently with HPLC analysis of the flavonoids rutin and quercetin. Rutin (quercetin-o-3-rutinoside) is liberated from the grapes during the first 10 days of the process and is hydrolysed as the vinification process proceeds. This explains the levels of the free quercetin in the wine and mutagenicity in the absence of faecalase treatment. Mutagenicity in the presence of faecalase during the first 26 days of the process correlates with the levels of rutin, and in the absence of faecalase the highest mutagenic activity detected (160th day) coincides with the highest level of free quercetin. Our results do not rule out the possibility that other mutagens are present in wines, in particular oxidative-type mutagens.
    背景与目标: : 使用Ames测定法在葡萄牙红酒的酿造过程中监测诱变活性。与类黄酮芦丁和槲皮素的HPLC分析同时评估了对粪便醛酶处理检测致突变性的依赖性。芦丁 (quercetin-o-3-rutinoside) 在该过程的前10天从葡萄中释放出来,并随着酿酒过程的进行而水解。这解释了葡萄酒中游离槲皮素的水平以及在没有粪醛酶处理的情况下的致突变性。在该过程的前26天中,在存在粪便醛酶的情况下的致突变性与芦丁的水平相关,并且在不存在粪便醛酶的情况下,检测到的最高诱变活性 (第160天) 与游离槲皮素的最高水平一致。我们的结果并不排除葡萄酒中存在其他诱变剂的可能性,特别是氧化型诱变剂。
  • 【临床推理的综合模型: 认知和元认知的双过程理论。】 复制标题 收藏 收藏
    DOI:10.1111/j.1365-2753.2012.01900.x 复制DOI
    作者列表:Marcum JA
    BACKGROUND & AIMS: RATIONALE AND AIM:Clinical reasoning is an important component for providing quality medical care. The aim of the present paper is to develop a model of clinical reasoning that integrates both the non-analytic and analytic processes of cognition, along with metacognition. METHOD:The dual-process theory of cognition (system 1 non-analytic and system 2 analytic processes) and the metacognition theory are used to develop an integrated model of clinical reasoning. RESULTS:In the proposed model, clinical reasoning begins with system 1 processes in which the clinician assesses a patient's presenting symptoms, as well as other clinical evidence, to arrive at a differential diagnosis. Additional clinical evidence, if necessary, is acquired and analysed utilizing system 2 processes to assess the differential diagnosis, until a clinical decision is made diagnosing the patient's illness and then how best to proceed therapeutically. Importantly, the outcome of these processes feeds back, in terms of metacognition's monitoring function, either to reinforce or to alter cognitive processes, which, in turn, enhances synergistically the clinician's ability to reason quickly and accurately in future consultations. CONCLUSIONS:The proposed integrated model has distinct advantages over other models proposed in the literature for explicating clinical reasoning. Moreover, it has important implications for addressing the paradoxical relationship between experience and expertise, as well as for designing a curriculum to teach clinical reasoning skills.
    背景与目标:
  • 【具有神经元应用的二维Ornstein Uhlenbeck过程的逆首次通过时间方法。】 复制标题 收藏 收藏
    DOI:10.3934/mbe.2019412 复制DOI
    作者列表:Civallero A,Zucca C
    BACKGROUND & AIMS: :The Inverse First Passage time problem seeks to determine the boundary corresponding to a given stochastic process and a fixed first passage time distribution. Here, we determine the numerical solution of this problem in the case of a two dimensional Gauss-Markov diffusion process. We investigate the boundary shape corresponding to Inverse Gaussian or Gamma first passage time distributions for different choices of the parameters, including heavy and light tails instances. Applications in neuroscience framework are illustrated.
    背景与目标: : 逆第一次通过时间问题寻求确定与给定随机过程和固定的第一次通过时间分布相对应的边界。在这里,我们在二维高斯-马尔可夫扩散过程的情况下确定该问题的数值解。对于不同的参数选择,包括重尾和轻尾实例,我们研究了与逆高斯或伽马首次通过时间分布相对应的边界形状。说明了在神经科学框架中的应用。
  • 【直接输注骨髓源性祖细胞和间接动员造血祖细胞对动脉粥样硬化斑块和炎症过程的影响。】 复制标题 收藏 收藏
    DOI:10.1016/j.ijcard.2013.07.229 复制DOI
    作者列表:Tousoulis D,Briasoulis A,Vogiatzi G,Valatsou A,Kourkouti P,Pantopoulou A,Papageorgiou N,Perrea D,Stefanadis C
    BACKGROUND & AIMS: BACKGROUND:We sought to investigate the effects of lin-/sca+ cells, endothelial progenitor cells (EPCs) and granulocyte colony-stimulating factor (G-CSF) administration on atherosclerotic plaque progression. METHODS:Apolipoprotein E-deficient (apoE(-/-)) mice were splenectomized and treated with high-cholesterol diet for 6 weeks in order to induce atherosclerotic plaque development. Bone marrow-derived Lin-/sca-1+ cells were isolated and further cultured to early growth endothelial progenitor cells (EPCs). Mice were divided in four groups (n=10/group) and received two intravenous injections of 5×10(5) cells (lin-/sca-1+ or EPCs), or granulocyte colony-stimulating factor (G-CSF 100 μg/kg/day) for 7 days or normal saline. The same interventions were administered to animals, which had undergone unilateral hind-limb ischemia. Effects on inflammatory parameters, lesion severity, and atherosclerotic plaque area size were assessed. RESULTS:The administration of both G-CSF and progenitor cells significantly decreased the levels of IL-6, 6 weeks after the initiation of treatment. Atherosclerotic lesion area was reduced by G-CSF (atherosclerotic plaque area percentage 22.94%±3.68, p=0.001), by lin-/sca-1+ (23.27%±5.98, p=0.002) and cultured EPCs (23.16±4.86%, p=0.002) compared to control (32.75%±7.05). In the atherosclerotic mice that underwent limb ischemia, the atherosclerotic plaque area, was not significantly different between the treatment groups cultured EPCs-treated mice and the control group (p=NS, for all). CONCLUSIONS:Direct infusion of progenitor cells and indirect mobilization of hematopoietic progenitor cells decreased plaque progression and levels of inflammatory molecules in a murine model of atherosclerosis. Treatment with G-CSF, lin-/sca-1+, or EPCs may exert beneficial effects on vascular inflammation and atherosclerotic plaque progression. However, the effects are diminished in an ischemic setting.
    背景与目标:
  • 【通过包括暗发酵,光发酵和产甲烷的三阶段过程提高小球藻生物质的能量转化效率。】 复制标题 收藏 收藏
    DOI:10.1016/j.biortech.2013.07.077 复制DOI
    作者列表:Xia A,Cheng J,Ding L,Lin R,Huang R,Zhou J,Cen K
    BACKGROUND & AIMS: :The effects of pre-treatment methods on saccharification and hydrogen fermentation of Chlorella pyrenoidosa biomass were investigated. When raw biomass and biomass pre-treated by steam heating, by microwave heating, and by ultrasonication were used as feedstock, the hydrogen yields were only 8.8-12.7 ml/g total volatile solids (TVS) during dark fermentation. When biomass was pre-treated by steam heating with diluted acid and by microwave heating with diluted acid, the dark hydrogen yields significantly increased to 75.6 ml/g TVS and 83.3 ml/g TVS, respectively. Steam heating with diluted acid is the preferred pre-treatment method of C. pyrenoidosa biomass to improve hydrogen yield during dark fermentation and photofermentation, which is followed by methanogenesis to increase energy conversion efficiency (ECE). A total hydrogen yield of 198.3 ml/g TVS and a methane yield of 186.2 ml/g TVS corresponding to an overall ECE of 34.0% were obtained through the three-stage process (dark fermentation, photofermentation, and methanogenesis).
    背景与目标: : 研究了预处理方法对小球藻生物质糖化和氢发酵的影响。当使用通过蒸汽加热,通过微波加热和通过超声处理的原始生物质和生物质作为原料时,在黑暗发酵期间,氢产率仅为8.8-12.7毫升/g总挥发性固体 (TVS)。当通过用稀酸进行蒸汽加热和用稀酸进行微波加热对生物质进行预处理时,暗氢产量分别显著增加至75.6毫升/g TVS和83.3毫升/g TVS。用稀酸蒸汽加热是C. pyrenoidosa生物质的首选预处理方法,以提高黑暗发酵和光发酵过程中的氢产量,随后是甲烷生成以提高能量转化效率 (ECE)。通过三阶段过程 (暗发酵、光发酵和产甲烷) 获得了198.3毫升/g TVS的总氢产率和186.2毫升/g TVS的甲烷产率,对应于34.0% 的总ECE。
  • 【大鼠胸内不溶性透明质酸的保留及其吸收过程。】 复制标题 收藏 收藏
    DOI:10.1177/0391398819885126 复制DOI
    作者列表:Uemura A,Ogawa S,Tanaka R
    BACKGROUND & AIMS: BACKGROUND:Post-thoracotomy adhesions are frequent postoperative complications. It has been reported that insoluble hyaluronic acid may prevent adhesions. MATERIALS AND METHODS:This study had two objectives: first, to determine the in vivo degradation and absorption process, as well as the intrathoracic retention, of solid insoluble hyaluronic acid membrane; and second, to elucidate the association between postoperative intrathoracic retention and the morphological changes of insoluble hyaluronic acid in 12 Wistar rats. Insoluble hyaluronic acid membranes were cut into 2.0 cm × 1.0 cm rectangles in a dry state. After weighing, the test membranes were soaked and washed with saline to be implanted after pericardiotomy via thoracotomy. At Days 4, 7, 10, 14, and 28 after implantation, the rats were euthanized, the chest was opened, and the condition and implantation site of the inserted test membrane were examined. RESULTS:Although approximately 10 days were required for the test membrane to decrease to half in the thoracic cavity, the intrathoracic remnant decreased to a mean of ~2% just 4 days later. CONCLUSION:This study clarified the time-dependent degradation process and remnants of insoluble hyaluronic acid in the thoracic cavity. A close relationship between the intrathoracic remnant of insoluble hyaluronic acid and its morphological change associated with degradation was demonstrated.
    背景与目标:
  • 【不同类型聚四氟乙烯 (PTFE) 假体在腹壁缺损修复性瘢痕形成过程中的行为。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Buján J,Contreras LA,Carrera-San Martín A,Bellón JM
    BACKGROUND & AIMS: Currently one of the most widely used prosthetic materials in the repair of abdominal wall defects, is expanded polytetrafluoroethylene (ePTFE). It has been suggested that its behavior with respect to the reparative process may depend on its structure. The aim of the present study was to evaluate the effect of the structure of 3 ePTFE prostheses on the scarring process in an abdominal-wall-defect experimental model. The prostheses employed were the Soft Tissue Patch (STP) which is laminar in structure, Mycro Mesh (MM) which is multilaminar with perforations, and the Dual Mesh (DM) prosthesis which has one non-porous surface. Abdominal wall defects (7 x 5 cm) were created in 36 New Zealand rabbits and repaired using fragments of STP, MM and DM. Follow-up periods were 14, 30, 60 and 90 days post-implant. At these times prostheses were macroscopically examined for the presence of infection and/or rejection and the formation of adhesions to abdominal viscera. Specimens were also taken for microscopic analysis (optical and scanning electron) and for immunohistochemical analysis using the rabbit macrophage-specific monoclonal antibody RAM-11. Labelled macrophage counts were performed at each follow-up session. No cases of infection or rejection were found. Loose adhesions between prosthesis and underlying viscera were observed in 2 of the STP, 4 of the MM and 2 of the DM implants. STP and DM implants were progressively encapsulated by organized connective tissue on both peritoneal and subcutaneous surfaces. Cellular colonization was observed on both STP surfaces and on the porous surface of the DM although no more than a third of the biomaterial was penetrated by cells in either case. Colonization was very slight at prosthesis anchorage points. MM implants differed only in the formation of connective tissue bridges in perforated areas, and cellular infiltration in interlaminar spaces. Macrophage response was similar in the 3 prostheses with a reduction in RAM-11 labelled cells (p < 0.05) between 14 and 90 days post-implant. We concludea) the 3 types of PTFE prosthesis induced low incidence of adhesion formation between biomaterial and viscera; b) integration mechanism of the 3 prostheses were similar and culminated with the encapsulation of the PTFE by the neoformed tissue; c) the macrophage response induced by the 3 prostheses was similar to that of any reparative process in the absence of biomaterial.

    背景与目标: 目前在腹壁缺损修复中应用最广泛的假体材料之一是膨体聚四氟乙烯 (ePTFE)。有人建议,其在修复过程中的行为可能取决于其结构。本研究的目的是在腹壁缺损实验模型中评估3种ePTFE假体的结构对瘢痕形成过程的影响。使用的假体是层状结构的软组织贴片 (STP),多层带穿孔的Mycro网 (MM) 和具有一个无孔表面的双网 (DM) 假体。在36只新西兰兔中产生腹壁缺损 (7 × 5厘米),并使用STP、MM和DM片段修复。随访时间分别为植入后14、30、60和90天。在这些时候,对假体进行了宏观检查,以检查是否存在感染和/或排斥以及与腹部内脏粘连的形成。还将标本用于显微镜分析 (光学和扫描电子) 以及使用兔巨噬细胞特异性单克隆抗体RAM-11进行免疫组织化学分析。在每个随访阶段进行标记的巨噬细胞计数。没有发现感染或排斥的病例。在2个STP,4个MM和2个DM植入物中观察到假体与下方内脏之间的松动粘连。STP和DM植入物逐渐被腹膜和皮下表面有组织的结缔组织包裹。尽管在任何一种情况下,细胞都不超过三分之一的生物材料被细胞穿透,但在STP表面和DM的多孔表面上均观察到细胞定植。假体锚固点的定植非常轻微。MM植入物的不同之处仅在于穿孔区域结缔组织桥的形成以及层间空间中的细胞浸润。3个假体中的巨噬细胞反应相似,植入后14至90天之间RAM-11标记的细胞减少 (p <0.05)。我们得出结论) 3种类型的聚四氟乙烯假体导致生物材料与内脏之间形成粘附的发生率较低; b) 3种假体的整合机制相似,并最终以新生组织对聚四氟乙烯的包封而告终; c) 在没有生物材料的情况下,由3个假体诱导的巨噬细胞反应与任何修复过程相似。

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