Pub Date : 2017-10-18DOI: 10.14293/S2199-1006.1.SOR-EARTH.A2TIA5.V2
W. Schrön
The deposition of solid material from the gas phase via chemical vapor transport (CVT) is a well-known process of industrial and geochemical relevance. There is strong evidence that this type of thermodynamically driven chemical transport reaction plays a significant role in certain natural processes. This article presents detailed evidence that CVT is a highly plausible mechanism for the formation of iron meteorites. In this study, naturally occurring CVT is referred to as “chemical fluid transport” (CFT) and the end products deposited from the gas phase as “fluidites.” Treating iron meteorites as cosmic fluidites enables simple solutions to be found to the problem of how they formed and to numerous related and in some cases unresolved questions. This study is based on a thermodynamic trend analysis of solid–gas equilibrium reactions involving chlorine- and fluorine-containing compounds of 42 chemical elements that include a systematic examination of reaction dominance switching behavior. In order to assess the transport behavior of the individual elements, the reaction-conditioned pressures p MeX were calculated from the equilibrium constants. For a selected group of minerals, the relative propensity of these minerals to deposit from the gas phase was then derived from the equilibrium constants. The study shows that octahedrites, hexahedrites and ataxites formed as a result of the transport of metal chlorides and fluorides (CFT) during accretion within the solar nebula. Siderophile elements are characterized by the similarities in their chemical transport properties. These chemical properties of the elements, expressed in the form of the reaction-conditioned pressure, play a key role in determining the chemical composition of iron meteorites. The mobilization process that leads to the formation of the gaseous metal halides MeX includes the reduction of oxides. The deposition of nickel–iron bodies occurs via back reaction after the transport of the gaseous halides. The back reaction leads to the thermodynamically favored deposition of schreibersite before troilite and of troilite before kamacite/taenite. The deposition temperature of octahedrites and hexahedrites lies below the temperature at which Widmanstätten patterns would be destroyed, while that of ataxites lies slightly above. Similarly, the occurrence of thermally instable cohenite in meteorites provides further support for the fluidite character of irons. The variation in the trace element concentrations in iron meteorites is explained by enrichment and depletion mechanisms in the gas phase. The striking correlation between gallium and germanium abundances in iron meteorites is the result of similarities regarding the mobilization phase and the reaction dominance switching behavior of both elements, and crystal isomorphism. These findings are supported by numerous arguments that provide evidence for the CFT model. The occurrence of the mineral lawrencite FeCl 2 in meteorites is interpre
{"title":"Formation of nickel–iron meteorites by chemical fluid transport","authors":"W. Schrön","doi":"10.14293/S2199-1006.1.SOR-EARTH.A2TIA5.V2","DOIUrl":"https://doi.org/10.14293/S2199-1006.1.SOR-EARTH.A2TIA5.V2","url":null,"abstract":"The deposition of solid material from the gas phase via chemical vapor transport (CVT) is a well-known process of industrial and geochemical relevance. There is strong evidence that this type of thermodynamically driven chemical transport reaction plays a significant role in certain natural processes. This article presents detailed evidence that CVT is a highly plausible mechanism for the formation of iron meteorites. In this study, naturally occurring CVT is referred to as “chemical fluid transport” (CFT) and the end products deposited from the gas phase as “fluidites.” Treating iron meteorites as cosmic fluidites enables simple solutions to be found to the problem of how they formed and to numerous related and in some cases unresolved questions. This study is based on a thermodynamic trend analysis of solid–gas equilibrium reactions involving chlorine- and fluorine-containing compounds of 42 chemical elements that include a systematic examination of reaction dominance switching behavior. In order to assess the transport behavior of the individual elements, the reaction-conditioned pressures p MeX were calculated from the equilibrium constants. For a selected group of minerals, the relative propensity of these minerals to deposit from the gas phase was then derived from the equilibrium constants. The study shows that octahedrites, hexahedrites and ataxites formed as a result of the transport of metal chlorides and fluorides (CFT) during accretion within the solar nebula. Siderophile elements are characterized by the similarities in their chemical transport properties. These chemical properties of the elements, expressed in the form of the reaction-conditioned pressure, play a key role in determining the chemical composition of iron meteorites. The mobilization process that leads to the formation of the gaseous metal halides MeX includes the reduction of oxides. The deposition of nickel–iron bodies occurs via back reaction after the transport of the gaseous halides. The back reaction leads to the thermodynamically favored deposition of schreibersite before troilite and of troilite before kamacite/taenite. The deposition temperature of octahedrites and hexahedrites lies below the temperature at which Widmanstätten patterns would be destroyed, while that of ataxites lies slightly above. Similarly, the occurrence of thermally instable cohenite in meteorites provides further support for the fluidite character of irons. The variation in the trace element concentrations in iron meteorites is explained by enrichment and depletion mechanisms in the gas phase. The striking correlation between gallium and germanium abundances in iron meteorites is the result of similarities regarding the mobilization phase and the reaction dominance switching behavior of both elements, and crystal isomorphism. These findings are supported by numerous arguments that provide evidence for the CFT model. The occurrence of the mineral lawrencite FeCl 2 in meteorites is interpre","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84589181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-10-03DOI: 10.14293/S2199-1006.1.SOR-SOCSCI.E0TQOE.v1
D. Hagmann
{"title":"The Digital Archaeology Collection on ScienceOpen: Meaning and Purpose","authors":"D. Hagmann","doi":"10.14293/S2199-1006.1.SOR-SOCSCI.E0TQOE.v1","DOIUrl":"https://doi.org/10.14293/S2199-1006.1.SOR-SOCSCI.E0TQOE.v1","url":null,"abstract":"","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79558291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-09-26DOI: 10.14293/S2199-1006.1.SOR-EARTH.ELCP1Y.v1
Dasapta Erwin Irawan
{"title":"Multivariate statistics and visualisation in earth science: It's not only about maps","authors":"Dasapta Erwin Irawan","doi":"10.14293/S2199-1006.1.SOR-EARTH.ELCP1Y.v1","DOIUrl":"https://doi.org/10.14293/S2199-1006.1.SOR-EARTH.ELCP1Y.v1","url":null,"abstract":"","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"22 5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80265605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-06-13DOI: 10.14293/S2199-1006.1.SOR-MED.AXK5RB.V2
S. Shu
Abstract A healthy, 8-year-old girl with a history of hematochezia underwent an uneventful fiber optic colonoscopy with propofol anesthesia. During the postoperative recovery period, she experienced acute-onset muscle rigidity, loss of consciousness, apnea, hypoxia, and hyperthermia. She was administered cardiopulmonary resuscitation and was treated with naloxone, mannitol, and midazolam. She regained consciousness after 14 hours. She underwent cerebral function rehabilitation and was discharged in 1 month without obvious neurologic sequelae. This case illustrates that propofol may affect the developing brain differently from the adult brain. Propofol-induced seizures can lead to life-threatening status epilepticus in children. Immediate diagnosis and effective treatment are essential.
{"title":"Anesthesia-related status epilepticus after fiber optic colonoscopy in a child","authors":"S. Shu","doi":"10.14293/S2199-1006.1.SOR-MED.AXK5RB.V2","DOIUrl":"https://doi.org/10.14293/S2199-1006.1.SOR-MED.AXK5RB.V2","url":null,"abstract":"Abstract\u0000A healthy, 8-year-old girl with a history of hematochezia underwent an uneventful fiber optic colonoscopy with propofol anesthesia. During the postoperative recovery period, she experienced acute-onset muscle rigidity, loss of consciousness, apnea, hypoxia, and hyperthermia. She was administered cardiopulmonary resuscitation and was treated with naloxone, mannitol, and midazolam. She regained consciousness after 14 hours. She underwent cerebral function rehabilitation and was discharged in 1 month without obvious neurologic sequelae. This case illustrates that propofol may affect the developing brain differently from the adult brain. Propofol-induced seizures can lead to life-threatening status epilepticus in children. Immediate diagnosis and effective treatment are essential.","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90408116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-06-08DOI: 10.14293/S2199-1006.1.SOR-MED.E2LMOE.v1
J. Tennant
{"title":"Better latte than never: Is coffee good for you health?: The science of coffee","authors":"J. Tennant","doi":"10.14293/S2199-1006.1.SOR-MED.E2LMOE.v1","DOIUrl":"https://doi.org/10.14293/S2199-1006.1.SOR-MED.E2LMOE.v1","url":null,"abstract":"","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78440477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-05-12DOI: 10.14293/S2199-1006.1.SOR-LIFE.EIOYQO.V1
P. Macklin
{"title":"Introduction: Open Source Cell Simulators: A curated guide to leading open source discrete cell models","authors":"P. Macklin","doi":"10.14293/S2199-1006.1.SOR-LIFE.EIOYQO.V1","DOIUrl":"https://doi.org/10.14293/S2199-1006.1.SOR-LIFE.EIOYQO.V1","url":null,"abstract":"","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85228249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-05-07DOI: 10.14293/S2199-1006.1.SOR-UNCAT.EITGTN.v1
A. Menke
Major depressive disorder (MDD) is a common, serious and in some cases life‐threatening condition and affects approximately 350 million people globally (Otte et al., 2016). The magnitude of the clinical burden reflects the limited effectiveness of current available therapies. The current prescribed antidepressants are based on modulating monoaminergic neurotransmission, i.e. they improve central availability of serotonin, norepinephrine and dopamine. However, they are associated with a high rate of partial or non-response, delayed response onset and limited duration. Actually more than 50% of the patients fail to respond to their first antidepressant they receive. Therefore there is a need of new treatment approaches targeting other systems than the monoaminergic pathway. One of the most robust findings in biological psychiatry is a dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis in major depression (Holsboer, 2000). Many studies observed an increased production of the corticotropin-releasing hormone (CRH) in the hypothalamus, leading to an increased release of adrenocorticotropic hormone (ACTH) from the pituitary and subsequently to an enhanced production of cortisol in the adrenal cortex. Due to an impaired sensitivity of the glucocorticoid receptor (GR) the negative feedback mechanisms usually restoring homeostasis after a stress triggered cortisol release are not functioning properly (Holsboer, 2000, Pariante and Miller, 2001). However, treatment strategies targeting the GR or the CRH receptors have not been successful for a general patient population. Selecting the right patients for these treatment alternatives may improve therapy outcome, since a dysregulation of the HPA axis affects only 40-60 % of the depressed patients. Thus, patients with a dysregulated HPA axis have first to be identified and then allocated to a specific treatment regime. Tests like the dexamethasone-suppression-test (DST) or the dex-CRH test have been shown to uncover GR sensitivity deficits, but are not routinely applied in the clinical setting. Recently, the dexamethasone-induced gene expression could uncover GR alterations in participants suffering from major depression and job-related exhaustion (Menke et al., 2012, Menke et al., 2013, Menke et al., 2014, Menke et al., 2016). Actually, by applying the dexamethasone-stimulation test we found a GR hyposensitivity in depressed patients (Menke et al., 2012) and a GR hypersensitivity in subjects with job-related exhaustion (Menke et al., 2014). These alterations normalized after clinical recovery (Menke et al., 2014). Interestingly, the dexamethasone-stimulation test also uncovered FKBP5 genotype dependent alterations in FKBP5 mRNA expression in depressed patients and healthy controls (Menke et al., 2013). FKBP5 is a co-chaperone which modulates the sensitivity of the GR (Binder, 2009). In addition, the dexamethasone-stimulation test provided evidence of common genetic variants that modulate the immedia
重度抑郁症(MDD)是一种常见的、严重的、在某些情况下危及生命的疾病，影响着全球约3.5亿人(Otte等人，2016)。临床负担的严重程度反映了现有治疗方法的有限有效性。目前处方的抗抑郁药是基于调节单胺能神经传递，即它们改善血清素、去甲肾上腺素和多巴胺的中枢可用性。然而，它们与部分或无反应率高、反应开始延迟和持续时间有限有关。事实上，超过50%的患者对他们第一次服用的抗抑郁药没有反应。因此，除了单胺能途径外，还需要针对其他系统的新治疗方法。生物精神病学中最有力的发现之一是重度抑郁症患者的下丘脑-垂体-肾上腺(HPA)轴失调(Holsboer, 2000)。许多研究观察到下丘脑促肾上腺皮质激素释放激素(CRH)的产生增加，导致垂体促肾上腺皮质激素(ACTH)的释放增加，随后肾上腺皮质皮质醇的产生增加。由于糖皮质激素受体(GR)的敏感性受损，通常在应激触发皮质醇释放后恢复体内平衡的负反馈机制不能正常运作(Holsboer, 2000; Pariante和Miller, 2001)。然而，针对GR或CRH受体的治疗策略在一般患者群体中尚未成功。为这些治疗方案选择合适的患者可能会改善治疗效果，因为下丘脑轴失调仅影响40- 60%的抑郁症患者。因此，HPA轴失调的患者必须首先被识别，然后分配到特定的治疗方案。地塞米松抑制试验(DST)或dex-CRH试验等试验已被证明可发现GR敏感性缺陷，但在临床环境中并未常规应用。最近，地塞米松诱导的基因表达可以揭示重度抑郁症和工作疲劳参与者的GR改变(Menke et al.， 2012, Menke et al.， 2013, Menke et al.， 2014, Menke et al.， 2016)。实际上，通过地塞米松刺激试验，我们发现抑郁症患者的GR敏感性较低(Menke et al.， 2012)，而工作疲劳受试者的GR敏感性较高(Menke et al.， 2014)。这些改变在临床恢复后正常化(Menke et al.， 2014)。有趣的是，地塞米松刺激试验还揭示了抑郁症患者和健康对照中FKBP5 mRNA表达的FKBP5基因型依赖性改变(Menke et al.， 2013)。FKBP5是调节GR敏感性的共同伴侣(Binder, 2009)。此外，地塞米松刺激试验提供了常见遗传变异的证据，这些变异调节了人类外周血中对GR激活的即时转录反应，并增加了患抑郁症和共遗传精神疾病的风险(Arloth et al.， 2015)。综上所述，分子地塞米松刺激试验可能有助于表征患有压力相关疾病的受试者亚组，并且从长远来看可能有助于指导治疗方案和预防策略。参考文献:Arloth J, Bogdan R, Weber P, Frishman G, Menke A, Wagner KV, Balsevich G, Schmidt MV, Karbalai N, Czamara D, Altmann A, Trumbach D, Wurst W, Mehta D, Uhr M, Klengel T, Erhardt A, Carey CE, Conley ED，重度抑郁症精神基因组学工作组C, Ruepp A, Muller-Myhsok B, Hariri AR, Binder EB，精神基因组学联盟PGC重度抑郁症工作组(2015)应激即时转录组反应的遗传差异预测风险相关的脑功能和精神疾病。神经元86:1189 - 1202。Binder EB(2009)糖皮质激素受体的共同伴侣FKBP5在情感和焦虑障碍的发病和治疗中的作用。精神神经内分泌学杂志34，增刊1:186-195。Holsboer F(2000)抑郁症的皮质类固醇受体假说。神经精神药理学23:477 - 501。Menke A, Arloth J, Best J, Namendorf C, Gerlach T, Czamara D, Lucae S, Dunlop BW, Crowe TM, Garlow SJ, Nemeroff CB, Ritchie JC, Craighead WE, Mayberg HS, Rex-Haffner M, Binder EB, Uhr M(2016)地塞米松血药浓度对糖皮质激素受体刺激试验的影响。心理神经内分泌学69:161 - 171。Menke A, Arloth J, Gerber M, Rex-Haffner M, Uhr M, Holsboer F, Binder EB, Holsboer- trachsler E, Beck J(2014)地塞米松刺激外周血糖皮质激素受体超敏反应对工作疲劳的影响。心理神经内分泌学44:35-46。 Menke A, Arloth J, Putz B, Weber P, Klengel T, Mehta D, Gonik M, Rex-Haffner M, Rubel J, Uhr M, Lucae S, Deussing JM, Muller-Myhsok B, Holsboer F, Binder EB(2012)地塞米松刺激的外周血糖皮质激素受体抵抗的敏感标志物。神经精神药理学37:1455 - 1464。陈晓明，陈晓明，陈晓明，陈晓明，陈晓明，陈晓明(2013)重度抑郁症患者应激激素失调程度与FKBP5基因变异的关系。基因，大脑行为，12:289-296。Otte C, Gold SM, Penninx BW, Pariante CM, Etkin A, Fava M, Mohr DC, Schatzberg AF(2016)重度抑郁症。Nature reviews疾病引物2:160 - 65。陈晓明，陈晓明(2001)糖皮质激素受体在重度抑郁症中的作用。生物精神病学49:391-404。
{"title":"Glucocorticoid Signaling in Stress-Related Psychiatric Disorders Uncovered by Dexamethasone-Induced Gene Expression","authors":"A. Menke","doi":"10.14293/S2199-1006.1.SOR-UNCAT.EITGTN.v1","DOIUrl":"https://doi.org/10.14293/S2199-1006.1.SOR-UNCAT.EITGTN.v1","url":null,"abstract":"Major depressive disorder (MDD) is a common, serious and in some cases life‐threatening condition and affects approximately 350 million people globally (Otte et al., 2016). The magnitude of the clinical burden reflects the limited effectiveness of current available therapies. The current prescribed antidepressants are based on modulating monoaminergic neurotransmission, i.e. they improve central availability of serotonin, norepinephrine and dopamine. However, they are associated with a high rate of partial or non-response, delayed response onset and limited duration. Actually more than 50% of the patients fail to respond to their first antidepressant they receive.\u0000Therefore there is a need of new treatment approaches targeting other systems than the monoaminergic pathway. One of the most robust findings in biological psychiatry is a dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis in major depression (Holsboer, 2000). Many studies observed an increased production of the corticotropin-releasing hormone (CRH) in the hypothalamus, leading to an increased release of adrenocorticotropic hormone (ACTH) from the pituitary and subsequently to an enhanced production of cortisol in the adrenal cortex. Due to an impaired sensitivity of the glucocorticoid receptor (GR) the negative feedback mechanisms usually restoring homeostasis after a stress triggered cortisol release are not functioning properly (Holsboer, 2000, Pariante and Miller, 2001).\u0000However, treatment strategies targeting the GR or the CRH receptors have not been successful for a general patient population. Selecting the right patients for these treatment alternatives may improve therapy outcome, since a dysregulation of the HPA axis affects only 40-60 % of the depressed patients. Thus, patients with a dysregulated HPA axis have first to be identified and then allocated to a specific treatment regime. Tests like the dexamethasone-suppression-test (DST) or the dex-CRH test have been shown to uncover GR sensitivity deficits, but are not routinely applied in the clinical setting. Recently, the dexamethasone-induced gene expression could uncover GR alterations in participants suffering from major depression and job-related exhaustion (Menke et al., 2012, Menke et al., 2013, Menke et al., 2014, Menke et al., 2016). Actually, by applying the dexamethasone-stimulation test we found a GR hyposensitivity in depressed patients (Menke et al., 2012) and a GR hypersensitivity in subjects with job-related exhaustion (Menke et al., 2014). These alterations normalized after clinical recovery (Menke et al., 2014).\u0000Interestingly, the dexamethasone-stimulation test also uncovered FKBP5 genotype dependent alterations in FKBP5 mRNA expression in depressed patients and healthy controls (Menke et al., 2013). FKBP5 is a co-chaperone which modulates the sensitivity of the GR (Binder, 2009).\u0000In addition, the dexamethasone-stimulation test provided evidence of common genetic variants that modulate the immedia","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"142 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82890670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-12-29DOI: 10.14293/S2199-1006.1.SOR-LIFE.Z72TP0.V1
Heidi A. Wright, B. Brehm-Stecher
Plant extracts have been used for millennia for treatment of disease, with much recent interest focusing on the antimicrobial activities of plant essential oils (EOs). Although EOs are active against common microbial pathogens, their effective use as topical, environmental, or food antimicrobials will require EO-based formulations with enhanced antimicrobial activities. In this study, two polyionic compounds, sodium polyphosphate (polyP, a polyanion) and polyethylenimine (PEI, a polycation), were evaluated for their abilities to enhance the antimicrobial activities of six EOs against the human pathogens Escherichia coli O157:H7, Salmonella enterica subsp. enterica ser. Minnesota, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, and Candida albicans. EOs tested were cinnamon, clove, regular and redistilled oregano, and two types of thyme oil. EOs were examined via disk diffusion and broth microdilution, either alone or in the presence of subinhibitory levels of polyP or PEI. Both polyP and PEI were found to be effective enhancers of EO activity against all strains examined, and calculation of fractional inhibitory indices for select EO/organism pairings demonstrated that true synergy was possible with this en‐ hancement approach. Experiments with a deep-rough strain of S. Minnesota probed the role of the outer membrane in both intrinsic resistance to EOs and enhancement by polyions. The use of polyP and PEI for boosting the antimicrobial activities of EOs may eventually facilitate the development of more effective EObased antimicrobial treatments for use in applications such as wound treatment, surface disinfection, or as generally recognized as safe antimicrobials for use in foods or on food contact surfaces.
{"title":"Sodium polyphosphate and polyethylenimine enhance the antimicrobial activities of plant essential oils","authors":"Heidi A. Wright, B. Brehm-Stecher","doi":"10.14293/S2199-1006.1.SOR-LIFE.Z72TP0.V1","DOIUrl":"https://doi.org/10.14293/S2199-1006.1.SOR-LIFE.Z72TP0.V1","url":null,"abstract":"Plant extracts have been used for millennia for treatment of disease, with much recent interest focusing on the antimicrobial activities of plant essential oils (EOs). Although EOs are active against common microbial pathogens, their effective use as topical, environmental, or food antimicrobials will require EO-based formulations with enhanced antimicrobial activities. In this study, two polyionic compounds, sodium polyphosphate (polyP, a polyanion) and polyethylenimine (PEI, a polycation), were evaluated for their abilities to enhance the antimicrobial activities of six EOs against the human pathogens Escherichia coli O157:H7, Salmonella enterica subsp. enterica ser. Minnesota, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, and Candida albicans. EOs tested were cinnamon, clove, regular and redistilled oregano, and two types of thyme oil. EOs were examined via disk diffusion and broth microdilution, either alone or in the presence of subinhibitory levels of polyP or PEI. Both polyP and PEI were found to be effective enhancers of EO activity against all strains examined, and calculation of fractional inhibitory indices for select EO/organism pairings demonstrated that true synergy was possible with this en‐ hancement approach. Experiments with a deep-rough strain of S. Minnesota probed the role of the outer membrane in both intrinsic resistance to EOs and enhancement by polyions. The use of polyP and PEI for boosting the antimicrobial activities of EOs may eventually facilitate the development of more effective EObased antimicrobial treatments for use in applications such as wound treatment, surface disinfection, or as generally recognized as safe antimicrobials for use in foods or on food contact surfaces.","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79267561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-12-29DOI: 10.14293/S2199-1006.1.SOR-LIFE.CMGPSN.V1
Heidi A. Wright, B. Brehm-Stecher
Antimicrobial peptides (AMPs) are effective components of the host immune response and are widely distributed throughout nature. Recently, nontoxic antimicrobial polymers that mimic the structures of naturally occurring AMPs have been designed and are under development commercially as novel therapeutics. These compounds have several potential advantages over natural AMPs, including greater stability and reduced immunogenicity compared to natural peptides, relatively simple and scalable syntheses and the ability to tailor or “fine tune” their activities through combinatorial approaches. In previous work, we demonstrated the utility of certain generally regarded as safe (GRAS) flavorant and aroma compounds as enhancers of uptake and activity of clinically important antibiotics (Brehm-Stecher & Johnson, 2003). Here, we have extended this approach to include enhancement of biomimetic antimicrobial polymers. Three low molecular weight (<1000 >D), broad-spectrum arylamide polymers (PolyMedix, Inc., Radnor, PA) were examined for their antimicrobial activities against gram-negative bacteria, gram-positive bacteria, yeast and filamentous fungi, both alone and when co-administered with sesquiterpenoid enhancers. Assay formats included disk diffusion, automated turbidimetry, time course (kinetic) plating of antimicrobial-treated cell suspensions, outer membrane assays with 1-N-phenylnaphthylamine (NPN) and transmission electron microscopy (TEM). Although results differed according to the polymer and test organism used, treatments containing sesquiterpenoids were marked by either increased ZOIs, decreased MICs or more rapid inactivation when compared with polymer-only treatments. Antimicrobial activity, expressed as decimal reduction times (D-value), showed that after 5 min, the combination of sesquiterpenoid and polymer was significantly different from the controls (p < 0.05) with a D-value of 3.92 min when incubated with Escherichia coli ATCC 25922. Collectively, our results indicate that the combination of sesquiterpenoidenhancing agents with biomimetic antimicrobial polymers shows promise for the development of new, fasteracting and more broadly effective antimicrobial therapies.
{"title":"Wide-spectrum biomimetic antimicrobial systems","authors":"Heidi A. Wright, B. Brehm-Stecher","doi":"10.14293/S2199-1006.1.SOR-LIFE.CMGPSN.V1","DOIUrl":"https://doi.org/10.14293/S2199-1006.1.SOR-LIFE.CMGPSN.V1","url":null,"abstract":"Antimicrobial peptides (AMPs) are effective components of the host immune response and are widely distributed throughout nature. Recently, nontoxic antimicrobial polymers that mimic the structures of naturally occurring AMPs have been designed and are under development commercially as novel therapeutics. These compounds have several potential advantages over natural AMPs, including greater stability and reduced immunogenicity compared to natural peptides, relatively simple and scalable syntheses and the ability to tailor or “fine tune” their activities through combinatorial approaches. In previous work, we demonstrated the utility of certain generally regarded as safe (GRAS) flavorant and aroma compounds as enhancers of uptake and activity of clinically important antibiotics (Brehm-Stecher & Johnson, 2003). Here, we have extended this approach to include enhancement of biomimetic antimicrobial polymers. Three low molecular weight (<1000 >D), broad-spectrum arylamide polymers (PolyMedix, Inc., Radnor, PA) were examined for their antimicrobial activities against gram-negative bacteria, gram-positive bacteria, yeast and filamentous fungi, both alone and when co-administered with sesquiterpenoid enhancers. Assay formats included disk diffusion, automated turbidimetry, time course (kinetic) plating of antimicrobial-treated cell suspensions, outer membrane assays with 1-N-phenylnaphthylamine (NPN) and transmission electron microscopy (TEM). Although results differed according to the polymer and test organism used, treatments containing sesquiterpenoids were marked by either increased ZOIs, decreased MICs or more rapid inactivation when compared with polymer-only treatments. Antimicrobial activity, expressed as decimal reduction times (D-value), showed that after 5 min, the combination of sesquiterpenoid and polymer was significantly different from the controls (p < 0.05) with a D-value of 3.92 min when incubated with Escherichia coli ATCC 25922. Collectively, our results indicate that the combination of sesquiterpenoidenhancing agents with biomimetic antimicrobial polymers shows promise for the development of new, fasteracting and more broadly effective antimicrobial therapies.","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"319 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77136518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-10-04DOI: 10.14293/S2199-1006.1.SOR-PHYS.A4HPPH.V1
Jackie Liu
By theorizing the physical reality through the deformation of an arbitrary cross-ratio, we leverage Galois differential theory to describe the dynamics of isomonodromic integratable system. We found a new description of curvature of spacetime by the equivalency of isomonodromic integratable system and Penrose’s spinor formalism of general relativity. Using such description, we hypothetically quantize the curvature of spacetime (gravity) and apply to the problem of the evolution of the universe. The Friedmann equation is recovered and compared so that the mathematical relationship among dark energy, matter (dark matter + ordinary matter), and ordinary matter, XM ’ 4Xb XK, is derived; the actual observed results are compared to this equation (calculated ΩM = 0.33 vs. observed ΩM = 0.31); the model might explain the origin of dark energy and dark matter of the evolution of the universe. INTRODUCTION We looked for the simplest mathematical object to identify the underlying reality of nature, and we found it to be cross-ratio. By defining cross-ratio over Riemann sphere, infinity is just another usual point; similarly, there shouldn’t be any point in the universe more special than others. However, the variety of nature must be realized as a condition for such an underlying object. In “Cross-ratio arbitrariness and the constraint to the parameter space of projective space basis” section, the article explains how potential physical varieties come from different representations of the same thing – cross-ratio deformation. So, the cross-ratio consists of both simplicity and variety. A successful example is like Einstein’s masterpiece – general theory of relativity. Although Einstein’s field equation is simple, many interesting solutions emerged. In “Cassidy’s work on isomonodromic system” section, we introduce Galois differential theory and related Cassidy’s work. It is a mathematical machinery to manifest the deformation of cross-ratio. Cassidy’s work consists of introducing a 2 by 2 matrix differential equation and related isomonodromic integratable system, so it can describe the deformation. By such machinery, we formulate an alternative theory of the dynamics of curvature of spacetime to recover the spinor general relativity equivalent counterpart (for which a brief introduction is given in “Brief overview of spinor formulation of general relativity” section). By such connection, we hypothetically claim the origin of spacetime is from the iso‐ monodromic integratable system, and spacetime is more fundamentally described by the curvature rather than metric or coordinated mathematical framework, that is, spinor formulation of general relativity might be more fundamental than classical general relativity; a similar argument was postulated by Penrose (1960). In “As an application to the problem of modeling the universe evolution” section, we apply the calculation of the deformation of the isomonodromic integratable system with certain simplified condition
{"title":"A quantum theory of spacetime in spinor formalism and the physical reality of cross-ratio representation: the equation of density parameters of dark energy, matter, and ordinary matter is derived: ΩM2 = 4 Ωb ΩΛ","authors":"Jackie Liu","doi":"10.14293/S2199-1006.1.SOR-PHYS.A4HPPH.V1","DOIUrl":"https://doi.org/10.14293/S2199-1006.1.SOR-PHYS.A4HPPH.V1","url":null,"abstract":"By theorizing the physical reality through the deformation of an arbitrary cross-ratio, we leverage Galois differential theory to describe the dynamics of isomonodromic integratable system. We found a new description of curvature of spacetime by the equivalency of isomonodromic integratable system and Penrose’s spinor formalism of general relativity. Using such description, we hypothetically quantize the curvature of spacetime (gravity) and apply to the problem of the evolution of the universe. The Friedmann equation is recovered and compared so that the mathematical relationship among dark energy, matter (dark matter + ordinary matter), and ordinary matter, XM ’ 4Xb XK, is derived; the actual observed results are compared to this equation (calculated ΩM = 0.33 vs. observed ΩM = 0.31); the model might explain the origin of dark energy and dark matter of the evolution of the universe. INTRODUCTION We looked for the simplest mathematical object to identify the underlying reality of nature, and we found it to be cross-ratio. By defining cross-ratio over Riemann sphere, infinity is just another usual point; similarly, there shouldn’t be any point in the universe more special than others. However, the variety of nature must be realized as a condition for such an underlying object. In “Cross-ratio arbitrariness and the constraint to the parameter space of projective space basis” section, the article explains how potential physical varieties come from different representations of the same thing – cross-ratio deformation. So, the cross-ratio consists of both simplicity and variety. A successful example is like Einstein’s masterpiece – general theory of relativity. Although Einstein’s field equation is simple, many interesting solutions emerged. In “Cassidy’s work on isomonodromic system” section, we introduce Galois differential theory and related Cassidy’s work. It is a mathematical machinery to manifest the deformation of cross-ratio. Cassidy’s work consists of introducing a 2 by 2 matrix differential equation and related isomonodromic integratable system, so it can describe the deformation. By such machinery, we formulate an alternative theory of the dynamics of curvature of spacetime to recover the spinor general relativity equivalent counterpart (for which a brief introduction is given in “Brief overview of spinor formulation of general relativity” section). By such connection, we hypothetically claim the origin of spacetime is from the iso‐ monodromic integratable system, and spacetime is more fundamentally described by the curvature rather than metric or coordinated mathematical framework, that is, spinor formulation of general relativity might be more fundamental than classical general relativity; a similar argument was postulated by Penrose (1960). In “As an application to the problem of modeling the universe evolution” section, we apply the calculation of the deformation of the isomonodromic integratable system with certain simplified condition","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89723625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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