检索结果-南通市图书馆

Polyelectrolyte Complexes between Hyperbranched and Linear Polysaccharides: Fucoidan/Chitosan

Chinese Journal of Polymer science 2024年第4期42卷 468-479页

作者： Ekaterina R.Gasilova Daria n.Poshina Aleksandra O.sitnikova natalia n.saprykina Yury A.skorik Institute of Macromolecular Compounds of the Russian Academy of sciences Bolshoi VO 31St.Petersburg199004Russian Federation

Polyelectrolyte complexes(PECs)of hyperbranched(HB)and linear polysaccharides are promising as more effective encapsulation agents compared to PECs formed by linear *** investigated the PECs between the HB anionic polysaccharide fucoidan(FUC)and the cationic linear polysaccharide chitosan(Cs).The FUC had a molecular weight(MW)of 30×*** PECs were prepared in three solvents(water,0.01 and 0.1 mol/L acetic acid)with Cs of MW of 15,110 and 170 kDa,and deacetylation degrees(DDA)of 70%and 97%.The structures of the PECs and the initial FUC were investigated by multi-angle static and dynamic light *** the FUC contained 18 wt%of—OsO3 groups and 5 wt%of uronic acid units,it was a“strong-weak”copolyanion,so the HB macromolecules of the FUC formed nanogel particles in 0.1 mol/L AcOH and open branched structures in water,as confirmed by the Kratky *** mixing the solutions of original components,the PEC structures underwent an equilibration period,the duration of which increased with the MW of *** the charge stoichiometry was approached,the PECs shrank;the fractal dimension approached unity,indicating the side-by-side packing of adjacent FUC branches with the help of *** aggregation in the vicinity of the charge compensation was hardly observed,as it occurred in a very narrow *** PEC content at theζ-potential inversion depended on solvents’pH and the DDA of *** the extreme case of core-shell PECs in 0.1 mol/L AcOH,obtained by mixing FUC nanogels with the solutions of high MW Cs of 97%DDA,the protruding tails of Cs formed a positively charged shell in the whole range of FUC content(10 wt%scanning electron microscopy and atomic force microscopy images of dried samples were discussed in relation to the light scattering results.

关键词： Polyelectrolyte complexes Chitosan Hyperbranched fucoidan Light scattering

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Long-term monitoring reveals the effect of precipitation and silviculture on nothofagus regeneration in northern Patagonia mixed forests

引用

Ecological Processes 2024年第2期13卷 103-117页

作者： Georgina sola Camila Mateo Alejandro Dezzotti Paula Marchelli Hernán Attis Beltrán Renato sbrancia Luis Chauchard Marcelo González Pe?alba Martín Lara Verónica El Mujtar Consejo nacional de Investigaciones Científicas y Técnicas (COnICET ) Asentamiento Universitario san Martín de los Andes (AUsMA-UnCo) Instituto de Investigaciones Forestales y Agropecuarias Bariloche (IFAB) Instituto Nacional de Tecnología Agropecuaria (INTA) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Departamento de Conservación y Manejo Parque Nacional Lanín- Administración de Parques Nacionales (PNL-APN)

Background Tree regeneration is a key component of resilience because it promotes post-disturbance recovery of forests. northwestern Patagonia from Argentina is occupied by nothofagus alpina（na）, n. obliqua（no）, and n. dombeyi（nd） forests that grow along an intense precipitation gradient, managed throughout shelterwood silvicultural system by technicians of the Lanin natural Reserve. The objective of this study was to evaluate the influence of seeding cuttings over the dynamics of nothofagus mixed forests across landscape（precipitation gradient） based mainly on the composition and abundance of tree regeneration, permanent sampling plots and generalized linear mixed models. In particular, we analysed:（i） the structure of sexual and asexual regeneration during nd > 20 years after harvest（the dynamics of managed forests）, and（ii） the structure of sexual regeneration in primary and managed forests after > 20 years of harvest（the effect of silviculture）.Results nd was the most abundant species in the regeneration of managed forests during all periods in both sites despite its lower contribution to the adult cohort. During the 10–20 years period after harvest, the humid site exhibited higher regeneration density than the mesic site(120,000 and 6000 ind ha-1, respectively), and it decreased afterwards. The number of established regeneration（> 2 m height） was lower for na in the mesic site and for no in the humid site(0 and 57 ind ha-1, respectively). However, in comparison to no, na showed a higher number of sprouted stumps and sprouts per stump, and a higher sprout height in the mesic site. no exhibited higher sprout mortality in the humid site. Finally, the regeneration of primary forests showed lower density and height, and a more balanced composition than that of managed *** The silvicultural effects on the mixed forest regeneration dynamics was strongly influenced by the condition of sites. Therefore, management prescriptions should be adj

关键词： nothofagus alpina nothofagus obliqua nothofagus dombeyi Basal sprouting shelterwood silvicultural system Ecological resilience

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Psychological consequences of a diagnosis of infertility in men:a systematic analysis

引用

Asian Journal of Andrology 2024年第1期26卷 10-19页

作者： sarah n Biggs Jane Halliday Karin Hammarberg Reproductive Epidemiology Murdoch Children's Research InstituteMelbourne 3052Australia Department of Paediatrics University of MelbourneMelbourne 3052Australia Public Health and Preventative Medicine Monash UniversityMelbourne 3004Australia Victorian Assisted Reproductive Treatment Authority Melbourne 3000Australia

Almost half of infertility cases involve male *** the consequence of a diagnosis of male infertility,as a sole or partial contributor to the couples'infertility,to the mental health of men is required to ensure clinical care meets their psychological *** aim of this systematic analysis was to synthesize the evidence regarding whether men diagnosed with male factor infertility experience greater psychological distress than(1)men described as fertile and(2)men in couples with other infertility *** databases were searched using a combination of Medical subject Headings(MesH)headings and keywords relating to male infertility and psychological *** search yielded 1016 unique publications,of which 23 were included:8 case-control,14 prospective cohort,and 1 data linkage *** aspects of psychological distress were identified depression,anxiety,self-esteem,quality of life,fertility-related stress,general psychological stress or well-being,and psychiatric ***-control studies reported that men with male factor infertility have more symptoms of depression,anxiety and general psychological distress,worse quality of some aspects of life,and lower self-esteem than *** men with male factor infertility were compared to men in couples with other causes of infertility,there were few differences in the assessed aspects of psychological *** methodological limitations within the studies,this systematic analysis suggests that the experience of infertility,irrespective of its cause,negatively affects men's mental health and demonstrates the need for assisted reproduction technology(ART)providers to consider men undergoing assisted reproduction as individuals with their own unique support needs.

关键词： anxiety depression infertility male mental health quality of life

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Imprints of a gravitational wave through the weak field deflection of photons

引用

Chinese Physics C 2024年第8期48卷 240-245页

作者： Reggie C.Pantig Ali Övgün Physics Department Mapúa University658 Muralla St.IntramurosManila 1002Philippines Physics Department Eastern Mediterranean UniversityFamagusta99628 North Cyprusvia Mersin 10Turkiye

In this study,we investigate the novel phenomenon of gravitational lensing experienced by gravitational waves traveling past a schwarzschild black hole perturbed by a specific,first-order,polar gravitational *** apply the Gauss-Bonnet theorem,finding a topological contribution to the deflection of light rays passing near the black *** demonstrate that the deflection angle can be determined by analyzing a region entirely outside the path of the light ray,leading to a calculation based solely on the parameters of the perturbing wave(Legendre polynomial order,l;frequency,σ).This approach offers a unique perspective on gravitational lensing and expands our understanding of black hole interactions with gravitational waves.

关键词： supermassive black holes gravitational waves chaos weak deflection angle Gauss-Bonnet theorem

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Transcriptomic responses to drought stress in the Patagonian southern beech nothofagus alpina

引用

Ecological Processes 2024年第2期13卷 192-203页

作者： Rita Maria Lopez Laphitz María Verónica Arana santiago Agustín Varela Leandro Aníbal Becker Carolina soliani María Marta Azpilicueta Paula Marchelli nicolás Bellora Instituto de Diversidad y Evolución Austral (CEnPAT COnICET ) Instituto de Investigaciones Forestales y Agropecuarias Bariloche (IFAB InTA COnICET ) Instituto de Tecnologías nucleares para la salud (COnICET )

Background Deciphering the genetic architecture of drought tolerance could allow the candidate genes identification responding to water stress. In the Andean Patagonian forest, the genus nothofagus represents an ecologically relevant species to be included in different genomic studies. These studies are scarce in south American ecosystems however represent an important source of genomic data in order to interpret future climate-change environment scenarios of these emblematic forests. Here, we achieved the assemblage of the transcriptome of n. alpina while searching for key genes of activated or suppressed metabolic pathways in response to drought *** De novo transcriptome assembly resulted in 104,030 transcripts. Following confirmation of drought conditions, based on reduction of leaf water potential and stomatal conductance, a differential gene expression analysis resulted in 2720 significantly expressed genes(1601 up-regulated and 1119 down-regulated). Enrichment analysis(over-representation analysis and gene set enrichment analysis) resulted in more than one hundred stress-responsive term ontologies(i.e. biological processes) and pathways. Terms such as response to abscisic acid and pathways such as plant hormone signal transduction or starch and sucrose metabolism were over-represented. Protein–protein interaction assessment resulted in networks with significantly expressed top common hub gene clusters(e.g. planttype cell wall biogenesis among down-regulated or ABA-signalling among up-regulated). These networks evidenced important regulators at gene expression such as transcriptional *** Responses of n. alpina seedlings to drought stress were evidenced by the activation of several genes linked to GO biological processes and KEGG pathways, which were mainly based on over-expression of specific protein kinases, phosphatases, synthases and transcription factors. This suggests an up-regulation of signalling pathways, triggered through pla

关键词： Climate change Differential gene expression Hub genes Patagonia Temperate forest

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Hepatic perivascular epithelioid cell tumors:Benign,malignant,and uncertain malignant potential

引用

World Journal of Gastroenterology 2024年第18期30卷 2374-2378页

作者： Marcelo Fabián Amante División Patología Hospital General de Agudos Cosme ArgerichBuenos Aires C1155AHAArgentina División Patología Hospital Alemán de Buenos AiresBuenos Aires C1155AHAArgentina

In 2013,the World Health Organization defined perivascular epithelioid cell tumor(PEComa)as“a mesenchymal tumor which shows a local association with vessel walls and usually expresses melanocyte and smooth muscle markers.”This generic definition seems to better fit the PEComa family,which includes angiomyolipoma,clear cell sugar tumor of the lung,lymphangioleiomyomatosis,and a group of histologically and immunophenotypically similar tumors that include primary extrapulmonary sugar tumor and clear cell myomelanocytic *** cell tumors with this immunophenotypic pattern have also had their malignant variants *** localizing to the liver,preoperative radiological diagnosis has proven to be very difficult,and most patients have been diagnosed with hepatocellular carcinoma,focal nodular hyperplasia,hemangioma,or hepatic adenoma based on imaging *** of a malignant variant of the liver have been ***,reports of malignant variants of these lesions have increased in recent ***,we support the use of the Folpe criteria,which in 2005 established the criteria for categorizing a PEComa as benign,malignant,or of uncertain malignant *** they are not considered ideal,they currently seem to be the best approach and could be used for the categorization of liver tumors.

关键词： PEComas Liver Pathology Malignant Benign Uncertain malignant potential

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Data-driven drug repositioning using olfactory omics profiles:challenges and perspectives in neurodegeneration

引用

neural Regeneration Research 2025年第7期20卷 1997-1998页

作者： Paz Cartas-Cejudo Adriana Cortés Mercedes Lachén-Montes Elena Anaya-Cubero Joaquín Fernández-Irigoyen Enrique santamaría Clinical neuroproteomics Unit Proteomics PlatformNavarrabiomedHospitalario Universitario de Navarra(HUN)Universidad Pública de Navarra(UPNA)IdiSNANavarra Institute for Health ResearchPamplonaSpain

Data-driven drug repositioning using olfactory omics profiles-challenges and perspectives in neurodegeneration:neurodegenerative diseases are characterized by progressive degeneration and loss of neuronal function in the central nervous *** diseases are often characterized as proteinopathies,which are disorders primarily driven by the aggregation or misfolding of specific amyloid proteins within cells,leading to their dysfunction and eventual *** the gain-of-function hypothesis related to the aggregation of these proteins,recently,an alternative hypothesis regarding the loss-of-function of the soluble monomeric proteins during the process of aggregation into amyloids is gaining *** last event is called proteinopenia and refers to conditions characterized by a deficiency or decrease in the levels of specific soluble proteins in the body(Ezzat et al.,2023).It has been demonstrated that levels of soluble proteins involved in neurodegenerative diseases are decreased.

关键词： diseases drug amyloid

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Contributions to the knowledge of Antarctodon sobrali(Mammalia:Astrapotheria)from the Eocene of Antarctica

引用

Advances in Polar science 2024年第1期35卷 48-62页

作者： Javier n.GELFO Consejo nacional de Investigaciones Científicasy Técnicas(COnICET) Buenos Aires C1425FQBArgentina División Paleontología Vertebrados Museo de La PlataFacultad de Ciencias Naturales y Museo de La PlataUniversidad Nacional de La PlataLa Plata B1900FWAArgentina

The Astrapotheria constitutes one of the five orders of extinct south American native ungulates,with a fossil record that also extends to the Eocene of the Antarctic *** contrast to the abundant specimens known for litoptern sparnotheriodontidae and metatherians,astrapotheres are represented by scant remains assigned to the endemic Antarctodon sobrali and indeterminate astrapotheres,restricted to levels 35C_(u0)and 35n of the Cucullaea I Allomember of the La Meseta *** discovery of alower molar assignable to this species in the Eocene levels of seymour(Marambio)Island,enables a revision of the diagnosis and the homologies of the dental characters used to describe this taxon.A reanalysis of its phylogenetic relationships reveals the nearly simultaneous presence of basal astrapotheres in the early Eocene of Itaboraí(Brazil),Patagonia,and West *** taxa are characterized by lacking dental specializations usually associated with more abrasive diets like terminal forms of Uruguaytheriinae and *** appears to have thrived on the Antarctic continent during the Early Eocene Climatic Optimum within the paleoclimatic context of a hot-house *** present conditions in Antarctica where no terrestrial mammals inhabit,the early Eocene climate was characterized by warmer temperatures and a biologically diverse environment rich in primary producers,dominated by nothofagus forests,encompassing both deciduous and evergreen forests,which supported a diverse assemblage of continental vertebrates.

关键词： Astrapotheria Antarctodon Eocene seymour Island La Meseta Formation

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

First evidence for chiral wobbling of triaxial nuclei

引用

nuclear science and Techniques 2024年第7期35卷 4-7页

作者： s.Frauendorf Department of Physics and Astronomy University of Notre DameNotre DameIN 46556USA

Chirality(Greek“handiness”)is a property of many com-plex *** molecules exist in two forms,one being the mirror image of the *** for our hands,it is impossible to make the images identical by a suitable *** two forms are called left-handed and *** have the same binding energy,because the electro-magnetic interaction,which holds the molecule together,does not change under a *** properties that are insensitive to the geometry are also the *** different geometry is the reason why the left-handed form turns the polarization plane of transmitted light in one direction by some angle while the right-handed form turns it in the oppo-site direction by the same ***,the geometrical differences between the two species may have other *** two species of the carvon molecule shown in Fig.1 taste quite differently.

关键词： turns Chiral mirror

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Tribological behavior of lubricant-impregnated porous polyimide

引用

Friction 2024年第4期12卷 711-725页

作者： Jinbang LI ningning ZHOU Janet s.s.WOnG school of Mechanical Engineering and Mechanics Ningbo UniversityNingbo 315211China Beijing Key Laboratory of Long-life Technology of Precise Rotation and Transmission Mechanisms Beijing Institute of Control EngineeringBeijing 100029China Department of Mechanical Engineering Imperial College LondonLondon SW72AZUK

Porous materials impregnated with lubricants can be used in conditions where limited lubricant is *** this work,three porous polyimides(PPI)with different densities were ***(PAO)impregnated PPI(iPPI)discs were rubbed against steel and sapphire *** operando observations of the iPPI-sapphire contacts show that oil is released under an applied load,forming a meniscus around *** at the outlet is created at high sliding *** amount of released oil increases with increasing PPI *** moduli,E*,estimated based on the actual contact size show that trapped oil in iPPIs contributes to load *** higher speeds,tribological rehydration of the contact occurs in low density iPPI,with that E*rises with *** high density PPIs,high speeds give a constantly high E*which is limited by the viscoelastic properties of the PPI network and possibly the rate of oil *** of iPPI-steel contacts is governed by the mechanical properties of the PPI,the flow of the lubricant,and the roughness of the PPI *** low-and medium-density(highly porous,high roughness)PPIs,large amount of oil is released,and lubrication is mainly via lubricant restricted in the contact in the pores and possibly tribological *** high density(low porosity)PPI,with lower roughness,hydrodynamic lubrication is achieved which gives the lowest *** results show that polymeric porous materials for effective lubrication require the optimization of its surface roughness,stiffness,oil flow,and oil retentions.

关键词： polyimide porous material friction mechanism polymer limited lubrication

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：