bluuebunny/crossref_metadata_2025 huggingface dataset:
Human DECR1 is an androgen-repressed survival factor that regulates PUFA oxidation to protect prostate tumor cells from ferroptosis
Authors: Nassar Zeyad D , Mah Chui Yan , Dehairs Jonas , Burvenich Ingrid JG , Irani Swati , Centenera Margaret M , Helm Madison , Shrestha Raj K , Moldovan Max , Don Anthony S , Holst Jeff , Scott Andrew M , Horvath Lisa G , Lynn David J , Selth Luke A , Hoy Andrew J , Swinnen Johannes V , Butler Lisa M
Published: July 2020

Fatty acid β-oxidation (FAO) is the main bioenergetic pathway in human prostate cancer (PCa) and a promising novel therapeutic vulnerability. Here we demonstrate therapeutic efficacy of targeting FAO in clinical prostate tumors cultured ex vivo, and identify DECR1, encoding the rate-limiting enzyme for oxidation of polyunsaturated fatty acids (PUFAs), as robustly overexpressed in PCa tissues and associated with shorter relapse-free survival. DECR1 is a negatively-regulated androgen receptor (AR) target gene and, therefore, may promote PCa cell survival and resistance to AR targeting therapeutics. DECR1 knockdown selectively inhibited β-oxidation of PUFAs, inhibited proliferation and migration of PCa cells, including treatment resistant lines, and suppressed tumor cell proliferation and metastasis in mouse xenograft models. Mechanistically, targeting of DECR1 caused cellular accumulation of PUFAs, enhanced mitochondrial oxidative stress and lipid peroxidation, and induced ferroptosis. These findings implicate PUFA oxidation via DECR1 as an unexplored facet of FAO that promotes survival of PCa cells.
DAZL mediates a broad translational program regulating expansion and differentiation of spermatogonial progenitors
Authors: Mikedis Maria M , Fan Yuting , Nicholls Peter K , Endo Tsutomu , Jackson Emily K , Cobb Sarah A , de Rooij Dirk G , Page David C
Published: July 2020

Fertility across metazoa requires the germline-specific DAZ family of RNA-binding proteins. Here we examine whether DAZL directly regulates progenitor spermatogonia using a conditional genetic mouse model and in vivo biochemical approaches combined with chemical synchronization of spermatogenesis. We find that the absence ofDazlimpairs both expansion and differentiation of the spermatogonial progenitor population. In undifferentiated spermatogonia, DAZL binds the 3' UTRs of ~2,500 protein-coding genes. Some targets are known regulators of spermatogonial proliferation and differentiation while others are broadly expressed, dosage-sensitive factors that control transcription and RNA metabolism. DAZL binds 3' UTR sites conserved across vertebrates at a UGUU(U/A) motif. By assessing ribosome occupancy in undifferentiated spermatogonia, we find that DAZL increases translation of its targets. In total, DAZL orchestrates a broad translational program that amplifies protein levels of key spermatogonial and gene regulatory factors to promote the expansion and differentiation of progenitor spermatogonia.
The Influence of Indian Ocean Dipole on Production of Tembang Fishing (Sardinella fimbriata) at Sunda Strait Indonesia
Authors: Amara Delima Mentari , Mulyani Yuniar , Khan Alexander M. A. , Hamdani Herman
Published: July 2020

Tembang is a pelagic fish which is important in Indonesia and the development on the Sunda Strait. The Indian Ocean Dipole could affect oceanography and at the same time will affect the population of fishes. The aim of this study was to determine the effect of IOD and oceanographic factors on the catch of Tembang fish. This research was conducted in the Sunda Strait waters by looking at the Dipole Mode Index (DMI) and oceanographic ocean conditions such as sea surface temperature and chlorophyll as well as the production of fish catches for 11 years from 2008-2018. IOD affects the catch of Tembang fish by 35.8%. Temperature influences the catch of Tembang fish in the Sunda Strait by 9.48%. Klorofil-a influences the catch of Tembang fish in Sunda Strait by 38.6%. DMI, Temperature, and Chlorophyll affect fish catches by 26.9%.
Microbial Quorum Sensing and Its Role in Biofilm Formation
Authors: Ullah Aqsa Sana
Published: July 2020

Quorum sensing is defined as the effect of fluctuation in cells density on the regulation of gene expression within the cell. Approximately all bacteria produce small molecules (auto-inducers) to control Quorum sensing. S-adenosylmethionine (SAM) is responsible for auto-inducers production in Gram-negative bacteria. Auto-inducers interaction with particular receptors provokes different behaviours that are under the control of Quorum sensing The presence of fungal Quorum sensing systems was bare eleven years before after the sighting that farnesol panels filamentation in the pathogenic polymorphic fungus Candida albicans. In the previous era, farnesol has been shown to play manifold roles in C. albicans physiology as a signalling molecule and encouragement damaging effects on host cells and other microbes. In addition to farnesol, the aromatic alcohol tyrosol was also initiated to be a C. albicans QSM regulatory growth, morphogenesis and bio film formation. In Saccharomyces cerevisiae, two other aromatic alcohols, phenyl ethanol and tryptophol were found to be QSMs regulating morphogenesis during nitrogen starvation conditions. Moreover, population density-dependent performances that look like QS have been labelled in numerous other fungal species. Although fungal QS investigation is still in its beginning, its detection has changed our opinions about the fungal kingdom and might ultimately lead to the growth of new antifungal therapeutics.
Phytochemical Analysis and Antioxidant Potential of Costus speciosus L.
Authors: Behera Archita , Devi Rajkumari Supriya , Pradhan Srimay , Biswal Somali , Jena Padan Kumar , Biswal Susanta K. , Kumar Sanjeet
Published: July 2020

Costus speciosus L. is a tuberous plant commonly available in wetlands and near water bodies throughout Odisha state and used as food and medicinal purposes. The tribal communities of the state used the rhizome to cure joint pain, skin infections and consume as nutraceutical. The above claims are supportive of the fact that the rhizome might have antioxidant potentials and might be rich with diverse secondary metabolites. Keeping this in view an attempt has been made to evaluate the bioactive compounds present in the plant parts and antioxidant potentials in order to validate the tribal claims. Results revealed that the plant parts are rich with phenolic compounds and have antioxidant potential.
Barite Concretions in Wadi Halfa Oolitic Ironstone Formation, North Sudan
Authors: Daoud Abazar M. A. , M. A. Rashed , Sediek Kadry N. , A. M. Elamein , A. M. Elsharief
Published: July 2020

During our examination of the outcrops of the sedimentary formations in northern Sudan, we found discoidal-shape grains of the heavy mineral, barite in a sandstone of the Wadi Halfa Oolitic Ironstone Formation, which was recorded by all the earlier workers as a reworked sandstone. Petrography-wise, the framework of the sandstone consists of very angular to angular quartz grains, in which monocrystalline grains dominate over polycrystalline grains. Barite is the main cementing material of this sandstone, which occurs as concretions. Barite concretions indicate that more of the original porosity has been destroyed by cementation rather than by compaction processes with the inter-granular porosity being reduced mainly due to cementation. The origin of these concretions, as a cementing material in the sandstone, is ascribed to the reaction of Ba with some soluble sulfate to form the extremely insoluble heavy barite that appears as rounded concretions. The sulfur of the sulfate may be from the hydrothermal fluids related to submarine volcanism and/or biogeochemical processes. The deposition of these concretions might have taken place not long after the formation of the sandstone. The source of the barium, however, remains an unsolved problem. Further work is needed to interpret the origin and occurrence of these concretions along the region of Wadi Halfa.
Cranberry Juice Inhibit Bacterial Pathogens Associated To Urinary Tract Infection
Authors: Coppini Camila , Gelinski Jane Mary L. N. , Frighetto Mônica
Published: July 2020

Aims: To evaluate in vitro antimicrobial potential of 35% reconstituted juice (RJCr) against bacterial pathogen related to urinary tract infections (UTIs).

Place and Duration of Study:  Food and Biotechnology Laboratory, Brazil.

Study Design: Cranberry juice for in vitro evaluation by agar well diffusion assay and direct in vitro assay.

Methodology: Cranberry fruits were used to produce RJCr pH 3. Five bacterial pathogens were tested: Escherichia coli ATCC 35218, Klebsiella pneumoniae ATCC 700603, Enterococcus faecalis ATCC 29212, Pseudomonas aeruginosa ATCC 27853 and Proteus mirabilis, an isolate of clinical origin. Two methods were used to assess antimicrobial activity. In the agar well diffusion (AWD) assay, each pathogen was inoculated on agar plates and the juice was added in wells drilled on this agar by incubation at 35°C/24hours. Then, the diameter of the inhibition zone was measured (mm). Based on dilutions methods, a direct in vitro assay (DA) was also performed. In test tubes 4.5 ml of RJCr was added an inoculum of each pathogen for a final concentration of >106 and <107 CFU.mL-1.The performance was evaluated based on CFU.mL-1 resulting on agar plates (35°C / 24 hours).

Results: By using AWD the RJCr inhibited E. coli and the average size of the diameter of inhibition halo reached 23.3 mm, that is, greater when compared to the group with Chloramphenicol (11.6 mm). However, for the other strains the RJCr was not inhibiting with this method. But, by using DA, the action of RJCr was inhibitory for all strains here tested, with an average of 5.1 Log cycles of reduction in relation to initial concentration. For E. coli and P. mirabilis the reduction reached six Log cycles.

Conclusion: The inhibitory effect of RJCr was evident to E. coli by both types of inhibitory methods, a relevant result since it is the most recurrent microorganism in UTIs. Cranberry juice was stronger in inhibiting E. coli than antibiotic chloramphenicol as observed by AWD. Thus, the study reinforces the importance of Cranberry, even in the form of juice, in inhibiting E. coli.
Extension Rules of Newman–Janis Algorithm for Rotation Metrics in General Relativity
Authors: Chou Yu-Ching,
Published: July 2020

Aims: The aim of this study is to extend the formula of Newman–Janis algorithm (NJA) and introduce the rules of the complexifying seed metric. The extension of NJA can help determine more generalized axisymmetric solutions in general relativity.Methodology: We perform the extended NJA in two parts: the tensor structure and the seed metric function. Regarding the tensor structure, there are two prescriptions, the Newman–Penrose null tetrad and the Giampieri prescription. Both are mathematically equivalent; however, the latter is more concise. Regarding the seed metric function, we propose the extended rules of a complex transformation by r2/Σ and combine the mass, charge, and cosmologic constant into a polynomial function of r.

Results: We obtain a family of axisymmetric exact solutions to Einstein’s field equations, including the Kerr metric, Kerr–Newman metric, rotating–de Sitter, rotating Hayward metric, Kerr–de Sitter metric and Kerr–Newman–de Sitter metric. All the above solutions are embedded in ellipsoid- symmetric spacetime, and the energy-momentum tensors of all the above metrics satisfy the energy conservation equations.

Conclusion: The extension rules of the NJA in this research avoid ambiguity during complexifying the transformation and successfully generate a family of axisymmetric exact solutions to Einsteins field equations in general relativity, which deserves further study.
The implementation of electronic records related to the nursing process: integrative review
Authors: Costa Cíntia da , Linch Graciele Fernanda da Costa
Published: July 2020

Objetivo O estudo objetivou identificar quais estratégias estão sendo utilizadas na implementação de registros eletrônicos relacionados ao processo de enfermagem, nas bases de dados: PubMed, Scopus e Web of Science. Métodos Trata-se de uma revisão integrativa na qual os descritores utilizados foram electronic healthrecords e nursing process. Resultados Os dados encontrados indicam que os estudos em sua maioria foram pesquisas quantitativas, publicadas no periódico Nursing informatics (Studies in Health Technology and Informatics) desenvolvidas em universidades e no continente americano. Conclusões Os dados apontam que a maior parte das pesquisas são referentes a usabilidade do registro eletrônico em saúde. Outros aspectos abordados foram as fragilidades e perspectivas associados ao uso do registro eletrônico, bem como o processo de enfermagem em sistemas informatizados.
Health promotion practices for elderly people: an integrative literature review
Authors: Silva Joyce Lane Braz Virgolino da , Queiroz Ronaldo Bezerra de , Bittencourt Greicy Kelly Gouveia Dias , Ferreira Olívia Galvão Lucena , Bezerra Valéria Peixoto , Piagge Carmem Silvia Laureanno Dalle
Published: July 2020

Objetivo: Caracterizar o conhecimento científico no período entre 2012 e 2017 que contemplam as práticas de promoção da saúde realizadas pelo NASF - AB para pessoa idosa. Métodos: Trata-se de uma revisão integrativa da literatura entre os anos 2012 e 2017, na Biblioteca Virtual de Saúde (BVS), nas bases de dados LILACS e MEDLINE e no Portal de Periódicos da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), na base de dados SCIELO, com a utilização dos descritores “atenção primária à saúde”, “saúde da família” e “promoção da saúde”. Resultados: Foram selecionados 10 artigos, sendo nove indexados na base Lilacs e um nas bases Lilacs, Medline e Scielo. Conclusão: Verificou-se ausência de práticas que envolvam todos os eixos da Política Nacional de Promoção da Saúde e da Política Nacional de Saúde da Pessoa Idosa.
A jump in an Arrhenius plot can be the consequence of a phase transition
Authors: Biosca J.A. , Travers F. , Barman T.E.
Published: July 2002

The temperature dependence of the kinetics of the binding of ATP to myosin subfragment−1 was studied by an ATP chase technique in a rapid−flow—quench apparatus: A temperature range of 30°C to −15°C was obtained with ethylene glycol as antifreeze. The Arrhenius plot of k 2 is discontinuous with a jump at 12°C. Above the jump ΔH ≠ = 9.5 kcal/mol, below ΔH ≠ = 28.5 kcal/mol. Few such Arrhenius plots are recorded in the literature but they are predicted from theory. Thus, we explain our results as a phase change of the subfragment 1−ATP system at 12°C. This is in agreement with certain structural studies.
Sequence preferences in the binding to DNA of triostin A and TANDEM as reported by DNase I footprinting
Authors: Low C.M.Loretta , Olsei Richard K. , Waring Michael J.
Published: July 2002

Six or seven triostin‐binding sites have been identified in a 160‐base‐pair DNA restriction fragment containing the tyr T promoter sequence. Each is centred round a CpG step, and the minimum binding site‐size appears to be six base pairs. The sites are practically the same as those reported for echinomycin by DNase I digestion. Only two sites are protected by binding of TANDEM, the des‐N‐tetramethyl analogue of trios‐tin A; they are centred around the sequences ATA or TAT.
Exclusive leukotriene C4 synthesis by purified human eosinophils induced by opsonized zymosan
Authors: Bruynzeel Pieter L.B. , Kok Paul T.M. , Hamelink Maartje L. , Kijne Arda M. , Verhagen Jan
Published: July 2002

Purified human eosinophils were challenged with N‐formyl‐methionyl‐leucyl‐phenylalanine, leukotriene B4, platelet‐activating‐factor, valyl‐glycyl‐seryl‐glutamic acid, phorbol myristate acetate, zymosan, opsonized zymosan and the calcium ionophore A23187 to induce leukotriene synthesis. Reversed‐phase high performance liquid chromatography analysis demonstrated the almost exclusive synthesis of leukotriene C4 by eosinophils of 11 healthy donors after challenge with opsonized zymosan [(22±4) × 106 molecules LTC4/cell, mean ± SE] or the calcium ionophore A23187 [(54 ± 7) × 106 molecules LTC4/cell, mean ± SE]. The other agents were not capable of inducing leukotriene formation. When in addition to opsonized zymosan N‐formyl‐methionyl‐leucyl‐phenylalanine or platelet‐activating factor were added a significant increase of the leukotriene C4 synthesis by eosinophils was observed. These results suggest that eosinophils might be triggered to produce considerable amounts of the spasmogenic leukotriene C4 in vivo by C3b‐ and/or IgG‐mediated mechanisms e.g. phagocytosis.
Sequence analysis of phosphoserine‐containing peptides
Authors: Meyer Helmut E. , Hoffmann-Posorske Edeltraut , Korte Horst , Heilmeyer Ludwig M.G.
Published: July 2002

Sequencing of phosphoserine‐containing peptides yields normally no identifiable PTH‐derivatives at those positions where phosphoserine is located. Here a new method is described which allows identification of the position of phosphoserine by chemical modification just before sequence analysis. In a one‐step microbatch reaction, phosphoserine present in the intact peptide can be transformed quantitatively into stable derivatives such as β‐methylaminoalanine (MAA), S‐ethanolcysteine or S‐ethylcysteine. These derivatives are detectable during microsequencing with less than 100 pmol peptide using an Applied Biosystems gas‐phase sequencer equipped with an on‐line PTH amino acid analyzer.
Basic fibroblast growth factor enhances the capacity of bone marrow cells to form bone‐like nodules in vitro
Authors: Noff Dina , Pitaru Sandu , Savion Naphtali
Published: July 2002

The role of basic fibroblast growth factor (bFGF) in the proliferation and differentiation of rat bone marrow cells in culture was studied. bFGF stimulated [3H]thymidine incorporation into these cells by 4‐fold at a concentration of 0.3 ng/ml and half‐maximal effect was observed at a concentration of 15 pg/ml. In addition to its mitogenic effect, bFGF stimulated alkaline phosphatase activity by 3.6‐fold. Continuous treatment with bFGF (for 21 days) resulted in a 6.3‐fold increase in the culture dish surface area covered by bone‐like mineralized tissue. Maximal bone‐like tissue formation was observed in the presence of 3 ng/ml bFGF with half‐maximal effect at a concentration of 0.3 ng/ml. These results indicate the possible role of bFGF in the proliferation of osteogenic rat bone marrow cells and their differentiation into cells of osteoblast‐like phenotype.
A CD study of interactions of ellipticine derivatives with DNA
Authors: Monnot Monique , Mauffret Olivier , Simon Valérie , Lescot Elie , Psaume Bernard , Saucier Jean-Marie , Belehradek Jean , Fermandjian Serge
Published: July 2002

UV‐absorption and circular dichroism (CD) experiments showed that ellipticine derivatives may interact with DNA according to 3 possible binding modes depending on their structure and concentration. The first mode concerned intercalation of 1‐methyl‐9‐hydroxyellipticine (1‐Me‐HE) with its long axis perpendicular to the long axis of base pairs. The same drug was able to bind to external sites (second mode) once the intercalation sites were saturated at high concentration. The third mode illustrated by 1,2‐dimethyl‐9‐hydroxyisoellipticinium (1‐Me‐isoNMHE), concerned self‐stacked molecules interacting at the surface of DNA. Biological significance of these different binding modes was then discussed in connection with in vitro cytotoxic activity of compounds.
3′‐Mercapto‐2′,3′‐dideoxynucleotides are high effective terminators of DNA synthesis catalyzed by HIV reverse transcriptase
Authors: Yuzhakov Alexander A. , Chidgeavadze Zurab G. , Beabealashvilli Robert Sh.
Published: July 2002

Four 3′‐mercapto‐2′,3′‐dideoxynucleoside 5′‐triphosphates (A, G, C and T) were tested as DNA chain terminator substrates for calf thymus α‐DNA polymerase, E. coli DNA polymerase I Klenow fragment, terminal deoxynucleotidyl transferase and reverse transcriptases of AMV, HIV and MLV viruses. It was shown that the analogues selectively and irreversibly terminated DNA chain elongation by AMV and HIV reverse transcriptases and the terminal transferase. Other DNA polymerases tested did not use the nucleotide analogues as chain terminator substrate.
Segments of Escherichia coli genome similar to the exons of human prothymosin α gene
Authors: Vartapetian Andrey , Chichkova Nina , Lyakhov Ilya , Makarova Tatyana , Evstafieva Alexandra , Bogdanov Alexey
Published: July 2002

Identification of the putative prothymosin α homolog in Escherichia coli cells prompted the search for a prothymosin α‐coding gene in the E. coli genome. A set of interspersed DNA segments was identified, which match various parts of the human prothymosin α molecule. Their location in the E. coli genome and high degree of similarity with the appropriate regions of the human prothymosin α gene suggest that some kind of trans‐splicing should exist in E. coli, which could be responsible for bringing these putative bacterial prothymosin α‐coding exons together.
Influence of illumination on the electronic interaction between 77Se and nickel in active F420‐non‐reducing hydrogenase from Methanococcus voltae
Authors: Sorgenfrei Oliver , Klein Albrecht , Albracht Simon P.J.
Published: July 2002

The selenium‐containing F420‐non‐reducing hydrogenase from Methanococcus voltae was anaerobically purified. The enzyme as isolated showed an EPR spectrum with g
x,y,z = 2.21, 2.15 and 2.01. Upon illumination this spectrum disappeared and a new signal with the lowest g value at 2.05 arose. EPR studies were carried out either with the enzyme containing natural selenium or enriched in the nuclear isotope 77Se. The hyperfine splitting caused by 77Se in the ‘dark’ signal is shown to be highly anisotropic. In contrast the splitting is nearly isotropic after illumination. A new model for the nickel site is proposed to explain these observations.
Okadaic acid inhibits insulin‐induced glucose transport in fetal brown adipocytes in an Akt‐independent and protein kinase C ζ‐dependent manner
Authors: Valverde Angela M. , Lorenzo Margarita , Navarro Paloma , Mur Cecilia , Benito Manuel
Published: July 2002

In the present study we have investigated the effect of increased serine/threonine phosphorylation of insulin receptor substrates‐1 and ‐2 (IRS‐1 and IRS‐2) by okadaic acid pretreatment on brown adipocyte insulin signalling leading to glucose transport, an important metabolic effect of insulin in brown adipose tissue. Okadaic acid pretreatment before insulin stimulation decreased IRS‐1 and IRS‐2 tyrosine phosphorylation in parallel to a decrease in their sodium dodecyl sulfate–polyacrylamide gel electrophoresis mobility. IRS‐1/IRS‐2‐associated p85α and phosphatidylinositol (PI) 3‐kinase enzymatic activity were partly reduced in brown adipocytes pretreated with okadaic acid upon stimulation with insulin. Furthermore, insulin‐induced glucose uptake was totally abolished by the inhibitor in parallel with a total inhibition of insulin‐induced protein kinase C (PKC) ζ activity. However, activation of Akt/PKB or p70 S6 kinase (p70s6k) by insulin remained unaltered. Our results suggest that downstream of PI 3‐kinase, insulin signalling diverges into at least two independent pathways through Akt/PKB and PKC ζ, the PKC ζ pathway contributing to glucose transport induced by insulin in fetal brown adipocytes.
Single mutation at the intersubunit interface confers extra efficiency to Cu,Zn superoxide dismutase
Authors: Stroppolo Maria Elena , Pesce Alessandra , Falconi Mattia , O'Neill Peter , Bolognesi Martino , Desideri Alessandro
Published: July 2002

The Val28→Gly single mutant at the subunit interface of Cu,Zn superoxide dismutase from Photobacterium leiognathi displays a k
cat/K
M value of 1.7×1010 M−1 s−1, twice that of the native enzyme. Analysis of the three‐dimensional structure indicates that the active site Cu,Zn center is not perturbed, slight structural deviations being only localized in proximity of the mutation site. The enzyme–substrate association rate, calculated by Brownian dynamics simulation, is identical for both enzymes, indicating that the higher catalytic efficiency of the Val28→Gly mutant is not due to a more favorable electrostatic potential distribution. This result demonstrates the occurrence of an intramolecular communication between the mutation site and the catalytic center, about 18 Å away and indicates a new strategy to encode extra efficiency within other members of this enzymatic family.
Highly increased levels of active stromelysin in rheumatoid synovial fluid determined by a selective fluorogenic assay
Authors: Beekman Bob , van El Benno , Drijfhout Jan Wouter , Ronday H.Karel , TeKoppele Johan M
Published: July 2002

Stromelysin‐1 (MMP‐3) is an important member of the matrix metalloproteinase family. In joint‐degrading diseases like arthritis, elevated levels of MMP‐3 protein are detected in synovial fluid using immunological methods. However, these methods do not discriminate between active and inactive enzyme. In the present study, a specific stromelysin activity assay was developed using the selective fluorogenic substrate TNO003 (Dabcyl‐Gaba‐Arg‐Pro‐Lys‐Pro‐Val‐Glu♦Nva‐Trp‐Arg‐Glu(EDANS)‐Ala‐Lys‐NH2, ♦=cleavage site). For its use in biological media, cleavage of TNO003 by enzymes other than stromelysin was effectively blocked by a proteinase inhibitor cocktail. Spiking of MMP‐3 to synovial fluid resulted in an MMP‐3 concentration‐dependent linear increase in activity. The measured MMP‐3 activity was not affected by the addition of MMP‐13, even in a 5‐fold excess over MMP‐3. Synovial fluid from rheumatoid arthritis patients demonstrated 100‐fold higher levels of active stromelysin than control synovial fluids.
Alternative pathways of xanthone biosynthesis in cell cultures of Hypericum androsaemum L
Authors: Schmidt Werner , Beerhues Ludger
Published: July 2002

The biosynthesis of xanthones was studied in cell cultures of Hypericum androsaemum L. We have detected a new benzophenone synthase, for which the preferred substrate is benzoyl‐CoA, itself supplied by 3‐hydroxybenzoate:coenzyme A ligase. The stepwise condensation of benzoyl‐CoA with three molecules of malonyl‐CoA, catalyzed by benzophenone synthase, yields 2,4,6‐trihydroxybenzophenone. This intermediate is subsequently converted by benzophenone 3′‐hydroxylase, a cytochrome P450 monooxygenase. These biosynthetic steps, leading to the formation of 2,3′,4,6‐tetrahydroxybenzophenone, represent an alternative pathway to that recently proposed for cell cultures of Centaurium erythraea [Peters et al., Planta (1997) in press].
A sterol biosynthetic pathway in Mycobacterium
Authors: Lamb David C. , Kelly Diane E. , Manning Nigel J. , Kelly Steven L.
Published: July 2002

The genome sequence of Mycobacterium tuberculosis (and also M. leprae) revealed a significant number of homologies to Saccharomyces cerevisiae sterol biosynthetic enzymes. We addressed the hypothesis of a potential sterol biosynthetic pathway existing in Mycobacterium using cultures of Mycobacterum smegmatis. Non‐saponifiable lipid extracts subjected to analysis by gas chromatography‐mass spectrometry (GC‐MS) showed cholesterol was present. Sterol synthesis by M. smegmatis was confirmed using 14C‐radiolabelled mevalonic acid and incorporation into C4‐desmethyl sterol co‐migrating with authentic cholesterol on TLC. The sterol biosynthetic pathway has provided a rich source of targets for commercially important bioactive molecules and such agents represent new opportunities for Mycobacteria chemotherapy.
A population of learners: A new way to measure organizational learning
Authors: Uzumeri Mustafa , Nembhard David
Published: July 2002

In this paper we describe an approach that enables managers to systematically describe patterns of skill learning in large populations of front‐line workers. The method fits individualized learning curves to the work performance histories of every member of a population. The resulting set of ‘best‐fit’ parameter estimates represents a parsimonious summary of the many learning behaviors that are taking place. A case study demonstrated the descriptive power of the model using electronically collected data on 3874 episodes of individual learning in a large US manufacturing firm.
Fetal malformations under lithium treatment
Authors: Eikmeier G
Published: July 2002

The case of fetal malformations with bilateral agenesis of the kidneys and severe cardiac defect under continuous lithium treatment during the first trimester is presented.
Overdose with sustained-release lithium preparations
Authors: Astruc B , Petit P , Abbar M
Published: July 2002

Acute lithium intoxication is potentially lethal. Compared to conventional lithium preparations, sustained-release lithium formulations present specific problems for medical practice in the case of overdose. We report a case of intoxication with 8000 mg of sustained-release lithium carbonate preparation (Teralithe 400 LP®). Twenty-five hours after the ingestion, the patient was still asymptomatic, despite a serum level in the toxic range. After comparison of this case with reports found in the Medline database, we consider the clinical management of such cases.
Identification and validation of novel DNA methylation markers for early diagnosis of lung adenocarcinoma
Authors: Li Miao , Zhang Chen , Zhou Lijun , Li Siyu , Cao Yuan Jie , Wang Longlong , Xiang Rong , Shi Yi , Piao Yongjun
Published: July 2020

Lung cancer has the highest mortality of all cancers worldwide. Epigenetic alterations have emerged as potential biomarkers for early diagnosis of various cancer tissue types. To identify methylation markers for early diagnosis of lung adenocarcinoma, we aimed to integrate genome‐wide DNA methylation and gene expression data from The Cancer Genome Atlas. To this end, we first examined the global DNA methylation pattern of lung adenocarcinoma and investigated the relationship between DNA methylation subtypes and clinical features. We then extracted differentially methylated and expressed genes, and adopted feature selection techniques to determine the final methylation markers. The performance of the markers in predicting lung adenocarcinoma was evaluated on three independent datasets from Gene Expression Omnibus. Protein levels of marker genes were validated by immunohistochemistry, and their biological function was further verified in vivo. We identified three novel methylation markers in lung adenocarcinoma including cg08032924, cg14823851, and cg19161124, mapping to CMTM2, TBX4, and DPP6, respectively. Validating these results on three independent datasets indicated that the three markers can achieve extremely high sensitivity and specificity in distinguishing lung adenocarcinoma from normal samples. Immunohistochemistry quantification results confirmed that markers are weakly expressed in human lung adenocarcinoma, and CMTM2 decreased tumor growth of mouse Lewis lung carcinoma in vivo. Overall, our study identified three novel methylation markers in lung adenocarcinoma which may contribute toward an improved diagnosis potentially leading to a better outcome for patients with lung adenocarcinoma.
Novel immune subtypes of lung adenocarcinoma identified through bioinformatic analysis
Authors: Qin Fang‐lu , Xu Zhan‐yu , Yuan Li‐qiang , Chen Wen‐jie , Wei Jiang‐bo , Sun Yu , Li Shi‐kang
Published: July 2020

The magnitude of the immune response is closely associated with clinical outcome in patients with cancer. However, finding potential therapeutic targets for lung cancer in the immune system remains challenging. Here, we constructed a vital immune‐prognosis genes (VIPGs) based cluster of lung adenocarcinoma (LUAD) from IMMPORT databases and The Cancer Genome Atlas. A transcription factor regulatory network for the VIPGs was also established. The tumor microenvironment of LUAD was analyzed using the ESTIMATE (Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data) algorithm and single‐sample Gene Set Enrichment Analysis. The immune checkpoints and genomic alterations were explored in the different immune clusters. We identified 15 VIPGs for patients with LUAD and clustered the patients into low‐immunity and high‐immunity subtypes. The immune score, stromal score and ESTIMATE score were significantly higher in the high‐immunity subtype, whereas tumor purity was higher in the low‐immunity subtype. In addition, the immune checkpoints cytotoxic T lymphocyte associate protein‐4(CTLA4), programmed cell death protein‐1 and programmed death‐ligand were elevated in the low‐immunity subtype. The genomic results also showed that the tumor mutation burden was higher in the high‐immunity subtype. Finally, Gene Set Enrichment Analysis showed that several immune‐related gene sets, including interleukin‐2/STAT5 signaling, inflammatory response, interleukin‐6/Janus kinase(JAK)/signal transducer and activator of transcription 3 (STAT3) signaling, interferon‐gamma response and allograft rejection, were elevated in the high‐immunity subtype. Finally, high‐immunity patients exhibited greater overall and disease‐specific survival outcome compared with low‐immunity patients (log rank P = 0.013 and P = 0.0097). Altogether, here we have identified 15 immune‐prognosis genes and a potential immune subtype for patients with LUAD, which may provide new insights into the prognosis and treatment of LUAD.
Archaeal Cell Walls
Authors: Meyer Benjamin H , Albers Sonja‐Verena
Published: July 2020

Next to the bacterial and eukaryal domains, Archaea form one of the three domains of life. Within the last decade, the phylogenetic tree of archaea has dramatically expanded and nowadays Archaea are found in almost every habitat, from extreme to moderate. The adaptation to these diverse environments might have resulted in the remarkably high variety of different archaeal cell envelope types. One major difference to bacteria is the lack of murein or a lipopolysaccharide (LPS)‐containing outer membrane.

The cell wall of many Archaea is formed by a proteinaceous surface (S‐) layer. S‐layer proteins have the intrinsic ability to form two‐dimensional crystals, which can have an oblique (p2), square (p4) or hexagonal (p3 or p6) symmetry. All currently studied archaeal S‐layer proteins were found to be modified by the attachment ofN‐linked and, in some cases, additionally byO‐linked glycans. However, also Archaea have been characterised which lack an S‐layer and possess instead a second outermost membrane or sugar polymers like pseudomurein, methanochondroitin, or heteropolysaccharides as their cell envelope. These polymeric cell wall structures can either form the sole cell wall structure or be supported by an additional S‐layer cover.

Key Concepts

Archaea do have peptidoglycan, it is called pseudomurein and different in its composition to murein.

Most studied Archaea have one cytoplasmic membrane, but more and more species are found which have two membranes.

Archaeal cell envelopes lack murein or a lipopolysaccharide (LPS)‐containing outer membrane.

Many Archaea possess a glycosylated proteinaceous surface layer (S‐layer) as their sole cell wall structure.

In some Archaea, the cell wall is composed of glycan polymers, like glutaminylglycan, heterosaccharide, methanochondroitin, or pseudomurein, which can be further supported by an S‐layer.
Enzymes: Irreversible Inhibition
Authors: McDonald Andrew G , Tipton Keith F
Published: July 2020

Many drugs that are in clinical use work by irreversibly inhibiting specific enzymes, either in the individual being treated or in an invading organism. Enzyme inhibitors are also of value for understanding the behaviour of individual enzymes and metabolic systems. Recovery from irreversible inhibition requires the synthesis of new enzyme. Although those irreversible inhibitors that react with specific groups in the enzyme protein generally inhibit more than one enzyme, those that initially form a noncovalent complex with the enzyme, with subsequent reaction within that complex leading to the formation of a covalent bond, can show a high degree of selectivity. Kinetic studies, which are detailed in this account, can be used to distinguish the different types of inhibition and the factors that contribute to effectiveness and selectivity.

Key Concepts

Irreversible inhibition cannot be reversed by the removal of the excess inhibitor from the system.

Recovery from reversible inhibition depends on the removal of the inhibitor from the system, whereas recovery from irreversible inhibition requires the synthesis of fresh enzyme.

Enzyme turnover in the tissues is a balance between the rate of its synthesis and degradation.

Nonspecific irreversible inhibitors can react with several groups of the same type in different proteins.

Specific irreversible inhibitors form an initial noncovalent complex with the enzyme before the reaction within that complex to form a covalent bond.

Active‐site‐directed inhibitors contain a reactive grouping attached to a substrate analogue.

Mechanism‐based inhibitors can be highly specific because they depend on the activity of the enzyme to form a reactive intermediate that then reacts irreversibly with the enzyme.

Suicide substrates behave as both substrates and irreversible enzyme inhibitors in divergent processes.

Dosage schedule for effective therapy with irreversible inhibitors is dependent on the half‐life of enzyme turnover.
Lipids
Authors: Yeagle Philip L
Published: July 2020

Lipids are molecular building blocks that form the most fundamental structures in biology, including the serum lipoproteins, the membranes of cells and cellular organelles and the membranes of enveloped viruses. Many lipids spontaneously form lipid bilayers, the fundamental architectural feature of all biological membranes. A nearly uncountable catalogue of lipid molecules is found in nature, their individual structures imparting a wide variety of properties essential to the structures and functions of biological membranes and lipoproteins in all life forms. Lipids regulate, often in specific ways, the functionality of biological membranes, through the properties of the lipid bilayer and by binding to membrane proteins. Lipids are at the centre of membrane fusion events essential for intracellular transport, endocytosis and viral infection of cells by enveloped viruses. Lipids are the metabolic precursors of some hormones and signalling molecules in cells.

Key Concepts

Phospholipids, as well as many other lipids, spontaneously form bilayer structures in water, as governed by the hydrophobic effect.

Lipid bilayers provide the fundamental architecture upon which all biological membranes are built.

Lipid bilayers in biological membranes are in the liquid crystal state, permitting lateral diffusion of components including proteins and lipids, and internal flexibility essential to membrane enzyme function.

Lipid bilayers determine many of the properties of biological membranes including their limited permeability.

Thousands of different lipid species are found in biological membranes, but they can be organised into a few major lipid classes.

Unsaturation in the hydrocarbon chains of lipid bilayers supports the liquid crystal state of bilayers in biology, essential to the proper functioning of membrane enzymes.

Although bilayers are inherently stable, defects in the bilayer structure are required to initiate critical membrane fusion events.

Individual membrane lipids play specific biological roles in membrane biology by modulating membrane enzyme activity through binding to membrane proteins.

Some lipids are second messengers in intracellular signalling systems.
Dating Apps
Authors: Comunello Francesca , Parisi Lorenza
Published: July 2020

This entry defines dating apps and the related main theoretical approaches. The diffusion of geolocalized apps and the datafication of society affect dating culture, leading toward instantaneous relationships that can be arranged according to the proximity of the users. Mobile hookup or dating practices were experimented in the early 2000s and LGBTQi people have historically been early adopters. Nowadays dating apps are more socially accepted, even if some social stigma persists in specific cultural contexts. Dating apps' functioning and main characteristics are analyzed from a gender perspective, revealing how interface and design features steer different usage practices. Dating apps can open new opportunities for meeting new people and experimenting with a freer sexual identity, however, representations often replicate conventional gender roles. Literature has underlined that, also in relation to usage strategies and relational patterns, traditional (normative) assumptions about gender and sexuality are at play, even if some apps and usage practices are challenging in heterosexual contexts, stereotypes of female objectification, and passivity.
Recent Progress in High‐Strength and Robust Regenerated Cellulose Materials
Authors: Tu Hu , Zhu Mengxiang , Duan Bo , Zhang Lina
Published: July 2020

High‐strength petroleum‐based materials like plastics have been widely used in various fields, but their nonbiodegradability has caused serious pollution problems. Cellulose, as the most abundant sustainable polymer, has a great chance to act as the ideal substitute for plastics due to its low cost, wide availability, biodegradability, etc. Herein, the recent achievements for developing cellulose “green” solvents and regenerated cellulose materials with high strength via the “bottom‐up” route are presented. Cellulose can be regenerated to produce films/membranes, hydrogels/aerogels, filaments/fibers, microspheres/beads, bioplastics, etc., which show potential applications in textiles, biomedicine, energy storage, packaging, etc. Importantly, these cellulose‐based materials can be biodegraded in soil and oceans, reducing environmental pollution. The cellulose solvents, dissolving mechanism, and strategies for constructing the regenerated cellulose functional materials with high strength and performances, together with the current achievements and urgent challenges are summarized, and some perspectives are also proposed. The near future will be an exciting era for high‐strength biodegradable and renewable materials. The hope is that many environmentally friendly materials with good properties and low cost will be produced for commercial use, which will be beneficial for sustainable development in the world.
Quantum Dots of [Na4Cs6PbBr4]8+, Water Stable in Zeolite X, Luminesce Sharply in the Green
Authors: Kim Joon Young , Shim Kyu In , Han Jeong Woo , Joo Jin , Heo Nam Ho , Seff Karl
Published: July 2020

Nanocrystals (NCs) of CsPbX3, X = Cl, Br, or I, have excellent photoluminescent properties: high quantum yield, tunable emission wavelengths (410−700 nm), and narrow emission band widths. CsPbBr3 NCs show high promise as a green‐emitting material for use in wide color gamut displays. CsPbBr3 NCs have, however, not been commercialized because they are sensitive to moisture and heat. To avoid these problems, this work attempts to introduce CsPbBr3 into five zeolites. The zeolite X product, Pb,Br,H,Cs,Na−X, shows superior stability toward moisture, maintaining its initial luminescence properties after being under water for more than a month. Its structure, determined using single‐crystal X‐ray crystallography, shows that quantum dots (QDs) of [Na4Cs6PbBr4]8+ (not of CsPbBr3) have formed. They are tetrahedral PbBr42− ions (Pb−Br = 3.091(11) Å) surrounded by Na+ and Cs+ ions. Each fills the zeolite's supercage with its Pb2+ ion precisely at the center, a position of high symmetry. The peaks in the emission spectra of Pb,Br,H,Cs,Na−X and the CsPbBr3 NCs are both at about 520 nm. The FWHM of Pb,Br,H,Cs,Na−X, however, is narrower than any previously reported for any of the CsPbBr3 NCs, and for zeolite Y and the various mesoporous materials treated with CsPbBr3.
Assembling Nano–Microarchitecture for Electromagnetic Absorbers and Smart Devices
Authors: Wang Xi‐Xi , Cao Wen‐Qiang , Cao Mao‐Sheng , Yuan Jie
Published: July 2020

Smart devices, nowadays, are inspiring the infinite vitality and possibilities of intelligent life, such as self‐power electromagnetic (EM) nanogenerator and microsensor, smart window, thermally‐driven EM absorber, interstellar energy deliverer, and so on. Herein, the latest and most impressive works of 3D nano–micro architectures and their smart EM devices are highly focused on. The most key information, including assembly strategy and mechanism, EM response, and approach‐structure‐function relationship, is extracted and well‐organized with profundity and easy‐to‐understand approach. The merit and demerit are revealed by comparison. What’s more, the brightest and most cutting‐edge smart EM devices constructed by 3D nano–micro architectures are reported as highlights, and the device principles are deeply dissected. Finally, a profound and top comment on the fast‐growing field as well as challenges are proposed, and the future directions are predicted intelligently.
On‐Demand Bacterial Reactivation by Restraining within a Triggerable Nanocoating
Authors: Feng Pingping , Cao Zhenping , Wang Xinyue , Li Juanjuan , Liu Jinyao
Published: July 2020

Bacteria have been widely exploited as bioagents for applications in diagnosis and treatment, benefitting from their living characteristics including colonization, rapid proliferation, and facile genetic manipulation. As such, bacteria being tailored to perform precisely in the right place at the right time to avoid potential side effects would be of great importance but has proven to be difficult. Here, a strategy of on‐demand bacterial reactivation is described by individually restraining within a triggerable nanocoating. Upon reaching at a location of interest, nanocoatings can be triggered to dissolution in situ and subsequently decoat the bacteria which are able to recover their bioactivities as needed. It is demonstrated that gut microbiota coated with an enteric nanocoating can respond to gastrointestinal environments and reactivate in the intestine by a pH‐triggered decoating. In virtue of this unique, coated bacteria remain inactive following oral administration to exempt acidic insults, while revive to restore therapeutic effects after gastric emptying. Consequently, improved oral availability and treatment efficacy are achieved in two mouse models of intestinal infection. Bacteria restrained by a triggerable nanocoating represent a smart therapeutic that can take effect when necessary. On‐demand bacterial reactivation suggests a robust platform for the development of precision bacterial‐mediated bioagents.
Crystal–Glass High‐Entropy Nanocomposites with Near Theoretical Compressive Strength and Large Deformability
Authors: Wu Ge , Balachandran Shanoob , Gault Baptiste , Xia Wenzhen , Liu Chang , Rao Ziyuan , Wei Ye , Liu Shaofei , Lu Jian , Herbig Michael , Lu Wenjun , Dehm Gerhard , Li Zhiming , Raabe Dierk
Published: July 2020

High‐entropy alloys (HEAs) and metallic glasses (MGs) are two material classes based on the massive mixing of multiple‐principal elements. HEAs are single or multiphase crystalline solid solutions with high ductility. MGs with amorphous structure have superior strength but usually poor ductility. Here, the stacking fault energy in the high‐entropy nanotwinned crystalline phase and the glass‐forming‐ability in the MG phase of the same material are controlled, realizing a novel nanocomposite with near theoretical yield strength (G/24, where G is the shear modulus of a material) and homogeneous plastic strain above 45% in compression. The mutually compatible flow behavior of the MG phase and the dislocation flux in the crystals enable homogeneous plastic co‐deformation of the two regions. This crystal–glass high‐entropy nanocomposite design concept provides a new approach to developing advanced materials with an outstanding combination of strength and ductility.