bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation of a cDNA coding for an ubiquitin‐conjugating enzyme UBC1 of tomato — the first stress‐induced UBC of higher plants12
Authors: Feussner Kirstin , Feussner Ivo , Leopold Ines , Wasternack Claus
Published: July 2002

A clone of an ubiquitin‐conjugating enzyme (UBC) was isolated from a λ‐ZAP‐cDNA library, generated from mRNA of tomato (Lycopersicon esculentum) cells grown in suspension for 3 days. The open reading frame called LeUBC1, encodes for a polypeptide with a predicted molecular mass of 21.37 kDa, which was confirmed by bacterial overexpression and SDS‐PAGE. Database searches with LeUBC1 showed highest sequence similarities to UBC1 of bovine and yeast. By Southern blot analysis LeUBC1 was identified as a member of a small E2 subfamily of tomato, presumably consisting of at least two members. As revealed by Northern blot analysis LeUBC1 is constitutively expressed in an exponentially growing tomato cell culture. In response to heat shock an increase in LeUBC1‐mRNA was detectable. A strong accumulation of the LeUBC1‐transcript was observed by exposure to heavy metal stress which was performed by treatment with cadmium chloride (CdCl2). The cellular uptake of cadmium was controlled via ICP‐MS measurements. The data suggest that like in yeast, in plants a certain subfamily of UBC is specifically involved in the proteolytic degradation of abnormal proteins as result of stress.
Dehydroepiandrosterone sulfate (DHEAS): identification of a carrier protein in human liver and brain
Authors: Kullak-Ublick Gerd-Achim , Fisch Thomas , Oswald Monika , Hagenbuch Bruno , Meier Peter J , Beuers Ulrich , Paumgartner Gustav
Published: July 2002

Dehydroepiandrosterone sulfate (DHEAS) is the major circulating steroid in man. Pharmacologically, it exerts marked neuropsychiatric effects. Since no target receptor has been identified, we investigated whether the organic anion transporting polypeptide (OATP), a multispecific steroid carrier, transports DHEAS. Expression of the human liver OATP in Xenopus laevis oocytes resulted in high‐affinity, partially Na+‐dependent uptake of [3H]DHEAS (K
m: 6.6 μmol/l). DHEAS transport was inhibited by bromosulfophthalein, bile acids, sulfated estrogens and dexamethasone. Northern blot analysis showed widespread expression of OATP in human brain. These data identify OATP as the first known target protein of DHEAS in human liver and brain.
Chemotactic and osmotic signals share a cGMP transduction pathway in Dictyostelium discoideum
Authors: Kuwayama Hidekazu , Van Haastert Peter J.M
Published: July 2002

In the ameboid eukaryote Dictyostelium discoideum, chemotactic stimulation by cAMP induces an increase of intracellular cGMP and subsequently the phosphorylation of myosin heavy chain II. Resistance to high osmotic stress also requires transient increases of intracellular cGMP and phosphorylation of myosin heavy chain II, although the kinetics is much slower than for chemotaxis. To examine if chemotaxis and osmotic stress share common signaling components we systematically analyzed the osmotic cGMP response and survival in chemotactic mutants with altered cGMP signaling. Null mutants with deletions of cell surface cAMP receptors or the associated GTP‐binding proteins Gα2 and Gβ show no cAMP‐induced cGMP response and chemotaxis; in contrast, osmotic stress induces the normal cGMP accumulation and survival. The same result was obtained with the non‐chemotactic mutant KI‐10, which lacks the activation of guanylyl cyclase by cAMP. This indicates that these components are required for chemotaxis but not osmotic cGMP signaling and survival. The potential guanylyl cyclase null mutant KI‐8 shows no chemotaxis, no osmotic cGMP increase and reduced survival in high osmolarity. Two types of cGMP‐binding protein mutants, KI‐4 and KI‐7, also show reduced tolerance during high osmotic stress. Taken together, these observations clarify that chemotactic and osmotic signals are detected by different mechanisms, but share a cGMP signaling pathway.
Enhancement and inhibition of snake venom phosphodiesterase activity by lysophospholipids
Authors: Mamillapalli Ramanaiah , Haimovitz Rachel , Ohad Mazor , Shinitzky Meir
Published: July 2002

Lysophospholipids are liberated during venomous action. In this study we demonstrated that lysophosphatidyl choline (LPC) of various acyl chains enhances considerably the activity of snake venom phosphodiesterase (PDE). Lysophosphatidic acid (LPA) and its cyclic form (cLPA), on the other hand, were found to inhibit this enzyme in a non‐competitive (LPA) or competitive (cLPA) manner. Both of these activities may contribute to the progression and subsidence of the poisoning profile. PDE from cellular origin was not substantially affected by any of the above lysophospholipids.
Cyclooxygenase‐2 up‐regulation after FLAP transfection in human adenocarcinoma cell line HT29 cl.19A
Authors: Battu Serge , Beneytout Jean Louis , Pairet Michel , Rigaud Michel
Published: July 2002

Five‐lipoxygenase‐activating protein (FLAP) is usually described as an essential protein to activate the leukotriene (LTs) synthesis via the 5‐lipoxygenase pathway. In the enterocyte model HT29 cl.19 A cell line, 5‐lipoxygenase metabolism was found despite the lack of FLAP expression. Therefore HT29 cl.19A represents an original mammalian model to study FLAP‐dependent leukotriene synthesis. In FLAP cDNA transfected HT29 cl.19 A cells, FLAP expression led to an increase in cyclooxygenase pathway products (mainly PGE2) without an increase in 5‐lipoxygenase metabolism. This increase in PGE2 synthesis was associated with a cyclooxygenase‐2 up‐regulation in comparison to untransfected HT29 cl.19A cells. These results suggest a possible interaction between the two major pathways of arachidonic acid metabolism.
Calmodulin dependence of NFκB activation
Authors: Hughes Kate , Antonsson Åsa , Grundstrøm Thomas
Published: July 2002

The NFκB family of transcription factors is regulated by inhibitory IκB proteins. A diversity of stimuli leads to the phosphorylation and subsequent degradation of IκB, releasing NFκB to act on its target genes. Calmodulin (CaM) is a key regulator of numerous cellular processes and is the predominant intracellular receptor for Ca2+ signals. Here we report that several CaM antagonists inhibit the activation of NFκB, and that this is due to the prevention of inducible IκB phosphorylation. Our results suggest that CaM is involved in the phosphorylation of IκB, a finding that may help in elucidating the mechanism of this critical step of NFκB activation.
Functional reconstitution of RNase P activity from a plastid RNA subunit and a cyanobacterial protein subunit
Authors: Pascual Alberto , Vioque Agustı́n
Published: July 2002

The plastid (cyanelle) from the Glaucocystophyceae alga Cyanophora paradoxa contains an RNase P RNA subunit (P RNA) similar to the cyanobacterial P RNA. We have synthesized this RNA by in vitro transcription and analyzed its activity in the absence or presence of the RNase P protein subunit (P protein) from Escherichia coli and the cyanobacterium Synechocystis sp. PCC 6803. In contrast to the bacterial P RNA, the cyanelle P RNA is not active in the absence of protein in any of the conditions tested. A functional enzyme could be reconstituted with the Synechocystis protein but not with the E. coli protein. This is the first demonstration of RNase P activity reconstitution from organellar and bacterial subunits.
The human and rat forms of multiple inositol polyphosphate phosphatase: functional homology with a histidine acid phosphatase up‐regulated during endochondral ossification
Authors: Caffrey James J. , Hidaka Kiyoshi , Matsuda Miho , Hirata Masato , Shears Stephen B.
Published: July 2002

We have derived the full‐length sequences of the human and rat forms of the multiple inositol polyphosphate phosphatase (MIPP); their structural and functional comparison with a chick histidine acid phosphatase (HiPER1) has revealed new information: (1) MIPP is approximately 50% identical to HiPER1, but the ER‐targeting domains are divergent; (2) MIPP appears to share the catalytic requirement of histidine acid phosphatases, namely, a C‐terminal His residue remote from the RHGxRxP catalytic motif; (3) rat MIPP mRNA is up‐regulated during chondrocyte hypertrophy. The latter observation provides a context for proposing that MIPP may aid bone mineralization and salvage the inositol moiety prior to apoptosis.
Amino acid residues in the transmembrane domain of the type 1 sigma receptor critical for ligand binding
Authors: Yamamoto Hideko , Miura Reiko , Yamamoto Toshifumi , Shinohara Keiko , Watanabe Masayuki , Okuyama Shigeru , Nakazato Atsuro , Nukada Toshihide
Published: July 2002

The type 1 sigma receptor expressed in Xenopus oocytes showed binding abilities for the sigma‐1 ligands, [3H](+)pentazocine and [3H]NE‐100, with similar kinetic properties as observed in native tissue membranes. Amino acid substitutions (Ser99Ala, Tyr103Phe and di‐Leu105,106di‐Ala) in the transmembrane domain did not alter the expression levels of the type 1 sigma receptor as determined by immunoblot analysis using an anti‐type 1 sigma receptor antiserum. By contrast, ligand binding was significantly suppressed by the substitutions. These findings provide evidence that the transmembrane domain of the type 1 sigma receptor plays a critical role in ligand binding of this receptor.
Hydrolysis of αs1‐ and β‐casein‐derived peptides with a broad specificity aminopeptidase and proline specific aminopeptidases from Lactococcus lactis subsp. cremoris AM2
Authors: Bouchier Paul J , FitzGerald Richard J , O'Cuinn Gerard
Published: July 2002

Aminopeptidase hydrolysis of αs1‐ and β‐casein‐derived synthetic peptides containing non‐consecutive and consecutive proline residues was characterised. Aminopeptidase P (Pep P) (EC 3.4.11.9) or post‐proline dipeptidyl aminopeptidase (PPDA) (EC 3.4.14.5) along with lysine‐paranitroanilide hydrolase (KpNA‐H) (EC 3.4.11.1) activities are required in the degradation of peptides containing non‐consecutive proline residues. However, both Pep P and PPDA along with KpNA‐H are required for hydrolysis of peptides containing consecutive proline residues. The results demonstrate the mechanism by which combinations of purified general and proline specific aminopeptidases from Lactococcus lactis subsp. cremoris AM2 hydrolyse peptides containing proline residues.
A novel dnaK operon from Porphyromonas gingivalis1
Authors: Yoshida Akihiro , Nakano Yoshio , Yamashita Yoshihisa , Oho Takahiko , Shibata Yukie , Ohishi Masamichi , Koga Toshihiko
Published: July 2002

The nucleotide sequence of the dnaK operon cloned from Porphyromonas gingivalis revealed that the operon does not contain homologues of either dnaJ or grpE. However, there were two genes which encode small heat shock proteins immediately downstream from the dnaK and they were transcribed together with dnaK as one unit. The ATPase activity of the P. gingivalis DnaK was synergistically stimulated up to 40‐fold in the simultaneous presence of Escherichia coli DnaJ and GrpE. These results suggest that the DnaK homologue of P. gingivalis, with its unique genetic structure and evolutionary features, works as a member of the DnaK chaperone system.
Macromolecular antimicrobial glycoprotein, achacin, expressed in a methylotrophic yeast Pichia pastoris
Authors: Ogawa Masahiro , Nakamura Soichiro , Atsuchi Tetsumori , Tamiya Toru , Tsuchiya Takahide , Nakai Shuryo
Published: July 2002

A cDNA encoding achacin, an antimicrobial glycoprotein from the body surface mucus of giant African snail Achacina fulica Férussac, was expressed in a methylotrophic yeast, Pichia pastoris, and recombinant achacin (rAch) was secreted in yeast minimal medium in a polyglycosylated form with 80 kDa. Carbohydrate analysis revealed that the glycosylated moiety of rAch was composed of 50 mol mannose and 2 mol N‐acetylglucosamine residues. Antimicrobial activity using Escherichia coli and Staphylococcus aureus showed that the rAch had a behavior similar to its native counterpart. The rAch showed so wide an antimicrobial spectrum that 0.1 mg/ml rAch inhibited the growth of Pseudomonas fluorescens, Staphylococcus epidermidis, and Streptococcus faecalis in addition to E. coli and S. aureus, whereas it did not appreciably affect the growth of Proteus mirabilis, Bacillus cereus and Micrococcus luteus. The rAch was also effective in preventing growth of Vibrio anguillarum and Vibrio parahaemolyticus. The results suggested that the rAch had great potential of using as an antimicrobial agent.
Exploiting retrograde transport of Shiga‐like toxin 1 for the delivery of exogenous antigens into the MHC class I presentation pathway
Authors: Noakes Karen L. , Teisserenc Hélène T. , Lord J.Michael , Dunbar P.Rod , Cerundolo Vincenzo , Roberts Lynne M.
Published: July 2002

Shiga‐like toxin 1 (SLT) from Escherichia coli 0157:H7 enters mammalian cells by endocytosis from the cell surface to the endoplasmic reticulum before translocating into the cytosol. Here, SLT was engineered at its N‐ or C‐terminus to carry a peptide derived from influenza virus Matrix protein for delivery to major histocompatibility complex (MHC) class I molecules. We show that SLT N‐Ma was capable of sensitising cells for lysis by appropriate cytotoxic T‐lymphocytes whilst no killing of SLT‐resistant cells was observed. Our results demonstrate that peptide was liberated intracellularly and that retrograde transport of a disarmed cytotoxic protein can intersect the MHC class 1 presentation pathway.
Point mutations within 663–666 bp of intron 6 of the human TDO2 gene, associated with a number of psychiatric disorders, damage the YY‐1 transcription factor binding site
Authors: Vasiliev Gennady V , Merkulov Vasily M , Kobzev Viktor F , Merkulova Tatyana I , Ponomarenko Mikhail P , Kolchanov Nikolay A
Published: July 2002

Single base mutations G→A at position 663 and G→T at position 666 of intron 6 of the human tryptophan oxygenase gene (TDO2) are associated with a variety of psychiatric disorders [Comings, D.E. et al. (1996) Pharmacogenetics 6, 307–318]. Binding of rat liver nuclear extract proteins to synthetic double‐strand oligonucleotides corresponding to three allelic states of the region between 651 bp and 680 bp of human TDO2 intron 6 has been studied by gel shift assay. It has been demonstrated that to each allelic state of the region there corresponds a specific set of proteins that interacts with it. With the aid of computer analysis and using specific anti‐YY‐1 antibodies it has been shown that both mutations damage the YY‐1 transcription factor binding site.
Epidemiology and time trends of gestational trophoblastic disease in Korea
Authors: Kim S.J. , Bae S.N. , Kim J.H. , Kim C.J. , Han K.T. , Chung J.K. , Lee J.M.
Published: July 2002

Objectives: For the purpose of determining the annual incidence and time trends of gestational trophoblastic disease (GTD), the medical records from 24 university hospitals, 13 private general hospitals and the Korean Research Institute of Gestational Trophoblastic Disease (KRI‐TRD) were analyzed from 1971 to 1995.

Materials & Results: From a total of 7198 GTD cases (H‐mole = 3831, Invasive mole = 2163, Choriocarcinoma = 1177, PSTT = 27) among 838659 deliveries between 1971 and 1995, the hospital‐based incidence of H‐mole per 1000 deliveries declined from 40.2 during 1971‐975, to 2.3 during 1991‐995. The population‐based incidence of H‐mole, hwoever, revealed an average of 2.05 per 1000 deliveries during 1991—995. Old age and gravidities as factors in GTD patients both decreased significantly during the study period. Time trends for the incidence of GTD in Korea revealed significant changes, not only a decrease in the incidence of GTD, but also an improvement in the annual remission rate. Korea's socio‐eonomic improvement in recent decades also contributed to the decreased incidence of GTD and the increased survival rates.
From progesterone to active Cdc2 in Xenopus oocytes: a puzzling signalling pathway
Authors: Karaiskou Anthi , Dupré Aude , Haccard Olivier , Jessus Catherine
Published: July 2002

Summry— Since almost two decades, it is known that progesterone is responsible of the release of the prophase I arrest of amphibian oocytes and leads to the activation of the universal MPF, through a puzzling transduction pathway. It involves negative regulation of the cAMP‐dependent protein kinase (PKA) and synthesis of new proteins, among them the c‐Mos protooncogene product. The implication of the Mos/mitogenic activated protein kinase (MAP kinase) pathway in Cdc2 activation has been extensively studied and is now at the centre of a controversial debate. In this paper, we discuss the current progress and our recent results on the molecular mechanisms allowing progesterone to activate MPF and propose a model to partly resolve the long‐standing inconsistencies concerning the role of Mos/MAP kinase during this process.
Up‐regulation of vascular endothelial growth factor in response to glucose deprivation
Authors: Satake Shosuke , Kuzuya Masafumi , Miura Hisayuki , Asai Toshinobu , Ramos Miguel A. , Muraguchi Masahiro , Ohmoto Yasukazu , Iguchi Akihisa
Published: July 2002

Vascular endothelial growth factor (VEGF), also known as a vascular permeability factor (VPF), is an endothelial specific mitogen and is a potent inducer of angiogenesis. Recently it has been reported that hypoxia induces VEGF mRNA expression in various cells. Since both oxygen and glucose are required for efficient production of energy, we examined the effect of glucose deprivation on VEGF mRNA expression and VEGF protein production in U‐937 (a human monocytic cell line) cells. Both the mRNA expression and secretion of VEGF increased after exposure to low glucose. Addition of L‐glucose, the L‐stereoisomer of D‐glucose, did not prevent the up‐regulation of VEGF expression. The conditioned medium from glucose‐deprived cells, followed by supplementation with glucose, did not up‐regulate VEGF mRNA expression in U‐937 cells. The low glucose‐induced VEGF mRNA expression returned to the control level after supplementation with D‐glucose. Furthermore, oligomycin, a mitochondrial ATP synthase inhibitor, increased VEGF protein production. The results suggest that the up‐regulation of VEGF mRNA in U‐937 cells in response to glucose deprivation is not mediated by autocrine factors from the cells nor is the osmotic change of the medium mediated by the deficiency of glucose metabolism in the cells. Our results also suggest that the intracellular ATP depletion due to glucose deprivation may be one of the causes for increased VEGF mRNA expression. We speculate that local hypoglycemia may act as an essential trigger for angiogenesis through the VEGF gene expression.
Rehabilitation of schizophrenic and other long-term mentally ill patients. Results from a prospective study of a comprehensive inpatient treatment program based on cognitive therapy
Authors: Svensson B. , Hansson L.
Published: July 2002

A total of 28 long-term mentally ill patients, the majority schizophrenic, treated with cognitive therapy in the context of milieu-therapy and group therapy, were investigated at admission and discharge with regard to changes in symptomatology, quality of life, global functioning, need for medication, and perceived target complaints. The results showed a significant relief in perceived burden of illness and an improvement in quality of life. A better pre-admission functioning with regard to social functioning, occupational function, and symptoms predicted a more favourable outcome.
Effect of an exercise programme for elderly patients with heart failure
Authors: Owen A. , Croucher L.
Published: July 2002

Aims:

Benefit from exercise training programmes for patients with chronic heart failure has been demonstrated in relatively young (mean age 60 years) and predominantly male subjects. This study was undertaken to assess the effect of an exercise programme for older subjects more representative of the general heart failure population.

Methods and Results:

Twenty‐two patients with chronic heart failure of mean age 81±4 years were recruited into the study. Twenty‐five percent were female and 31% were in chronic atrial fibrillation. A crossover study design was employed. The programme consisted of once weekly exercise sessions tailored to the abilities of elderly subjects and lasted for 12 weeks. Fifteen subjects completed the exercise component and nine the control component. The programme resulted in a 20% relative increase in 6‐min walk test distance (ANCOVA: P<0.012). There was no improvement in quality of life as measured by the Living With Heart Failure Questionnaire, but the majority of subjects reported subjective improvement in wellbeing.

Conclusion:

Elderly patients with chronic heart failure can benefit from an appropriately designed exercise programme and should not be excluded from future large scale trials.
Efficient Single‐Dose Induction of Osteogenic Differentiation of Stem Cells Using Multi‐Bioactive Hybrid Nanocarriers
Authors: Tavares Márcia T. , Oliveira Mariana B. , Gaspar Vítor M. , Mano João F. , S. Farinha José Paulo , Baleizão Carlos
Published: September 2020

Bone regeneration requires the presence of specific factors to induce the differentiation of stem cells into osteoblasts. These factors induce osteogenesis by stimulating the expression of bone‐related proteins, bone cell proliferation and differentiation. Herein, bioactive mesoporous silica nanoparticles are doped with calcium and phosphate ions while the porous network is loaded with dexamethasone (MSN‐CaPDex). The bioactive MSN‐CaPDex nanocarriers are prepared without affecting the narrow size distribution, pore structure, and morphology of the MSNs, while incorporating multi‐stimuli, complementary ionic/biochemical bioactive mediators. The bioactive nanocarriers induce osteogenic differentiation of human bone marrow mesenchymal stem cells (hBM‐MSCs) after a single‐dose administration, and without the need for further soluble osteogenic factors, in contrast to the standard continuous stimulation provided by osteogenic medium. The hBM‐MSCs exhibit several biomarkers of osteogenic differentiation, including alkaline phosphatase peaking at early time points, secretion of osteopontin and osteocalcin, and deposition of a calcium‐rich matrix. Overall, by inducing the osteogenic differentiation of stem cells with a single‐dose administration and without requiring repeated osteogenic supplementation, the newly synthesized multi‐bioactive hybrid nanocarrier shows great potential for bone tissue engineering applications.
Additives Engineered Nonflammable Electrolyte for Safer Potassium Ion Batteries
Authors: Liu Gang , Cao Zhen , Zhou Lin , Zhang Jiao , Sun Qujiang , Hwang Jang‐Yeon , Cavallo Luigi , Wang Limin , Sun Yang‐Kook , Ming Jun
Published: September 2020

Potassium ion batteries (KIBs) are attracting great attention as an alternative to lithium‐ion batteries due to lower cost and better global sustainability of potassium. However, designing electrolytes compatible with the graphite anode and addressing the safety issue of highly active potassium remains challenging. Herein, a new concept of using additives to engineer non‐flammable electrolytes for safer KIBs is introduced. It is discovered that the additives, such as the ethylene sulfate (i.e., DTD), can make the electrolyte of 1.0 m potassium bis(fluorosulfonyl) imide in trimethyl phosphate compatible with graphite anode for the first time, without the need of concentrated electrolyte strategies. A new coordination mechanism of additives in the electrolyte is presented. It is shown that the additive can change the K+ solvation structure and then determine the interfacial behaviors of K+‐solvent on electrode interface, which are critical to affect the graphite performance (i.e., K+‐solvent co‐insertion, or K+ (de‐)intercalation). Then, an extremely high potassium storage capability is obtained in graphite electrode for potassium (ion) batteries, particularly the presented high‐performance graphite|K0.69CrO2 full battery fully demonstrates the practical application of this newly designed electrolyte. This additive‐based strategy can offer more opportunities to tune the electrolyte properties and then serve for the more mobile ion battery system.
Phosphorus Pentamers: Floating Nanoflowers form a 2D Network
Authors: Zhang Wei , Enriquez Hanna , Tong Yongfeng , Mayne Andrew J. , Bendounan Azzedine , Dappe Yannick J. , Kara Abdelkader , Dujardin Gérald , Oughaddou Hamid
Published: September 2020

An experimental investigation of a new polymorphic 2D single layer of phosphorus on Ag(111) is presented. The atomically‐resolved scanning tunneling microscopy images show a new 2D material composed of freely‐floating phosphorus pentamers organized into a 2D layer, where the pentamers are aligned in close‐packed rows. The scanning tunneling spectroscopy measurements reveal a semiconducting character with a band gap of 1.20 eV. This work presents the formation at low temperature of a new polymorphic 2D phosphorus layer composed of a floating 2D pentamer structure. The smooth curved terrace edges and a lack of any clear crystallographic orientation with respect to the Ag(111) substrate at room temperature indicates a smooth potential energy surface that is reminiscent of a liquid‐like growth phase. This is confirmed by density functional theory calculations that find a small energy barrier of only 0.17 eV to surface diffusion of the pentamers (see Supporting Information). The formation of extended, homogeneous domains is a key ingredient to opening a new avenue to integrate this new 2D material into electronic devices.
Moving Alkyl‐Chain Branching Point Induced a Hierarchical Morphology for Efficient All‐Small‐Molecule Organic Solar Cells
Authors: Zhou Ruimin , Jiang Zhaoyan , Shi Yanan , Wu Qiong , Yang Chen , Zhang Jianqi , Lu Kun , Wei Zhixiang
Published: September 2020

The optimization of bulk heterojunction morphology is one of the most challenging topics in all‐small‐molecule organic solar cells. Herein, three small molecular donors based on dithieno[2,3‐d;2′,3′‐d′]benzo[1,2‐b;4,5‐b′]dithiophene (DTBDT) unit by systematically moving the branching point of the alkyl chain have been designed, synthesized, and applied in organic solar cells. Modifying the branching points enables the properties of the aggregation state to be tuned, and an efficient nanofiber‐based hierarchical morphology is successfully demonstrated by combining with different nonfullerene acceptors. The molecules with far branching points can form nanofibers in active layers, and theses nanofibers help the charge separation and charge transport in a large donor‐rich or acceptor‐rich domain of approximately 100 nm. Using nonfullerrene Y6 as an acceptor, the highest power conversion efficiency of 14.78% is obtained, which is one of the highest efficiencies in all‐small‐molecule organic solar cells. The strategy of modification of alkyl side chain branching points can be a practical way to actualize crystallinity control and active layer morphology for improving the performance of all‐small‐molecule organic solar cells.
Integration and Synergy of Organic Single Crystals and Metal–Organic Frameworks in Core–Shell Heterostructures Enables Outstanding Gas Selectivity for Detection
Authors: Zheng Jianzhong , Pang Kanglei , Liu Xu , Li Shunxing , Song Rui , Liu Yaling , Tang Zhiyong
Published: September 2020

Controllable integration of two or more functional components is one of the most convenient and effective ways to obtain composite advanced materials with collective properties and improved performance. In this work, in combination with organic single crystals and metal–organic frameworks (MOFs), a novel 1D well‐defined core–shell heterostructure with single copper phthalocyanine (CuPc) ribbon cores coated with a uniform isoreticular MOF‐3 (IRMOF‐3) shell is successfully constructed. Impressively, thanks to performance the integration and synergy of the CuPc cores and the IRMOF‐3 shells, the sensor devices based on such single heterostructures exhibit outstanding selectivity for NH3 detection at ≈60% relative humidity at room temperature, the current response of which to NH3 is around 34–265 times the magnitude of response to ten potential interfering gases even in the case of the 1:100 concentration ratio of NH3 (5 ppm) and the interfering gases (500 ppm). Moreover, the detection limit of such CuPc@IRMOF‐3 sensors toward NH3 is estimated to be 52 ppb (signal to noise ratio = 3) based on 11 blank determinations, and good stability and reusability can also be achieved. This work highlights that the integration of organic single crystals and MOFs into well‐defined structures offers a new opportunity for high‐performance gas sensors.
Plasmonic Oxygen‐Deficient TiO2‐x Nanocrystals for Dual‐Band Electrochromic Smart Windows with Efficient Energy Recycling
Authors: Zhang Shengliang , Cao Sheng , Zhang Tianran , Lee Jim Yang
Published: September 2020

Dual‐band electrochromic smart windows capable of the spectrally selective modulation of visible (VIS) light and near‐infrared (NIR) can regulate solar light and solar heat transmittance to reduce the building energy consumption. The development of these windows is however limited by the number of available dual‐band electrochromic materials. Here, plasmonic oxygen‐deficient TiO2‐x nanocrystals (NCs) are discovered to be an effective single‐component dual‐band electrochromic material, and that oxygen‐vacancy creation is more effective than aliovalent substitutional doping to introduce dual‐band properties to TiO2 NCs. Oxygen vacancies not only confer good near‐infrared (NIR)‐selective modulation, but also improve the Li+ diffusion in the TiO2‐x host, circumventing the disadvantage of aliovalent substitutional doping with ion diffusion. Consequently optimized TiO2‐x NC films are able to modulate the NIR and visible light transmittance independently and effectively in three distinct modes with high optical modulation (95.5% at 633 nm and 90.5% at 1200 nm), fast switching speed, high bistability, and long cycle life. An impressive dual‐band electrochromic performance is also demonstrated in prototype devices. The use of TiO2‐x NCs enables the assembled windows to recycle a large fraction of energy consumed in the coloration process (“energy recycling”) to reduce the energy consumption in a round‐trip electrochromic operation.
Light‐to‐Heat Photothermal Dynamic Properties of Polypyrrole‐Based Coating for Regenerative Therapy and Lab‐on‐a‐Chip Applications
Authors: Ulasevich Sviatlana , Ryzhkov Nikolay V. , Andreeva Daria V. , Özden Dilek Sura , Piskin Erhan , Skorb Ekaterina V.
Published: September 2020

Targeted delivery and release of biomolecules, e.g., bone morphogenetic protein (BMP‐2), are gaining high interest due to the application for tissue engineering, diagnostics, surface‐enhanced therapy and lab‐on‐a‐chip. Here, a new hybrid temperature‐responsive system consisting of polypyrrole (PPy) layer, mesoporous titania surface (TMS), and BMP‐2 is proposed. The PPy layer has the light‐to‐heat photothermal property. Dynamic behavior of the PPy layer in response to light can regulate release of BMP‐2. The PPy‐based coatings on TMS have shown to be efficient for storage of BMP‐2 and can be tuned to release BMP‐2 under irradiation. Moreover, the possibility of local delivery and generation of a gradual release of BMP‐2 for regulated cell growth is shown. Furthermore, the fabricated surfaces possess excellent biocompatibility and low cytotoxicity for MC3T3‐E1 cells. It is shown that the released BMP‐2 can effectively promote osteogenic differentiation of MC3T3‐E1 cells. Thus, the TMS/PPy–BMP‐2 is suggested to prolong targeted release of the BMP‐2 for more than 25 days which stimulates osteoblasts’ proliferation. The new stimuli‐responsive hybrid system is promising for targeted, localized, sustained drug release and application in bone tissue engineering.
On‐Chip Rotation of Caenorhabditis elegans Using Microfluidic Vortices
Authors: Pan Peng , Laver John D. , Qin Zhen , Zhou Yuxiao , Peng Ran , Zhao Lijun , Xie Hui , Calarco John A. , Liu Xinyu
Published: September 2020

Precise and controllable rotation of small biological samples is essential to many biological and medical applications. This paper reports, an easy‐to‐use microfluidic device to rotate single nematode worm Caenorhabditis elegans in a reliable and controllable fashion, which was enabled by on‐chip generation of stable microscale vortices inside a worm‐loaded microchannel by fluidic shear stress. To test the capability of the proposed device, single worms were successfully rotated in continuous and stepwise modes. Using this device, clear visualization of all dopaminergic neurons in the head of a C. elegans was demonstrated by capturing fluorescence images of the worm body at several rotational angles. Multiple perspectives of individual neurons of a multi‐color fluorescent transgenic worm were also obtained at high resolution using laser‐scanning confocal microscopy. The results show that this microfluidic rotation device provides a simple solution to overcoming limitations of confocal microscopy when imaging relatively thick tissue samples such as an adult C. elegans, and is compatible with multiple fluorescent proteins with different spectral properties. With its controllability, precision, and simplicity in fabrication and operation, this microfluidic device has important utility in model organism studies.
Organic Photovoltaic Modules Built on Paper Substrates
Authors: Jayaraman Eswaran , Iyer S. Sundar Kumar
Published: September 2020

Organic photovoltaic (OPV) modules, which are attractive for large‐volume high‐throughput production, can become more environmentally sustainable with eco‐friendly flexible substrates such as paper. This article reports fabrication and performance of 108 cm2 active area 12 by 12 cm OPV, built on 15 by 15 cm paper substrates. Active area power conversion efficiency (PCE) values up to 2.38 and 4.23% respectively for poly(3‐hexylthiophene) (P3HT):[6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) and poly({4,8‐bis[(2‐ethylhexyl)oxy]benzo[1,2‐b:4,5‐b′]dithiophene‐2,6‐diyl}{3‐fluoro‐2‐[(2‐ethylhexyl)carbonyl]thieno[3,4‐b]thiophenediyl}) (PTB7):PCBM blend heterojunction photoactive layer modules under AM1.5G spectrum one sun (100 mW cm−2) intensity illumination are demonstrated. Due to better spectrum matching, for 1000 lux cool‐white light emitting diode (LED) illumination, the power density demonstrated is up to 12 µW cm−2 for these modules, which is comparable to 13 µW cm−2 from a (standard illumination PCE 15%) silicon PV device for the same illumination. These results make OPV on environment friendly paper substrate, an attractive option for practical applications.
Sunlike White Quantum Dot Light‐Emitting Diodes with High Color Rendition Quality
Authors: Hong Ahyoung , Kim Jaeyun , Kwak Jeonghun
Published: September 2020

Although it is demanded for general lighting sources to have high color rendition qualities close to natural daylight, it is difficult to make sunlike artificial illuminants due to limited tunability of phosphors and complicated fabrication processes. On the contrary, white‐emitting quantum dot (QD) light‐emitting diodes (QLEDs) can be easily produced by mixing several colors of QDs in a single emitting layer (EML). In this work, sunlike white QLEDs showing high color rendition qualities are demonstrated by incorporating five (red, yellow, green, cyan, and blue) or six (additional violet) primary colors of QDs in the EML. Based on the simulation and optimization of the multichromatic spectra, the pentachromatic and hexachromatic white QLEDs exhibit the superb color rendering index of 96–98, the color quality scales of 95–97, and the spectral similarity index of up to 86, with tunable correlated color temperatures from daylight to overcast sky. The Förster resonant energy transfers between six colors of QDs are also investigated with time‐resolved photoluminescence spectroscopy. The analysis of the pentachromatic and hexachromatic white QLEDs with the sunlike spectra suggests that white QLEDs can be a promising candidate for next‐generation solid‐state lighting devices.
Coupled Toroidal Dipole Modes in Silicon Nanodisk Metasurface: Polarization Independent Narrow Band Absorption and Directional Emission
Authors: Hasebe Hiroaki , Sugimoto Hiroshi , Hinamoto Tatsuki , Fujii Minoru
Published: September 2020

Besides the fundamental Mie resonance modes of high‐index dielectric nanostructures, an extended multipole family, i.e., toroidal multipoles, provide great opportunities for engineering a new class of nanophotonic devices. Here, it is demonstrated theoretically and experimentally that a hexagonal array of circular silicon (Si) nanodisks (NDs) supports intra‐ and inter‐ND toroidal dipole (TD) modes. The key concept is the alignment of Si NDs near the anapole state condition for constructive interaction of the TD modes between neighboring NDs. Numerical simulation reveals that strong field confinement by the coupled TD modes enhances the absorption 120‐fold at the resonance wavelength compared to that of a flat Si film with the same thickness. In this study, macroscopic scale hexagonal Si ND arrays are fabricated using a colloidal lithography, and spectrally selective absorption enhancement due to the TD modes is demonstrated. Furthermore, it is demonstrated that a dipolar emitter can also excite TD modes, which modify the spectral shape and the directionality of the emission.
An Unorthodox Mechanism Underlying Voltage Sensitivity of TRPV1 Ion Channel
Authors: Yang Fan , Xu Lizhen , Lee Bo Hyun , Xiao Xian , Yarov‐Yarovoy Vladimir , Zheng Jie
Published: September 2020

While the capsaicin receptor transient receptor potential vanilloid 1 (TRPV1) channel is a polymodal nociceptor for heat, capsaicin, and protons, the channel's responses to each of these stimuli are profoundly regulated by membrane potential, damping or even prohibiting its response at negative voltages and amplifying its response at positive voltages. Therefore, voltage sensitivity of TRPV1 is anticipated to play an important role in shaping pain responses. How voltage regulates TRPV1 activation remains unknown. Here, it is shown that voltage sensitivity does not originate from the S4 segment like classic voltage‐gated ion channels; instead, outer pore acidic residues directly partake in voltage‐sensitive activation, with their negative charges collectively constituting the observed gating charges. Outer pore gating‐charge movement is titratable by extracellular pH and is allosterically coupled to channel activation, likely by influencing the upper gate in the ion selectivity filter. Elucidating this unorthodox voltage‐gating process provides a mechanistic foundation for understanding TRPV1 polymodal gating and opens the door to novel approaches regulating channel activity for pain management.
Stable Heating Above 900 K in the Field Emission of ZnO Nanowires: Mechanism for Achieving High Current in Large Scale Field Emitter Arrays
Authors: Chen Yicong , Luo Shisong , Cao Xiuqing , Li Yufeng , She Juncong , Deng Shaozhi , Chen Jun
Published: September 2020

The thermal runaway of a quasi‐1D (Q1D) field emitter is an important cause of vacuum breakdown, which limits the field emission current density in field emitter arrays (FEAs). Comprehensive knowledge on the self‐heating process of zinc oxide (ZnO) nanowires is important for obtaining a high breakdown field for activating more emitters. This work investigates the self‐heating model of individual ZnO nanowire by considering the thermal field emission current distribution along the nanowire. Theoretical calculations suggest that the thermal field emission distribution along the nanowire can be reflected on the profile of the field emission pattern, which offers a method for determining its temperature. The field emission ring pattern is experimentally observed in the ZnO nanowire, whose intensity profile indicates that the nanowire can be steadily heated above 900 K. Considering the high breakdown field of high‐thermal stability ZnO nanowires, the field emission current density of ≈1.4 mA cm−2 can be achieved using these nanowires in a 3.5‐inch FEA. These findings provide an alternative method for measuring the Q1D field emitter temperature and a guideline for improving the field emission current from large‐scale Q1D FEAs.
Labor Issues in the Food Supply Chain Amid the COVID‐19 Pandemic
Authors: Luckstead Jeff , Nayga Rodolfo M. , Snell Heather A.
Published: September 2020

The impacts of COVID‐19 on labor in the food supply chain and on workers’ decisions to accept essential jobs are discussed. We then analyze surveys administered to low‐skilled domestic workers before and during the pandemic to assess respondents' attitudes toward food production, guest workers, immigration policy, and the government's response to COVID‐19. Results suggest the outbreak resulted in respondents, on average, shifting their view toward food being a national security issue and a higher degree of empathy for H‐2A workers. Regression analysis shows that gender, current agricultural workers, and information on COVID‐19 and agricultural field workers influenced respondents' answers.
Allelic distribution of ABO gene in Chinese centenarians
Authors: Zhu Ying , Liang Yu , Khan Abdul Haseeb , Dong Minghua , Wan Yiqi , Sun Zhichao , Zeng Yi , Nie Chao , Tian Xiao‐Li
Published: September 2020

Objective

Human ABO blood groups are determined by the alleles A, B, and O (O01 and O02) of the ABO gene and have been linked to the risks for cardiovascular diseases and cancers that affect lifespan.

We examined the genetic associations of the ABO gene and blood groups with longevity.

Methods

We inspected the frequencies of the A, B, O, and O02 alleles in a large Chinese centenarian population (n = 2201) and in middle‐aged controls (n = 2330). The single nucleotide polymorphisms were selected as allele A (rs507666), B (rs8176743, rs8176746, and rs8176749), O (rs687289), and O02 (rs688976, rs549446, and rs512770).

Results

Supported by allelic and genotypic association studies, the frequencies of blood types A, B, O, and AB in centenarian versus control participants were not statistically different: 0.2821 versus 0.2781 (χ2 = 0.09, P = 0.76), 0.2867 versus 0.3060 (χ2 = 2.03, P = 0.15), 0.3380 versus 0.3159 (χ2 = 2.52, P = 0.11), and 0.0859 versus 0.0910 (χ2 = 0.37, P = 0.54), respectively. Sex had little effect on these distributions.

Conclusion

Integrated with other previous reports, we conclude from this large Chinese cohort that genetic variants of the ABO gene and blood groups are not associated with longevity.
Molecular thermodynamic understanding of transport behavior of CO2 at the ionic liquids‐electrode interface
Authors: Wang Yanlei , Qian Cheng , Huo Feng , Xu Baohua , He Hongyan , Zhang Suojiang
Published: September 2020

The transport behavior of CO2 at the ionic liquids (ILs)‐electrode interface was revealed from the thermodynamic view via molecular dynamics simulations. The hopping and self‐diffusive mechanisms were identified in the interfacial and bulk region, and thereafter a hopping‐diffusion model was developed to evaluate the transport resistance of CO2 from bulk to the interface. Meanwhile, the vibrational spectrum and entropy change of CO2 at the interface were calculated using the thermodynamic analysis method. For ILs with the same cation ([Emim]+), both transport resistance and entropy decrease follow the order: [BF4]− < [AC]− < [NO3]−, indicating [BF4]− possesses the faster CO2 transport efficiency across the electrical double layer. Furthermore, the methyl substitution effect on transport and thermodynamic properties was clarified, indicating the coupling relation between the transport process and thermodynamic advantage. These findings can lay the ground for the molecule design of ILs‐electrode interface in the applications in the chemical engineering field.
Simple synthesis of the novel Cu‐MOF catalysts for the selective alcohol oxidation and the oxidative cross‐coupling of amines and alcohols
Authors: Ghamari Kargar Pouya , Aryanejad Sima , Bagherzade Ghodsieh
Published: September 2020

A novel porous metal–organic framework {Cu2(bbda)0.5(Hbbda)1.5(OAc)1.5.8H2O} (UoB‐5) was synthesized under ultrasound irradiation by employing a new Schiff base ligand H2bbda (4,4′(1,4‐phenylene bis (azanylylidene)) bis (methanylylidene))dibenzoic acid) and was fully characterized. The microporous nature of UoB‐5 was confirmed by gas‐sorption measurements. This framework acted as a highly effective heterogeneous catalyst for the alcohol oxidation reaction with tert‐butyl hydroperoxide (t‐BuOOH) as an oxidant. The presence of coordinatively unsaturated metal sites in UoB‐5 could be the reason for high performance in this reaction. Furthermore, using the long linker with the free ‐NC group and uncoordinated ‐N atom on the wall of the pores created UoB‐5 an excellent candidate for the catalytic activities without activation of the framework. It was confirmed with the heterogeneous catalytic experiments on the one‐pot tandem synthesis of imines from benzyl alcohols and anilines. Eventually, the new Cu‐MOF (UoB‐5) could be an alternative catalyst as a more economically favorable and environmentally friendly in the catalysis field.
Genetic analysis of the diet of red‐footed boobies (Sula sula) provisioning chicks at Ulupa'u Crater, O'ahu
Authors: Donahue Sarah E. , Adams Josh , Renshaw Mark A. , Hyrenbach K. David
Published: September 2020

The diet of red‐footed boobies (Sula sula) provisioning chicks was quantified using 106 regurgitations collected from 81 adults over two study years with contrasting oceanographic conditions: 2014 and 2015.

A total of 1,049 prey items were sorted into three broad categories (fish, squid, and other, consisting of highly‐digested ‘mush’ and parasitic isopods) and assigned a categorical freshness value of 1 (perfect condition), 2 (superficial digestion), or 3 (highly digested and incomplete).

A total of 492 undigested prey items (freshness 1 and 2) were measured and sampled for genetic identification with 401 (82%) successfully identified. Rarefaction analyses suggested robust diet sampling, with 32 documented species: 29 fishes and three squids.

While the prey‐specific index of relative importance highlighted that fish dominated the diet in 2014 (32.3% fish, 15.1% squid) and in 2015 (29.9% fish, 22.3% squid), diet composition varied significantly between the two study years.

The purpleback flying squid (Stenoteuthis oulaniensis) accounted for 98.7% (232 of 236) of the identified squid specimens. Mantle lengths were significantly longer in 2015 (7.2 ± 1.1 SD cm) than in 2014 (6.3 ± 1.7 SD cm).

These results indicate a higher relative abundance and size of the epipelagic squids available to foraging red‐footed boobies in 2015, during warm‐water conditions associated with the positive phase of the El Niño Southern Oscillation.

Due to their diverse diet, red‐footed boobies are useful bioindicators of epipelagic nekton assemblages during changing oceanographic conditions. Moreover, their reliance on the purpleback flying squid makes these seabirds ideal samplers of the juveniles of this poorly studied species.

Understanding how interannual and longer‐term oceanographic variability affects central‐place foraging seabirds and the recruitment and abundance of their squid prey is critical for precautionary ecosystem‐based fisheries management of oceanic islands and the surrounding marine environment.