bluuebunny/crossref_metadata_2025 huggingface dataset:
Streptomyces matensis laminaripentaose hydrolase is an ‘inverting’ β‐1,3‐glucanase
Authors: Nishimura T. , Bignon C. , Allouch J. , Czjzek M. , Darbon H. , Watanabe T. , Henrissat B.
Published: July 2002

The laminaripentaose‐producing β‐1,3‐glucanase of Streptomyces matensis is a member of the glycoside hydrolase family GH‐64. We have constructed and purified a recombinant hexahistidine‐tagged form of the enzyme for characterisation. The enzyme, which exists as a monomer in solution, hydrolyses β‐1,3‐glucan by a mechanism leading to overall inversion of the anomeric configuration. This is the first determination of the mechanism prevailing in glycoside hydrolase family GH‐64 and this is the first characterisation of an ‘inverting’ β‐1,3‐glucanase.
Ca2+ transport into an intracellular acidic compartment of Candida parapsilosis
Authors: Milani Graziela , Schereiber Angelica Z , Vercesi Anibal E
Published: July 2002

In this report, we study Ca2+ transport in permeabilized Candida parapsilosis spheroplasts prepared by a new technique using lyticase. An intracellular non‐mitochondrial Ca2+ uptake pathway, insensitive to orthovanadate and sensitive to the V‐H+‐ATPase inhibitor bafilomycin A1, nigericin and carbonyl cyanide p‐trifluoromethoxyphenylhydrazone was characterized. Acidification of the compartment in which Ca2+ accumulated was followed using the fluorescent dye acridine orange. Acidification was stimulated by the Ca2+ chelator EGTA and inhibited by Ca2+. These results, when added to the observation that Ca2+ induces alkalization of a cellular compartment, provide evidence for the presence of a Ca2+/nH+ antiporter in the acid compartment membrane. Interestingly, like in acidocalcisomes of trypanosomatids, the antioxidant 3,5‐dibutyl‐4‐hydroxytoluene inhibits the V‐H+‐ATPase. In addition, the antifungal agent ketoconazole promoted a fast alkalization of the acidic compartment. Ketoconazole effects were dose‐dependent and occurred in a concentration range close to that attained in the plasma of patients treated with this drug.
The protein tyrosine kinase p56lck regulates the serine‐base exchange activity in Jurkat T cells
Authors: Marhaba Rachid , Dumaurier Marie-Jeanne , Pelassy Claudette , Batoz Michelle , Peyron Jean Francois , Breittmayer Jean-Philippe , Aussel Claude
Published: July 2002

© 1997 Federation of European Biochemical Societies.
CPP32 activation during dolichyl phosphate‐induced apoptosis in U937 leukemia cells
Authors: Yokoyama Yoshiko , Okubo Tomoko , Ozawa Satoshi , Nagai Fumiko , Ushiyama Keiko , Kano Itsu , Shioda Masaki , Kubo Hirotaka , Takemura Mariko , Namiki Hideo , Yasugi Etsuko , Oshima Mieko , Seyama Yousuke , Kano Kazutaka
Published: July 2002

Treatment of U937 cells with dolichyl phosphate led to an increase in the activity of the ICE family protease CPP32, accompanied with cleavage of pre‐CPP32 to generate p17. Peptide inhibitors YVAD‐cmk and Z‐Asp‐CH2‐DCB (specific to ICE) and DEVD‐cho (specific to CPP32) blocked the dolichyl phosphate‐induced apoptosis. The dolichyl phosphate‐induced increase of CPP32 activity was inhibited by adenylate cyclase inhibitors, SQ 22536 and 2′,5′‐dideoxyadenosine. Dolichyl phosphate caused a transient increase of intracellular cAMP concentration. The results suggest that modulation of cAMP synthesis due to the stimulation of adenylate cyclase by dolichyl phosphate plays a critical role in CPP32 activation and apoptosis.
Activation of c‐Jun N‐terminal kinase during ischemia and reperfusion in mouse liver
Authors: Onishi Ichiro , Tani Takashi , Hashimoto Tetsuo , Shimizu Kouichi , Yagi Masao , Yamamoto Ken-ichi , Yoshioka Katsuji
Published: July 2002

We have generated a mouse model for hepatic ischemia in which surgical subcutaneous transposition of the spleen allows hepatic ischemia to be applied without affecting other tissues. Using this mouse model we investigated the relationship between the length of ischemic periods in the liver and subsequent liver function; furthermore, we assayed the activation of c‐Jun N‐terminal kinase (JNK) during ischemia and reperfusion. Although prior to this study only the activated form of JNK was known to be translocated to the nucleus, we found that JNK translocates to the nucleus during ischemia without activation and is then activated during reperfusion. These results suggest a novel mechanism of JNK activation.
Son1p is a component of the 26S proteasome of the yeast Saccharomyces cerevisiae
Authors: Fujimuro M , Tanaka K , Yokosawa H , Toh-e A
Published: July 2002

A son1 mutant was isolated as a mutant showing synthetic lethality with nin1‐1 which is defective in the p31 component of the regulatory subunit of the yeast 26S proteasome. son1Δ showed a synthetic effect with sen3Δ and sun1Δ, both components of the 26S proteasome, and with cdc28‐1N. The 26S proteasome was partially purified from the wild type yeast. The FPLC fractions were analyzed by Western blotting using anti‐Son1p antibody and antibodies against some authentic subunits of the 26S proteasome, and we found that Son1p co‐migrated with components of the 26S proteasome. The 26S proteasome containing fraction was immunoprecipitated with anti‐Son1p antibody. The resultant precipitate contained Nin1p, Sun1p, TBP1, and the 20S proteasome. Combining genetic and biochemical results together, we concluded that Son1p is a component of the yeast 26S proteasome.
RETRACTED: GlcNAc‐terminated glycodendrimers form defined precipitates with the soluble dimeric receptor of rat natural killer cells, sNKR‐P1A
Authors: Bezouška Karel , Křen Vladimír , Kieburg Christoffer , Lindhorst Thisbe K
Published: July 2002

Link to the institute's press release: http://www.biomed.cas.cz/mbu/doc/VyjadreniEK.PDF
ATP‐dependent copper transport by the Menkes protein in membrane vesicles isolated from cultured Chinese hamster ovary cells
Authors: Voskoboinik Ilia , Brooks Hilary , Smith Suzanne , Shen Peiyan , Camakaris James
Published: July 2002

The Menkes (MNK) protein is a vital component of copper homeostasis in mammalian cells. In this paper we provide the first biochemical evidence that the MNK protein functions as a copper‐translocating P‐type ATPase in mammalian cells. The enzyme activity in membrane vesicles prepared from Chinese hamster ovary cells overexpressing MNK was ATP‐dependent, correlated with the amount of MNK and followed Michaelis‐Menten kinetics with respect to copper. The copper transport was observed only under reducing conditions suggesting MNK transports Cu(I). This study opens the way to detailed structure‐function studies and assessment of functional MNK derived from patients with Menkes disease.
Proprotein cleavage of E‐cadherin by furin in baculovirus over‐expression system: potential role of other convertases in mammalian cells
Authors: Posthaus Horst , Dubois Claire M. , Laprise Marie-Hélène , Grondin Francine , Suter Maja M. , Müller Eliane
Published: July 2002

Sequence analysis of the adhesion molecule E‐cadherin had revealed a multibasic motif [4PArg‐Gln‐Lys‐Arg1P], reminiscent of the minimal cleavage signal for furin, the prototype of the proprotein convertase family, and/or other members sharing similar sequence specificity. Mutation of this site was sufficient to abolish processing of E‐cadherin in fibroblasts reinforcing the possibility that proprotein convertases are involved in the maturation of this adhesion molecule. Here we demonstrate that even though furin can efficiently and specifically cleave proE‐cadherin in a baculovirus‐based co‐expression system, the furin‐deficient LoVo cells were found to process endogenous E‐cadherin as efficiently as normal cell lines. This suggests, for the first time, that E‐cadherin is not only a substrate for furin but for other mammalian convertases sharing similar sequence specificity.
Archaeal cold‐adapted proteins: structural and evolutionary analysis of the elongation factor 2 proteins from psychrophilic, mesophilic and thermophilic methanogens1
Authors: Thomas Torsten , Cavicchioli Ricardo
Published: July 2002

To identify structural features important for low temperature activity in archaeal proteins, elongation factor 2 (EF‐2) genes (aef2) were sequenced from psychrophilic, mesophilic and thermophilic methanogens. Scatter plots were used to compare evolutionary distances for EF‐2 amino acid sequences vs. 16S‐rRNA sequences from methanogens growing at diverse temperatures. The absence of a temperature bias for the rate of protein vs. nucleic acid evolution demonstrated the importance of comparing closely related proteins in order to identify changes indicative of thermal adaptation. Three‐dimensional modelling of the new EF‐2 sequences enabled the identification of amino acid residues that may be important for conferring low temperature activity and included greater structural flexibility produced by fewer salt bridges, less packed hydrophobic cores and the reduction of proline residues in loop structures.
The assumption that nitric oxide inhibits mitochondrial ATP synthesis is correct
Authors: Brookes Paul S. , Bolaños Juan P. , Heales Simon J.R.
Published: July 2002

The assumption that reversible inhibition of mitochondrial respiration by nitric oxide (NO⋅) represents inhibition of ATP synthesis is unproven. NO⋅ could theoretically inhibit the oxygen consumption with continued ATP synthesis, by acting as an electron acceptor from cytochrome c or as a terminal electron acceptor in stead of oxygen. We report here that NO⋅ does reversibly inhibit brain mitochondrial ATP synthesis with a time course similar to its inhibition of respiration. Whilst such inhibition was largely reversible, there appeared to be a small irreversible component which may theoretically be due to peroxynitrite formation, i.e. as a result of the reaction between NO⋅ and superoxide, generated by the mitochondrial respiratory chain.
Quality control: from molecules to organelles
Authors: Luzikov Valentin N
Published: July 2002

There is a vast body of literature on the quality control of protein folding and assembly into multisubunit complexes. Such control takes place everywhere in the cell. The correcting mechanisms involve cytosolic and organellar proteases; the result of such control is individual molecules with proper structure and individual complexes both with proper stoichiometry and proper structure. Obviously, the formation of organelles as such requires some additional criteria of correctness and some new mechanisms of their implementation. It is proposed in this article that the ability to carry out an integral (key) function may serve as a criterion of correct organelle assembly and that autophagy can be accepted as a mechanism eliminating the assembly mistakes.
A combinatorial approach to producing sterically stabilized (Stealth) immunoliposomal drugs
Authors: Ishida Tatsuhiro , Iden Debbie L , Allen Theresa M
Published: July 2002

We have developed a method for producing sterically stabilized immunoliposomal drugs (SIL) readily applicable to a ‘mix and match’ combinatorial approach for the simple manufacture of a variety of ligand‐targeted liposomal drugs. Ligands coupled to the terminus of polyethylene glycol (PEG) in micelles formed from PEG‐lipid derivatives (mPEG2000‐DSPE) could be transferred into preformed, drug‐containing liposomes from the micelles in a temperature‐ and time‐dependent manner. Antibody densities up to 100 μg antibody/μmol of phospholipid, and up to 3 mol% of mPEG2000‐DSPE, could be simultaneously transferred from the ligand‐coupled micelles into the liposomal outer monolayer with negligible drug leakage from liposomes during transfer and good stability in human plasma. Transfer of anti‐CD19 into SIL resulted in a three‐fold increase in binding of these liposomes to CD19+ human B cell lymphoma cells.
Environmental influence on reproductive health
Authors: Bhatt R.V
Published: July 2002

A rise in industrialization and the consequent environmental pollution, an increase in the use of synthetic chemicals and repeated exposure to hazardous compounds at the workplace and at home adversely affects reproductive health. Biohazardous compounds, some of which act as endocrine disrupters, are being increasingly implicated in infertility, menstrual irregularities, spontaneous abortions, birth defects, endometriosis and breast cancer. In some cases, women are at a greater risk than men, especially with the rise in environmental estrogens. Only a fraction of these chemicals have been adequately examined for toxicity and for synergistic effects due to multiple exposures. There is a need for a greater awareness and vigilance of the effects of environmental pollution on reproductive health.
Pregnancy complicated by pre‐eclampsia–eclampsia with HELLP syndrome
Authors: Vigil‐De Gracia P.
Published: July 2002

Objective: To determine the incidence of, and assess the relationship between liver enzymes and platelet counts with the severity of HELLP (hemolysis elevated liver enzymes and low platelet count) syndrome, and describe incidences of serious maternal complications. Materials and methods: Retrospective descriptive study of patients with pre‐eclampsia–eclampsia complicated by HELLP syndrome that occurred over a 3‐year period in Panama. The primary outcome included: platelet count; serum aspartate aminotransferase; serum alanine aminotransferase; symptoms and complications among class 1, 2, and 3 HELLP. Results: There were 558 pregnancies complicated by severe pre‐eclampsia and 26 by eclampsia. The incidence of HELLP syndrome among women with severe pre‐eclampsia in our population was 12% and among women with eclampsia was 34.6%, (P<0.0008); with a total incidence of 16%. Epigastric pain, visual symptoms and hematuria increased with the severity of HELLP syndrome. Hematuria was the fourth symptom, but was significantly (P=0.002) associated with class 1 HELLP. There were significant differences in the platelet count, and liver enzymes among the classes of HELLP syndrome. Abruptio placentae, acute renal failure and disseminated intravascular coagulation were the most frequent maternal complications. There were two maternal deaths. Conclusions: This study supports the theory that HELLP syndrome is associated with increased maternal morbidity and mortality. Our data suggest that certain subgroups of patients with class 1 HELLP syndrome (‘classic or true HELLP’) are at increased risk for serious maternal complications, including those with: platelet counts below 50 000/μl; lactic dehydrogenase≥2000 IU/l; aspartate aminotranferase≥500 IU/l; alanine aminotransferase≥300 IU/l; and hematuria.
Nerve growth factor brain concentration and stress: changes depend on type of stressor and age
Authors: Scaccianoce Sergio , Lombardo Katia , Angelucci Luciano
Published: July 2002

In the relationship between the hippocampus and the hypothalamo–pituitary–adrenocortical axis, trophic and tropic actions of nerve growth factor are involved in parallel with those on the cholinergic nuclei of the basal forebrain. Here, we report the changes produced by stress activation of the hypothalamo–pituitary–adrenocortical axis on hippocampal and basal forebrain nerve growth factor concentrations in 3‐month‐old male Wistar rats. The stressors used were: restraint; cold exposure; foot‐shock; and rotatory platform. Restraint stress tended to reduce nerve growth factor in the hippocampus and reduced it significantly in the basal forebrain. Nerve growth factor levels in the hippocampus were not modified by cold exposure. However, a single unrepeated exposure significantly increased nerve growth factor in the basal forebrain. Both acute and chronic foot‐shock reduced nerve growth factor in the hippocampus, leaving the levels in the basal forebrain unmodified. Acute but not chronic rotatory platform reduced nerve growth factor in the hippocampus, while showing a tendency, more pronounced after chronic application, toward an increase in the basal forebrain. Since with aging both activity of the hypothalamus–pituitary–adrenal axis and nerve growth factor trophic and tropic functions change, we studied the effect of restraint and cold stress in the 24‐month‐old male rat. The variations in nerve growth factor concentrations in the basal forebrain following stress activation are no longer present in the aged rat. The picture that emerges is indicative of a complex relationship between stress and nerve growth factor which is influenced by the kind of stressor and by age. Lack of uniformity in the effects produced by different stressors might reside in different qualitative and/or quantitative degree of involvement of neurotransmitters and/or neurohormones for each of them.
Effects of theft stereotype on bystander recall, interpretation, and punishment for male and female juvenile thieves
Authors: Shapiro Lauren R.
Published: May 2021

Sex disparities in the incidence‐arrest statistics for juvenile thieves may stem from preconceived stereotypes impacting bystanders' social‐cognitive processing of a bicycle theft. After reading vignettes describing a bicycle theft, bystanders' reliance on male‐as‐juvenile‐thief stereotypes enhanced their recall of crime and appearance features for the male thief and in their interpretation of his intimidation of a child victim. Bystander sex also affected the results by enhancing appearance recall for the same sex thief. Women interpreted the intentions of the adolescent thieves as stealing, whereas men interpreted the intentions as borrowing. Bystanders endorsed the decision for the father to bring the stolen bicycle to the attention of the police, especially when the victim was a girl, and agreed the police should be involved. The bystanders would be credible witnesses as they could provide the actus reus and mens rea to support a case of larceny‐theft and describe the thief.
Lipid Metabolism in Ferroptosis
Authors: Lin Zhi , Liu Jiao , Kang Rui , Yang Minghua , Tang Daolin
Published: May 2021

Lipid metabolism is a complex biochemical process that participates in the regulation of cell survival and death. Ferroptosis is a form of iron‐dependent regulated cell death driven by abnormal lipid metabolism, leading to lipid peroxidation and subsequent plasma membrane rupture. A variety of antioxidant systems and membrane repair pathways can diminish oxidative damage, enabling survival and growth in response to ferroptotic signals. Such impairment of ferroptosis machinery is implicated in various pathological conditions and diseases, especially cancer and tissue damage. It is discussed here how lipid metabolism pathways, including lipid synthesis, degradation, storage, transformation, and utilization, modulate ferroptosis sensitivity or tolerance in different models, especially cancer.
Benzylammonium‐Mediated Formamidinium Lead Iodide Perovskite Phase Stabilization for Photovoltaics
Authors: Alanazi Anwar Q. , Almalki Masaud H. , Mishra Aditya , Kubicki Dominik J. , Wang Zaiwei , Merten Lena , Eickemeyer Felix T. , Zhang Hong , Ren Dan , Alyamani Ahmed Y. , Albrithen Hamad , Albadri Abdulrahman , Alotaibi Mohammad Hayal , Hinderhofer Alexander , Zakeeruddin Shaik M. , Schreiber Frank , Hagfeldt Anders , Emsley Lyndon , Milić Jovana V. , Graetzel Michael
Published: May 2021

There is an ongoing surge of interest in the use of formamidinium (FA) lead iodide perovskites in photovoltaics due to their exceptional optoelectronic properties. However, thermodynamic instability of the desired cubic perovskite (α‐FAPbI3) phase at ambient conditions leads to the formation of a yellow non‐perovskite (δ‐FAPbI3) phase that compromises its utility. A stable α‐FAPbI3 perovskite phase is achieved by employing benzylammonium iodide (BzI) and the microscopic structure is elucidated by using solid‐state NMR spectroscopy and X‐ray scattering measurements. Perovskite solar cells based on the FAPbI3(BzI)0.25 composition achieve power conversion efficiencies exceeding 20%, which is accompanied by enhanced shelf‐life and operational stability, maintaining 80% of the performance after one year at ambient conditions.
Triboelectric Nanogenerators for Therapeutic Electrical Stimulation
Authors: Conta Giorgio , Libanori Alberto , Tat Trinny , Chen Guorui , Chen Jun
Published: May 2021

Current solutions developed for the purpose of in and on body (IOB) electrical stimulation (ES) lack autonomous qualities necessary for comfortable, practical, and self‐dependent use. Consequently, recent focus has been placed on developing self‐powered IOB therapeutic devices capable of generating therapeutic ES for human use. With the recent invention of the triboelectric nanogenerator (TENG), harnessing passive human biomechanical energy to develop self‐powered systems has allowed for the introduction of novel therapeutic ES solutions. TENGs are especially effective at providing ES for IOB therapeutic systems given their bioconformability, low cost, simple manufacturability, and self‐powering capabilities. Due to the key role of naturally induced electrical signals in many physiological functions, TENG‐induced ES holds promise to provide a novel paradigm in therapeutic interventions. The aim here is to detail research on IOB TENG devices applied for ES‐based therapy in the fields of regenerative medicine, neurology, rehabilitation, and pharmaceutical engineering. Furthermore, considering TENG‐produced ES can be measured for sensing applications, this technology is paving the way to provide a fully autonomous personalized healthcare system, capable of IOB energy generation, sensing, and therapeutic intervention. Considering these grounds, it seems highly relevant to review TENG‐ES research and applications, as they could constitute the foundation and future of personalized healthcare.
Magnetic Properties of Efficient Catalysts Based on La‐Doped Ceria‐Supported Nickel Nanoparticles for rWGS Reaction. Influence of Ni Loading
Authors: Alvarez‐Galvan Consuelo , Martínez Jose Luis , Capel‐Sanchez Maricarmen , Pascual Laura , Alonso Jose Antonio
Published: May 2021

The influence of Ni loading on Ce0.9La0.1O1.95‐supported Ni catalysts for CO2 reduction with hydrogen (reverse water gas shift reaction) is studied. The samples are prepared by solution combustion synthesis (SCS), leading to materials with high thermal resistance, purity, and crystallinity, consisting of metallic nickel nanoparticles supported on La‐doped ceria. The study of the ferromagnetic Curie temperature (TC) and magnetization cycles suggest that the Ni nanoparticles are superparamagnetic, exhibiting magnetic order at room temperature, with TC strongly dependent on the particle size; this spans from 1.9, up to 80 nm. The structural study from synchrotron X‐ray diffraction data and Raman spectroscopy clearly show the presence of oxygen vacancies in the fluorite crystal structure of the Ce0.9La0.1O2−δ matrix, which increase in the spent catalysts by forming a greater proportion of Ce3+ compared with their fresh counterparts. This is confirmed from the Raman spectra, showing an increase in the relative intensity of the band placed between 520 and 610 cm−1. All the catalysts show very high reaction rate per unit mass of catalyst; the CO2 conversion after 6 h for the catalyst with 10% Ni molar (Ni0.1/Ce0.9La0.1) is 57% (2.4 moles CO·h−1·g catalyst−1), very close to the thermodynamic equilibrium (59.3%).
A New Approach to Stable Cationic and Anionic Redox Activity in O3‐Layered Cathode for Sodium‐Ion Batteries
Authors: Voronina Natalia , Yaqoob Najma , Kim Hee Jae , Lee Kug‐Seung , Lim Hee‐Dae , Jung Hun‐Gi , Guillon Olivier , Kaghazchi Payam , Myung Seung‐Taek
Published: May 2021

Herein, stable cationic and anionic redox in an O3‐type layered Na[Ni2/3Ru1/3]O2 cathode for sodium‐ion batteries (SIBs) is revealed. Density functional theory (DFT) calculation shows that the electron density features change in density of state with mixing of delocalized valence states as well as localized deeper energy states of O(p), Ni(d), and Ru(d) for the highly desodiated Na1−x[Ni2/3Ru1/3]O2 electrode, revealing the covalent characteristic of the transition metal (TM)O and TMTM bonds in the charged system. These properties lead to cycling stability for 200 cycles, with ≈79% of the capacity retained at a rate of 1C (210 mA g−1). Operando X‐ray diffraction, X‐ray absorption spectroscopy, and DFT calculations reveal the reversible electrochemical activity of the Ni2+/Ni3+ and O2−/O1− redox reactions, which are sustainable throughout the cycles. In addition, no loss of oxygen from the crystal structure of Na[Ni2/3Ru1/3]O2 occurs according to differential electrochemical mass spectrometry. The findings provide additional insight into the complex mechanism of the oxygen redox activity of high‐capacity O3‐type cathode materials for SIBs, encouraging further studies on their development.
Toward Low‐Temperature Lithium Batteries: Advances and Prospects of Unconventional Electrolytes
Authors: Zhang Jinning , Zhang Jianjun , Liu Tingting , Wu Han , Tian Songwei , Zhou Lixue , Zhang Botao , Cui Guanglei
Published: May 2021

Lithium batteries have been widely used in various fields such as portable electronic devices, electric vehicles, and grid storages devices. However, the low temperature‐tolerant performances (−70 to 0 °C) of lithium batteries are still mainly hampered by low ionic conductivity of bulk electrolyte and interfacial issues. In general, there are four threats in developing low‐temperature lithium batteries when using traditional carbonate‐based electrolytes: 1) low ionic conductivity of bulk electrolyte, 2) increased resistance of solid electrolyte interphase (SEI), 3) sluggish kinetics of charge transfer, 4) slow Li diffusion throughout bulk electrodes. Meanwhile, conventional electrolytes have been close to the upper limit of optimum low‐temperature performance owing to their intrinsic molecular structural properties. As a result, it is urgent to design unconventional electrolytes with lower melting point and higher ionic conductivity. Herein, the recent key advances in regard to unconventional electrolytes including fluorinated ester, ethyl acetate, gamma‐butyrolactone, liquefied gas, ether, plastic crystal, and aqueous electrolytes are overviewed. Solvation structure modification and SEI optimization of unconventional electrolytes for low‐temperature lithium batteries are focused. Finally, aiming at the deficiencies in current understanding, the inherent limitations and envision the future prospects of low‐temperature lithium batteries are explored.
Electrospun nanofibers fromferrocene‐containingmultiblock copolymers prepared viaRAFTpolymerization withF127modified precursor
Authors: Zhou Yingxue , Ma Jianhua , Gao Chaofeng , Fan Xiaodong , Lashari Najeeb ur Rehman , Li Junpeng
Published: May 2021

Electrospun nanofibers from copolymers composed of ferrocene side chains and PEO100‐PPO65‐PEO100(F127) were fabricated in chloroform andN,N–dimethyl formamide solutions (V/V = 95:5) at room temperature. Ferrocene‐containing multiblock copolymers (PFcMAn‐F127‐PFcMAn) were synthesized through reversible addition‐fragmentation chain transfer polymerization using s‐1‐dodecyl‐s''‐ (α, α'‐dimethyl‐α''‐acetic acid) trithiocarbonate (DDMAT) modified F127 with 2‐ (methacryloyloxy) ethyl ferrocencarboxylate (FcMA). The structures of as‐obtained chemicals were characterized by FTIR,1H NMR, and13C NMR. Additionally, the block copolymers molecular weight and polydispersity were measured using gel permeation chromatography. The electrochemical responsiveness of the polymers was investigated using cyclic voltammetry as well as the thermal stabilities of polymers and precursors were tested through DSC and TGA. The morphologies of electrospun fibers were observed through field emission scanning electronic spectroscopy and a fibrous diameter of 300–1100 nm was obtained. The results indicated that the suitable molecular weight of ferrocene ‐containing polymer would be processed in nanofibrous.
Effect of the spray drying conditions on the physicochemical and structural characteristics and the stability of chia oil microparticles
Authors: Fernandes Sibele Santos , Greque Leonardo , Santos Maria de Fatima C. , de Novais Leice M. R. , D'Oca Caroline D. R. M. , Prentice Carlos , Salas‐Mellado Myriam de las M.
Published: May 2021

Chia oil has a high content of linolenic and linoleic acids, which are essential for the human body. However, their high degree of unsaturation (double bonds) makes the oil very susceptible to oxidation. In this context, the use of spray drying can be useful strategy to minimize the oxidation of this oil. Thus, the aim was to assess the effects of inlet temperature and feed rate conditions involved in the spray drying process on the physicochemical and morphological characteristics, and stability of the chia oil microparticles with maltodextrin and GA. The microparticles were obtained with a yield of 50%, encapsulation efficiency greater than 87%, low‐moisture content, and mean particle sizes ranging from 3.01 to 4.11 μm. The thermal evaluation and storage evidenced an increase in stability. The 1H HR‐MAS NMR technique showed that the microparticles maintained the characteristic fatty acid profile of chia oil and seeds. Results indicate that the microencapsulation methodology was suitable for preparing microparticles containing chia oil.
Synthesis of succinic acid‐based polyamide through direct solid‐state polymerization method: Avoiding cyclization of succinic acid
Authors: Li Haijie , Shang Yuting , Huang Wenrui , Xue Bingfeng , Zhang Xiaomeng , Cui Zhe , Fu Peng , Pang Xinchang , Zhao Qingxiang , Liu Minying
Published: May 2021

Succinic acid is an important synthetic monomer but it is difficult to use it as a precursor for synthesizing high molecular weight polyamide, due to its tendency to perform intra‐cyclization reaction at high temperature. In order to solve this problem, in this paper, the direct solid‐state polymerization (DSSP) method with the initial reactant, nylon salt which was composed of 1, 5‐diaminopentane, succinic acid, and terephthalic acid, was applied to synthesize the bio‐based copolyamide PA 5T/54. In comparison with the conventional melting polymerization method, the DSSP method can prevent the cyclization reaction of succinic acid effectively due to the lower reacting temperature as well as the restriction effect of the nylon salt. As a result, the product fabricated by DSSP method has higher molecular weight and much lighter color from red to white. Therefore, the DSSP method is advantageous for the synthesis of the polymers or copolymers composed of the succinic acid as the monomer. Furthermore, the polymerization mechanism proposed in this work can serve as a guidance for the design of the molecular structure and control of the polymerization process.
Centrifugally spun starch/polyvinyl alcohol ultrafine fibrous membrane as environmentally‐friendly disposable nonwoven
Authors: Li Xianglong , Liu Jing , Lu Yishen , Hou Teng , Zhou Jing , Wang Antuo , Zhang Xianggui , Yang Bin
Published: May 2021

We developed a new environmentally‐friendly disposable nonwoven based on centrifugally spun ST/PVA ultrafine fibrous membrane in this research. The effects of ST/PVA ratio as well as formic acid post‐treatment on thermal properties, tensile strength, and disposability of fibrous membranes were studied. To observe the morphology and chemical structures changing of fibers during fabrication and post‐treatment, the obtained fibers were characterized by scanning electron microscopy, x‐ray diffraction, and Fourier transform infrared spectroscopy. The fibrous membranes with uniform fiber diameters and excellent disposability properties were formed. The ST/PVA ratio of fibers was optimized according to the disposability and tensile strength of the fibrous membranes. Disintegration of untreated and post‐treatment fibrous membrane with ST/PVA ratio of 3/1 was over 80% and 40%, respectively, and the tensile strength was improved over two times comparing with pure starch fibrous membrane.
White Light Luminescence from a Homo‐conjugated Molecule with Thermally Activated Delayed Fluorescence
Authors: Zhou Ying , Li Yao , Zhang Rong , Zhao Dahui , Yan Qifan
Published: May 2021

Luminophores with tunable emission properties are appealing due to various applications. Among those properties, thermally activated delayed fluorescence (TADF) has been attracting enormous research interests. Herein, we synthesized a 9,9’‐spirobifluorene based homo‐conjugated molecule 1, which connects a diphenylamino moiety as electron donor and a naphthalimide group as electron acceptor via 2,2’‐positions of spirofluorene. Compound 1 displays dual emission behaviour with both blue and orange fluorescence. The one orange fluorescence around 555 nmshows sensitivity to oxygen and a prolonged lifetime of 284 ns in degassed toluene. Such characteristics imply TADF nature for this emission from a charge‐transfer excited state. The other emission at 440 nm with blue colour displayed resistance to oxygen quenching and a normal fluorescence lifetime of 1.5 ns. Compared with control molecule, this emission band is assigned as conventional fluorescence from a localized excited state. In addition, dual emission property allows molecule 1 to be modulated to emit white photoluminescence in thin film with a CIE color coordinate of (0.25, 0.33).
Transient ammonia stress on Chinese hamster ovary (CHO) cells yield alterations to alanine metabolism and IgG glycosylation profiles
Authors: Synoground Benjamin F. , McGraw Claire E. , Elliott Kathryn S. , Leuze Christina , Roth Jada R. , Harcum Sarah W. , Sandoval Nicholas R.
Published: May 2021

Background

Ammonia concentrations typically increase during mammalian cell cultures, mainly due to glutamine and other amino acid consumption. An early ammonia stress indicator is a metabolic shift with respect to alanine. To determine the underlying mechanisms of this metabolic shift, a Chinese hamster ovary (CHO) cell line with two distinct ages (standard and young) was cultured in parallel fed‐batch bioreactors with 0 mM or 10 mM ammonia added at 12 h. Reduced viable cell densities were observed for the stressed cells, while viability was not significantly affected. The stressed cultures had higher alanine, lactate, and glutamate accumulation. Interestingly, the ammonia concentrations were similar by Day 8.5 for all cultures. We hypothesized the ammonia was converted to alanine as a coping mechanism. Interestingly, no significant differences were observed for metabolite profiles due to cell age. Glycosylation analysis showed the ammonia stress reduced galactosylation, sialylation, and fucosylation. Transcriptome analysis of the standard‐aged cultures indicated the ammonia stress had a limited impact on the transcriptome, where few of the significant changes were directly related metabolite or glycosylation reactions. These results indicate that mechanisms used to alleviate ammonia stress are most likely controlled post‐transcriptionally, and this is where future research should focus.
Inflammation can increase hepcidin in HFE‐hereditary hemochromatosis
Authors: Moris Wenke , Verhaegh Pauline L. M. , Masclee Ad A. M. , Swinkels Dorine W. , Laarakkers Coby M. , Koek Ger H. , van Deursen Cees Th. B. M.
Published: May 2021

We present a p.C282Y homozygous patient with high hepcidin levels and normal iron parameters during systemic inflammation. This suggests that in the absence of a proper functioning HFE, resulting in blockage of the BMP/SMAD pathway, the innate low hepcidin concentration can be upregulated by inflammation, probably via the JAK/STAT3 pathway.
Mixing Performance of Baffles in Shear‐Thinning Fluids
Authors: Furukawa Haruki , Mizuno Yoshito , Kato Yoshihito
Published: May 2021

The mixing performance of baffles placed with a clearance between them and the mixing vessel wall was investigated in a shear‐thinning fluid, and decolorization experiments were conducted to observe the mixing pattern under no‐baffle, standard baffle, and inner‐baffle conditions. Velocity fields were obtained by particle image velocimetry to clarify the mixing mechanism in the fluid. No isolated mixing region was seen under the inner‐baffle condition, and this condition promoted homogeneous mixing. The velocity profile clarified that the inner baffle prevented secondary circulation flow from forming an isolated mixing region and, thus, promoted homogeneous mixing in the fluid. An inner baffle with a small impeller can obtain homogeneous mixing in shear‐thinning fluids.
Rapid real‐world data analysis of patients with cancer, with and without COVID‐19, across distinct health systems
Authors: Hwang Clara , Izano Monika A. , Thompson Michael A. , Gadgeel Shirish M. , Weese James L. , Mikkelsen Tom , Schrag Andrew , Teka Mahder , Walters Sheetal , Wolf Frank M. , Hirsch Jonathan , Rivera Donna R. , Kluetz Paul G. , Singh Harpreet , Brown Thomas D.
Published: May 2021

Background

The understanding of the impact of COVID‐19 in patients with cancer is evolving, with need for rapid analysis.

Aims

This study aims to compare the clinical and demographic characteristics of patients with cancer (with and without COVID‐19) and characterize the clinical outcomes of patients with COVID‐19 and cancer.

Methods and Results

Real‐world data (RWD) from two health systems were used to identify 146 702 adults diagnosed with cancer between 2015 and 2020; 1267 COVID‐19 cases were identified between February 1 and July 30, 2020. Demographic, clinical, and socioeconomic characteristics were extracted. Incidence of all‐cause mortality, hospitalizations, and invasive respiratory support was assessed between February 1 and August 14, 2020. Among patients with cancer, patients with COVID‐19 were more likely to be Non‐Hispanic black (NHB), have active cancer, have comorbidities, and/or live in zip codes with median household income <$30 000. Patients with COVID‐19 living in lower‐income areas and NHB patients were at greatest risk for hospitalization from pneumonia, fluid and electrolyte disorders, cough, respiratory failure, and acute renal failure and were more likely to receive hydroxychloroquine. All‐cause mortality, hospital admission, and invasive respiratory support were more frequent among patients with cancer and COVID‐19. Male sex, increasing age, living in zip codes with median household income <$30 000, history of pulmonary circulation disorders, and recent treatment with immune checkpoint inhibitors or chemotherapy were associated with greater odds of all‐cause mortality in multivariable logistic regression models.

Conclusion

RWD can be rapidly leveraged to understand urgent healthcare challenges. Patients with cancer are more vulnerable to COVID‐19 effects, especially in the setting of active cancer and comorbidities, with additional risk observed in NHB patients and those living in zip codes with median household income <$30 000.
Tatt‐BiLSTM: Web service classification with topical attention‐based BiLSTM
Authors: Kang Guosheng , Xiao Yong , Liu Jianxun , Cao Yingcheng , Cao Buqing , Zhang Xiangping , Ding Linghang
Published: May 2021

With the rapid growth of the number of Web services on the Internet, how to classify Web services correctly and efficiently become particularly important in service management tasks, such as service discovery, service selection, service ranking, and service recommendation. Existing functionality‐based service classification techniques have some drawbacks: (1) the keyword order and context information are not considered; (2) the embedding features of keywords are taken as equal importance to learn the classification model; (3) the topic number is hard to determine manually. Due to these drawbacks, the accuracy of service classification needs to be improved further. At present, deep learning techniques show the strong power in modeling complex and nonlinear function relationship. Thus, to address the problems above, this paper exploits attention mechanism to combine the local implicit state vector of Bidirectional Long Short‐Term Memory Network (BiLSTM) and the global hierarchical Dirichlet process (HDP) topic vector, and proposes a Web service classification approach with topical attention‐based BiLSTM. Specifically, BiLSTM is used to automatically learn the keyword feature representations of Web services. Then, the topic vectors of Web service documents are obtained with HDP by offline training, and topic attention mechanism is adopted to strengthen the feature representation by discriminating the importance or weight of different keywords in Web service documents. Finally, the enhanced Web service feature representation is used as the input of a softmax neural network layer to perform the classification prediction for Web services. Extensive experiments are conducted to validate the effectiveness of the proposed approach.
Spanking found to increase fear response in children's brains
Authors: Knopf Alison
Published: May 2021

Not surprisingly, spanking children — done by 50% of parents in the United States — elevates fearfulness in children. Researchers writing in the March/April issue of Child Development have now found proof of the connection in the elevated neural response in these children's brains to any possible threat. The study was funded by the National Institute of Mental Health.
Advocates concerned about pandemic‐era alcohol marketing and youth
Authors: Knopf Alison
Published: May 2021

The National Institute on Alcohol Abuse and Alcoholism (NIAAA) has a page devoted to updates on state alcohol policies adopted in response to the pandemic, but it has no information on the effects of these policies, which include expanded home delivery, curbside pickup, to‐go cocktails, and more. The policies were meant to limit virus exposure.
Perceived social support and discrimination and oral health behaviors in adolescents
Authors: Amin Maryam , Schumacher Christian , Bohlouli Babak
Published: May 2021

Objectives

The aims of this study were to examine the associations between perceived social support and oral health behaviors among adolescents and if this perception had a protective effect against the influence of perceived racial discrimination on oral health behaviors in this population.

Material and methods

Participants of this cross‐sectional study were adolescents aged 12–18 years recruited from University dental clinic. They completed a questionnaire comprising three sections: demographics (14 items), oral health behaviors (6 items), and validated Personal Resource Questionnaire (25 items). Perceived discrimination was evaluated by a question asking if the adolescent had ever experienced discrimination based on their race.

Results

Of 252 participants, mean (SD) age of 14 (1.8) years, 60% were girls, 56% were self‐identified as White, and 81% were born in Canada. Discrimination was reported by 21%. Frequency of toothbrushing and self‐rated oral health were significantly associated with increased levels of perceived social support. Sugar consumption was significantly different for participants with and without perceived racial discrimination (p‐value = 0.002). Perceived social support did not act as a buffer against perceived racial discrimination for sugar consumption (OR = 1.00; 95% CI: 0.98–1.01).

Conclusions

Adolescents' perceived social support affected some aspects of their oral health but did not moderate the influence of perceived racial discrimination.
Non‐linear coherent structures in multi‐species dusty plasma
Authors: Shome Arpita , Pramanik Sourav
Published: May 2021

In a fluid description, theoretical investigation has been carried out to explore how the presence of two‐temperature electron fluids (hot and cold) influences the characters of dust acoustic solitary waves, double layers, bipolar structures, etc. in a multi‐component dusty plasma, composed of isothermal electrons and ions, along with the negatively charged, cold dusts. A reductive perturbation method is used to derive the well‐known Korteweg‐de Vries (KdV) equation, which describes the basic nature of the dust acoustic solitary waves. Two values of critical ion density exist, which distinguish the regions of compressive and rarefactive solitary waves in parametric space. The critical points directly depend on the densities and temperatures of the electron fluids. With increasing temperature of hot electron fluid, one of the two critical ion densities decreases, and the other one increases. Ultimately, they merge with each other when the temperature of hot electrons reaches a particular value. The amplitude of the dust acoustic soliton gets modified due to the presence of two‐temperature electron fluids. The study is extended further by deriving modified KdV and Gardner equations at the vicinity of critical points. The Gardner equation reveals the existence of double layer and bipolar structures. In these processes, the effects higher‐order nonlinearities are incorporated methodically, by implementing appropriate stretching of the coordinates. Sagdeev's pseudopotential analysis shows that large amplitude rarefactive solitary waves only exist when the corresponding Mach number (M) lies within 1 < M < Mc. The upper bound, Mc increases with the hot electron temperature and cold electron density. The results presented in this investigation are believed to be applicable in the laboratory and astrophysical plasmas.
Thyroid cancer, recent advances in diagnosis and therapy
Authors: Nabhan Fadi , Dedhia Priya H. , Ringel Matthew D.
Published: May 2021

Over the past several decades, the approach to the diagnosis and management of patients with follicular cell‐derived thyroid cancer has evolved based on improved classification of patients better matching clinical outcomes, as well as advances in imaging, laboratory, molecular technologies and knowledge. While thyroid surgery, radioactive iodine therapy and TSH suppression remain the mainstays of treatment, this expansion of knowledge has enabled de‐escalation of therapy for individuals diagnosed with low‐risk well‐differentiated thyroid cancer; better definition of treatment choices for patients with more aggressive disease; and improved ability to optimize treatments for patients with persistent and/or progressive disease. Most recently, the advancement of knowledge regarding the molecular aspects of thyroid cancer has improved thyroid cancer diagnosis and has enabled individualized therapeutic options for selected patients with the most aggressive forms of the disease. Guidelines from multiple societies across the world reflect these changes, which focus on taking a more individualized approach to clinical management. In this review, we discuss the current more personalized approach to patients with follicular cell‐derived thyroid cancer and point toward areas of future research still needed in the field.
A computed tomography signs quantization analysis method for pulmonary nodules malignancy grading
Authors: Chen Hao , Xia Yu , Duan Hongbai , Ban Duo , Yang Qing , Qiang Yongqian
Published: May 2021

In order to improve the accuracy of pulmonary nodules malignancy grading, we propose a method to implement quantitative analysis for lung nodules using computed tomography (CT) signs. Firstly, we construct feature sets of CT signs by combing the radiomics features with the higher‐order features extracted from a convolutional neural network. Secondly, on the basis of the mixed feature set, an evolutionary ensemble learning mechanism is used to generate a classifier to get the quantitative scores for seven lung nodule CT signs. Finally, the scores of seven CT signs are input into a multiclassifier optimized by the differential evolution algorithm to acquire the grade of malignancy. In the experimental study, 2000 lung nodule samples from the LIDC‐IDRI dataset were used to train and test the evolutionary ensemble learner and malignancy classifier. The results show that the recognition accuracy of seven CT signs can reach more than 0.964. Comparison with many typical algorithms, the proposed method not only gets higher accuracy in pulmonary nodules malignancy grading but also can make the result more interpretable.