bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Nanocrystalline Cores for EMI Suppression in Cables
Authors: Suarez Adrian , Victoria Jorge , Torres Jose , A. Martinez Pedro , Amaro Andrea , Martos Julio
Published: March 2021

Electromagnetic interferences (EMI) can cause different kinds of problems in digital and analog systems, leading to malfunctions, system reboots, or even permanent damage to the system if this is not adequately designed or protected. Nowadays, most electronic products are connected to the main power network or are designed to be interconnected with others through cables. These cable interconnections are becoming more difficult due to the rigid restrictions related to the accomplishment of electromagnetic compatibility (EMC) compliance. When the cables of a system represent an EMI source, it cannot pass the conducted or radiated emissions test. A widely used technique to reduce these problems is applying an EMI suppressor such as a sleeve core. This EMI suppressor provides selective attenuation of undesired interference components that the designer may wish to suppress, and it does not significantly affect the intended signal. This contribution focuses on analyzing different nanocrystalline (NC) EMI suppressors’ performance intended for attenuating interferences in cables. Some NC novel samples are characterized and compare to MnZn and NiZn cores to determine this novel material’s effectiveness compared to the conventional ceramic solutions by analyzing samples with different dimensions.
Formulae of Sediment Transport in Steady Flows (Part 1)
Authors: Yang Shu-Qing , AL-Fadhly Ishraq
Published: March 2021

This paper makes an attempt to answer why the observed critical shear stress for incipient sediment motion sometimes deviates from the Shields curve largely, and the influence of vertical velocity is analyzed as one of the reasons. The data with d50 = 0.016 ∼ 29.1 mm from natural streams and laboratory channels were analyzed. These measured data do not always agree with the Shields diagram’s prediction. The reasons responsible for the deviation have been re-examined and it is found that, among many factors, the vertical motion of sediment particles plays a leading role for the invalidity of Shield’s prediction. The positive/negative deviations are associated with the up/downward vertical velocity in decelerating/accelerating flows, and the Shields diagram is valid only when flow is uniform. A new theory for critical shear stress has been developed, a unified critical Shields stress for sediment transport has been established, which is valid to predict the critical shear stress of sediment with/without vertical motion.
Structural and Biological Basis for Proprioception
Authors: A. Vega José , Cobo Juan
Published: March 2021

The proprioception is the sense of positioning and movement. It is mediate by proprioceptors, a small subset of mechanosensory neurons localized in the dorsal root ganglia that convey information about the stretch and tension of muscles, tendons, and joints. These neurons supply of afferent innervation to specialized sensory organs in muscles (muscle spindles) and tendons (Golgi tendon organs). Thereafter, the information originated in the proprioceptors travels throughout two main nerve pathways reaching the central nervous system at the level of the spinal cord and the cerebellum (unconscious) and the cerebral cortex (conscious) for processing. On the other hand, since the stimuli for proprioceptors are mechanical (stretch, tension) proprioception can be regarded as a modality of mechanosensitivity and the putative mechanotransducers proprioceptors begins to be known now. The mechanogated ion channels acid-sensing ion channel 2 (ASIC2), transient receptor potential vanilloid 4 (TRPV4) and PIEZO2 are among candidates. Impairment or poor proprioception is proper of aging and some neurological diseases. Future research should focus on treating these defects. This chapter intends provide a comprehensive update an overview of the anatomical, structural and molecular basis of proprioception as well as of the main causes of proprioception impairment, including aging, and possible treatments.
The Link between Electrical Properties of COVID-19 and Electromagnetic Radiation
Authors: K. Al Sarkhi Awaad
Published: March 2021

The ability of a new vaccine design based on control the intracellular physiological consequences of both the electrical properties and the electromagnetic radiation interactions between a virus and a host cell, which is a method to strengthen immune system develop protection against COVID-19 and new strains. The capacity of COVID-19 to bind to angiotensin-converting enzyme 2 (ACE2) and immune evasion mechanisms are only one of the properties required to stimulate a preventative immune response. In this chapter, a multidimensional new strategy is used to exemplify the empowerment function intracellular and extracellular level information can play in the support of immunogen against COVID-19 pathogens. Besides during this chapter, the nature of electromagnetic radiation is described as a vibrating string based on a string-theory and unification of electromagnetic radiation and gravitational waves by supporting with multiple cites strong evidence. Overall, we demonstrate a new approach to understand the important role of the physiological consequences of the interplay between the immune system and COVID-19 and designing vaccine strategy immunogens that take advantage of that information against COVID-19 and new strains.
Research Trends in the Measurement of Entrepreneurial Education: A Bibliographic Coupling Analysis
Authors: Pertuz Vanessa , Francisco Miranda Luis
Published: March 2021

The literature recognizes the importance of entrepreneurship for the development of students’ job skills and for the socio-economic development of the countries, however, there are mixed results regarding the impact of entrepreneurial education and few validated measures for its evaluation. According to the above, we conducted a bibliometric study related to trends in the measurement of entrepreneurial education. We performed a bibliographic coupling analysis to identify the most relevant publications in this field of study. We identified eleven research trends: (1) Entrepreneurial self-efficacy. (2) Entrepreneurial intention. (3) Entrepreneurship education in higher education institutions. (4) Entrepreneurial skills. (5) Individual and national level determinants of entrepreneurial activity. (6) Drivers of entrepreneurial intention. (7) Assessment instruments of entrepreneurial education impact. (8) University entrepreneurship education program. (9) Social impact of entrepreneurship education. (10) Pedagogies used in entrepreneurship education. (11) Effectiveness of entrepreneurial education. We suggest future lines of research based on the results of our study.
Recent Advances in the Diagnosis and Management of Herpetic Keratitis
Authors: Nowińska Anna
Published: March 2021

The chapter is focused on one of the major cause of keratitis - Herpetic keratitis, its epidemiology, natural course, clinical forms, prognosis, diagnosis and treatment. The estimated global incidence of HSV keratitis is roughly 1,5 million, including 40,000 new cases of each year. Patients are usually affected in the early decades of live, therefore the disease has a severe impact on quality of life and quality of vision in young, productive adults. The author describes the detailed corneal characteristics, provides slit lamp photographs, optical coherence tomography scans and confocal microscopy results of different forms of the HSV keratitis: epithelial, stromal, necrotizing and endothelial. The chapter also discusses recent methods of diagnosis based on PCR testing as well as established and future methods of treatment based on the latest research results.
First records and two new species of sipunculans (Sipuncula) from the Southern Mexican Pacific
Authors: Silva-Morales Itzahí , Gómez-Vásquez Julio D.
Published: March 2021

Sipunculans are a poorly studied group in the Tropical Eastern Pacific. For the Southern Mexican Pacific (SMP) there is only one record of a sipunculan species. The main objective of this work was to determine the species composition of the phylum Sipuncula present in the SMP. The study area covered three Mexican states: Guerrero, Oaxaca and Chiapas; specimens from 28 localities were examined from both intertidal and subtidal zones. A total of 551 specimens were reviewed, from which 11 species were identified. Five of them have previously been recorded in the Tropical Eastern Pacific (TEP): Apionsoma (A.) hespera comb. nov., A. (Edmondsius) pectinatum, Aspidosiphon (A.) elegans, Phascolosoma (P.) puntarenae and Themiste (T.) hennahi; four species are similar to nominal species: Sipunculus (S.) cf. polymyotus, Siphonosoma cf. vastum, Siphonosoma cf. cumanense and Phascolosoma (P.) cf. perlucens; and two new species are described: Aspidosiphon (Paraspidosiphon) cutleri sp. nov. and Aspidosiphon (Paraspidosiphon) pastori sp. nov. A checklist and an identification key for all sipunculan species from the TEP are presented. The checklist includes 53 taxa, 25 of which are questionable records. This work generated 11 new records of sipunculans in the SMP and five new records in the TEP.
Qual o futuro da disciplina Arte a partir da BNCC do Ensino Médio?
Authors: Cruvinel Tiago
Published: March 2021

Este artigo propõe uma discussão sobre a estrutura da BNCC (Base Nacional Comum Curricular) do Ensino Médio, de modo a analisar os conceitos de competência gerais que sustentam o documento, a partir da teoria de Philippe Perrenoud. Este texto é o resultado da pesquisa de pós-doutorado do autor. Trata-se de uma contribuição aos docentes de Arte (Teatro, Dança, Artes Visuais ou Música), no intuito de auxiliá-los na elaboração de um pensamento crítico e estratégico para lidar com a BNCC, que se encontra em vias de implementação em todos os estados brasileiros. Ao final, é proposta uma reflexão sobre o futuro da disciplina Arte no atual contexto político.
Reprogramming of translation in yeast cells impaired for ribosome recycling favors short, efficiently translated mRNAs
Authors: Gaikwad Swati , Ghobakhlou Fardin , Young David J , Visweswaraiah Jyothsna , Zhang Hongen , Hinnebusch Alan G
Published: March 2021

In eukaryotes, 43S preinitiation complex (PIC) formation is a rate-determining step of translation. Ribosome recycling following translation termination produces free 40S subunits for re-assembly of 43S PICs. Yeast mutants lacking orthologs of mammalian eIF2D (Tma64), and either MCT-1 (Tma20) or DENR (Tma22), are broadly impaired for 40S recycling; however, it was unknown whether this defect alters the translational efficiencies (TEs) of particular mRNAs. Here, we conducted ribosome profiling of a yeast tma64∆/tma20∆ double mutant and observed a marked reprogramming of translation, wherein the TEs of the most efficiently translated (‘strong’) mRNAs increase, while those of ‘weak’ mRNAs generally decline. Remarkably, similar reprogramming was seen on reducing 43S PIC assembly by inducing phosphorylation of eIF2α or by decreasing total 40S subunit levels by depleting Rps26. Our findings suggest that strong mRNAs outcompete weak mRNAs in response to 43S PIC limitation achieved in various ways, in accordance with previous mathematical modeling.
Needs of family members of patients admitted to a university hospital critical care unit, Izmir Turkey: comparison of nurse and family perceptions
Authors: Büyükçoban Sibel , Mermi Bal Zehra , Oner Ozlem , Kilicaslan Necmiye , Gökmen Necati , Ciçeklioğlu Meltem
Published: March 2021

Purpose:

This study aims to compare the perceptions of nurses and families on the needs of the relatives of the patients in Intensive Care Unit (ICU).

Methods

This cross-sectional study was conducted in the ICU of a university hospital. The study comprised 213 critical care patients’ relatives and 54 nurses working in the same ICU. Data were collected using the Turkish version of Critical Care Family Needs Inventory (CCFNI) and a questionnaire on the characteristics of the participants. The difference between the perceptions of families and nurses was analyzed using Student t-test. Results: CCFNI’s assurance/proximity subscale mean scores ranked first among bothpatients and nurses. The item “To be assured the best care possible is being given to the patient” was the top priority for both groups. Mean assurance/proximity and information dimensions of relatives were significantly higher compared to nurses (p < 0.001). No significant difference was found between the perception of patient relatives and nurses related to support and comfort dimensions (p < 0.05).

Conclusion

The needs of the relatives of patients are underestimated by nurses. This inhibited the performance of ICU nurses in line with the holistic care approach. Educational objectives that include the needs of ICU patients’ relatives should be incorporated into the undergraduate and in-service training of nurses. Policies should be established to create space and time for effective relative-nurse communication.
Flavors of Monks’ Poetry: On a Witty Disparagement and Its Influences
Authors: Protass Jason
Published: March 2021

This essay focuses on a humorous metaphor that appears prominently in critiques of Buddhist monks’ poetry, from the eleventh century onward. Alluding to the monastic vegetarian diet, critics leveled that monks’ poetry had “a whiff of vegetables” (cai qi 菜氣), “the flavor of cabbage and bamboo shoots” (shusun qi 蔬筍氣), or “the taste of pickled stuffing” (suanxian qi 酸餡氣) . The double meaning of qi 氣 is literally flavor or smell and by extension also refers to an individual’s literary style and character. Members of the literati largely agreed that such flavors described what was distinctive about typical monks’ poetry, and debated whether monks ought to rid their poems of vegetal qualities such as plainness and narrowly repetitive themes . Other critics argued that monks’ poetry is an acquired taste, rich with delicate poetics well worth savoring. I conclude by observing how some modern scholars have uncritically reiterated the logic of this witty disparagement, and I suggest alternative directions for further study of monks’ poetry .
An Analysis of Carbon Market and Carbon Credits in India
Authors: Gorain Subrata , Malakar Ayushman , Chanda Subhajit
Published: March 2021

Global climate change is becoming an alarming problem of the 21st century, with global warming as the biggest challenge. Anthropogenic activities have added significant quantities of greenhouse gases (GHGs) to the atmosphere ever since the Industrial Revolution. The agriculture sector is a significant source of GHG emission in many countries. Crop stubble burning or agricultural biomass burning is one of the highest contributors to this emission. In India, around 92 million tons of crop residue is burned every year, causing several negative impacts on the climate as well as on human health. Under the Kyoto Protocol, Carbon trading and Clean Development Mechanism (CDM) are the two robust processes to mitigate the GHG emissions for any country. In this study, we have assessed the overview of world’s carbon market and analysed how much carbon credit India may have traded in the world carbon market, if emission from the crop residue burning was stopped in the Indian agricultural sector. Further we have fitted an econometric model to determine the effect of carbon trading on other stock market variable.
Waste Tire Pyrolysis Product: An Alternative to Petrochemical Feedstock
Authors: Egwuonwu Christian C. , Arinze Rosemary U. , Agbata Paul C. , Ike Vera C.
Published: March 2021

Aim: The amount of waste tire generated constantly in the modern society is on a rapid increase due to the world’s urbanization, industrialization and population increase. This research was conducted to recover useful products from waste tyre and harness the possibility of using these products as a petrochemical feedstock alternative.

Study Design: Conventional pyrolysis was used to produce bio char, bio-oil and bio-gas

Place and Duration of Study: The research was carried out in the department of Pure and Industrial Chemistry and Mechanical Engineering Nnamdi Azikiwe University between January 2020 and march 2020

Methodology: Waste tyre was pyrolyzed using a conventional pyrolysis over three different temperature 400,550 and 750oC. The yield of the oil and char was determined by weight measurement, while that of gas was determined by mass balancing. The oil produced was characterized using GC/MS (gas chromatography/mass spectrometry)

Results: The percentage yield of char, oil and gas at 400oC, 550oC and 750oC respectively are 62, 24, 14; 48, 36.2, 15.8 and 42, 40, 18. The statistical analysis of yield gave a p-value of 0.785211 this showed that there is no significant change across the three samples statistically. The GC/MS analyses of the oil showed that the oil contains more than 35 compounds of which 6 accounted for more than 50% of the oil, these six include d-limonene with 12.83%, 1-2- benzene dicarboxylic acid with 10.48%, benzene, 1-ethyl-3methyl with 8.89%, benzene 1-methyl-3-(1-methylethyl) with 8.6%, benzene 1-ethenyl-4-methyl with 6.13% and hexadecenoic acid at 5.27%,while another six accounted for less than 5% of the oil, they includes (1-methylenebut-2-enyl)benzene with 0.89%, 1-methylbut-1,3-dienyl)benzene with 0.71%, naphthalene-2,7-dimethyl with 0.71%, quinoline with 0.96%, Spiro[4,5]dec-7-ene,1,8-dimethyl-4-(1-methylethenyl) with 0.74%, phenol 4-(1,1,3,3-tetramethylbutyl).

Conclusion: The composition of tire derived oil are very important petrochemicals derivatives which can be separated or can be used as feedstocks for petrochemical industries.
Rice Husk Dust and NPK Improve Soil Chemical Properties and Growth Response of Jatropha
Authors: Donatus E. O. Azu , Essien B. A. , Nwanja O. U. , Nweke P. E.
Published: March 2021

The present study investigated the combined effect of rice husk dust (RHD) (0.1.2.3.4 and 5 ton ha-1) and NPK 10:10:10 fertilizer (0, 1, 2, 3, 4 and 5 ton ha-1) arranged factorially in Randomized Complete Block Design(RCBD)on selected soil fertility indices (pH, organic carbon, organic matter, total nitrogen, available phosphorus, exchangeable bases, exchangeable acidity and effective cation exchange capacity) and growth parameters of Jatropha (number of leaves, plant height, number of branches and stem girth) in an ultisol of southeastern Nigeria. Results showed significant (P<0.05) improvement in all soil chemical properties and growth parameters of plant compared to control which had no treatment. However, the effects varied with treatment levels and interactions. While the effects increased with rate of application, interactions consistently showed superior effect on all parameters studied. Thus, combining rice husk dust (RHD) and NPK may increase the soil fertility and growth of Jatropha. Treatments combination of5tonha-1 RHD and 3tonha-1 NPK and 5tonha-1 RHD and 5tonha-1 NPK relatively gave the most appreciable result in soil chemical properties and growth of Jatropha respectively, thus are recommended.
Review of Neural Network Algorithm and its Application in Temperature Control of Distillation Tower
Authors: Zhao Ningrui , Lu Jinwei
Published: March 2021

Distillation process is a complex process of conduction, mass transfer and heat conduction, which is mainly manifested as follows: The mechanism is complex and changeable with uncertainty; the process is multivariate and strong coupling; the system is nonlinear, hysteresis and time-varying. Therefore, traditional control methods are difficult to accurately control, but neural networks can greatly improve this problem. This article introduces the basic concepts of distillation tower temperature control, comprehensively introduces the application of various neural network algorithms in distillation tower temperature control, and compares their advantages and disadvantages and their effect. At present, there are many researches on neural network control of distillation tower temperature. The methods are different and each has its own merits. This article has carried out a systematic review to provide reference for the development of related industries.
Determination of Bioactive Compounds and Antimicrobial Capabilities of Purified Nymphaea lotus Linn. (Nymphaeaceae) Extract to Multidrug Resistant Enteric Bacteria
Authors: Adenola O. J. , Adeleke S. T.
Published: March 2021

The increase in multidrug resistance bacteria is a major issue of concern to researchers and healthcare experts. There is a continuous effort by the researchers to innovate new methods of prevention and treatment of infections caused by multidrug resistance bacteria. The occurrence of bioactive compounds and antimicrobial capabilities of Nymphaea lotus Linn. (Nymphaeaceae) extract against multidrug resistant enteric bacteria were studied by assessing in-vitro antibacterial properties of the extract using agar well diffusion technique. Fourier Transform Infrared Spectrophotometer (FTIR) spectra revealed the presence of thirty (30) functional groups in purified ethanol extract of N. lotus root. Also, Gas Chromatography-Mass Spectrophotometry revealed the presence of different bioactive compounds (5-Nonanol, 2-Pentanone, 4-hydroxy-4-methyl-, Azulene, Tetradecanoic acid, 2-Chloroethyl vinyl sulfide, Decanoic acid, ethyl ester, Phytol, 1-Hexadecyne, 2-octenoic acid, Methyl-n-hexadecyl ketone, Hexadecanoic acid, methyl ester, and n-Hexadecanoic acid) in purified ethanol extract of N. lotus root which can be used in production of antimicrobial drugs. Five fractions of purified ethanol extract of N. lotus root (fraction 3-7) had significant zone of inhibition. Fraction four had the highest zone of inhibition 23.67 ± 0.88 mm while fraction seven had the least zone of inhibition 2.67 ± 1.33 mm.
The disulphide bonds of an Asian influenza virus neuraminidase
Authors: Ward Colin W. , Colman Peter M. , Laver W.Graeme
Published: July 2002

The arrangement of the disulphide bonds in the pronase‐released neuraminidase heads of the Asian influenza virus A/Tokyo/3/67 have been examined by cyanogen bromide fragmentation, enzymic digestion and diagonal peptide mapping. There are 9 intrachain disulphide bridges and one interchain bridge which links pairs of monomers at the distal end of the stalk region of the neuraminidase tetramer. The disulphide bond arrangements of the remaining 3 half‐cystine residues in the membrane‐embedded stalk region of the neuraminidase were not examined.
Control of chloroplast electron transport by phosphorylation of thylakoid proteins
Authors: Horton Peter
Published: July 2002

Several chloroplast membrane proteins can become phosphorylated by a membrane protein kinase. The kinase is activated when the electron carriers (plastoquinone) between photosystem II and photosystem I are reduced. Phosphorylation of the light harvesting complex of photosystem II causes a decrease in energy transferred to photosystem II and increase in the rate of excitation of photosystem I. This process, which is mediated by lateral diffusion of the phosphorylated complex serves to regulate the relative rates of electron transfer through the two photosystems. Phosphorylation may also have an important role in balancing the rate of excitation of photosystem II with the capacity for photosynthetic carbon metabolism and in controlling the functional state of photosystem II.
The effect of thylakoid lipids on an oxygen‐evolving Photosystem II preparation
Authors: Gounaris Kleoniki , Whitford David , Barber James
Published: July 2002

The lipid content of a Photosystem II preparation, derived by Triton X‐100 fractionation of spinach thylakoid membranes, which retained high rates of oxygen evolution was examined. It was found that the detergent treatment resulted in a preferential loss of digalactosyldiacylglycerol. The effect on this preparation of exogenously added lipids, or lipid mixtures, purified from thylakoids was investigated. Addition of total polar lipid extract stimulated the rates of oxygen evolution, the same effect being achieved with isolated digalactosyldiacylglycerol or phosphatidylcholine alone. The stimulation of oxygen evolution was dependent on the degree of unsaturation of the lipids used and on the relative amounts of acidic lipids present in the mixtures. Addition of isolated acidic lipids alone resulted in a complete inhibition of oxygen evolution. The results are discussed in terms of the possible involvement of thylakoid lipids in the molecular organisation of the Photosystem II oxygen‐evolving system.
The study of the state [P870+ B800−] in bacterial reaction centers by selective picosecond and low‐temperature spectroscopies
Authors: Shuvalov V.A. , Klevanik A.V.
Published: July 2002

The selective picosecond excitation of Rhodopseudomonas sphaeroides (R‐26) reaction centers (RCs) at 870 nm induces the formation of the transient state within <1 ps followed by the conversion into the state PF (P± Bph±− during 7 ± 2 ps at both 293 K and 110 K. The transient state including the intense bleaching at 800 nm has been shown not to be due: (a) to photon excitation at 870 nm; (b) the excitation of P+; (c) photoselection effects. The transient state is interpreted as the state 1[P+B−] in agreement with earlier works. The primary formation of the state 1P+B−] and the big effective singlet‐triplet splitting in this state correspond to the spectral splitting of the P band at 900 nm in R‐26 RCs and at 1000 nm in Rhodopseudomonas viridis RCs found at 4.2 K and attributed to the optical transition to both 1P and 1[P+B−] states.
Stimulation of a cyclic electron‐transfer pathway around photosystem II by phosphorylation of chloroplast thylakoid proteins
Authors: Horton Peter , Lee Pam
Published: July 2002

Fluorescence induction kinetics of phosphorylated and unphosphorylated chloroplast thylakoid membranes have been studied under low light intensity. Hydroxylamine is able to enhance the fluorescence yield to a greater extent in phosphorylated membranes in both the presence and absence of DCMU. Examination of the light intensity dependence of the fluorescence yields leads to the conclusion that protein phosphorylation enhances the efficiency of a NH2OH‐sensitive cyclic electron‐transfer pathway around photosystem II.
Amino acid sequence of the cooperative homodimeric hemoglobin from the mollusc Scapharca inaequivalvis and topology of the intersubunit contacts
Authors: Petruzzelli Raffaele , Goffredo Bianca M. , Barra Donatella , Bossa Francesco , Boffi Alberto , Verzili Daniela , Ascoli Franca , Chiancone Emilia
Published: July 2002

The dimeric hemoglobin (HbI) from Scapharca inaequivalvis is highly homologous to the other known dimeric Arcid hemoglobins. The sequence has a distinctive hydrophobicity profile in the region corresponding to the E and F helices with respect to both the hemoglobin and myoglobin chains from vertebrates due to the presence of several additional hydrophobic residues. The characteristic topology of the E and F helices is conserved in all the known sequences of Arcid hemoglobins including that of the so‐called α chain of the tetrameric component from Anadara trapezia. The rationale for this conservation lies in the unusual assembly of Arcid hemoglobins where the E and F helices are involved in the interdimeric contact. It is suggested that the extra hydrophobic residues play a major role in the assembly of the basic dimeric unit in these hemoglobins.
Possible involvement of two proteins (phosphoprotein and CD9(p24)) in regulation of platelet calcium fluxes
Authors: Enouf J. , Bredoux R. , Boucheix C. , Mirshahi M. , Soria C. , Levy-Toledano S.
Published: July 2002

The monoclonal antibody ALB6 directed against the leukocyte differentiation antigen CD9 (p24) increases the calcium incorporation into isolated platelet membrane vesicles enriched in internal membranes. The similarities of the effects of both the monoclonal antibody and the catalytic subunit of the cAMP‐dependent protein kinase (C. subunit), which phosphorylates a protein of an apparent molecular mass of 23 kDa, led us to investigate the relationship between CD9 (p24) and the 23‐kDa phosphoprotein (p23). ALB6 IgG does not inhibit the C.subunit‐induced phosphorylation of p23 and the immunoadsorption by ALB6 IgG of p24 associated to membrane vesicles does not alter the phosphorylation pattern. Thus, proteins of similar molecular mass appear to be involved in calcium fluxes: one is recognized by the ALB6 antibody while the other can be phosphorylated by the C‐subunit.
Identification of the plasmid‐encoded immunity protein for colicin El in the inner membrane of Escherichia coli
Authors: Goldman Ken , Suit Joan L. , Kayalar Celik
Published: July 2002

Maxicell
Col El plasmid
Immunity protein
Hydrophobicity calculation
Single‐chain precursor of renal γ‐glutamyl transpeptidase
Authors: Tate Suresh S.
Published: July 2002

The two subunits of γ‐glutamyl transpeptidase (EC 2.3.2.2) are derived from a single‐chain glycosylated precursor. A small fraction of the propeptide survives proteolytic processing in the rat kidney and has been purified by an immunoaffinity technique. The propeptide contains determinants for both the subunits and its amino acid composition resembles that of the dimeric enzyme. However, the propeptide exhibits less than 2% of the transpeptidase activity shown by the dimeric enzyme.
Purification and properties of an oxygen‐evolving reaction center complex from photosystem II membranes
Authors: Ghanotakis Demetrios F. , Yocum Charles F.
Published: July 2002

A method is reported for the isolation of a highly resolved oxygen‐evolving photosystem II reaction center preparation. This preparation can be separated from the more complex photosystem II membranes isolated by the procedure of Berthold et al. [(1981) FEBS Lett. 134, 231‐234] by use of octylglucopyranoside at elevated ionic strengths; the oxygen‐evolving material can be collected by centrifugation at relatively low g values (40000 × g) in yields estimated to be more than 80%. This new preparation lacks the 17 and 23 kDa extrinsic polypeptides; addition of calcium and chloride produces activities approaching 1000 μmol O2/h per mg chlorophyll. Although activity is maximal in the presence of 2,5‐dichloro‐β‐benzoquinone, the response of activity to ferricyanide and 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea indicates that the reducing side of photosystem II has been modified in this new oxygen‐evolving reaction center preparation.
Direct photoaffinity labeling of soluble GTP‐binding proteins in Dictyostelium discoideum
Authors: Schleicher Michael , Witke Walter , Isenberg Gerhard
Published: July 2002

Major cytoplasmic GTP‐binding proteins in Dictyostelium discoideum were identified by direct photoaffinity labeling with [α‐32P]GTP. Three actin‐binding proteins and a protein with an apparent molecular mass of 24 kDa (p24) could be labeled with [α‐32P]GTP. p24 binds to DEAE‐cellulose, behaves like a monomer during gel filtration and was purified to homogeneity by GTP‐affinity chromatography. In comparison to other nucleotide triphosphates the binding of GTP to p24 is highly specific.
Lipogenesis in isolated human sebaceous glands
Authors: Cassidy D.M. , Lee C.M. , Laker M.F. , Kealey T.
Published: July 2002

Lipogenesis in isolated human sebaceous glands from [U‐14C]glucose, [U‐14C]leucine, [U‐14C]isoleucine, and [U‐14C]valine has been determined by thin‐layer chromatography. Total lipogenesis from 2 [U‐14C]glucose was 114.8 ± 22.3 per h (mean ± SE), with 53.8% being incorporated into triglycerides, 20.2% into squalene, 12.8% into phospholipids, 2.1% into cholesterol and 7.1% into wax monoester and cholesterol ester and 5% into di‐ and monoglycerides and free fatty acids. Total lipogenesis from 2 [U‐14C]leucine, 2 mmo [U‐14C]isoleucine, and 2 [U‐14C]valine in the presence of 2 glucose was 26, 29 and 9%, respectively, of that seen with 2 glucose alone. The pattern of 14C distribution in the various lipid classes from the three U‐14C‐labelled branched‐chain amino acids was not significantly different from that seen with [U‐14C]glucose.
Structure and expression of the human calcitonin/CGRP genes
Authors: Steenbergh P.M. , Höppener J.W.M. , Zandberg J. , Visser A. , Lips C.J.M. , Jansz H.S.
Published: July 2002

Recently, we have reported the isolation of cDNA encoding a second human calcitonin gene‐related peptide (hCGRP‐II) [(1985) FEBS Lett. 183, 403‐407]. In this report we describe the isolation and characterization of the gene encoding hCGRP‐II. This gene, designated CALC‐II, is structurally closely related to the known CALC‐I gene encoding human calcitonin (hCT) and hCGRP‐I. In constrast to CALC‐I, CALC‐II does not seem to be alternatively expressed. The formation of a second, hCT‐like mRNA by differential splicing of CALC‐II transcripts is unlikely in view of the structure of CALC‐II, and could not be demonstrated in tissues known to express CALC‐I and CALC‐II.
Synthesis and absolute configuration of optically pure enantiomers of a ϰ‐opioid receptor selective agonist
Authors: DeCosta Brian , George Clifford , Rothman Richard B. , Jacobson Arthur E. , Rice Kenner C.
Published: July 2002

The enantiomers of U50,488 (1, in fig. 1), ligands highly selective for ϰ‐opioid receptors, have been prepared by a refined procedure and their optical purity demonstrated. The absolute configuration of (+)‐trans‐2‐pyrrolidinyl‐N‐methylcyclohexylamine, a chemically versatile intermediate for synthesis of analogs of ϰ‐opioid receptor ligands with defined chirality, has been determined to be 1S,2S by X‐ray crystallographic analysis. This intermediate has been used to synthesize the optically pure U50,488 enantiomers with known absolute configuration.
Similarities between a predicted secondary structure for the M1 RNA ribozyme and the tRNA binding center of 16 S rRNA from E. coli
Authors: Boehm Siegfried
Published: July 2002

We propose a new model for the secondary structure of the M1 RNA component of E. coli RNase P which is based on significant sequence homologies with parts of the E. coli 16 S rRNA. A large domain of the new model resembles closely the secondary structure of the tRNA binding center of 16 S rRNA. We suggest that this domain of M1 RNA when functioning as a ribozyme binds the mature part of the precursor tRNA.
Aromatic ring cleavage of a β‐biphenyl ether dimer catalyzed by lignin peroxidase of phanerochaete chrysosporium
Authors: Miki Keiji , Renganathan V. , Mayfield Mary B. , Gold Michael H.
Published: July 2002

Under aerobic conditions homogeneous lignin peroxidase catalyzed the oxidation of 1‐(4'‐methoxyphenyl)‐2‐(2″,5′‐dimethoxy‐4″‐phenylphenoxy)‐1,3‐dihydroxypropane (I) to yield four products: 1‐(4'‐methoxy‐phenyl)‐1,2,3‐trihydroxypropane (X), 4‐[α‐hydroxy‐α‐(4'‐methoxyphenyl)‐methyl]‐1,3‐dioxolane‐2‐one (V), 4‐(4'‐methoxyphenyl)‐5‐hydroxymethyl‐1,3‐dioxolane‐2‐one (VI) and 5‐hydroxy‐5‐carbomethoxy‐4‐phenyl‐oxol‐3‐en‐2‐one (VIII). V, VI and VIII are all products of ring opening reactions. When the reaction was conducted under anaerobic conditions, the substrate was oxidized but no ring‐cleaved products were detected. During the oxidation of I, 4 atoms of 18O from 18O2 were incorporated into the lactol product VIII.
Separation of damage specific DNA endonuclease activities present in calf thymus
Authors: Helland Dag E. , Male Rune , Kleppe Kjell
Published: July 2002

A DNA endonuclease activity present in calf thymus specific for incision on DNA damaged by ultraviolet light, osmium tetroxide, potassium permanganate, hydrogen peroxide and acid has been purified from whole cell extracts. The enzymatic activity was heterogeneous both with regard to molecular mass and charge. The molecular mass of the enzyme varied from 25 to 35 kDa, but the different enzymatic species appeared to possess similar activities. The enzymes acted equally well on damage in supercoiled and relaxed forms of DNA. It further had a narrow optimum with regard to salt concentrations, the optimum activity being observed at a concentration of KCl from 40 to 65 mM.
Vapor‐phase modification of sulfhydryl groups in proteins
Authors: Amons R.
Published: July 2002

Proteins and peptides are readily and specifically modified at their sulfhydryl groups by the vapors of a mixture of 4‐vinylpyridine and tributylphosphine. The phenylthiohydantoin derivative of S‐β‐(4‐pyridylethyl) cysteine formed during sequence analysis is easily detectable in current identification systems.
Relaxed thiol substrate specificity of glutathione transferase effected by a non‐substrate glutathione derivative
Authors: Principato Giovanni B. , Danielson U.Helena , Mannervik Bengt
Published: July 2002

Rat glutathione transferase 4‐4 catalysed the conjugation of 2‐mercaptoethanol with 1‐chloro‐2,4‐dinitrobenzene in the presence of S‐methyl‐glutathione. The reaction was linearly dependent on enzyme concentration and saturation was seen with respect to both 2‐mercaptoethanol and S‐methyl‐glutathione concentration. High concentrations of S‐methyl‐gluta‐thione were inhibitory. The results suggest that the natural substrate glutathione has two distinct functions in the normal catalytic reaction, (i) induction of a catalytically competent conformation of the enzyme and (ii) provision of the substrate sulfhydryl group in the reaction catalyzed.
HPLC study on the ‘history’ dependence of gramicidin A conformation in phospholipid model membranes
Authors: Bañó M.C. , Braco L. , Abad C.
Published: July 2002

A novel HPLC methodology for the study of gramicidin A reconstituted in model membranes has been tested in comparison with circular dichroism data. It is shown that this chromatographic technique not only corroborates most of the recent spectroscopic results but allows one to explain them in terms of mass fractions of different actual conformational species of GA in the phospholipid assemblies. In particular, the dependence of the inserted peptide configuration on the organic solvent and other parameters involved in the ‘history’ of the sample preparation and handling has been analyzed by HPLC in two phospholipid model systems: small unilamellar vesicles and micelles. Moreover, a slow conformational transition of GA towards a β6.3‐helical configuration, accelerated by heat incubation, has been also chromatographically visualized and quantitatively interpreted.
Sequence similarity between dopamine β‐hydroxylase and peptide α‐amidating enzyme: Evidence for a conserved catalytic domain
Authors: Southan Christopher , Kruse Lawrence I.
Published: July 2002

A comparison of human dopamine β‐hydroxylase (EC 1.14.17.1) with bovine peptide C‐terminal α‐amidating enzyme (EC 1.14.17.3), revealed a 28% identity extending throughout a common catalytic domain of approximately 270 residues. The shared biochemical properties of these two enzymes from neurosecretory granules suggests that the sequence similarity reflects a genuine homology and provides a structural basis for a new family of copper type II, ascorbate‐dependent monooxygenases.
Adenine nucleotides regulate Ca2+ transport in brain mitochondria
Authors: Rottenberg Hagai , Marbach Miriam
Published: July 2002

Adenine nucleotides (ADP>ATP) greatly enhance Ca2+ uptake and retention in rat brain mitochondria. In the presence of both spermine and ADP, brain mitochondria sequester Ca2+ down to cellular free Ca2+ levels, suggesting a role for mitochondria in modulating Ca2+ cycles in brain cells. Analysis of the effects of various inhibitors on Ca2+ uptake and efflux suggest that locking the ADP/ATP translocator in its M‐state stimulates electrogenic Ca2+ uptake and, to a lesser extent, inhibits Ca2+ efflux. It is suggested that this effect is due to a modulation of the surface charge on the M‐side which enhances Ca2+ dissociation from the carriers.
A novel TIMP‐insensitive type IV collagen‐degrading metalloproteinase from murine metastatic sarcoma cells
Authors: Kato Yoichi , Ogawa Kohei , Yamamoto Shuji , Abe Shigeto , Kishi Jun-ichi , Hayakawa Taro
Published: July 2002

A novel type IV collagen‐degrading metalloproteinase was purified from the conditioned media of a murine metastatic sarcoma cell line. The molecular weight of the purified enzyme was determined to be 100 kDa by SDS‐PAGE, while 700 kDa by gel filtration suggesting that the enzyme has a multimer structure. This enzyme degrades type IV collagen, but neither type I collagen nor casein. The failure of trypsin treatment to enhance the enzyme activity suggested that the purified enzyme did not require activation. Although the enzyme seems to be classified as a matrix metalloproteinase, it was inhibited by neither tissue inhibitor of metalloproteinases (TIMP) nor TIMP‐2 and thus represents a novel type IV collagen‐degrading metalloproteinase.
The caffeine‐sensitive Ca2+ store in bovine adrenal chromaffin cells; an examination of its role in triggering secretion and Ca2+ homeostasis
Authors: Cheek Timothy R. , O'Sullivan Antony J. , Moreton Roger B. , Berridge Michael J. , Burgoyne Robert D.
Published: July 2002

The effect of caffeine on catecholamine secretion and intracellular free Ca2+ concentration ([Ca2+]i) in bovine adrenal chromaffin cells was examined using single fura‐2‐loaded cells and cell populations. In cell populations caffeine elicited a large (∼200 nM) transient rise in [Ca2+]i that was independent of external Ca2+. This rise in [Ca2+]i triggered little secretion. Single cell measurements of [Ca2+]i showed that most cells responded with a large (> 200 nM) rise in [Ca2+]i, whereas a minority failed to respond. The latter, whose caffeine‐sensitive store was empty, buffered a Ca2+ load induced by a depolarizing stimulus more effectively than those whose store was full. The caffeine‐sensitive store in bovine chromaffin cells may be involved in Ca2+ homeostasis rather than in triggering exocytosis.
A 53 kDa protein binds to the negative regulatory region of JC virus early promoter
Authors: Sharma Arun K. , Kumar Gyanendra
Published: July 2002

Using gel retardation and photocrosslinking experiments, we have identified proteins of about 53 kDa in size in both rat glioma (C6) and cervical carcinoma (HeLa) cell extracts which bind to the negative regulatory region or JC virus (JCV) early promoter. The glial cell protein binds to its cognate promoter element with lesser affinity when compared to the protein present in HeLa cells. Futher, these proteins interacted differentially to an oligonucleotide, containing the neighboring cis‐acting domain, which is recognized by nuclear factor 1 (NFI). These findings suggest that the interactions of the 53 kDa HeLa protein may contribute to the regulation of JCV early promoter in HeLa cells.
The complete amino acid sequence of the haemorrhagic factor LHFII, a metalloproteinase isolated from the venom of the bushmaster snake (Lachesis muta muta)
Authors: Sanchez Eladio Flores , Diniz Carlos Ribeiro , Richardson Michael
Published: July 2002

The complete amino acid sequence the haemorrhagic agent LHFII, a Zn and Ca containing metalloproteinase isolated from the venom of the Bushmaster snake Lachesis muta muta was determined by automated and DABITC/PITC microsequencing of the intact protein, fragments derived by cleavage with cyanogen bromide, and peptides resulting from enzymatic digestions with trypsin and the protease from S. aureas V8. The protein is composed of 200 residues and exhibits considerable sequence homology with the haemorrhagic toxins from a number of other snake venoms, and some metalloproteinases in the region of the putative Zn‐binding sites.
Evidence that nebulin is a protein‐ruler in muscle thin filaments
Authors: Labeit S. , Gibson T. , Lakey A. , Leonard K. , Zeviani M. , Knight P. , Wardale J. , Trinick J.
Published: July 2002

Partial amino acid sequence was obtained from the massive myofibrillar protein nebulin. This consists of repeating motifs of about 35 residues and super‐repeats of 7 × 35 = 245 residues. The repeat‐motifs are likely to be largely α‐helical and to interact with both actin and tropomyosin in thin filaments. Nebulin from different species was found to vary in size in proportion to filament length. The data are consistent with the proposal that nebulin acts as a protein‐ruler to regulate precise thin filament assembly.
Introduction of BAPTA into intact rat submandibular acini inhibits mucin secretion in response to cholinergic and β‐adrenergic agonists
Authors: Mills C.Lloyd , Dormer R.L , McPherson M.A
Published: July 2002

Incorporation of the calcium chelator BAPTA into isolated, intact rat submandibular acini by hypotonic swelling, resulted in complete inhibition of carbamylcholine, noradrenaline and isoproterenol stimulation of mucin secretion. No effects or intracellular BAPTA on cell viability or β‐adrenergic stimulation of cyclic AMP formation were observed. The data are the first to demonstrate that calcium is necessary for β‐adrenergic stimulation of secretion and suggest that Ca2+ provides a common link in the triggering of exocytosis.
Characterization of myocardial extracellular ATP receptors by photoaffinity labelling and functional assays
Authors: Giannattasio Bartolo , Powers Kit , Scarpa Antonio
Published: July 2002

Extracellular ATP receptors in rat ventricular myocytes were investigated through intact cell photolabelling followed by protein isolation. 8‐Azido‐ATP (8Az‐ATP) was used for labelling under specific conditions determined by parallel functional studies. In those studies ATP‐induced cytosolic Ca2+ transients were irreversibly and specifically inhibited by UV‐photolyzed 8Az‐ATP, but not by 2‐azido‐ATP (2Az‐ATP), even in the presence of high concentrations of phosphonucleotides not affecting myocardial ATP receptors. Under those conditions background labelling is minimized and radioactive 8Az‐ATP specifically labels a band of 45–48 kDa on a SDS gel. Labelling under the above conditions in the presence of ATPγS or 2‐methylthio‐ATP (2‐meSATP), which are distinct for two functionally different cardiac ATP receptors, shows two different proteins within the same band consistent with the possible labelling of these two receptors.
The γ‐subunit of the principal G‐protein from squid (Loligo forbesi) photoreceptors contains a novel N‐terminal sequence
Authors: Lott J.Shaun , Ryba Nicholas J.P. , Pottinger John D.D. , Keen Jeffrey N. , Carne Alan , Findlay John B.C.
Published: July 2002

The squid (Loligo forbesi) visual system presents as accessible a system for study of G‐protein mediated signal transduction as the vertebrate rod outer segment with the added advantage that the major G‐protein is a member of the Gq‐class. Here the cDNA clone encoding the γ‐subunit of this G‐protein is reported, thereby completing the molecular cloning of the heterotrimeric G‐protein. The deduced protein structure of G‐γ has relatively little sequence identity with known mammalian counterparts particularly in comparison with the relatively high degree found for both the α‐ and β‐subunits of this protein. In particular, the N‐terminus of the squid visual G‐γ contains a repetitive, highly charged region, rich in lysine and glutamate, that has no parallel in other G‐proteins. The amino acid sequence of a number of peptides derived by chemical cleavage of G‐γ accounted for much of the protein sequence predicted from the cDNA, including the unusual N‐terminal region.
Cyclin E enhances P53‐mediated transactivation
Authors: Segawa Kaoru , Hokuto Isamu , Minowa Akiko , Ohyama Kyoji , Takano Toshiya
Published: July 2002

Plasmids expressing G1 and G2 cyclins were introduced into the Saos‐2 cell system monitoring p53‐mediated transactivation [(1993) Oncogene 8, 543]. Cyclin E, but not other cyclins, enhanced the p53‐mediated transactivation about 2‐fold. Co‐transfection of a CDK2 expression plasmid caused a 30% increase in the extent of the p53‐mediated transactivation. Moreover, the transfected p53 protein became phosphorylated coordinately with the enhanced transactivation. The close correlation between transactivation and p53 phosphorylation suggests that phosphorylation is involved in positive regulation for the transactivation by p53.