bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibitors of the proteasome block the myogenic differentiation of rat L6 myoblasts
Authors: Kim Sang Soo , Rhee Sangmyung , Lee Kun Ho , Kim Jung Hwa , Kim Hye Sun , Kang Man-Sik , Chung Chin Ha
Published: July 2002

Myogenesis is characterized by membrane fusion and accumulation of muscle specific proteins. We have previously shown that nitric oxide acts as a messenger for membrane fusion. Here we show that inhibitors of the proteasome, such as lactacystin, reversibly block both the fusion of L6 myoblasts and the accumulation of muscle specific proteins, such as myosin heavy chain (MHC). The inhibitors also reversibly prevented the induction of the NF‐κB activity, which is required for the expression of nitric oxide synthase (NOS). Moreover, the inhibition of the NF‐κB activity occurred in parallel with that of the NOS activity upon treatment with increasing concentrations of lactacystin. While pyrrolidine dithiocarbamate, an inhibitor of NF‐κB, blocked both membrane fusion and accumulation of MHC, N
G‐monomethyl‐l‐arginine, a specific inhibitor of NOS, inhibited only the fusion. These results suggest that the proteasome plays an essential role in the regulation of myogenic differentiation through the activation of NF‐κB and that the target of NF‐κB for the expression of muscle specific proteins is distinct from that for myoblast fusion.
Antibodies against type II phospholipase A2 prevent renal injury due to ischemia and reperfusion in rats
Authors: Takasaki Jun , Kawauchi Yasushi , Urasaki Tetsuya , Tanaka Hideyuki , Usuda Shinji , Masuho Yasuhiko
Published: July 2002

This study was performed to determine the involvement of type II phospholipase A2 (PLA2‐II) in renal injury caused by ischemia and reperfusion. Ischemia and reperfusion significantly elevated levels of blood urea nitrogen and serum creatinine in rats. These increases were significantly reduced by i.v. administration of rabbit IgG F(ab′)2 fragments against rat PLA2‐II. Increased levels of acid‐stable PLA2 activity in the kidney were caused by ischemia and reperfusion, and were suppressed by administration of anti‐PLA2‐II F(ab′)2. Increased levels of myeloperoxidase activity, a marker of neutrophil infiltration, in the kidney were also reduced after anti‐PLA2‐II F(ab′)2 treatment. These results suggest that PLA2‐II plays a pivotal role in pathogenesis of ischemia and reperfusion injury through induction of neutrophil infiltration.
GD1α‐replica peptides functionally mimic GD1α, an adhesion molecule of metastatic tumor cells, and suppress the tumor metastasis
Authors: Ishikawa Dai , Kikkawa Hironori , Ogino Koichi , Hirabayashi Yoshio , Oku Naoto , Taki Takao
Published: July 2002

A novel peptide technology to produce mimicking peptides of carbohydrate moiety (which we propose to name glyco‐replica peptides) is a useful tool to elucidate the functions of glycoconjugate. Carbohydrate moiety of ganglioside GD1α functions as a molecule involved in the adhesion between murine highly metastatic lymphoma RAW117‐H10 cells and hepatic sinusoidal endothelial (HSE) cells. To prepare peptides which mimic the carbohydrate structure of GD1α, phage clones expressing peptides which bound to a monoclonal antibody against GD1α (KA17) were isolated from a phage‐displayed random peptide library. Four phage clones having affinity to the monoclonal antibody KA17 were isolated, and these clones showed inhibitory effect on the binding of KA17 to GD1α. The amino acid sequences of the displayed pentadecamers were determined, and one of the phages displaying sequence WHWRHRIPLQLAAGR bound to HSE cells directly and showed the highest inhibitory effect on the adhesion between RAW117‐H10 cells and HSE cells. The synthesized peptides having the same sequences to the displayed 15mers in the four isolated phage clones also showed the inhibitory effect on the adhesion of RAW117‐H10 cells to HSE cells, and, again, the WHWRHRIPLQLAAGR peptide showed the highest inhibitory effect. Furthermore, intravenous injection of the peptide brought almost complete inhibition of the metastasis of RAW117‐H10 cells to lung and spleen, and about 50% inhibition of the liver metastasis. These results indicate that GD1α plays an important role for metastasis of RAW117‐H10 cells, and the peptides obtained by the present procedure are able to mimic the functional role of the glycoconjugate.
Transcription factor AP‐2 activity is modulated by protein kinase A‐mediated phosphorylation
Authors: Garcı́a Miguel Angel , Campillos Mónica , Marina Anabel , Valdivieso Fernando , Vázquez Jesús
Published: July 2002

We recently reported that APOE promoter activity is stimulated by cAMP, this effect being mediated by factor AP‐2 [Garcı́a et al. (1996) J. Neurosci. 16, 7550–7556]. Here, we study whether cAMP‐induced phosphorylation modulates the activity of AP‐2. Recombinant AP‐2 was phosphorylated in vitro by protein kinase A (PKA) at Ser239. Mutation of Ser239 to Ala abolished in vitro phosphorylation of AP‐2 by PKA, but not the DNA binding activity of AP‐2. Cotransfection studies showed that PKA stimulated the effect of AP‐2 on the APOE promoter, but not that of the S239A mutant. Therefore, cAMP may modulate AP‐2 activity by PKA‐induced phosphorylation of this factor.
cAMP inhibits translation by inducing Ca2+/calmodulin‐independent elongation factor 2 kinase activity in IPC‐81 cells
Authors: Hovland R. , Eikhom T.S. , Proud C.G. , Cressey L.I. , Lanotte M. , Døskeland S.O. , Houge G.
Published: July 2002

Treatment of IPC‐81 cells led to inhibition of protein synthesis, which was accompanied by an increase in the average size of polysomes and a decreased rate of elongation, indicating that it involved inhibition of peptide chain elongation. This inhibition was also associated with increased phosphorylation of elongation factor eEF2 (which inhibits its activity) and enhanced Ca2+/calmodulin‐independent activity of eEF2 kinase. Previous work has shown that phosphorylation of eEF2 kinase by cAMP‐dependent protein kinase (cAPK) in vitro induces such activator‐independent activity, and the present data show that such a mechanism can occur in intact cells to link physiological levels of cAPK activation with inhibition of protein synthesis.
Cellular localization and evolution of prolactin receptor mRNA in ovine endometrium during pregnancy
Authors: Cassy Sandrine , Charlier Madia , Guillomot Michel , Pessemesse Laurence , Djiane Jean
Published: July 2002

In this study, we have investigated the expression of the prolactin receptor gene in ovine endometrium during oestrus cycle and pregnancy. Using reverse transcription‐PCR analysis, we provided evidence that the prolactin receptor gene is specifically transcribed in this tissue. As shown by Northern blot analysis, the level of the prolactin receptor transcripts increased dramatically during late pregnancy. In situ hybridization experiments revealed that prolactin receptor mRNA was specifically expressed in the glandular compartment and confirmed the dramatic increase of its expression that occurs at the end of pregnancy. Taken together, these findings are consistent with a putative role of prolactin and/or related molecules in the regulation of the proliferation of the glandular compartment and/or in the control of the secretory activity of the endometrium.
Identification of a ribonuclease H gene in both Mycoplasma genitalium and Mycoplasma pneumoniae by a new method for exhaustive identification of ORFs in the complete genome sequences
Authors: Bellgard Matthew I , Gojobori Takashi
Published: July 2002

Exhaustive identification of open reading frames in complete genome sequences is a difficult task. It is possible that important genes are missed. In our efforts to reanalyze the intergenic regions of Mycoplasma genitalium and Mycoplasma pneumoniae, we have newly identified a number of new open reading frames (ORFs) in both M. genitalium and M. pneumoniae. The most significant identification was that of a ribonuclease H enzyme in both species which until now has not been identified or assumed absent and interpreted as such. In this paper we discuss the biological importance of RNase H and its evolutionary implication. We also stress the usefulness of our method for identifying new ORFs by reanalyzing intergenic regions of existing ORFs in complete genome sequences.
Change in lactate production in Myc‐transformed cells precedes apoptosis and can be inhibited by Bcl‐2 overexpression
Authors: Papas Klearchos K , Sun Lei , Roos Eric S , Gounarides John S , Shapiro Michael , Nalin Carlo M
Published: July 2002

As a result of Myc‐dependent transcription of the LDH‐A gene, Myc‐transformed cells (Rat1‐Myc) exhibit increased lactate production rates (LPR) even under aerobic conditions (the Warburg effect). Recently, the increased susceptibility to stress‐induced apoptosis associated with Myc transfection has been linked to the overexpression of the LDH‐A gene. In this report we demonstrate that the overexpression of the anti‐apoptotic protein Bcl−2 in Rat1‐Myc cells (Rat1‐Myc‐Bcl−2) reduces the molar ratio of lactate production to glucose consumption (Y
L/G). The Bcl−2 induced reduction in Y
L/G may be associated with reduced expression of the LDH‐A gene, or a decrease in LDH‐A activity. Stimulation of apoptosis by staurosporine, a protein kinase C inhibitor, reduces the LPR in Rat1‐Myc cells in a dose‐dependent manner. The staurosporine effect on the LPR is rapid and precedes the execution phase of apoptosis as defined by caspase activation and PARP cleavage. This effect on LPR is completely blocked by Bcl‐2 overexpression. Serum starvation alone does not affect the LPR of Rat1‐Myc or Rat1‐Myc‐Bcl‐2 cells; however, the effect of staurosporine on the LPR of Rat1‐Myc cells is potentiated by serum starvation. These data demonstrate that Bcl‐2 overexpression reduces the Y
L/G in Rat1‐Myc cells, perhaps via a reduction in the activity or expression of the LDH‐A gene, and this reduction may desensitize cells to some pro‐apoptotic stimuli. The reduction in LPR in response to staurosporine may be an early step in the induction of apoptosis in Rat1‐Myc cells. By abolishing the reduction in LPR, Bcl‐2 may protect Rat1‐Myc cells from staurosporine‐induced apoptosis. Moreover, the lack of effect by serum starvation on the LPR supports a model in which serum starvation induces apoptosis through a pathway distinct from that of the staurosporine and glucose‐dependent apoptotic pathway(s) in Myc‐transformed cells.
Lack of c‐Jun activity increases survival to cisplatin
Authors: Sánchez-Pérez Isabel , Perona Rosario
Published: July 2002

Antineoplasic agents such as cisplatin and adriamycin execute their pharmacological role by triggering apoptosis. We have studied the mechanism of apoptosis induction by cisplatin and adriamycin. Both drugs activated JNK with slow and persistent kinetics. Adriamycin activated caspase‐3 before the rise in JNK activity, while the response to cisplatin occurs hours after JNK activation. The increase in JNK activity was necessary for cisplatin‐mediated apoptosis but it was dispensable for adriamycin‐induced cell death. Cells derived from c‐jun knock out mice were more resistant to cisplatin cell death than normal cells, but no difference was observed in response to adriamycin. Activation of JNK and cell death by cisplatin is mediated by the MEKK1/SEK1 cascade, since expression of dominant negative expression vectors of these kinases blocked both processes. p38 was also activated by cisplatin with similar kinetics as JNK. AP‐1 complexes were activated by cisplatin including mainly c‐jun/ATF‐2 heterodimers suggesting that AP‐1‐dependent transcription partially mediated cisplatin‐induced apoptosis.
Production of an immunoenzymatic tracer combining a scFv and the acetylcholinesterase of Bungarus fasciatus by genetic recombination
Authors: Choumet Valerie , Cousin Xavier , Bon Cassian
Published: July 2002

We constructed a plasmid containing a chimeric gene composed of the gene encoding acetylcholinesterase (AChE) from Bungarus fasciatus venom and a gene encoding a single chain antibody fragment (scFv) directed against one of the two subunits of a presynaptic neurotoxin from rattlesnake. Large quantities of the fusion protein were produced in the culture medium of transfected COS cells. Fusion to AChE did not affect the ability of the scFv to recognise its antigen. Similarly, the AChE activity was not impaired in the fusion. The fusion protein was purified from the culture medium in a single step by affinity chromatography. The immunoconjugate obtained consisted of a soluble monomeric form of AChE fused to scFv. It was monovalent and had a molecular weight of 94 kDa. The properties of this scFv‐AChE fusion show that the simple, reproducible preparation of various recombinant monovalent immunoenzymatic tracers with low molecular weight is possible. In addition, in the construct presented, the scFv domain can be easily changed to another one taking advantage of the SfiI‐NotI restriction sites surrounding this domain.
A mosquito (Anopheles stephensi) angiotensin I‐converting enzyme (ACE) is induced by a blood meal and accumulates in the developing ovary
Authors: Ekbote U , Coates D , Isaac R.E
Published: July 2002

Angiotensin I‐converting enzyme (ACE) has a key role in regulating levels of several circulating peptides in mammals and has a vital role in male fertility. ACE has recently been found in insects, where its role is unclear. A mutant allele of the ACE gene (Ance) of Drosophila melanogaster is embryonic lethal, indicating an important role for the enzyme in development. We now report the presence of ACE in female Anopheles stephensi mosquitoes and that the enzyme is induced by a blood‐meal. ACE accumulates in developing ovaries and passes into the mosquito eggs, where it may play a role in the metabolism of peptides during embryogenesis. The ovarian ACE has an M
r of 70 kDa and is inhibited by captopril and lisinopril with IC50 values of 0.1 μM and 0.6 μM, respectively.
Calcium/calmodulin‐dependent protein kinase II activity is increased in sarcoplasmic reticulum from coronary artery ligated rabbit hearts
Authors: Currie Susan , Smith Godfrey L
Published: July 2002

A protein kinase activity intrinsic to the sarcoplasmic reticulum was studied in normal and hypertrophied rabbit hearts. The relationship between this kinase activity and phospholamban phosphorylation was examined. Calmodulin‐dependent kinase II activity was found to be increased in sarcoplasmic reticulum preparations from hypertrophied hearts compared with normal. This was evident by measuring the phosphotransferase activity of the kinase and also by examining phospholamban phosphorylation by electrophoretic band shift analysis. Increased phospholamban phosphorylation by Calmodulin‐dependent protein kinase II was dependent on prior phosphorylation by cAMP‐dependent protein kinase, indicating potential crosstalk. Specific immunoblot analysis of the rabbit sarcoplasmic reticulum identified the presence of the δ form of calmodulin dependent protein kinase II and showed it to be up‐regulated in hypertrophied hearts.
Functional regulation of metabotropic glutamate receptor type 1c: a role for phosphorylation in the desensitization of the receptor
Authors: Ciruela Francisco , Giacometti Angelo , McIlhinney R.A.Jeffrey
Published: July 2002

The phosphorylation and desensitization of metabotropic glutamate receptor type 1c in response to agonist and phorbol esters has been studied. Specific immunoprecipitation of mGluR1c from cells treated with agonist or PMA showed a time‐dependent increase in the phosphorylation of a membrane protein with the same molecular weight as the dimeric form of the receptor. Measurements of inositol phosphate production showed a rapid functional desensitization of about 90% after agonist treatment, whereas treatment with PMA caused only a 30% loss in the same time. The extent of receptor phosphorylation following the different treatments paralleled the desensitization of the receptor. These results strongly suggest that phosphorylation of the dimeric form of mGluR1c, as a functionally active form, may play a role in its rapid desensitization.
New ice‐binding face for type I antifreeze protein
Authors: Baardsnes Jason , Kondejewski Leslie H. , Hodges Robert S. , Chao Heman , Kay Cyril , Davies Peter L.
Published: July 2002

Type I antifreeze protein (AFP) from winter flounder is an alanine‐rich, 37 amino acid, single α‐helix that contains three 11 amino acid repeats (Thr‐X2‐Asx‐X7), where X is generally Ala. The regularly spaced Thr, Asx and Leu residues lie on one face of the helix and have traditionally been thought to form hydrogen bonds and van der Waals interactions with the ice surface. Recently, substitution experiments have called into question the importance of Leu and Asn for ice‐binding. Sequence alignments of five type I AFP isoforms show that Leu and Asn are not well conserved, whereas Ala residues adjacent to the Thr, at right angles to the Leu/Asn‐rich face, are completely conserved. To investigate the role of these Ala residues, a series of Ala to Leu steric mutations was made at various points around the helix. All the substituted peptides were fully α‐helical and remained as monomers in solution. Wild‐type activity was retained in A19L and A20L. A17L, where the substitution lies adjacent to the Thr‐rich face, had no detectable antifreeze activity. The nearby A21L substitution had 10% wild‐type activity and demonstrated weak interactions with the ice surface. We propose a new ice‐binding face for type I AFP that encompasses the conserved Ala‐rich surface and adjacent Thr.
Molecular cloning and characterization of a rice dehydroascorbate reductase
Authors: Urano Jun'ichi , Nakagawa Tomofumi , Maki Yasushi , Masumura Takehiro , Tanaka Kunisuke , Murata Norio , Ushimaru Takashi
Published: July 2002

Plant dehydroascorbate reductase (DHAR), which re‐reduces oxidized ascorbate to maintain an appropriate level of ascorbate, is very important, but no gene or cDNA for plant DHAR has been cloned yet. Here, we describe a cDNA for a rice glutathione‐dependent DHAR (designated DHAR1). A recombinant Dhar1p produced in Escherichia coli was functional. The expression sequence tag database suggests that Dhar1p homologs exist in various plants. Furthermore, the rice Dhar1p has a low similarity to rat DHAR, although the rice enzyme has a considerably higher specific activity than the mammalian one. The mRNA level of DHAR1, the protein level of Dhar1p and the DHAR activity in rice seedlings were elevated by high temperature, suggesting the protection role of DHAR at high temperature.
Gadolinium inhibits thymidine incorporation and induces apoptosis in chondrocytes
Authors: Greisberg Justin K. , Wolf Jennifer Moriatis , Wyman James , Zou Lijun , Terek Richard M.
Published: July 2002

Magnetic resonance arthrography, a procedure where contrast agents containing gadolinium are administered intra‐articularly, has become a useful tool in musculoskeletal diagnosis. Although considered safe for systemic use, toxicities in some tissues have been identified for both free gadolinium ion and the gadolinium chelates used as contrast. In this study, the effects of short‐term exposure of articular chondrocytes to gadolinium contrast were examined by assaying for proteoglycan synthesis, cell proliferation, and apoptosis. Bovine chondrocytes were grown in monolayer culture and exposed to gadodiamide for 16 h. Proteoglycan synthesis was measured through incorporation of radiolabeled sulfate. Uptake of radiolabeled thymidine assessed cell proliferation. Apoptosis was detected using the TUNEL assay, where DNA strand breaks characteristic of apoptosis are labeled with fluorescent nucleotide. Proteoglycan synthesis was stimulated by lower dose exposure to gadodiamide. At higher doses, proteoglycan synthesis returned to baseline. Cell proliferation decreased following exposure to gadodiamide in a dose‐dependent manner. Chondrocyte apoptosis was induced in a dose‐dependent manner. Further work is needed to determine if these in vitro effects are present in the intact joint. © 2001 Orthopaedic Research Society. Punlished by Elsevier Science Ltd. All rights reserved.
The behavioral functions of the cholinergic basalforebrain : lessons from 192 IgG‐SAPORIN
Authors: Wrenn Craige C. , Wiley Ronald G.
Published: July 2002

Until recently, our understanding of the functional neuroanatomy of the cholinergicbasal forebrain (CBF) has been hindered by the lack of a lesioning technique that is truly selective.The development of the immunotoxin 192 IgG‐saporin (192‐sap) has greatly improved our abilityto create specific lesions of the CBF. Rats with such lesions have been studied in a wide variety ofbehavioral paradigms of learning, memory, and attention. Complete or near‐complete destructionof the CBF results in deficits in a variety of behavior paradigms including passive avoidance,spatial tasks (water and radial mazes), delayed matching to position/sample, and attentional tasks.However, interpretation of many experiments is hampered by incomplete lesions and/orconcomitant damage to cerebellar Purkinje neurons. Future studies will need to address theseissues. Recent development of a similar immunotoxin that is effective in primates should permitmore sophisticated behavioral analysis of CBF function. Additionally, immunotoxins selective forother types of neurons, such as the noradrenergic selective anti‐DBH‐saporin, will permit analysisof the behavioral functions of other diffusely projecting systems and how these other systems mayinteract with the CBF.
Dehydroepiandrosterone selectively inhibits production of tumor necrosis factor α and Interlukin‐6 in astrocytes
Authors: Kipper‐Galperin Marianne , Galilly Ruth , Danenberg Haim D. , Brenner Talma
Published: July 2002

Dehydroepiandrosterone (DHEA) is a native neurosteroid with immunomodulating activity. DHEA effectively protects animals from several viral, bacterial and parasitic infections and it was suggested that its age‐associated decline is related with immunosenescence. In the present study we examined the ability of DHEA to inhibit the production of inflammatory mediators by mycoplasma‐stimulated glial cells and to change the course of acute central nervous system (CNS) inflammatory disease in vivo. Addition of DHEA (10 μg/ml) markedly inhibited tumor necrosis factor α (TNFα) and interlukin‐6 (IL‐6) production (98 and 95%, respectively), whereas nitric oxide (NO) and prostaglandin E2 (PGE2) production was not affected. However, daily administration of 0.5 mg DHEA to mice or 5 mg to rats did not change the clinical outcome of experimental autoimmune encephalomyelitis (EAE).
Foreign direct investment in Ukraine since transition
Authors: Ishaq Mohammed
Published: July 2002

Since independence Ukraine has attracted very little foreign direct investment, both in absolute terms, and relative to other transition economies. This is the case when we analyse the ratio of FDI to GDP and exports, and the amount of FDI per capita. This paper examines the causes of the low level of FDI, and offers some policy prescriptions which may help to reverse this unfavourable trend.
Campylobacter myocarditis; loose bowels and a baggy heart
Authors: Cox I.D. , Fluck D.S. , Joy M.D.
Published: July 2002

We report an unusual case of acute myocarditis associated with Campylobacter jejuni enterocolitis leading to severe impairment of left ventricular systolic function. Contrast‐enhanced cardiac magnetic resonance imaging was used to confirm the presence of acute myocardial inflammation and its resolution.
Influence of carvedilol on the benefits of physical training in patients with moderate chronic heart failure
Authors: Forissier J.F. , Vernochet P. , Bertrand P. , Charbonnier B. , Monpère C.
Published: July 2002

Aims:

To evaluate prospectively the impact of carvedilol on a short‐term physical training program in stable patients with moderate chronic heart failure (CHF), and to analyze parameters predictive of improvement after training.

Methods and results:

Thirty‐eight patients with CHF were referred for cardiac rehabilitation. Etiology was ischemic in 26 patients, dilated in 12 patients and left ventricular ejection fraction was < 35%. Patients were classified into three groups: group 1 (n ‐ 14) ‐ ACE inhibitors, diuretics and digitalis; group 2 (n ‐ 11) ‐ idem group 1+cardioselective beta‐blocker; group 3 (n ‐ 13) ‐ idem group 1+carvedilol. Exercise tests with VO2 measurement were performed before and after a 4‐week exercise training program. Patients with carvedilol experienced a 16.6% increase in peak VO2 which was similar to the 13.9% increase in the group with cardioselective beta‐blocker and to the 18.5% in the group without beta‐blocker. Moreover non‐ischemic etiology of CHF was the only parameter predictive of improvement after training (P ‐ 0.02).

Conclusions:

Addition of carvedilol did not alter benefits of a short‐term physical training program in patients with moderate CHF. No baseline characteristic except for etiology of CHF was predictive of a response to training.
Facet Control for Trap‐State Suppression in Colloidal Quantum Dot Solids
Authors: Xia Yong , Chen Wei , Zhang Peng , Liu Sisi , Wang Kang , Yang Xiaokun , Tang Haodong , Lian Linyuan , He Jungang , Liu Xinxing , Liang Guijie , Tan Manlin , Gao Liang , Liu Huan , Song Haisheng , Zhang Daoli , Gao Jianbo , Wang Kai , Lan Xinzheng , Zhang Xiuwen , Müller‐Buschbaum Peter , Tang Jiang , Zhang Jianbing
Published: April 2020

Trap states in colloidal quantum dot (QD) solids significantly affect the performance of QD solar cells, because they limit the open‐circuit voltage and short circuit current. The {100} facets of PbS QDs are important origins of trap states due to their weak or missing passivation. However, previous investigations focused on synthesis, ligand exchange, or passivation approaches and ignored the control of {100} facets for a given dot size. Herein, trap states are suppressed from the source via facet control of PbS QDs. The {100} facets of ≈3 nm PbS QDs are minimized by tuning the balance between the growth kinetics and thermodynamics in the synthesis. The PbS QDs synthesized at a relatively low temperature with a high oversaturation follow a kinetics‐dominated growth, producing nearly octahedral nanoparticles terminated mostly by {111} facets. In contrast, the PbS QDs synthesized at a relatively high temperature follow a thermodynamics‐dominated growth. Thus, a spherical shape is preferred, producing truncated octahedral nanoparticles with more {100} facets. Compared to PbS QDs from thermodynamics‐dominated growth, the PbS QDs with less {100} facets show fewer trap states in the QD solids, leading to a better photovoltaic device performance with a power conversion efficiency of 11.5%.
Microbial Polyhydroxyalkanoates and Nonnatural Polyesters
Authors: Choi So Young , Cho In Jin , Lee Youngjoon , Kim Yeo‐Jin , Kim Kyung‐Jin , Lee Sang Yup
Published: April 2020

Microorganisms produce diverse polymers for various purposes such as storing genetic information, energy, and reducing power, and serving as structural materials and scaffolds. Among these polymers, polyhydroxyalkanoates (PHAs) are microbial polyesters synthesized and accumulated intracellularly as a storage material of carbon, energy, and reducing power under unfavorable growth conditions in the presence of excess carbon source. PHAs have attracted considerable attention for their wide range of applications in industrial and medical fields. Since the first discovery of PHA accumulating bacteria about 100 years ago, remarkable advances have been made in the understanding of PHA biosynthesis and metabolic engineering of microorganisms toward developing efficient PHA producers. Recently, nonnatural polyesters have also been synthesized by metabolically engineered microorganisms, which opened a new avenue toward sustainable production of more diverse plastics. Herein, the current state of PHAs and nonnatural polyesters is reviewed, covering mechanisms of microbial polyester biosynthesis, metabolic pathways, and enzymes involved in biosynthesis of short‐chain‐length PHAs, medium‐chain‐length PHAs, and nonnatural polyesters, especially 2‐hydroxyacid‐containing polyesters, metabolic engineering strategies to produce novel polymers and enhance production capabilities and fermentation, and downstream processing strategies for cost‐effective production of these microbial polyesters. In addition, the applications of PHAs and prospects are discussed.
Analyzing Energy Materials by Cryogenic Electron Microscopy
Authors: Ren Xiao‐Chuan , Zhang Xue‐Qiang , Xu Rui , Huang Jia‐Qi , Zhang Qiang
Published: April 2020

Safe and high‐energy‐density rechargeable batteries are increasingly indispensable in the pursuit of a wireless and fossil‐free society. Advancements in present battery technologies and the investigation of next‐generation batteries highly depend on the ever‐deepening fundamental understanding and the rational designs of working electrodes, electrolytes, and interfaces. However, accurately analyzing energy materials and interfaces is severely hindered by their intrinsic limitations of air and electron‐beam sensitivity, which restrains the research of energy materials in a low‐efficiency trial‐and‐error paradigm. The emergence of cryogenic electron microscopy (cryo‐EM) has enabled the nondestructive characterization of air‐ and electron‐beam sensitive energy materials in the microscale and nanoscale, and even at atomic resolutions, affording closer insights into the primary chemistry and physics of working batteries. Herein, the development of cryo‐EM and the applications in detecting energy materials are reviewed and analyzed from its overwhelming advantages in disclosing the underlying mystery of energy materials. Critical sample preparation methods as the precondition for cryo‐EM are compared, which strongly affect the characterization accuracy. Furthermore, new developments in the analysis of energy materials, especially bulk electrodes and interfaces in lithium metal batteries, are presented according to different functions of cryo‐EM. Finally, future directions of cryo‐EM for analyzing energy materials are prospected.
A Novel Single‐Atom Electrocatalyst Ti1/rGO for Efficient Cathodic Reduction in Hybrid Photovoltaics
Authors: Liang Suxia , Zhu Chao , Zhang Naitian , Zhang Shuo , Qiao Botao , Liu Hua , Liu Xiaoyan , Liu Zheng , Song Xuedan , Zhang Heming , Hao Ce , Shi Yantao
Published: April 2020

Single‐atom catalysts (SACs) are a frontier research topic in the catalysis community. Carbon materials decorated with atomically dispersed Ti are theoretically predicted with many attractive applications. However, such material has not been achieved so far. Herein, a Ti‐based SAC, consisting of isolated Ti anchored by oxygen atoms on reduced graphene oxide (rGO) (termed as Ti1/rGO), is successfully synthesized. The structure of Ti1/rGO is characterized by high‐angle annular dark‐field scanning transmission electron microscopy and X‐ray absorption fine structure spectroscopy, being determined to have a five coordinated local structure TiO5. When serving as non‐Pt cathode material in dye‐sensitized solar cells (DSCs), Ti1/rGO exhibits high electrocatalytic activity toward the tri‐iodide reduction reaction. The power conversion efficiency of DSCs based on Ti1/rGO is comparable to that using conventional Pt cathode. The unique structure of TiO5 moieties and the crucial role of atomically dispersed Ti in Ti1/rGO are well understood by experiments and density functional theory calculations. This emerging material shows potential applications in energy conversion and storage devices.
An Antiaging Electrolyte Additive for High‐Energy‐Density Lithium‐Ion Batteries
Authors: Han Jung‐Gu , Hwang Chihyun , Kim Su Hwan , Park Chanhyun , Kim Jonghak , Jung Gwan Yeong , Baek Kyungeun , Chae Sujong , Kang Seok Ju , Cho Jaephil , Kwak Sang Kyu , Song Hyun‐Kon , Choi Nam‐Soon
Published: April 2020

High‐capacity Li‐rich layered oxide cathodes along with Si‐incorporated graphite anodes have high reversible capacity, outperforming the electrode materials used in existing commercial products. Hence, they are potential candidates for the development of high‐energy‐density lithium‐ion batteries (LIBs). However, structural degradation induced by loss of interfacial stability is a roadblock to their practical use. Here, the use of malonic acid‐decorated fullerene (MA‐C60) with superoxide dismutase activity and water scavenging capability as an electrolyte additive to overcome the structural instability of high‐capacity electrodes that hampers the battery quality is reported. Deactivation of PF5 by water scavenging leads to the long‐term stability of the interfacial structures of electrodes. Moreover, an MA‐C60‐added electrolyte deactivates the reactive oxygen species and constructs an electrochemically robust cathode‐electrolyte interface for Li‐rich cathodes. This work paves the way for new possibilities in the design of electrolyte additives by eliminating undesirable reactive substances and tuning the interfacial structures of high‐capacity electrodes in LIBs.
Factors driving cereal response to fertilizer microdosing in sub‐Saharan Africa: A meta‐analysis
Authors: Ouedraogo Yacouba , Taonda Jean‐Baptiste Sibiri , Sermé Idriss , Tychon Bernard , Bielders Charles L.
Published: April 2020

Fertilizer microdosing (FM) is being promoted in sub‐Saharan Africa (SSA) to boost crop productivity on smallholder farms. However, yield response variability is a barrier to adoption. We conducted a meta‐analysis to analyze the variability in cereal crop yield response to FM and to determine the main factors associated with this variability. Thirty publications pertaining to millet [Pennisetum glaucum (L.) R. Br.], sorghum (Sorghum bicolor L. Moench) or maize (Zea mays L.) were assessed. Factors analyzed were crop type, rainfall, soil texture, type and rate of fertilizer, and complementary practices. On average, FM improved millet, sorghum and maize crop yields by 68%. Yield response tended to increase with increasing rainfall and the largest yield gains were observed in medium‐textured soils (81%), as compared to light (61%) and heavy‐textured soils (30%). The combined application of N and P performed better than either element alone. Crop response tended to increase with increasing rates of N. In the case of P, this was true only on light textured‐soils. On medium‐textured soils, the response appeared independent of the rate of P. There was a synergetic effect of water conservation measures on the performance of FM, while combining FM with organic matter (OM) amendments decreased its performance. Results highlighted major trends in cereal crop response to FM that could be used to prioritize target areas. However, these may require additional, site‐specific field experiments, especially for factors for which little data is currently available.
Corporate social responsibility and dynamic productivity change in the US food and beverage manufacturing industry
Authors: Kapelko Magdalena , Oude Lansink Alfons , Guillamon‐Saorin Encarna
Published: April 2020

This study examines the relationship between corporate social responsibility (CSR) and dynamic productivity change of each input employed and investment undertaken in the US food and beverage manufacturing industry. We compute input‐ and investment‐specific dynamic Luenberger indicators and decompose them into the contributions of input‐ and investment‐specific dynamic technical inefficiency changes and dynamic technological changes. We then relate these indicators to an overall CSR measure and aspect‐specific CSR measures (governance, environment, and social). Our results confirm that the association between CSR and productivity change has different signs and effects on specific inputs or investments. We also find that only certain aspects of CSR participate in the association between CSR and dynamic productivity change and its components. [EconLit citations: C61, D24, L66, M14].
Chemical reaction modeling of industrial scale nitrocellulose production for military applications
Authors: Sullivan Francis , Simon Laurent , Ioannidis Nikolaos , Patel Subhash , Ophir Zohar , Gogos Costas , Jaffe Michael , Tirmizi Shakeel , Bonnett Peter , Abbate Philip
Published: April 2020

A model was developed to describe the nitration of cellulose in mixed acids used in the production of military grade nitrocellulose. Acid dissociation, swelling, diffusion, and chemical reaction were considered to model the nitration of industrially important cellulose materials for given reaction times and conditions. This model is supported by experimental work conducted to measure the dynamics of swelling and diffusion in wood pulp slivers, and the model was validated using the results of lab‐scale nitration reactions. Microcomputed tomography was also used to perform a structural analysis of wood pulp slivers that were cut on industrial, rotary cutting machines to evaluate features that may influence the reactivity of these materials.
Comment on “Realization of Lewis Basic Sodium Anion in the NaBH3−Cluster”
Authors: Pan Sudip , Frenking Gernot
Published: April 2020

We challenge the interpretation of the chemical bond in NaBH3−proposed by Liu et al. We argue that NaBH3−has an electron‐sharing Na−BH3−covalent bond rather than a dative bond Na−→BH3.
Structural Diversity and Magnetic Properties of Hybrid Ruthenium Halide Perovskites and Related Compounds
Authors: Vishnoi Pratap , Zuo Julia L. , Strom T. Amanda , Wu Guang , Wilson Stephen D. , Seshadri Ram , Cheetham Anthony K.
Published: April 2020

There has been a great deal of recent interest in extended compounds containing Ru3+ and Ru4+ in light of their range of unusual physical properties. Many of these properties are displayed in compounds with the perovskite and related structures. Here we report an array of structurally diverse hybrid ruthenium halide perovskites and related compounds: MA2RuX6 (X=Cl or Br), MA2MRuX6 (M=Na, K or Ag; X=Cl or Br) and MA3Ru2X9 (X=Br) based upon the use of methylammonium (MA=CH3NH3+) on the perovskite A site. The compounds MA2RuX6 with Ru4+ crystallize in the trigonal space group
and can be described as vacancy‐ordered double‐perovskites. The ordered compounds MA2MRuX6 with M+ and Ru3+ crystallize in a structure related to BaNiO3 with alternating MX6 and RuX6 face‐shared octahedra forming linear chains in the trigonal
space group. The compound MA3Ru2Br9 crystallizes in the orthorhombic Cmcm space group and displays pairs of face‐sharing octahedra forming isolated Ru2Br9 moieties with very short Ru–Ru contacts of 2.789 Å. The structural details, including the role of hydrogen bonding and dimensionality, as well as the optical and magnetic properties of these compounds are described. The magnetic behavior of all three classes of compounds is influenced by spin–orbit coupling and their temperature‐dependent behavior has been compared with the predictions of the appropriate Kotani models.
Der Feigenkaktus und die Cochenillelaus
Authors: Rösemann Ulrich
Published: April 2020

In der Sonne sitzen und genüsslich einen leicht bitteren Läuseextrakt zu sich nehmen – bis zum Jahr 2006 ganz normal – ohne dass sich der Konsument des berühmten Getränks geekelt hätte. Der Extrakt aus der Cochenille‐Laus wurde inzwischen durch einen synthetischen Farbstoff ersetzt. Dabei spielten sicherlich die Kosten eine ausschlaggebende Rolle. Aber auch heute noch wird natürliches Cochenille für die Rotfärbung von Textilien eingesetzt.
Das Zoologische Forschungsmuseum Alexander Koenig – Leibniz‐Institut für Biodiversität der Tiere
Authors: Heine Sabine
Published: April 2020

Das Forschungsmuseum Alexander Koenig hat eine lange Tradition als Bildungsort. Seit seiner Eröffnung im Jahre 1934 vereint es Forschung und Bildung in allen Bereichen der Zoologie. In den Anfängen der Bundesrepublik Deutschland spielte das Gebäude eine geschichtsträchtige Rolle und beherbergte kurz das Büro von Konrad Adenauer. Heute zeigt das Museum in der Dauerausstellung „Unser blauer Planet – Leben im Netzwerk“ die verschiedenen Lebensräume der Erde.
Electronic personal assessment questionnaire for vascular conditions (ePAQ-VAS): development and validity
Authors: Aber A , Phillips P , Hughes J , Keetharuth A D , Rooney G , Radley S , Walters S , Nawaz S , Jones G , Michaels J
Published: April 2020

Background

This paper describes the development and validation of an electronic personal assessment questionnaire for vascular conditions (ePAQ-VAS) that captures the symptomatology, quality of life and clinically relevant data of patients presenting to vascular services.

Methods

A two-stage survey was conducted in patients attending a tertiary vascular department. Patients completed the ePAQ-VAS remotely online, or on site using an electronic tablet. In the first stage of the survey, the responses were used to perform confirmatory factor analysis to assess the construct validity and remove redundant items. The internal reliability of disease-specific scales was investigated. In the second stage of the survey, the acceptability, known-group validity, test–retest reliability, and responsiveness of ePAQ-VAS was assessed.

Results

In total, 721 patients completed ePAQ-VAS. Their mean(s.d.) age was 63·5(15·7) years and 468 (64·9 per cent) were men. Some 553 patients (76·7 per cent) completed the questionnaire in clinic and the remainder completed the questionnaire online. The results of the confirmatory factor analysis confirmed the conceptual model for ePAQ-VAS structure and eliminated six items. Internal reliability was acceptable for all the scales (Cronbach's α greater than 0·7). The test–retest reliability measured by the intraclass correlation coefficient ranged from 0·65 to 0·99. The results showed that the instrument was responsive over time with the standardized response mean ranging from 0·69 to 1·60.

Conclusion

ePAQ-VAS is a holistic data-collection process that is relevant to vascular service users and has potential to contribute to patient-focused care and the collection of aggregate data for service evaluation. A demonstration version of the final version of ePAQ can be viewed at http://demo-questionnaire.epaq.co.uk/home/project?id=VASC_1.7&page=1.
The membranous septum revisited: A glimpse of our anatomical past
Authors: De Almeida Marcos C. , Sanchez‐Quintana Damian , Anderson Robert H.
Published: April 2020

The so‐called membranous septum is the fibrous component of the septal structures within the heart. It is relatively subtle in its appearance, but of considerable significance to the understanding of cardiac function and cardiac disease, both congenital and acquired. Surprisingly, its existence was seemingly unknown until the early decades of the 19th century. At this time, those writing in the English language described it as the “undefended space,” recognizing its importance in the setting of its aneurysmal dilation, and as the site of septal defects. By the initial decade of the 20th century, it had come to be recognized as the landmark to the site of atrioventricular bundle. Over the first decade of the 21st century, its clinical significance has been emphasized in the context of transcutaneous replacement of the aortic valve. In this review, we describe our own recent investigations of this fibrous part of the septal structures. At the same time, we provide a glimpse of our anatomic past, explaining how its initial description relied on the observations of young physicians taking their first steps in the investigation of cardiac anatomy.
Allelopathic Effects of Castanea henryi Aqueous Extracts on the Growth and Physiology of Brassica pekinensis and Zea mays
Authors: Ming Yue , Hu Guan‐Xing , Li Jing , Zhu Zhou‐Jun , Fan Xiao‐Ming , Yuan De‐Yi
Published: April 2020

The present study investigated the allelopathic effects of aqueous extracts of Castanea henryi litter on the growth and physiological responses of Brassica pekinensis and Zea mays. Treatment with high concentrations of leaf extract (0.05 g/ml for B. pekinensis and 0.10 g/ml for Z. mays) significantly increased malonaldehyde content and reduced seed germination, seedling growth, chlorophyll content, and the activity levels of antioxidant enzymes. These effects generally increased with increasing extract concentration. However, in Z. mays, low extract concentrations actually promoted seed germination, shoot growth, chlorophyll content, and antioxidant enzyme activity. The allelopathic effects of the various C. henryi extracts decreased as follows: leaf extract > twig extract > shell extract. Eleven potential allelochemicals including rutin, quercetin, luteolin, procyanidin A2, kaempferol, allantoin, propionic acid, salicylic acid, jasmonic acid, methylmalonic acid, and gentisic acid were identified in the leaves of C. henryi which were linked to the strongest allelopathic effects. These findings suggest that the allelopathic effects of C. henryi differ depending on receptor plant species, and that leaves are the most allelopathic litter in C. henryi.
Ion Dynamics of Water‐in‐Salt Electrolyte with Organic Solvents in Nanoporous Supercapacitor Electrodes
Authors: Li Changwen , Bo Zheng , Yang Huachao , Yang Jinyuan , Kong Jing , Wu Shenghao , Yan Jianhua , Cen Kefa , Ostrikov Kostya (Ken)
Published: April 2020

Water‐in‐salt electrolytes blended with organics solvents, that is, organic solvent/water mixed electrolytes, are promising for applications in next‐generation energy storage devices vitally needed for industrial electrification and decarbonization. However, the electrolyte ion diffusion behaviors within nanoporous supercapacitor electrodes are poorly understood. Here a systematic investigation into supercapacitor resistances and ion kinetics is carried out experimentally and with numerical simulations. The electrochemical results on the nanoporous electrodes reveal a nonmonotonic (decreasing, increasing, and then decreasing) trend of supercapacitor resistances with increasing solvent mobility, challenging the long‐held views that supercapacitor resistances decrease with elevated mobility of organic solvent. The abnormal trend is examined by numerical molecular dynamics simulations of electrolyte ion diffusion within 0.95 nm nanochannels. The electrolyte conductivity is related to cation–anion interactions within nanochannels. We further confirm the crucial interplay of the van der Waals sizes of solvent molecules and channel width in determining electrolyte conductivity in nanoporous electrodes.