bluuebunny/crossref_metadata_2025 huggingface dataset:
Glycolytic pathway intermediates activate cardiac ryanodine receptors
Authors: Kermode Helen , Chan Wei Mun , Williams Alan J. , Sitsapesan Rebecca
Published: July 2002

During myocardial ischaemia and reperfusion, enhancement of glycolytic activity occurs and this may lead to fluctuating levels of glycolytic intermediates [1–3]. We demonstrate that sugar phosphate intermediates of glycolysis, particularly fructose‐1,6‐diphosphate (FDP; 100 μM–10 mM), can activate sheep cardiac ryanodine receptor (RyR) channels incorporated into bilayers (open probability (Po) increases up to approximately 0.6) and stimulate [3H]ryanodine binding (>200%) to isolated cardiac sarcoplasmic reticulum (SR) membrane vesicles. The relative effectiveness of the sugar phosphates in stimulating [3H]ryanodine binding and increasing the Po of the channels was FDP>glucose‐1‐phosphate (G‐1‐P)>fructose‐6‐phosphate (F‐6‐P)>glucose‐6‐phosphate (G‐6‐P). These novel properties of the sugar phosphate compounds indicate that changes in glycolytic flux may influence the release of SR Ca2+ by modulating RyR channel gating.
Estrogen protects neuronal cells from the cytotoxicity induced by acetylcholinesterase‐amyloid complexes
Authors: Bonnefont Andrea B , Muñoz Francisco J , Inestrosa Nibaldo C
Published: July 2002

The senile plaques present in Alzheimer's disease (AD) are composed of a core of amyloid β‐peptide (Aβ) plus several proteins including acetylcholinesterase (AChE). Recently we found that AChE forms complexes with the Aβ peptide in vitro and that these are more cytotoxic than Aβ fibrils alone. Considering that estrogen has been reported to act as a protective agent against Aβ‐induced cytotoxicity, the effect of 17β‐estradiol was studied in rat pheochromocytoma (PC12) and mouse neuroblastoma (Neuro 2a) cells exposed to either Aβ alone or AChE‐Aβ complexes. Estrogen showed a powerful protective effect in response to the challenge of AChE‐Aβ complexes as well as with Aβ fibrils. This was also the case for other cytotoxic agents such as glutamate and H2O2. Our results suggest a common mechanism for cellular protection by estrogen against the toxicity of both Aβ fibrils and AChE‐Aβ complexes, likely avoiding the free radical apoptotic pathway.
Irreversible conversion of xanthine dehydrogenase into xanthine oxidase by a mitochondrial protease
Authors: Saksela Mika , Lapatto Risto , Raivio Kari O
Published: July 2002

Irreversible conversion of xanthine dehydrogenase (XDH) to its oxygen free radical producing oxidase (XO) form occurs through an uncharacterized proteolytic process, which was studied in human liver. Upon incubation of fresh unfrozen liver cytosol, XDH remained intact. When recombinant human XDH was coincubated with subcellular fractions of human liver, the mitochondrial intermembrane space was shown to contain a heat‐labile activity that converted XDH irreversibly to XO. This activity is resistant to inhibitors of all major groups of proteases. We postulate that this novel type of proteolytic enzyme is released into the cytosol upon mitochondrial damage.
Locust corpora cardiaca contain an inactive adipokinetic hormone
Authors: Siegert Karl J.
Published: July 2002

A neuropeptide from the migratory locust, Locusta migratoria, has been identified as a novel member of the family of adipokinetic hormones (AKHs). The peptide is probably synthesised in the brain because it is the first AKH found in the storage lobe, whilst the three ‘classic' Locusta AKHs are present in the glandular lobe of the corpora cardiaca. In locusts, the peptide has no biological activity usually associated with AKHs. There is only 36–56% sequence identity with the three Lom‐AKHs, but 78% identity with the Drosophila melanogaster AKH, Drm‐HrTH. The new peptide is active in the American cockroach, Periplaneta americana, and was provisionally named ‘L. migratoria hypertrehalosaemic hormone', Lom‐HrTH; its biological role in locusts remains to be established. The high degree of identity with Drm‐HrTH suggests that Lom‐HrTH is an ancient molecule.
Transforming growth factor‐β1 inhibits expression of selenoprotein P in cultured human liver cells
Authors: Mostert Volker , Dreher Ingeborg , Köhrle Josef , Abel Josef
Published: July 2002

The effect of cytokines on the expression of selenoprotein P (SeP) in the human liver cell line HepG2 was investigated. Treatment with interleukin‐1β, interferon‐γ, and tumor necrosis factor‐α had no effect on SeP levels in culture media or on SeP mRNA expression. Conversely, Western analysis revealed a dose‐dependent reduction of SeP content in culture medium after treatment with transforming growth factor (TGF)‐β1 with an IC50 of 31 pM. Treatment with 100 pM TGF‐β1 for 48 h led to a decrease to 21±9% of controls. RT‐PCR analysis of SeP mRNA expression demonstrated an inhibition of SeP transcription to 40±2% of control levels after 24 h. The expression of a luciferase reporter construct under control of the human SeP promoter was downregulated by TGF‐β1 treatment in a dose‐dependent fashion indicating a transcriptional regulation of the SeP gene by TGF‐β1.
Phage display reveals a novel interaction of human tear lipocalin and thioredoxin which is relevant for ligand binding
Authors: Redl Bernhard , Merschak Petra , Abt Beate , Wojnar Petra
Published: July 2002

Human tear lipocalin (TL) is an unusual member of the lipocalin protein family, since it is known to bind a large variety of lipophilic ligands in vivo and acts as a cysteine proteinase inhibitor in vitro. It is suggested to function as a physiological protection factor by scavenging lipophilic potentially harmful compounds. Since protein‐protein interaction or macromolecular complexation is a common feature of many lipocalins, we applied phage display technology to identify TL interacting proteins. By panning of a human prostate cDNA phagemid library against purified TL we isolated a thioredoxin (Trx) encoding phage clone. Biochemical analysis revealed that TL indeed interacts with Trx and is reduced by this redox protein. Reduction of the TL‐specific disulfide bond is of functional relevance, since the reduced protein shows a nine‐fold increase in ligand affinity when tested with retinoic acid as ligand.
The management of gestational trophoblastic disease in developing countries such as malaysia
Authors: Sivanesaratnam V.
Published: July 2002

Gestational trophablastic disease is a common gynaecological problem in Malaysia. The incidence of molar pregnancy is 2.8 per 1000 deliveries, being more common amongst the Chinese. The preferred method of evacuation is suction curettage; complete evacuation of the uterus was not achieved at the first attempt in 25 per cent of cases. Partial moles in our centre comprised 30 per cent of all moles. This is potentially malignant and needs follow‐up for a complete mole. In the management of an invasive mole, chemotherapy should not be withheld in the presence of metastases and failure of regression of hCG. The role of prophylactic hysterectomy and prophylactic chemotherapy in the management of molar pregnancyis discussed “Selective preventive chemotherapy” in patients at “risk” appears appropriate. Chemotherapy remains the main modality of treatment for gestational trophoblastic tumours (GTT). We categorised our patients into low, medium and high‐risk groups; survivals were 100, 98, and 61.7 percent respectively. These patients when categorised according to FIGO staging had survivals of 100, 80, 78.6 and 68.2 per cent respectively for stages 1, 2, 3 and 4 respectively. The reasons for the poor suvival in the ‘high‐risk’ group are discussed. Colour doppler blood flow studies are now being carried out; its role needs further evaluation. Surgery and radiotherapy have only a limited role in the management of these cases.
Changing face of gestational trophoblastic tumor
Authors: Martin B.H. , Kim J.H.
Published: July 2002

During the years there have been many advances in the diagnosis and treatment of gestational trophoblastic tumor (GTT) with marked improvement in the outcome. At the same time in Korea there have been many social and economic changes which also have had a marked influence on the outcome. The purpose of this study was to review the changes that have occured among patients admitted to Il Sin Christian Hospital, Pusan, Korea over the past four dccades.
An empirical test of the rigid flexibility model
Authors: Collins Robert S , Cordon Carlos , Julien Denyse
Published: July 2002

This paper summarises the findings of an empirical study to test the validity of the ‘rigid flexibility’ [Collins, R.S., Schmenner, R., 1993. Achieving rigid flexibility: factory focus for the 1990s. Eur. Manage. J., 11 (4) 443–447.] model for manufacturing strategy. The basic tenet of the model is that flexibility in manufacturing, and thereby responsiveness to market requirements, is achieved through simplicity in process and discipline in procedures. The empirical study was carried out using the merged Made in Europe (Hanson et al., 1994) and Made in Switzerland (Collins et al., 1996) database, derived from a benchmarking study of manufacturing practice and performance at some 800 plants in five European countries. The model is considered in relation to two other models for manufacturing strategy, namely the trade‐off and cumulative models. In addition, differences between countries in the adoption of the rigid flexibility model are also considered. The results of the empirical test of the rigid flexibility model were positive, and the model has proven to be valid and applicable in whole or in part across several European countries.
Conditional immortalization of hair cells from the inner ear
Authors: Holley M.C. , Nishida Y. , Grix N.
Published: July 2002

The aim of this work was to culture conditionally immortalized cells that possess the potential to differentiate into mechanosensory hair cells. Utricular epithelia at embryonic stage E16 were cultured from the vestibular system of the H2kbtsA58 transgenic mouse (Immortomouse) that carries a conditionally expressed immortalizing gene derived from the simian virus 40. Immunolabelling showed that the immortalizing transgene product, the T antigen (Tag), was expressed in utricular cells under permissive conditions and that it was inactivated under non‐permissive conditions. Several morphologically distinct cell types proliferated when Tag was expressed, including those that resembled fibroblasts, nerve cells and epithelial cells. Mixed cultures of cells from the utricle, passaged up to 50 times every 3–4 days over a period of 5 months, were subsequently allowed to differentiate for 10 days by transferring them to non‐permissive conditions. Monoclonal antibody markers were used to locate expression of hair cell specific antigens. One antibody that normally labels stereociliary bundles from postnatal stage P4–6 labelled cellular projections from a population of spheroid cells that were distributed across the culture surface. A second antibody that normally labels stereociliary bundles did not label the same structures. We conclude that utricular hair cell progenitors can be derived from the H2kbtsA58 transgenic mouse but that under the experimental conditions used they do not follow the normal pattern of differentiation.
Predictors of compliance with neuroleptic medication among inpatients with schizophrenia: a discriminant function analysis
Authors: Donohoe G. , Owens N. , O’Donnell C. , Burke T. , Moore L. , Tobin A. , O’Callaghan E.
Published: July 2002

Objective. To identify clinically useful predictors of adherence to medication among persons with schizophrenia. Method. We evaluated levels of compliance with neuroleptic medication among 32 consecutive admissions with DSM-III-R schizophrenia from a geographically defined catchment area using a compliance interview. We also assessed symptomatology, insight, neurological status and memory. Results. Less than 25% of consecutive admissions reported being fully compliant. Drug attitudes were the best predictor of regular compliance, symptomatology the best predictor of noncompliance, and memory the best predictor of partial compliance with neuroleptic medication. Conclusions. These data emphasise the complexity of factors that influence whether a person adheres to his medication regimen. Furthermore, they suggest that these factors may vary within the same person over time.
Differences in interleukins’ patterns between dysthymia and major depression
Authors: Schlatter J. , Ortuño F. , Cervera-Enguix S.
Published: July 2002

We assessed whether cytokine production–interleukin (IL)-1β, IL-6 and tumour necrosis factor-α (TNFα)–is affected in depressed patients, dysthymia (Dt) and major depression (MD), and its association with various parameters of severity and clinical course. We found a possible different pattern of interleukin production between Dt and MD.
Historical memory as a source of conflicts in Eastern Europe1
Authors: Jedlicki Jerzy
Published: July 2002

Memory of collective wrongs and atrocities suffered in the past from another nation or ethnic group often burdens a present conflict with strong resentment and makes it appear as a historical repetition or redress. There are many examples in recent history of Eastern Europe, the Balkans included, when vivid and deliberately inflamed historical reminiscences make it virtually impossible to negotiate a compromise solution of a crisis. Only when national memory has been “cooled” and sacrosanct historical places and symbols has lost some of their mobilizing force, may human relations between the enemy communities be restored.
Holding company affiliation versus branching by independent banks: A cost analysis for interstate banking
Authors: Chen Joyce T. , Chen Chong‐Tong , Rezvanian Rasoul
Published: July 2002

Prohibition of interstate branching forced nearly all banks interested in interstate expansion to establish holding company affiliations. But it is not clear whether holding‐company affiliation or branching by independent banks is preferable for consumers. By contrasting 1994 data of consolidated multibank holding companies with that of independent banks with branches, we assess their relative scale economies and cost advantages by asset size. Our analysis supports the assertion of the U. S. Department of Treasury that expansion through interstate branching would provide immediate cost savings and increase consumer benefits.
Identifying sources of metabolomic diversity and reconfiguration in peach fruit: taking notes for quality fruit improvement
Authors: Drincovich María F.
Published: June 2021

The metabolomic content determines many of the important features of a fruit, such as its taste, flavor, color, nutritional value, and abiotic or biotic resistance. Peach (Prunus persica (L.) Batsch) is one of the best genetically characterized species used as a model for Rosaceae, the drupes of which are a source of minerals, vitamins, fiber, and antioxidant compounds for healthy diets around the world. During the last few years, a great advance in the analysis of the metabolic diversity and reconfiguration in different peach varieties in response to developmental and environmental factors has occurred. These studies have shown that the great phenotypic diversity among different peach varieties is correlated with differential metabolomic content. Besides, the fruit metabolome of each peach variety is not static; on the contrary, it is drastically configured in response to both developmental and environmental signals, and moreover, it was found that these metabolic reconfigurations are also variety dependent. In the present review, the main sources of metabolic diversity and conditions that induce modifications in the peach fruit metabolome are summarized. It is postulated that comparison of the metabolic reconfigurations that take place among the fruits from different varieties may help us better understand peach fruit metabolism and their key drivers, which in turn may aid in the future design of high‐quality peach fruits.
Interpretative Phenomenological Analysis in Genetics Research
Authors: Starr Rachel A , Smith Jonathan A
Published: June 2021

Interpretative phenomenological analysis (IPA) is a qualitative approach to psychological research with epistemological roots in phenomenology, hermeneutics and idiography. IPA involves an in‐depth focus on phenomena from the perspective of the lived experience of participants who are considered in their social and personal contexts. IPA has a strong history of use in health psychology and subsequently has become popular across a wide range of research areas. IPA has been used to explore the often complex psychological issues associated with genetic and genomic science and medicine. A range of experiential questions such as how individuals perceive risk, the quandaries associated with getting a genetic test, what is felt to be helpful in genetic counselling, how people understand genetic transmission such as in the case of gamete donation, and the experiences of those living with, or affected by, genetic conditions in a plethora of ways, have all been beneficially investigated.

Key Concepts

Interpretative phenomenological analysis (IPA) is a qualitative approach to psychological research which allows researchers to conduct detailed explorations of how individuals make sense of their personal and social worlds.

IPA is based on a commitment to explore, interpret and attempt to understand participants' situated experiences, rather than categorise, measure or quantify aspects of mental life.

The psychological issues associated with genetics and genomics may be complex, emotive, dilemmatic and dynamic and present different demands upon psychological research from those generated by nongenetic areas of science and medicine.

IPA was developed to be methodologically adaptive and versatile and is thus well suited to respond to the growing range of questions about health, reproduction and indeed human life generated by expanding genetic and genomic knowledge.

IPA has been used to explore psychological aspects of genetics and genomics such as the perception of risk, experiences of genetic counselling, the complexities of living with a genetic condition both for affected individuals and also their families, carers and clinicians, questions associated with genetic testing and understandings of genetic transmission such as gamete donation or being a carrier of a genetic condition.

Expanding genetic and genomic knowledge has led to increasing opportunities for researchers, clinicians and individuals to ask a growing range of questions about health, reproduction and indeed human life. As genetic and genomic science continues to develop, the sensitivity and flexibility conferred by IPA continue to offer a particular suitability towards this expanding area and the new or unfamiliar issues which may yet emerge.
Ethical Issues Affecting the Healthcare of Minor Adolescents and Their Participation in Research
Authors: Michaud Pierre‐André
Published: June 2021

Health professionals providing care to adolescents aged 10–19, or those conducting research face numerous ethical issues linked with the unique characteristics of minor individuals, neither children nor adults usually considered as fully competent. This contribution reviews the general principles of clinical ethics as applied to minor adolescents; it proposes a structured approach to assessing the autonomous decision‐making capacity of the young patient; it then provides a step‐by‐step procedure as how to address situation raising ethical dilemmas or conflicts, both in clinical situation and in instances leading to the involvement of the adolescent in a clinical trial. It stresses the pivotal role of the health care professional in respecting the adolescednts' rights and in establishing a respectful, empathetic and trustful relationship with his young patient, as well as the usefulness to involve in any situation parents or caregivers in the discussion, with the adolescent's consent.

Key Concepts

Minor adolescents, neither children nor fully competent adults, have specific health care needs such as the respect of privacy and their involvement in decision‐making.

Even as minor individuals, adolescents have a right to participate in decision affecting their health, and in some instances to benefit from confidentiality.

In adopting an empathetic and respectful communication style, the health care professional improved the adolescent's capacity for autonomous decision‐making.

The health care professional can address situations raising ethical dilemmas in a step‐by‐step structured process which – whenever possible – also include the participation of the parents or caregivers.

The principles and strategies proposed in the article apply to clinical care as well as the inclusion of adolescents in clinical trials implying the use of new drugs or devices.
Ion Channels
Authors: Lipscombe Diane , Toro Cecilia P
Published: June 2021

Ion channels are membrane proteins that create specialised routes for ions to cross cell membrane lipid bilayers with high selectivity and at relatively high speeds. All cells of all organisms use ion channels to control a range of functions. The majority of electrical membrane signals originate from the flow of select ions through ion channels. Cellular control of ion channel activity is critical for unicellular and multicellular organisms to respond to their environments. Avoiding external threats, seeking nutrients, adapting to normal developmental processes, creating memories and modifying outputs according to previous events all involve ion channel activity. Ion channel dysfunction underlies multiple human disorders and diseases: developmental disorders, pain syndromes that include extreme pain as well as congenital indifference to pain, certain types of migraines, epilepsies, ataxias, paralyses, cardiac arrhythmias, developmental disorders, psychiatric illness, male infertility, immunodeficiency and renal failure can all be due to malfunctioning ion channels. Thus, ion channels are critically important drug targets for the treatment of a great many illnesses and disorders in multiple organs and body systems.

Key Concepts

Ion channels are found in all living cells.

Ion channels create specialised routes for ions to cross biological cell membranes.

Ion concentration gradients create ion driving forces that regulate membrane potential.

Ion channels are gated (opened and closed) by a wide range of biological signals.

Ion channels are selectively permeable to specific ions.

A range of extracellular, intracellular and membrane signals alter the activity of ion channels.

Abnormal ion channel function underlies many disorders and diseases.
Porifera (Sponges): Recent Knowledge and New Perspectives
Authors: Borchiellini Carole , de Pao Mendonca Kassandra , Vernale Amélie , Rocher Caroline , Ereskovsky Alexander , Vacelet Jean , Renard Emmanuelle
Published: June 2021

Porifera, commonly named sponges, are devoid of head, digestive tract, nervous system, muscles or any other organs. Despite this anatomical and morphological simplicity, they are true animals or metazoans. Sponges are a successful group of mostly marine filter feeders that represent a major life form of several aquatic ecosystems. Efficient water filtration is performed by a network of pores (at the origin of their name), chambers and canals. Sponges are currently considered as one of the best candidates as sister group to all other animals; these organisms have therefore a key phylogenetic position. Recent studies have shown that they possess an unexpected molecular complexity raising exciting questions about early animal evolution. These results yielded an increased interest in the biology of these strange animals, and some sponge species can be considered as biological experimental models.

Key Concepts

As adults, sponges are sedentary filter feeder animals.

The water flow is canalised in an aquiferous system composed of inhalant and exhalant pores (ostia and oscula), canals and choanocyte chambers.

At present, the number of formally described sponge species is more than 9000.

Sponges are divided into four clades (rank Class): Hexactinellida, Demospongiae, Calcarea and Homoscleromorpha.

As sponges are devoid of organs, their individual cells or cell layers ensure vital functions. One cell type may have several functions.

Sponges have high regeneration capabilities as well as a high capacity of cell transdifferentiation.

Sponges often use both asexual and sexual reproduction.

Most of the key transcription families and main signalling pathways required for other metazoans development and body patterning are present in sponges.

The increasing interest for sponge biology improves our understanding of animal evolution and marine ecosystems.
Macular Degeneration, Age Related
Authors: Haim Liron Naftali Ben , Duncan Jacque L , Zayit‐Soudry Shiri
Published: June 2021

Macular degeneration comprises a group of diseases characterised by progressive deterioration of the retinal photoreceptors, retinal pigment epithelial cells and underlying choriocapillaris, causing progressive central vision loss. The most common form of macular degeneration is age‐related macular degeneration (AMD), the leading cause of irreversible blindness among elderly patients in developed countries. Other types of hereditary early‐onset macular dystrophies share clinical characteristics with AMD, but a monogenetic basis for many of these conditions has been found. Recent advances in clinical and genetic research have led to a better understanding of the genetics and pathophysiology of AMD, which is currently viewed as a complex disorder in which multiple susceptibility genes combined with environmental factors play a role. The management of neovascular AMD has changed dramatically with the introduction of anti‐VEGF drugs, but treatment options for other types of macular degeneration remain limited because the aetiology and pathogenesis are incompletely defined.

Key Concepts

Macular degeneration refers to a group of diseases characterised by photoreceptor cell degeneration and death, leading to central vision loss.

Recent advances in optical coherence tomography (OCT) technology have led to its major role in diagnosis and management of macular degeneration.

Monthly follow‐up of patients with neovascular AMD is recommended for best visual outcome.

Regular anti‐VEGF therapy with intravitreal injections of ranibizumab, aflibercept or bevacizumab is currently considered to be the standard treatment for neovascular AMD.

Ongoing clinical trials are investigating the efficacy and safety of combination treatments for neovascular AMD and treatments for other forms of macular degeneration.

Research efforts are directed at prevention of AMD and stem cell and gene therapy treatments for Stargardt disease.
Design of PI controller parameters of a CSI‐fed SCIM drive ensuring high damping ratio and maximum system stability
Authors: Tripathi Saurabh Mani , Vaish Rachna , Pandey Ashok Kumar
Published: June 2021

The control scheme for an electric motor drive is generally implemented by involving proportional‐integral (PI) controllers in current and speed feedback control loops. A good design of PI controller parameters has always been a challenging task for control system design engineers. This paper describes the D‐decomposition method for the design of the parameters of involved DC‐link current and speed PI controllers in closed‐loop scheme of a pulse width‐modulated, current source inverter (CSI)‐fed squirrel‐cage induction motor drive. The PI controllers ensure the stable operation of CSI‐fed induction motor in natural unstable operating region of its torque‐slip characteristic. In order to achieve smoother speed tracking performance with minimum overshoot/undershoot, the damping ratio has been pre‐specified while designing the PI controller parameters using the D‐decomposition method. Simulation results have been presented to confirm the design and have been compared with the results already published.
Re‐Looking into the Active Moieties of Metal X‐ides (X‐ = Phosph‐, Sulf‐, Nitr‐, and Carb‐) Toward Oxygen Evolution Reaction
Authors: Luo Ruipeng , Qian Zhengyi , Xing Lixin , Du Chunyu , Yin Geping , Zhao Shenlong , Du Lei
Published: June 2021

Non‐precious metal‐based catalysts for oxygen evolution reaction (OER) have been extensively studied, among which the transition metal X‐ides (including phosph‐ides, sulf‐ides, nitr‐ides, and carb‐ides) materials are emerging as promising candidates to replace the benchmark Ir/Ru‐based materials in alkaline media. However, it is controversial whether the metal Xides host the real active sites since these metal Xides are thermodynamically unstable under a harsh OER environment—it has been reported that the initial metal Xides can be electrochemically oxidized and transformed into corresponding oxides and (oxy)hydroxides. Therefore, the metal Xides are argued as “pre‐catalysts”; the electrochemically formed oxides and (oxy)hydroxides are believed as the real active moieties for OER. Herein, the recent advances in understanding the transformation behavior of metal Xides during OER are re‐looked; importantly, hypotheses are provided to understand why the electrochemically formed oxides and (oxy)hydroxides catalysts derived from metal Xides are superior for OER to the as‐prepared metal oxides and (oxy)hydroxides catalysts.
Energy Storage Mechanism, Challenge and Design Strategies of Metal Sulfides for Rechargeable Sodium/Potassium‐Ion Batteries
Authors: Pan Qingguang , Tong Zhaopeng , Su Yuanqiang , Qin Sheng , Tang Yongbing
Published: June 2021

Rechargeable sodium/potassium‐ion batteries (SIBs/PIBs) with abundant reserves of Na/K and low cost have been a promising substitution to commercial lithium‐ion batteries. As for pivotal anode materials, metal sulfides (MSx) exhibit an inspiring potential due to the multitudinous redox storage mechanisms for SIBs/PIBs applications. Nevertheless, they still confront several bottlenecks, such as the low electrical conductivity, poor ionic diffusivity, sluggish interfacial/surface reaction kinetics, and severe volume expansion, which distinctly restrain the battery performance. Meanwhile, the systematic insights into the design strategies of MSx for SIBs/PIBs have been seldom elaborated. In this review, the energy storage mechanism, challenge, and design strategies of MSx for SIBs/PIBs are expounded to address the above predicaments. In particular, design strategies of MSx are highlighted from the aspects of morphology modifications involving 1D/2D/3D configurations, atomic‐level engineering containing heteroatom doping, vacancy creation, and interlayer spacing expansion, and MSx composites with other MSx, metal oxides, carbonaceous, and graphite materials to boost the comprehensive electrochemical performance of SIBs/PIBs. Furthermore, prospects are presented for the further advance of MSx to surmount imminent challenges, hoping to forecast feasible future orientations in this field.
Achieving 256 × 256‐Pixel Color Images by Perovskite‐Based Photodetectors Coupled with Algorithms
Authors: Ji Zhong , Liu Yujin , Yao Manhong , Zhang Zibang , Zhong Jingang , Mai Wenjie
Published: June 2021

Perovskites have been found with their exceptional optoelectronic properties that may bring new options to high‐performance cameras. However, the best images obtained by perovskite‐based photodetectors (PDs) have only 32 × 32 pixels, far below megapixels of camera images. In this study, a perovskite single‐PD color imaging prototype coupled with computation algorithms is fabricated, by which images with 256 × 256 pixels, whose quality has prevailed over those obtained by any perovskite‐based device so far are obtained. The technology shows its unique advantages by obtaining satisfying photographs, even when the PD is covered with frosted glass/moving smoke or facing a wall instead of the target, in addition to possessing some ability to resist ambient light interference. Moreover, a new Q factor is proposed to evaluate new‐material‐based PD for the imaging technology and prove its usability by comparing an atomic‐layer‐deposition (ALD)‐Al2O3 optimized CsBi3I10 PD and an unoptimized CsBi3I10 PD. Finally, the material choices are successfully extended to other types of perovskites, including photovoltaic MAPbI3 PD (structure: Spiro‐OMeTAD/MAPbI3/SnO2/FTO), ALD‐Al2O3 MAPbI3 PD, and ALD‐Al2O3 CsPbBr3 PD. The technology may bring an innovative approach to improve the performance of cameras and extend the application range of advanced functional materials.
Designed Giant Room‐Temperature Electrocaloric Effects in Metal‐Free Organic Perovskite [MDABCO](NH4)I3 by Phase–Field Simulations
Authors: Gao Rongzhen , Shi Xiaoming , Wang Jing , Zhang Guangzu , Huang Houbing
Published: June 2021

Achieving a colossal room‐temperature electrocaloric effect is essential for practical solid‐state refrigeration applications with low‐cost and high‐efficiency. Here, through the design of applying external stimuli (hydrostatic pressure and misfit strain), giant room‐temperature electrocaloric effects in the bulk and thin film of metal‐free organic perovskite [MDABCO](NH4)I3 are obtained by using a combination of thermodynamic calculations and phase–field simulations. Under the hydrostatic pressure of 1 GPa, there emerges excellent room‐temperature (300 K) electrocaloric performance with the temperature change (ΔT) of 8.41 K at 30 MV m−1 and electrocaloric strength (ΔT/ΔE) of 0.63 K m MV−1 at 10 MV m−1, respectively. The prominent electrocaloric effects of MDABCO(NH4)I3 may be related to its rapid change rates of free energy barrier height. Additionally, it can be found that some stripe domains and non‐180° domain walls form in the [MDABCO](NH4)I3 bulk, which is consistent with the experimental results. This work not only provides new insights into organic perovskite [MDABCO](NH4)I3, but also guides for further developing to realize remarkable room‐temperature electrocaloric cooling.
High‐Performance ITO‐Free Perovskite Solar Cells Enabled by Single‐Walled Carbon Nanotube Films
Authors: Zhang Jing , Hu Xiangang , Li Hui , Ji Kangyu , Li Bowei , Liu Xueping , Xiang Yuren , Hou Pengxiang , Liu Chang , Wu Zhiheng , Shen Yonglong , Stranks Samuel D. , Silva S. Ravi P. , Cheng Hui‐Ming , Zhang Wei
Published: June 2021

The unprecedented advancement in power conversion efficiencies (PCEs) of perovskite solar cells (PSCs) has rendered them a promising game‐changer in photovoltaics. However, unsatisfactory environmental stability and high manufacturing cost of window electrodes are bottlenecks impeding their commercialization. Here, a strategy is introduced to address these bottlenecks by replacing the costly indium tin oxide (ITO) window electrodes via a simple transfer technique with single‐walled carbon nanotubes (SWCNTs) films, which are made of earth‐abundant elements with superior chemical and environmental stability. The resultant devices exhibit PCEs of ≈19% on rigid substrates, which is the highest value reported to date for ITO‐free PSCs. The facile approach for SWCNTs also enables application in flexible PSCs (f‐PSCs), delivering a PCE of ≈18% with superior mechanical robustness over their ITO‐based counterparts due to the excellent mechanical properties of SWCNTs. The SWCNT‐based PSCs also deliver satisfactory performances on large‐area (1 cm2 active area in this work). Furthermore, these SWCNT‐based PSCs can retain over 80% of original PCEs after exposure to air over 700 h while ITO‐based devices only sustain ≈60% of initial PCEs. This work paves a promising way to accelerate the commercialization of ITO‐free PSCs with reduced material cost and prolonged lifetimes.
Measurement of Onset of Structural Relaxation in Melt‐Quenched Phase Change Materials
Authors: Kersting Benedikt , Sarwat Syed Ghazi , Le Gallo Manuel , Brew Kevin , Walfort Sebastian , Saulnier Nicole , Salinga Martin , Sebastian Abu
Published: June 2021

Chalcogenide phase change materials enable non‐volatile, low‐latency storage‐class memory. They are also being explored for new forms of computing such as neuromorphic and in‐memory computing. A key challenge, however, is the temporal drift in the electrical resistance of the amorphous states that encode data. Drift, caused by the spontaneous structural relaxation of the newly recreated melt‐quenched amorphous phase, has consistently been observed to have a logarithmic dependence in time. Here, it is shown that this observation is valid only in a certain observable timescale. Using threshold‐switching voltage as the measured variable, based on temperature‐dependent and short timescale electrical characterization, the onset of drift is experimentally measured. This additional feature of the structural relaxation dynamics serves as a new benchmark to appraise the different classical models to explain drift.
Bioinspired Self‐Assembling Materials for Modulating Enzyme Functions
Authors: Du Peidong , Xu Shichao , Xu Zhi‐Kang , Wang Zhen‐Gang
Published: June 2021

Enzymes tend to malfunction when they work out of their natural cellular environments. Engineering a favorable microenvironment around enzymes has emerged as an effective strategy to finely tune the enzymatic functions and reshape the biocatalytic activities. Supramolecular self‐assembly provides a bottom‐up approach for spatial arrangement of functional groups and fabrication of materials with tailorable local properties. In this review, the progress in designing, creating, and tailoring the enzyme microenvironments is discussed, with the bioinspired self‐assembling materials as the scaffolds built from molecular building blocks. The relationship between the physicochemical properties and the local environments (pH, substrates, or hydration) of the scaffolds, and the catalytic properties of the scaffolded enzymes are focused upon. The power of the self‐assembly to regulate the catalytic systems dynamically is also highlighted. In the end, an outlook on the obstacles, possible solutions, and future directions on the microenvironment engineering of enzymes is provided.
Improved Small Extracellular Vesicle Secretion of Rat Adipose‐Derived Stem Cells by Microgrooved Substrates through Upregulation of the ESCRT‐III‐Associated Protein Alix
Authors: Ji Yurong , Han Weiju , Fu Xiaoling , Li Jing , Wu Qi , Wang Yingjun
Published: June 2021

Mesenchymal stem cell‐derived small extracellular vesicles (MSC‐sEVs) hold great potential for regenerative therapies and have received considerable research attention in recent years. However, the use of MSC‐sEVs is limited by very low yield in routine culture conditions and suboptimal potency for certain diseases. Thus, strategies that enable the production of sufficient quantities of sEVs with desired therapeutic cargo in a facile and inexpensive way are in high demand. This study finds that the microgrooved substrates stimulate rat adipose‐derived mesenchymal stem cells (rASCs) to produce a larger quantity of sEVs than the flat substrates. Further investigation suggests that the ESCRT‐III‐associated protein Alix may be involved in mediating the elevated sEV production of rASCs on the microgrooved substrates. Besides, the cargo of sEVs is altered. SEVs secreted by rASCs on the microgrooved substrates carry higher levels of proangiogenic miRNAs and growth factors than those secreted by rASCs on the flat substrates. Functional assessments demonstrate that sEVs from rASCs on microgrooved substrates enhance the angiogenic properties of Human umbilical vein endothelial cells. The findings demonstrate that substrate topography is an effective regulator of the sEVs secretion by rASCs and highlight the potential of using microgrooved substrates as a platform to produce rASC‐sEVs rich in pro‐angiogenic factors.
Magnetoelectric Nanoparticles Incorporated Biomimetic Matrix for Wireless Electrical Stimulation and Nerve Regeneration
Authors: Zhang Yusheng , Chen Suping , Xiao Zhanwen , Liu Xiaoyin , Wu Chengheng , Wu Kai , Liu Amin , Wei Dan , Sun Jing , Zhou Liangxue , Fan Hongsong
Published: June 2021

Electrical stimulation is regarded pivotal to promote repair of nerve injuries, however, failed to get extensive application in vivo due to the challenges in noninvasive electrical loading accompanying with construction of biomimetic cell niche. Herein, a new concept of magneto responsive electric 3D matrix for remote and wireless electrical stimulation is demonstrated. By the preparation of magnetoelectric core/shell structured Fe3O4@BaTiO3 NPs‐loaded hyaluronan/collagen hydrogels, which recapitulate considerable magneto‐electricity and vital features of native neural extracellular matrix, the enhancement of neurogenesis both in cellular level and spinal cord injury in vivo with external pulsed magnetic field applied is proved. The findings pave the way for a novel class of remote controlling and delivering electricity through extracellular niches‐mimicked hydrogel network, arising prospects not only in neurogenesis but also in human–computer interaction with higher resolution.
Marked Passivation Effect of Naphthalene‐1,8‐Dicarboximides in High‐Performance Perovskite Solar Cells
Authors: Zhang Zhihao , Gao Yifeng , Li Zicheng , Qiao Lu , Xiong Qiu , Deng Longhui , Zhang Zilong , Long Run , Zhou Qin , Du Yitian , Lan Zhang , Zhao Yanfei , Li Chen , Müllen Klaus , Gao Peng
Published: June 2021

As game‐changers in the photovoltaic community, perovskite solar cells are making unprecedented progress while still facing grand challenges such as improving lifetime without impairing efficiency. Herein, two structurally alike polyaromatic molecules based on naphthalene‐1,8‐dicarboximide (NMI) and perylene‐3,4‐dicarboximide (PMI) with different molecular dipoles are applied to tackle this issue. Contrasting the electronically pull–pull cyanide‐substituted PMI (9CN‐PMI) with only Lewis‐base groups, the push–pull 4‐hydroxybiphenyl‐substituted NMI (4OH‐NMI) with both protonic and Lewis‐base groups can provide better chemical passivation for both shallow‐ and deep‐level defects. Moreover, combined theoretical and experimental studies show that the 4OH‐NMI can bind more firmly with perovskite and the polyaromatic backbones create benign midgap states in the excited perovskite to suppress the damage by superoxide anions (energetic passivation). The polar and protonic nature of 4OH‐NMI facilitates band alignment and regulates the viscosity of the precursor solution for thicker perovskite films with better morphology. Consequently, the 4OH‐NMI‐passivated perovskite films exhibit reduced grain boundaries and nearly three‐times lower defect density, boosting the device efficiency to 23.7%. A more effective design of the passivator for perovskites with multi‐passivation mechanisms is provided in this study.
Effective Piezo‐Phototronic Enhancement of Flexible Photodetectors Based on 2D Hybrid Perovskite Ferroelectric Single‐Crystalline Thin‐Films
Authors: Ding Ran , Lyu Yongxin , Wu Zehan , Guo Feng , Io Weng Fu , Pang Sin‐Yi , Zhao Yuqian , Mao Jianfeng , Wong Man‐Chung , Hao Jianhua
Published: June 2021

2D hybrid perovskites are very attractive for optoelectronic applications because of their numerous exceptional properties. The emerging 2D perovskite ferroelectrics, in which are the coupling of spontaneous polarization and piezoelectric effects, as well as photoexcitation and semiconductor behaviors, have great appeal in the field of piezo‐phototronics that enable to effectively improve the performance of optoelectronic devices via modulating the electro‐optical processes. However, current studies on 2D perovskite ferroelectrics focus on bulk ceramics that cannot endure irregular mechanical deformation and limit their application in flexible optoelectronics and piezo‐phototronics. Herein, we synthesize ferroelectric EA4Pb3Br10 single‐crystalline thin‐films (SCFs) for integration into flexible photodetectors. The in‐plane multiaxial ferroelectricity is evident within the EA4Pb3Br10 SCFs through systematic characterizations. Flexible photodetectors based on EA4Pb3Br10 SCFs are achieved with an impressive photodetection performance. More importantly, optoelectronic EA4Pb3Br10 SCFs incorporated with in‐plane ferroelectric polarization and effective piezoelectric coefficient show great promise for the observation of piezo‐phototronic effect, which is capable of greatly enhancing the photodetector performance. Under external strains, the responsivity of the flexible photodetectors can be modulated by piezo‐phototronic effect with a remarkable enhancement up to 284%. Our findings shed light on the piezo‐phototronic devices and offer a promising avenue to broaden functionalities of hybrid perovskite ferroelectrics.
Narrow‐Bandgap Single‐Component Polymer Solar Cells with Approaching 9% Efficiency
Authors: Li Siying , Yuan Xin , Zhang Qilin , Li Bin , Li Yuxiang , Sun Jianguo , Feng Yifeng , Zhang Xuning , Wu Ziang , Wei Huan , Wang Mei , Hu Yuanyuan , Zhang Yuan , Woo Han Young , Yuan Jianyu , Ma Wanli
Published: June 2021

Two narrow‐bandgap block conjugated polymers with a (D1–A1)–(D2–A2) backbone architecture, namely PBDB‐T‐b‐PIDIC2T and PBDB‐T‐b‐PTY6, are designed and synthesized for single‐component organic solar cells (SCOSCs). Both polymers contain same donor polymer, PBDB‐T, but different polymerized nonfullerene molecule acceptors. Compared to all previously reported materials for SCOSCs, PBDB‐T‐b‐PIDIC2T and PBDB‐T‐b‐PTY6 exhibit narrower bandgap for better light harvesting. When incorporated into SCOSCs, the short‐circuit current density (Jsc) is significantly improved to over 15 mA cm−2, together with a record‐high power conversion efficiency (PCE) of 8.64%. Moreover, these block copolymers exhibit low energy loss due to high charge transfer (CT) states (Ect) plus small non‐radiative loss (0.26 eV), and improved stability under both ambient condition and continuous 80 °C thermal stresses for over 1000 h. Determination of the charge carrier dynamics and film morphology in these SCOSCs reveals increased carrier recombination, relative to binary bulk‐heterojunction devices, which is mainly due to reduced ordering of both donor and acceptor fragments. The close structural relationship between block polymers and their binary counterparts also provides an excellent framework to explore further molecular features that impact the photovoltaic performance and boost the state‐of‐the‐art efficiency of SCOSCs.
Highly Efficient Full‐Color Inorganic LEDs on a Single Wafer by Using Multiple Adhesive Bonding
Authors: Mun Seung‐Hyun , Kang Chang‐Mo , Min Jung‐Hong , Choi Soo‐Young , Jeong Woo‐Lim , Kim Gi‐Gwan , Lee Je‐Sung , Kim Kyung‐Pil , Ko Heung Cho , Lee Dong‐Seon
Published: June 2021

Monolithic integration is a promising way to realize full‐color high‐resolution displays. However, it is still a challenge to realize a highly efficient full‐color light‐emitting diode (LED) adopting color conversion layer. In this work, red, green, and blue inorganic LED thin films grown on respective substrates for high‐quality epitaxial layers are integrated on a single substrate using a multiple adhesive bonding technique. It is verified that the stacked thin films are structurally stable. After the multiple bonding, respective subpixels are formed by using standard photolithography only without a mass transfer process, showing the possibility of applying them to a high‐resolution micro‐LED display. Even after the bonding, the device still maintains high efficiency without deteriorating performance. The integrated subpixels are not only independently operated by controlling input power, but the light emission can also cover a wide range of the color space, about 83% compared to Rec.2020 color space.