bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sonic hedgehog is involved in osteoblast differentiation by cooperating with BMP‐2
Authors: Yuasa Takahito , Kataoka Hiroko , Kinto Naoki , Iwamoto Masahiro , Enomoto‐Iwamoto Motomi , Iemura Shun‐ichiro , Ueno Naoto , Shibata Yasuaki , Kurosawa Hisashi , Yamaguchi Akira 
Published: October 2002

AbstractThe roles of Sonic hedgehog (Shh) and Bone morphogenetic protein‐2 (Bmp‐2) in osteoblast differentiation were investigated using in vitro cell systems. Recombinant amino‐terminal portion of SHH (rSHH‐N) dose dependently stimulated ALP activity in C3H10T1/2 and MC3T3‐E1 cells. rSHH‐N induced expression of Osteocalcin mRNA in C3H10T1/2 cells. A soluble form of the receptor for type IA BMP receptor antagonized rSHH‐N‐induced ALP activity in C3H10T1/2 and MC3T3‐E1 cells, indicating that BMPs are involved in SHH‐induced osteoblast differentiation. Simultaneous supplement with rSHH‐N and BMP‐2 synergistically induced ALP activity and expression of Osteocalcin mRNA in C3H10T1/2 cells. Pretreatment with rSHH‐N for 6 h enhanced the response to BMP‐2 by increasing ALP activity in C3H10T1/2 and MC3T3‐E1 cells. Stimulatory effects of rSHH‐N and additive effects with rSHH‐N and BMP‐2 on ALP activity were also observed in mouse primary osteoblastic cells. Transplantation of BMP‐2 (1 μg) into muscle of mice induced formation of ectopic bone, whereas transplantation of r‐SHH‐N (1–5 μg) failed to generate it. These results indicate that Shh plays important roles in osteoblast differentiation by cooperating with BMP. © 2002 Wiley‐Liss, Inc.
Bone morphogenetic protein‐2 modulation of chondrogenic differentiation in vitro involves gap junction‐mediated intercellular communication
Authors: Zhang Wei , Green Colin , Stott N. Susan 
Published: October 2002

AbstractUndifferentiated mesenchymal cells in the limb bud integrate a complex array of local and systemic signals during the process of cell condensation and chondrogenic differentiation. To address the relationship between bone morphogenetic protein (BMP) signaling and gap junction‐mediated intercellular communication, we examined the effects of BMP‐2 and a gap junction blocker 18 alpha glycyrrhetinic acid (18α‐GCA) on mesenchymal cell condensation and chondrogenic differentiation in an in vitro chondrogenic model. We find that connexin43 protein expression significantly correlates with early mesenchymal cellular condensation and chondrogenesis in high‐density limb bud cell culture. The level of connexin43 mRNA is maximally upregulated 48 h after treatment with recombinant human BMP‐2 with corresponding changes in protein expression. Inhibition of gap junction‐mediated intercellular communication with 2.5 μM 18α‐GCA decreases chondrogenic differentiation by 50% at 96 h without effects on housekeeping genes. Exposure to 18α‐GCA for only the first 24–48 h after plating does not affect condensation or later chondrogenic differentiation suggesting that gap junction‐mediated intercellular communication is not critical for the initial phase of condensation but is important for the onset of differentiation. 18α‐GCA can also block the chondrogenic effects of BMP‐2 without effects on cell number or connexin43 expression. These observations demonstrate 18α‐GCA‐sensitive regulation of intercellular communication in limb mesenchymal cells undergoing chondrogenic differentiation and suggest that BMP‐2 induced chondrogenic differentiation may be mediated in part through the modulation of connexin43 expression and gap junction‐mediated intercellular communication. J. Cell. Physiol. 193: 233–243, 2002. © 2002 Wiley‐Liss, Inc.
Gene expression in peripheral arterial chemoreceptors
Authors: Gauda Estelle B. 
Published: October 2002

AbstractThe peripheral arterial chemoreceptors of the carotid body participate in the ventilatory responses to hypoxia and hypercapnia, the arousal responses to asphyxial apnea, and the acclimatization to high altitude. In response to an excitatory stimuli, glomus cells in the carotid body depolarize, their intracellular calcium levels rise, and neurotransmitters are released from them. Neurotransmitters then bind to autoreceptors on glomus cells and postsynaptic receptors on chemoafferents of the carotid sinus nerve. Binding to inhibitory or excitatory receptors on chemoafferents control the electrical activity of the carotid sinus nerve, which provides the input to respiratory‐related brainstem nuclei. We and others have used gene expression in the carotid body as a tool to determine what neurotransmitters mediate the response of peripheral arterial chemoreceptors to excitatory stimuli, specifically hypoxia. Data from physiological studies support the involvement of numerous putative neurotransmitters in hypoxic chemosensitivity. This article reviews how in situ hybridization histochemistry and other cellular localization techniques confirm, refute, or expand what is known about the role of dopamine, norepinephrine, substance P, acetylcholine, adenosine, and ATP in chemotransmission. In spite of some species differences, review of the available data support that 1) dopamine and norepinephrine are synthesized and released from glomus cells in all species and play an inhibitory role in hypoxic chemosensitivity; 2) substance P and acetylcholine are not synthesized in glomus cells of most species but may be made and released from nerve fibers innervating the carotid body in essentially all species; 3) adenosine and ATP are ubiquitous molecules that most likely play an excitatory role in hypoxic chemosensitivity. Microsc. Res. Tech. 59:153–167, 2002. © 2002 Wiley‐Liss, Inc.
Regulation of gene expression for neurotransmitters during adaptation to hypoxia in oxygen‐sensitive neuroendocrine cells
Authors: Paulding Waltke R. , Schnell Phillip O. , Bauer Amy L. , Striet Justin B. , Nash James A. , Kuznetsova Anna V. , Czyzyk‐Krzeska Maria F. 
Published: October 2002

AbstractReduced oxygen tension (hypoxia) in the environment stimulates oxygen‐sensitive cells in the carotid body (CB). Upon exposure to hypoxia, the CB immediately triggers a reflexive physiological response, thereby increasing respiration. Adaptation to hypoxia involves changes in the expression of various CB genes, whose products are involved in the transduction and modulation of the hypoxic signal to the central nervous system (CNS). Genes encoding neurotransmitter‐synthesizing enzymes and receptors are particularly important in this regard. The cellular response to hypoxia correlates closely with the release and biosynthesis of catecholamines. The gene expression of tyrosine hydroxylase (TH), the rate‐limiting enzyme for catecholamine biosynthesis, is regulated by hypoxia in the CB and in the oxygen‐sensitive cultured PC12 cell line. Recently, genomic microarray studies have identified additional genes regulated by hypoxia. Patterns of gene expression vary, depending on the type of applied hypoxia, e.g., intermittent vs. chronic. Construction of a hypoxia‐regulated, CB‐specific, subtractive cDNA library will enable us to further characterize regulation of gene expression in the CB. Microsc. Res. Tech. 59:178–187, 2002. © 2002 Wiley‐Liss, Inc.
Oxidation of small alkenes at high temperature
Authors: Heyberger Barbara , Belmekki Najib , Conraud Valérie , Glaude Pierre‐Alexandre , Fournet René , Battin‐Leclerc Frédérique 
Published: October 2002

AbstractIf the mechanism of formation of alkenes, the main primary products of the combustion of alkanes above 1000 K, is now well understood, their ways of degradation have been much less studied. Following a previous modeling of the oxidation of propene in a static and a jet‐stirred reactors by using an automatically generated mechanism, the present paper shows new validations of the same mechanism for ignition delays in a shock tube. It also describes the extension of the rules used for the automatic generation to the case of 1‐butene. The predictions of the mechanism produced for the oxidation of 1‐butene are compared successfully with two sets of experimental results: the first obtained in a jet‐stirred reactor between 900 and 1200 K; the second being new measurements of ignitions delays behind reflected shock waves for temperatures from 1200 up to 1670 K, pressures from 6.6 to 8.9 atm, equivalence ratios from 0.5 to 2, and with argon as bath gas. Flux and sensitivity analyses show that the role of termination reactions involving the very abundant allylic radicals is less important for 1‐butene than for propene. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 666–677, 2002
Gas‐phase reactions of Cl atoms with propane, n‐butane, and isobutane
Authors: Sarzynski Dariusz , Sztuba Barbara 
Published: October 2002

AbstractUsing the relative kinetic method, rate coefficients have been determined for the gas‐phase reactions of chlorine atoms with propane, n‐butane, and isobutane at total pressure of 100 Torr and the temperature range of 295–469 K. The Cl2 photolysis (λ = 420 nm) was used to generate Cl atoms in the presence of ethane as the reference compound. The experiments have been carried out using GC product analysis and the following rate constant expressions (in cm3 molecule−1 s−1) have been derived: (7.4 ± 0.2) × 10−11 exp [‐(70 ± 11)/ T], Cl + C3H8 → HCl + CH3CH2CH2; (5.1 ± 0.5) × 10−11 exp [(104 ± 32)/ T], Cl + C3H8 → HCl + CH3CHCH3; (7.3 ± 0.2) × 10−11 exp[−(68 ± 10)/ T], Cl + n‐C4H10 → HCl + CH3 CH2CH2CH2; (9.9 ± 2.2) × 10−11 exp[(106 ± 75)/ T], Cl + n‐C4H10 → HCl + CH3CH2CHCH3; (13.0 ± 1.8) × 10−11 exp[−(104 ± 50)/ T], Cl + i‐C4H10 → HCl + CH3CHCH3CH2; (2.9 ± 0.5) × 10−11 exp[(155 ± 58)/ T], Cl + i‐C4H10 → HCl + CH3CCH3CH3 (all error bars are ± 2σ precision). These studies provide a set of reaction rate constants allowing to determine the contribution of competing hydrogen abstractions from primary, secondary, or tertiary carbon atom in alkane molecule. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 651–658, 2002
Composition cascade control for chemical reactors
Authors: Alvarez‐Ramirez Jose , Valencia Jesus , Morales America 
Published: October 2002

AbstractEventhough the composition control of chemical reactors is an old, widely studied, and still relevant problem in chemical process control, it still presents some aspects that remain unexplored or unresolved. For instance, a unifying approach is needed to systematize the existing ad hoc controller constructions, to rigorously explain their remarkable robustness property, and to explore the possibility of improving their construction and functioning. In this paper, some aspects of these control problems are addressed by resorting to recently developed approaches in constructive non‐linear control, yielding a systematic controller construction coupled to a simple tuning scheme that can be executed with standard tuning rules, a closed‐loop stability criterion, and an explanation of the closed‐loop dynamics behaviour. Specifically, a linear cascade (master/slave) control configuration is proposed, which leads to global internal stability of the controlled system with asymptotic regulation of the output‐stream composition about a given desired setpoint. A simulation example is used to illustrate the results. Copyright © 2002 John Wiley & Sons, Ltd.
A Magnet‐Driven Soft Bistable Actuator
Authors: Chen Zhou , Kong Shangcheng , He Yunhu , Chen Shiting , Wang Wanying , Jin Lihan , Zhang Shun , Hong Ying , Pan Lulu , Wu Haikun , Xie Youneng , Linghu Changhong , Mao Zhengyi , Yang Zhengbao , Chan Chi Hou , Song Jizhou , Lu Jian 
Published: January 2024

AbstractBistable morphing structures are widely used as actuation mechanisms in soft actuators, soft robotics, energy absorbers, mechanical computers, optical lenses, metamaterials, and flexible electronics. However, untethered actuators, repetitive actuators, and hybrid‐assembly (containing in‐plane‐assembly and out‐of‐plane‐assembly) actuators remain challenging to realize using existing bistable structures, which hinders the novel application of such actuators in research, engineering, and daily life. This problem is solved by fabricating a magnet‐driven soft bistable actuator (MSBA) unit. The self‐buckling of the circular polydimethylsiloxane (PDMS) sheet ensures the bistability of the actuator and allows it to operate as an independent unit, free of external constraints. The reorientation of neodymium‐iron‐boron (NdFeB) microparticles embedded in the PDMS sheet enables the dome‐shaped actuators to exhibit repetitive snapping under the stimulus of a direction‐switching magnetic field. The potential of this MSBA unit in bionics, electronics, and biomechanics applications is demonstrated in systematic studies involving modification of the buckling deflection and magnetic moment density. The MSBA unit exhibits excellent performance in hybrid designs and intelligent systems.
A Hybrid Photocatalytic System Splits Atmospheric Water to Produce Hydrogen
Authors: He Linglong , Zeng Xianghui , Chen Hui , Zhao Lei , Huang Zhaohui , Wang Daheng , He Xuan , Fang Wei , Du Xing , Li Weixin 
Published: January 2024

AbstractLarge‐scale photocatalytic water‐splitting panel reactor system is developed and demonstrated its commercial feasibility. However, water scarcity is one of the leading challenges for the sustainable development of photocatalytic hydrogen generation in a well‐lit area. Here, a water harvesting form air‐photothermal water evaporation‐photocatalytic hydrogen evolution (AWPH) system is devised. The hybrid system comprising carbonized wood (CWx) combined with the hygroscopic salt ZnCl2 and Pt‐modified g‐C3N4 nanosheets (Pt‐CN) as a photocatalyst is developed, in which the carbonized wood has a vertical pore structure that can provide attachment sites for the hygroscopic salt. The water adsorbed by ZnCl2 is driven along the vertical pore channels to the photocatalyst due to the photothermal conversion effect. The bi‐phase interfaces of vapor/photocatalyst/hydrogen produced by the photothermal‐photocatalytic system significantly reduce the interface barrier and substantially lower the resistance to hydrogen transport. CW550 exhibited a water uptake of 0.56 g g−1 and hydrogen yield of 21.99 µmol cm−2 under 100 mW cm−2 illumination at a flow rate of 2 mL min−1 for 5 h and a half at atmospheric pressure.
Sub‐Stoichiometric Covalent Organic Frameworks
Authors: Qian Cheng , Li Xing , Teo Wei Liang , Gao Qiang , Wei Wei 
Published: January 2024

AbstractCovalent organic frameworks (COFs) have garnered significant attention for nearly two decades due to their exceptional structural designs, tunable properties, and wide‐ranging applications. Recently, a novel subclass of COFs known as partially condensed, sub‐stoichiometric COFs (ss‐COFs) has emerged. This presents a promising new avenue for constructing distinct COF structures in contrast to fully condensed, stoichiometric COFs (fc‐COFs). ss‐COFs are deliberately designed with periodic unreacted functional groups, thereby giving rise to intriguing electronic, optical, and catalytic properties. The deviation from conventional stoichiometric approach opens up new prospects to tailor material properties for unexplored applications. Here, this review focuses on the latest advancements and breakthroughs in ss‐COFs, including topological design, structure characterization, synthetic method, and practical applications. From their basic designing principles to cutting‐edge properties, it will be explored how ss‐COFs are paving the way for COFs research and pushing the boundaries toward new scientific and technological possibilities.
Electro‐induced Crystallization Over Amorphous Indium Hydroxide Gels Toward Ampere‐Level Current Density Formate Electrosynthesis
Authors: Zhao Jia Yue , Huang Kai , Liu Changwei , Wu Xuefeng , Xu Yi Ning , Li Jiayu , Zhu Minghui , Dai Sheng , Lian Cheng , Liu Peng Fei , Yang Hua Gui 
Published: January 2024

AbstractElectrochemical CO2 reduction reaction (CO2RR) provides a promising way for producing value‐added fuels and chemicals via renewable electricity. However, the dynamic reconstruction of electrocatalysts of atomic active sites hinders in‐depth understanding of catalytic mechanism and further industrial application, especially under ampere‐level current density conditions. In this work, electro‐induced crystallization is reported over an amorphous Indium hydroxide gel (In gel) catalyst, which generates active sites for efficient and selective CO2RR. Molecular dynamic calculation reveals the crystallization process can maintain amorphous In‐OH species on the surface while generating crystallized metallic In under electroreduction condition; structural characterizations prove that the derived partially crystallized In gel is stable consisting of amorphous/crystalline interface, even biased at a high polarization potential of −4 V versus reversible hydrogen electrode. The resultant partially crystalized In gel exhibits a highly selective CO2RR performance toward formate under an ampere‐level current density up to 1200 mA cm−2 simultaneously with 91.89% Faradaic efficiency, which can motivate a high formate generation rate of 20.55 mmol h−1 cm−2. The operando Raman spectroscopic and density functional theoretic results demonstrate the optimized adsorption of *HCOO intermediate for the enhanced formate activity and selectivity over the partially crystallized In gel.
Self‐Mixed Biphasic Liquid Metal Composite with Ultra‐High Stretchability and Strain‐Insensitivity for Neuromorphic Circuits
Authors: Lee Do Hoon , Lim Taesu , Pyeon Jeongsu , Park Hyunmin , Lee Sang‐Won , Lee Seungkyu , Kim Wonsik , Kim Min , Lee Jeong‐Chan , Kim Do‐Wan , Han Seungmin , Kim Hyoungsoo , Park Steve , Choi Yang‐Kyu 
Published: January 2024

AbstractNeuromorphic circuits that can function under extreme deformations are important for various data‐driven wearable and robotic applications. Herein, biphasic liquid metal particle (BMP) with unprecedented stretchability and strain‐insensitivity (ΔR/R0 = 1.4@ 1200% strain) is developed to realize a stretchable neuromorphic circuit that mimics a spike‐based biologic sensory system. The BMP consists of liquid metal particles (LMPs) and rigid liquid metal particles (RLMPs), which are homogeneously mixed via spontaneous solutal‐Marangoni mixing flow during coating. This permits facile single step patterning directly on various substrates at room temperature. BMP is highly conductive (2.3 × 106 S/m) without any post activation steps. BMP interconnects are utilized for a sensory system, which is capable of distinguishing variations of biaxial strains with a spiking neural network, thus demonstrating their potential for various sensing and signal processing applications.
High‐Performance Organic Narrow Dual‐Band Circular Polarized Light Detection for Encrypted Communications and Color Imaging
Authors: Wang Qingkai , Bao Jinying , Zhang Yajie , Wang Yuheng , Qiu Dingding , Yang Jiaxin , Zhang Jianqi , Gao Hanfei , Wu Yuchen , Dong Huanli , Yang Huai , Wei Zhixiang 
Published: January 2024

AbstractConventional circularly polarized light (CPL) detectors necessitate several optical elements, posing difficulties in achieving miniature and integrated devices. Recently developed organic CPL detectors require no additional optical elements but usually suffer from low detectivity or low asymmetry factor (g‐factor). Here, an organic CPL detector with excellent detectivity and a high g‐factor is fabricated. By employing an inverted quasi‐planar heterojunction (IPHJ) structure and incorporating an additional liquid crystal film, a CPL detector with an outstanding g‐factor of 1.62 is developed. Unfavorable charge injection is effectively suppressed by the IPHJ structure, which reduces the dark current of the organic photodetector. Consequently, a left CPL detectivity of 6.16 × 1014 Jones at 640 nm is realized, surpassing all of the latest photodiode‐type CPL detectors. Adopting a liquid crystal film with adjustable wavelengths of selectively reflected light, the hybrid device achieves narrow dual‐band CPL detection, varying from 530 to 640 nm, with a half‐maximum full width below 90 nm. Notably, the device achieves excellent stability of 260 000 on/off cycles without attenuation. To the best of the authors’ knowledge, all these features have rarely been reported in previous work. The CPL detector arrays are also demonstrated for encrypted communications and color imaging.
UV‐Light Generation in Micelles via Triplet‐Triplet Annihilation Upconversion – Towards Synthetic Applications
Authors: Jeyaseelan R. , Utikal M. , Næsborg L. 
Published: January 2024

AbstractOver the last century UV‐light mediated processes gave access to synthetically valuable products. Some of the disadvantages encountered when performing such UV‐light triggered synthetic reactions are the necessity for special glassware (quartz), the environmentally unfriendly irradiation sources and the need for oxygen removal, often via time consuming freeze‐pump‐thaw cycles. In addition, the penetration of UV‐light into the reaction mixture is a challenge due to absorption effects and scattering. A solution to these disadvantages could be triplet‐triplet annihilation upconversion performed under micellar reaction conditions. Hereby, UV‐light can be generated in the reaction mixture using visible light irradiation. In addition, the aqueous micellar medium can allow for the process to occur without the need for oxygen removal. This concept has been sporadically demonstrated and holds a great promise for the development of UV‐light promoted photochemical reactions under milder and more benign reaction conditions that may eventually allow for the development of scale up protocols.
Generation of a Hydrophobic Protrusion on Nanoparticles to Improve the Membrane‐Anchoring Ability and Cellular Internalization
Authors: Xia He , Zhou Wenjuan , Li Dezheng , Peng Fan , Yu Liyang , Sang Yuanhua , Liu Hong , Hao Aijun , Qiu Jichuan 
Published: January 2024

AbstractControlling the nanoparticle‐cell membrane interaction to achieve easy and fast membrane anchoring and cellular internalization is of great importance in a variety of biomedical applications. Here we report a simple and versatile strategy to maneuver the nanoparticle‐cell membrane interaction by creating a tunable hydrophobic protrusion on Janus particles through swelling‐induced symmetry breaking. When the Janus particle contacts cell membrane, the protrusion will induce membrane wrapping, leading the particles to docking to the membrane, followed by drawing the whole particles into the cell. The efficiencies of both membrane anchoring and cellular internalization can be promoted by optimizing the size of the protrusion. In vitro, the Janus particles can quickly anchor to the cell membrane in 1 h and be internalized within 24 h, regardless of the types of cells involved. In vivo, the Janus particles can effectively anchor to the brain and skin tissues to provide a high retention in these tissues after intracerebroventricular, intrahippocampal, or subcutaneous injection. This strategy involving the creation of a hydrophobic protrusion on Janus particles to tune the cell‐membrane interaction holds great potential in nanoparticle‐based biomedical applications.