bluuebunny/crossref_metadata_2025 huggingface dataset:
Sedimentary environment and palaeogeography of the ?Palaeocene-Middle Eocene Kashkan Formation, Zagros fold-thrust belt, SW Iran
Authors: Yeganeh Bizhan , Feiznia Sadat , van Loon A.
Published: April 2012

Sedimentary environment and palaeogeography of the ?Palaeocene-Middle Eocene Kashkan Formation, Zagros fold-thrust belt, SW Iran

The Kashkan Formation (?Palaeocene to Middle Eocene) in the Zagros fold-thrust belt, SW Iran, which is intercalated between to marine limestone formations, consists of conglomerates, sandstones and siltstones. The sedimentology and the palaeogeography of the Kashkan Formation had not received any attention thus far, but have now been studied in seven sections, situated in the province of Lorestan. The sediments form twelve lithofacies, three ichnosubfacies and seven architectural elements, which are described, depicted and analysed. The analysis leads to the conclusion that most sediments accumulated in a low-sinuosity, low-gradient braided-river system (characterised by mainly unidirectional palaeocurrent directions, and by sheetfloods), that occasionally showed meandering characteristics (represented by overbank deposits and large bars). The deposits of this system closely resemble those of the South Saskatchewan River in Canada, which is considered as the classical example of a sand-bed braided river. The river flowed roughly from North to South, as deduced by palaeocurrent indicators such as imbrication and large-to medium-scale trough cross-stratification (direction measured in the trough axes). This current direction is supported by the southward to south-westward thinning of the formation and by the diminishing average grain size in the same direction. The trace fossils in the Kashban Formation fit all in theSkoyeniaichnofacies, which has here three ichnosubfacies which allow a more detailed palaeoenvironmental reconstruction, indicating that the braided stream passed into the low-energy shoreface zone of a tidally-influenced sea.
Mesozoic mass extinctions and angiosperm radiation: does the molecular clock tell something new?
Authors: Ruban Dmitry
Published: April 2012

Mesozoic mass extinctions and angiosperm radiation: does the molecular clock tell something new?

Angiosperms evolved rapidly in the late Mesozoic. Data from the genetic-based approach called ‘molecular clock’ permit an evaluation of the radiation of flowering plants through geological time and of the possible influences of Mesozoic mass extinctions. A total of 261 divergence ages of angiosperm families are considered. The radiation of flowering plants peaked in the Albian, early Campanian, and Maastrichtian. From the three late Mesozoic mass extinctions (Jurassic/Cretaceous, Cenomanian/Turonian, and Cretaceous/Palaeogene), only the Cretaceous/Palaeogene event coincided with a significant, abrupt, and long-term decline in angiosperm radiation. If their link will be further proven, this means that global-scale environmental perturbation precluded from many innovations in the development of plants. This decline was, however, not unprecedented in the history of the angiosperms. The implication of data from the molecular clock for evolutionary reconstructions is limited, primarily because this approach deals with only extant lineages.
Ultrasonography as a diagnostic and prognostic approach in cattle and buffaloes with fatty infiltration of the liver
Authors: Tharwat M.
Published: April 2012

Ultrasonography as a diagnostic and prognostic approach in cattle and buffaloes with fatty infiltration of the liver

The aim of the present study was to determine whether ultrasonographic evaluation of the hepatic parenchyma could be used as a diagnostic and prognostic approach in cows and buffaloes with hepatic lipidosis. For this purpose, cows (n=16) and buffaloes (n=10) with fatty infiltration of the liver were examined by ultrasonography. Treated cows and buffaloes were monitored for hepatic changes ultrasonographically, biochemically and histologically. Clinical findings were non-specific and included anorexia, recumbency, muzzle necrosis, and icteric mucosal membranes. Laboratory data revealed neutrophilia, hyper γ-globulinemia, elevated activities of aspartate aminotransferase, γ-glutamyl transpeptidase, creatine kinase and lactate dehydrogenase, and high concentrations of insulin, total bilirubin, non-esterified fatty acids and β-hydroxyl butyric acid. Laboratory results 7, and 21 days after treatment showed progressive improvement in the chemistry profile. On admission, ultrasonographic examination of the hepatic parenchyma in cows and buffaloes revealed either increased or decreased hepatic echogenicity; histologic examination revealed marked fatty infiltration of the hepatocytes. One week after treatment, the hepatic parenchyma was visualized easily, liver boundaries were clearly imaged, and histologic examination of hepatic specimen showed a moderate degree of fatty infiltration. Three weeks after treatment, the hepatic parenchyma was almost similar to normal, the hepatic and portal blood vessels could be easily imaged, and the histologic picture had greatly improved where the liver resembled the normal organ. Six cows and seven buffaloes made a full recovery while the remaining ten cows and three buffaloes were slaughtered and thoroughly examined postmortem. Ultrasonography showed a good correlation with histologic and laboratory findings.
The xCELLigence system for real-time and label-free analysis of neuronal and dermal cell response to Equine Herpesvirus type 1 infection
Authors: Golke A. , Cymerys J. , Słońska A. , Dzieciątkowski T. , Chmielewska A. , Tucholska A. , Bańbura M.
Published: April 2012

The xCELLigence system for real-time and label-free analysis of neuronal and dermal cell response to Equine Herpesvirus type 1 infection

Real-time cell electronic sensing (RT-CES) based on impedance measurements is an emerging technology for analyzing the status of cells in vitro. It allows label-free, real time monitoring of the biological status of cells. The present study was designed to assess dynamic data on the cell processes during equine herpesvirus type 1 (EHV-1) infection of ED (equine dermal) cells and primary murine neuronal cell culture. We have demonstrated that the xCELLigence system with dynamic monitoring can be used as a rapid diagnostic tool both to analyze cellular behavior and to investigate the effect of viral infection.
The viability of the genetically diverse C. jejuni and C. coli strains in the macrophage J774 cell line
Authors: Krutkiewicz A. , Klimuszko D.
Published: April 2012

The viability of the genetically diverse C. jejuni and C. coli strains in the macrophage J774 cell line

The intracellular survival of Campylobacter has been described within epithelial cells as well as in macrophages in vitro. The goal of this study was to estimate the viability of the genetically diverse C. jejuni and C. coli strains in the macrophage J774 cell line. Strains selected for analysis differed with regard to the occurrence of genes encoding specific virulence factors. The present work indicates that was no correlation between the source of isolates and relative intracellular survival.
Detection and identification of banned Processed Animal Protein in feedingstuffs by microscopic and PCR methods
Authors: Weiner A. , Gołębiowska A. , Paprocka I. , Kwiatek K.
Published: April 2012

Detection and identification of banned Processed Animal Protein in feedingstuffs by microscopic and PCR methods

The aim of the study was to present the results of comparative evaluation of the usefulness of PCR and microscopic methods for the detection of Processed Animal Protein (PAP) in feedingstuffs. In the validation study, the limit of the detection for PCR was determined on 0.05% for beef, 0.1% for pork and 0.2% for poultry meat and bone meal (MBM). Among 62 doubtful samples of feedingstuffs examined by microscopic method 41 (66.13%) were found as positive. Based on the results obtained with the use of the microscopic and PCR methods it is possible to state that the molecular biology methods can, at present, be used as a supplementary method in PAP detection. Key worlds: animal feedingstuffs, meat and bone meal, PCR, PAP
The role of metal ions in biological oxidation - the past and the present
Authors: Kleczkowski M. , Garncarz M.
Published: April 2012

The role of metal ions in biological oxidation - the past and the present

Two theories, one based on the metabolism of inorganic substances, the other on metabolism of organic substances, have played an important role in the explanation of the origin of life. They demonstrate that the original environment of life on Earth was seawater containing micronutrients with structural, metabolic and catalytic activity. It is assumed that the first primitive organisms lived around 3.8 billion years ago and it was also then that the first catalytic reaction involving metal ions occurred. Biological oxidation leading to oxidative stress and cell damage in animals represents one of these types of reactions which are responsible for many animal diseases. The role of prooxidative and antioxidative actions of transition metal ions as well as their neuropathological consequences have therefore been the topic for many research projects. There is hope that metal chelates and antioxidants might prove to be a modern mode of therapy for i.e. neurogenerative diseases. The aim of this review is to show the evolution of scientific knowledge on metal ions, their biological oxidation, and an overview of their role in physiology and in pathological processes.
Pre-glacial sedimentary facies of the Point Thomas Formation (Eocene) at Cytadela, Admiralty Bay, King George Island, West Antarctica
Authors: Mozer Anna
Published: April 2012

Pre-glacial sedimentary facies of the Point Thomas Formation (Eocene) at Cytadela, Admiralty Bay, King George Island, West Antarctica

New evidence of Eocene preglacial environments has been found on the southern coast of Ezcurra Inlet on King George Island, South Shetland Islands, West Antarctica. Plant remains (trunks, leaves, detritus) and carbonaceous seams and beds occur in sedimentary strata in a 4 km long Cytadela outcrop of the Point Thomas Formation. They are an evidence for the presence and diversity of terrestrial vegetation in the northern Antarctic Peninsula region. The forests were composed mostly of Podocarpaceae-Araucaria-Nothofagus, with an undergrowth of hygrophilous and thermophilous ferns, and grew on volcanic slopes and surrounding lowland areas of King George Island during breaks in volcanic activity. The succession that crops out at Cytadela provides a record of changing climatic conditions from a warm and wet climate with extensive vegetation to a much drier climate with limited vegetation and ubiquitous weathering of volcanic bedrock. The geochemical indices of weathering (CIA, PIA and CIW) have narrow and relatively high value ranges (76-88), suggesting moderate to high chemical weathering under warm and humid climate conditions. The decrease in humidity and the decline in plant life through the succession can be related to the gradually cooling climate preceding development of the Oligocene ice cover across the Antarctic continent.
Application of Robust Estimation Methods for the Analysis of Outlier Measurements / Aplikácia Robustných Odhadovacích Metód Pri Analýze Odľahlých Meraní
Authors: Gašincová Silvia , Gašinec Juraj , Weiss Gabriel , Labant Slavomír
Published: April 2012

The basis of mathematical analysis of geodetic measurements is the method of least squares (LSM), whose bicentenary we celebrated in 2006. In geodetic practice, we quite often encounter the phenomenon when outlier measurements penetrate into the set of measured data as a result of e.g. the impact of physical environment. That fact led to modifications of LSM that have been increasingly published mainly in foreign literature in recent years. The mentioned alternative estimation methods are e.g. robust estimation methods and methods in linear programming. The aim of the present paper is to compare LSM with the robust estimation methods on an example of a regression line.
Variations autour de la tâche dans l'enseignement / apprentissage des langues aujourd'hui
Authors: Nissen Elke
Published: April 2012

Cet article se donne pour objectif d'identifier les types de tâches, et leurs dénominateurs communs, qui sont présentés aujourd'hui – où "l'approche par les tâches" est soutenue par le Conseil de l'Europe – aux apprenants. Il analyse pour cela les articles issus de deux numéros de revues et un ouvrage collectif récents. Il apparaît que la grande majorité des scénarios pédagogiques s'y inscrit dans la perspective actionnelle... du moins d'après la déclaration des auteurs, car leur définition de ce qu'est une tâche ne correspond pas toujours à celle du CECR. Pour le public visé, étudiants ou professionnels, on propose le plus souvent des mono-tâches, mais également des projets, ou encore des simulations avec un enchaînement de plusieurs tâches. Elles s'inscrivent généralement dans la (future) réalité sociale des apprenants, mais certaines laissent également la place à des thèmes artistiques ou (inter)culturels. Contrairement à ce que l'on aurait pu attendre dans une démarche qui responsabilise l'apprenant, le recours à Internet n'est pas toujours systématique.
EFFECT OF PURIFIED ALGINATE MICROCAPSULES ON THE REGENERATION OF CHONDROCYTES
Authors: Hwang Ji Hye , Kim On You , Kim A Ram , Bae Ji Yeon , Jeong Su Mi , Shim Jung Bo , Yoon Kun Ho , Lee Dongwon , Khang Gilson
Published: April 2012

Adult articular cartilage tissue has poor capability of self-repair. Therefore, a variety of tissue engineering approaches are motivated by the clinical need for articular repair. Alginate has been used as a biomaterial for cartilage regeneration. The alginate is a natural polymer that is extracted from seaweeds and purification. However, the main drawback is the immune rejection in vivo. To overcome this problem, we have developed the biocompability of alginate using modified Korbutt method. After alginate was purified, purified alginate microcapsules were used in cartilage regeneration. Chondrocytes were seeded in purified and nonpurified alginate microcapsules, and then cell viability, proliferation and phenotype were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay. Reverse transcriptase-polymerase chain reaction (RT-PCR) was conducted to confirm mRNA expression on collagen type I and collagen type II for chondrocytes phenotype. Hematoxylin and eosin (H&E) and Safranin-O histological staining showed tissue growth at the interface during the first 10 days. In this study, chondrocytes in purified alginate microcapsules had higher cell viability, proliferation and more phenotype expression than those in nonpurified alginate microcapsules. The results suggest that the purified alginate microcapsule is useful for cartilage regeneration.
A REMOTE GAZE TRACKING SYSTEM USING GRAY-DISTRIBUTION-BASED VIDEO PROCESSING
Authors: Yang Xiao-Hui , Sun Jian-De , Liu Ju , Li Xin-Chao , Yang Cai-Xia , Liu Wei
Published: April 2012

Gaze tracking has drawn increasing attention and applied wildly in the areas of disabled aids, medical diagnosis, etc. In this paper, a remote gaze tracking system is proposed. The system is video-based, and the video is captured under the illumination of near infrared light sources. Only one camera is employed in the system, which keeps the equipment portable for the users. The corneal glints and the pupil center, whose extraction accuracy determines the performance of the gaze tracking system, are obtained according to the gray distribution of the video frame. And then, the positions of the points on the screen that the user fixating are estimated by the gaze tracking algorithm based on cross-ratio-invariant. Additionally, a calibration procedure is necessary to eliminate the error produced by the deviation of the optical and visual axes. The proposed remote gaze tracking system has a low computational complexity and high robustness, and experiment results indicate that it is tolerant of head movement and still works well for users wearing glasses as well. Besides, the angle error of the gaze tracking system is 0.40 degree of the subjects without glasses, correspondingly, 0.48 degree of the subjects with glasses, which is comparable to most of the existing commercial systems and promising for most of the potential practical applications.
IN-SITU CHARACTERIZATIONS OF 1–200 MHz RADIO FREQUENCY SIGNAL COUPLING WITH HUMAN BODY
Authors: Nie Zedong , Leng Tengfei , Wang Wenchen , Guan Feng , Huang Bangyu , Wang Lei
Published: April 2012

Wireless communication within body proximal has shown great promise for the construction of body sensor network (BSN) and body area network (BAN), wherein multiple master and slave nodes were typically deployed on different human body sites for physiological measurements or personal entertainment. We reported the in-situ experiments to characterize body-proximal electric coupling over various carrier frequencies (1–200 MHz), multiple subjects and different body postures. To improve the signal fidelity and minimize the ground return path, all experiments were performed in a shielded radiofrequency (RF) chamber with single electrode configuration and battery-operated transmitter/receiver — the setup has never been reported in other literatures. Results obtained from 15 subjects quantified the attenuation patterns of the RF signal coupling with human body. The average coupling loss was approximately 24 dB at 30 MHz whist the receiver electrode was attached at a distance of 10 cm from the transmitter electrode, and the on-body coupling loss followed a two-piecewise fitting over distance. In comparison, 30 MHz RF signals propagated 1 m from body to air and from air to air were attenuated 70 dB and 80 dB, respectively. The standard deviations representing different subjects and daily variations were less than 2 dB at 30 MHz when the coupling distance was 10 cm. The difference in signal attenuation was always less than 2 dB for various postures including standing, sitting and squatting. It concluded that the RF signal within the frequency range of 25–30 MHz is capable of providing a robust and subject-independent wireless link for body-proximal BSN/BAN applications.
QUANTITATIVE EVALUATION OF MULTIVARIATE ANALYSIS METHODS FOR EXCITATION–EMISSION SPECTROSCOPY
Authors: Yu Chun , Hsiao Tzu-Chien , Lin Chii-Wann
Published: April 2012

Multivariable Analysis Methods have been used widely in Spectroscopy Analysis. Partial least square (PLS) and principal component analysis (PCA) are the two most popular methods due to their excellent ability in data components analysis and results prediction. This work derived 1D/2D PLS and 1D/2D PCA based on the viewpoint of three-layer artificial neural networks, and uses theoretical proving to figure out the essences of these two methods. Two 2D experimental dataset was used to verify the calibration and prediction ability, furthermore, the similarity and dissimilarity of PLS and PCA. The finding showed that both the 1D/2D PLS and 1D/2D PCA methods use maximum covariance and minimum sum of square error to figure out the relationship between independent and dependent variables. The dissimilarity is that, weight vectors calibration of PLS is cross-correlation, and that of PCA is autocorrelation. The difference causes that the PCA method would keep more principal characters than PLS under insufficient sample among and provides better calibration ability. PLS would provide higher performance in prediction under sufficient sample among. For the needs of system implementation of spectroscopic measurement and analysis, this study designed "Multivariate Analysis Toolkits for LabVIEW" for the convenient implementation in automatic measurement system integration.
Sphingosine Analogue AAL-R Increases TLR7-Mediated Dendritic Cell Responses via p38 and Type I IFN Signaling Pathways
Authors: Seo Young-Jin , Pritzl Curtis J. , Vijayan Madhuvanthi , Blake Celeste R. , McClain Mariah E. , Hahm Bumsuk
Published: April 2012

Sphingosine analogues display immunosuppressive activities and thus have therapeutic potential in the treatment of autoimmune diseases. In this study, we investigated the effects of the sphingosine analogue AAL-R (FTY720 derivative) on dendritic cell (DC) response upon TLR stimulation. Unlike its known immunosuppressive activity, AAL-R increased TLR7-mediated DC responses by elevating the levels of MHC class I and costimulatory molecules and type I IFN expression and by enhancing the capacity of DCs to induce CD8+ T cell proliferation. Importantly, the stimulatory activity of AAL-R was dependent on type I IFN signaling, as type I IFN receptor-deficient DCs failed to respond to AAL-R. Also, AAL-R activated p38 MAPK to increase type I IFN synthesis and TLR7-mediated DC maturation. These findings enhance our understanding of sphingosine regulation of the host immune system, in particular upon pathogenic infections.
NLRC5 Controls Basal MHC Class I Gene Expression in an MHC Enhanceosome-Dependent Manner
Authors: Neerincx Andreas , Rodriguez Galaxia M. , Steimle Viktor , Kufer Thomas A.
Published: April 2012

Nucleotide-binding domain and leucine-rich repeat (NLR) proteins play important roles in innate immune responses as pattern-recognition receptors. Although most NLR proteins act in cell autonomous immune pathways, some do not function as classical pattern-recognition receptors. One such NLR protein is the MHC class II transactivator, the master regulator of MHC class II gene transcription. In this article, we report that human NLRC5, which we recently showed to be involved in viral-mediated type I IFN responses, shuttles to the nucleus and activates MHC class I gene expression. Knockdown of NLRC5 in different human cell lines and primary dermal fibroblasts leads to reduced MHC class I expression, whereas introduction of NLRC5 into cell types with very low expression of MHC class I augments MHC class I expression to levels comparable to those found in lymphocytes. Expression of NLRC5 positively correlates with MHC class I expression in human tissues. Functionally, we show that both the N-terminal effector domain of NLRC5 and its C-terminal leucine-rich repeat domain are needed for activation of MHC class I expression. Moreover, nuclear shuttling and function depend on a functional Walker A motif. Finally, we identified a promoter sequence in the MHC class I promoter, the X1 box, to be involved in NLRC5-mediated MHC class I gene activation. Taken together, this suggested that NLRC5 acts in a manner similar to class II transactivator to drive MHC expression and revealed NLRC5 as an important regulator of basal MHC class I expression.
NLRC5 Cooperates with the RFX Transcription Factor Complex To Induce MHC Class I Gene Expression
Authors: Meissner Torsten B. , Liu Yuen-Joyce , Lee Kyoung-Hee , Li Amy , Biswas Amlan , van Eggermond Marja C. J. A. , van den Elsen Peter J. , Kobayashi Koichi S.
Published: April 2012

Tight regulation of MHC class I gene expression is critical for CD8 T cell activation and host adaptive-immune responses. The promoters of MHC class I genes contain a well-conserved core module, the W/S-X-Y motif, which assembles a nucleoprotein complex termed MHC enhanceosome. A member of the nucleotide-binding domain, leucine-rich repeat (NLR) protein family, NLRC5, is a newly identified transcriptional regulator of MHC class I genes. NLRC5 associates with and transactivates the proximal promoters of MHC class I genes, although the molecular mechanism of transactivation has not been understood. In this article, we show that NLRC5-mediated MHC class I gene induction requires the W/S and X1, X2 cis-regulatory elements. The transcription factors RFX5, RFXAP, and RFXANK/B, which compose the RFX protein complex and associate with the X1 box, cooperate with NLRC5 for MHC class I expression. Coimmunoprecipitation experiments revealed that NLRC5 specifically interacts with the RFX subunit RFXANK/B via its ankyrin repeats. In addition, we show that NLRC5 can cooperate with ATF1 and the transcriptional coactivators CBP/p300 and general control nonderepressible 5, which display histone acetyltransferase activity. Taken together, our data suggest that NLRC5 participates in an MHC class I-specific enhanceosome, which assembles on the conserved W/S-X-Y core module of the MHC class I proximal promoters, including the RFX factor components and CREB/ATF1 family transcription factors, to promote MHC class I gene expression.
Myeloid Cell-Derived Hypoxia-Inducible Factor Attenuates Inflammation in Unilateral Ureteral Obstruction-Induced Kidney Injury
Authors: Kobayashi Hanako , Gilbert Victoria , Liu Qingdu , Kapitsinou Pinelopi P. , Unger Travis L. , Rha Jennifer , Rivella Stefano , Schlöndorff Detlef , Haase Volker H.
Published: April 2012

Renal fibrosis and inflammation are associated with hypoxia, and tissue pO2 plays a central role in modulating the progression of chronic kidney disease. Key mediators of cellular adaptation to hypoxia are hypoxia-inducible factor (HIF)-1 and -2. In the kidney, they are expressed in a cell type-specific manner; to what degree activation of each homolog modulates renal fibrogenesis and inflammation has not been established. To address this issue, we used Cre-loxP recombination to activate or to delete both Hif-1 and Hif-2 either globally or cell type specifically in myeloid cells. Global activation of Hif suppressed inflammation and fibrogenesis in mice subjected to unilateral ureteral obstruction, whereas activation of Hif in myeloid cells suppressed inflammation only. Suppression of inflammatory cell infiltration was associated with downregulation of CC chemokine receptors in renal macrophages. Conversely, global deletion or myeloid-specific inactivation of Hif promoted inflammation. Furthermore, prolonged hypoxia suppressed the expression of multiple inflammatory molecules in noninjured kidneys. Collectively, we provide experimental evidence that hypoxia and/or myeloid cell-specific HIF activation attenuates renal inflammation associated with chronic kidney injury.
Selective Blockade of Herpesvirus Entry Mediator–B and T Lymphocyte Attenuator Pathway Ameliorates Acute Graft-versus-Host Reaction
Authors: del Rio Maria-Luisa , Jones Nick D. , Buhler Leo , Norris Paula , Shintani Yasushi , Ware Carl F. , Rodriguez-Barbosa Jose-Ignacio
Published: April 2012

The cosignaling network mediated by the herpesvirus entry mediator (HVEM; TNFRSF14) functions as a dual directional system that involves proinflammatory ligand, lymphotoxin that exhibits inducible expression and competes with HSV glycoprotein D for HVEM, a receptor expressed by T lymphocytes (LIGHT; TNFSF14), and the inhibitory Ig family member B and T lymphocyte attenuator (BTLA). To dissect the differential contributions of HVEM/BTLA and HVEM/LIGHT interactions, topographically-specific, competitive, and nonblocking anti-HVEM Abs that inhibit BTLA binding, but not LIGHT, were developed. We demonstrate that a BTLA-specific competitor attenuated the course of acute graft-versus-host reaction in a murine F1 transfer semiallogeneic model. Selective HVEM/BTLA blockade did not inhibit donor T cell infiltration into graft-versus-host reaction target organs, but decreased the functional activity of the alloreactive T cells. These results highlight the critical role of HVEM/BTLA pathway in the control of the allogeneic immune response and identify a new therapeutic target for transplantation and autoimmune diseases.
Defective Autoimmune Regulator-Dependent Central Tolerance to Myelin Protein Zero Is Linked to Autoimmune Peripheral Neuropathy
Authors: Su Maureen A. , Davini Dan , Cheng Philip , Giang Karen , Fan Una , DeVoss Jason J. , Johannes Kellsey P. A. , Taylor Lorelei , Shum Anthony K. , Valenzise Mariella , Meloni Antonella , Bour-Jordan Helene , Anderson Mark S.
Published: April 2012

Chronic inflammatory demyelinating polyneuropathy is a debilitating autoimmune disease characterized by peripheral nerve demyelination and dysfunction. How the autoimmune response is initiated, identity of provoking Ags, and pathogenic effector mechanisms are not well defined. The autoimmune regulator (Aire) plays a critical role in central tolerance by promoting thymic expression of self-Ags and deletion of self-reactive T cells. In this study, we used mice with hypomorphic Aire function and two patients with Aire mutations to define how Aire deficiency results in spontaneous autoimmune peripheral neuropathy. Autoimmunity against peripheral nerves in both mice and humans targets myelin protein zero, an Ag for which expression is Aire-regulated in the thymus. Consistent with a defect in thymic tolerance, CD4+ T cells are sufficient to transfer disease in mice and produce IFN-γ in infiltrated peripheral nerves. Our findings suggest that defective Aire-mediated central tolerance to myelin protein zero initiates an autoimmune Th1 effector response toward peripheral nerves.
Checks and Balances on FDA’s Authority
Authors: Lynch Holly Fernandez , Lurie Peter , Cohen I. Glenn
Published: June 2024

In this Viewpoint, the authors refute recent suggestions that the US Food and Drug Administration (FDA) is not accountable for its decisions, pointing out the legal, legislative, and executive checks and balances on the agency.
Hydrophobic Electron‐Transport Layer for Efficient Tin‐Based Perovskite Solar Cells
Authors: He Feifei , Li Tianpeng , Shen Tao , Zhao Yinghan , Jin Zuoming , Zhang Zhiguo , Pu Yu , Deng Liangliang , Qin Lang , Zhan Yiqiang , Liu Yunqi , Wang Yang , Liang Jia
Published: June 2024

With excellent biocompatibility, a narrow bandgap, and long thermal carrier lifetime, tin‐based perovskite solar cells (TPSCs) are promising within the solar technology. The fullerene derivative indene‐C60 bisadduct (ICBA) is recognized as the most efficient electron‐transport material for TPSCs, thanks to its suitable band structure. Nevertheless, the limited electron transport capability and susceptibility to moisture penetration of ICBA have hindered the progress of TPSCs. Herein, the study proposes a new hydrophobic electron‐transport layer (ETL) comprising a surface‐anchored non‐fullerene n‐type semiconducting polymer layer, poly (naphthalene diimide‐alt‐dithiophenebezothiadiazole) (PNDI‐BT), in conjunction with ICBA. PNDI‐BT exhibits high electron mobilities, a fitting band structure, robust interaction with Sn‐based perovskites, and exceptional moisture resistance, effectively addressing the shortcomings of ICBA. Consequently, this innovative hydrophobic ETL of PNDI‐BT/ICBA enhances electron transport and protects Sn‐based perovskites from moisture. As a result, the inverted TPSCs with the new hydrophobic ETL achieve an impressive efficiency of 13.90%, surpassing TPSCs with the ICBA layer (12.75%). Moreover, even after 1000 h of storage in ambient atmosphere, the encapsulated TPSC maintains a remarkable 81% of its initial efficiency. This comprehensive study seamlessly integrates the synthesis of non‐fullerene n‐type semiconducting polymer and device fabrication, providing valuable insights into designing cutting‐edge ETL structure for inverted TPSCs.
A Versatile C/Fe3O4/C Self‐Heating Electrode for Universal Application of Alternating Magnetic Fields in Electrocatalytic Hydrogen Production
Authors: Zhan Helong , Jiang Zhenzhen , Luo Xingfang , Huang Yuan , Ye Daojian , Xu Weiyang , Hu Ce , Zhou Hang , Lei Wen , Yuan Cailei
Published: June 2024

The high‐frequency alternating magnetic field (AMF) is considered as a fascinating heating treatment that provides a noninvasive solution to enhance the catalytic efficiency of electrocatalyst. However, practical applications of AMF in electrochemistry are primarily concentrated on magnetic mediums. To broaden its application into nonmagnetic catalysts, herein, a practicable method is reported by modifying the working electrode substrate with magnetic Fe3O4 nanoparticles (NPs), which serves as both substrate and self‐heating medium by virtue of its rapid and efficient magnetic heating effect associated with Néel relaxation triggered by external high‐frequency AMF, thus boosting the catalyst performance upon it. To verify it, Pt NPs and Pt single atoms (SAs), as two representative non‐magnetic catalyst, are selected for trials. The results, reveal that, when AMF is applied, Pt NPs@C/Fe3O4/C and Pt SAs@C/Fe3O4/C display remarkable enhancement of hydrogen evolution reaction magnetocurrent density respectively by ≈ 146% and ≈185%, whereas on unmodified bare glassy carbon there both show unnoticeable change in catalytic performance. The developed strategy opens up a vast space for exploiting the energy of a weak, non‐invasive magnetic field.
Evolution of Naturally Dried MXene‐Based Composite Aerogels with Flash Joule Annealing for Large‐Scale Production of Highly Sensitive Customized Sensors
Authors: Zhu Wenqi , Zhuang Yuhang , Weng Jianqiang , Huang Qinzhui , Lai Guobin , Li Liuyan , Chen Meixin , Xia Kailai , Lu Zhixing , Wu Mingmao , Zou Zhigang
Published: June 2024

MXene aerogels, known for good electrical properties, offer immense potential for the development of high‐sensitivity pressure sensors. However, the intrinsic challenges stemming from the poor self‐assembly capability and high hydrophilicity of MXene impede the natural drying process of MXene‐based hydrogels, thereby constraining their application on a large scale in sensor technology. Herein, a graphene‐assisted approach aimed at modulating the hydrophobicity and enhancing framework strength of MXene through a well‐designed prefreezing technique incorporating 3D spherical macroporous structures is proposed. This synergistic strategy enables the fabrication of naturally dried MXene aerogels across various size scales. Moreover, the integration of 3D spherical macroporous structures improves elasticity and electrical responsiveness of aerogels. Consequently, the aerogel sensor exhibits great performances, including high sensitivity (1250 kPa−1), low detection limit (0.4 Pa), wide frequency response range (0.1–8 Hz), and excellent stability (1000 cycles). This sensor proves adept at monitoring pressure signals ranging from lightweight paper to human motion. Additionally, the application of customized laser engraving endows aerogels with unique functionalities, such as compressibility and immunity to strain, stretchability and resistance to compression, as well as wind detection. Thus, the proposed approach holds significant promise as a scalable method for the mass production of aerogels with versatile applications.
Similarities and Differences between Gas Diffusion Layers Used in Proton Exchange Membrane Fuel Cell and Water Electrolysis for Material and Mass Transport
Authors: Zhang Tao , Meng Ling , Chen Chengcheng , Du Lei , Wang Ning , Xing Lixing , Tang Chunmei , Hu Jian , Ye Siyu
Published: June 2024

Proton‐exchange membrane fuel cells (PEMFCs) and water electrolysis (PEMWE) are rapidly developing hydrogen energy conversion devices. Catalyst layers and membranes have been studied extensively and reviewed. However, few studies have compared gas diffusion layers (GDLs) in PEMWE and PEMFC. This review compares the differences and similarities between the GDLs of PEMWE and PEMFC in terms of their material and mass transport characteristics. First, the GDL materials are selected based on their working conditions. Carbon materials are prone to rapid corrosion because of the high anode potential of PEMWEs. Consequently, metal materials have emerged as the primary choice for GDLs. Second, the mutual counter‐reactions of the two devices result in differences in mass transport limitations. In particular, water flooding and the effects of bubbles are major drawbacks of PEMFCs and PEMWE, respectively; well‐designed structures can solve these problems. Imaging techniques and simulations can provide a better understanding of the effects of materials and structures on mass transfer. Finally, it is anticipated that this review will assist research on GDLs of PEMWE and PEMFC.
Integration of Functional Human Auditory Neural Circuits Based on a 3D Carbon Nanotube System
Authors: Lou Yiyun , Ma Jiaoyao , Hu Yangnan , Yao Xiaoying , Liu Yaoqian , Wu Mingxuan , Jia Gaogan , Chen Yan , Chai Renjie , Xia Mingyu , Li Wenyan
Published: June 2024

The physiological interactions between the peripheral and central auditory systems are crucial for auditory information transmission and perception, while reliable models for auditory neural circuits are currently lacking. To address this issue, mouse and human neural pathways are generated by utilizing a carbon nanotube nanofiber system. The super‐aligned pattern of the scaffold renders the axons of the bipolar and multipolar neurons extending in a parallel direction. In addition, the electrical conductivity of the scaffold maintains the electrophysiological activity of the primary mouse auditory neurons. The mouse and human primary neurons from peripheral and central auditory units in the system are then co‐cultured and showed that the two kinds of neurons form synaptic connections. Moreover, neural progenitor cells of the cochlea and auditory cortex are derived from human embryos to generate region‐specific organoids and these organoids are assembled in the nanofiber‐combined 3D system. Using optogenetic stimulation, calcium imaging, and electrophysiological recording, it is revealed that functional synaptic connections are formed between peripheral neurons and central neurons, as evidenced by calcium spiking and postsynaptic currents. The auditory circuit model will enable the study of the auditory neural pathway and advance the search for treatment strategies for disorders of neuronal connectivity in sensorineural hearing loss.
Bioengineered Model of Human LGMD2B Skeletal Muscle Reveals Roles of Intracellular Calcium Overload in Contractile and Metabolic Dysfunction in Dysferlinopathy
Authors: Khodabukus Alastair , Prabhu Neel K. , Roberts Taylor , Buldo Meghan , Detwiler Amber , Fralish Zachary D. , Kondash Megan E. , Truskey George A. , Koves Timothy R. , Bursac Nenad
Published: June 2024

Dysferlin is a multi‐functional protein that regulates membrane resealing, calcium homeostasis, and lipid metabolism in skeletal muscle. Genetic loss of dysferlin results in limb girdle muscular dystrophy 2B/2R (LGMD2B/2R) and other dysferlinopathies – rare untreatable muscle diseases that lead to permanent loss of ambulation in humans. The mild disease severity in dysferlin‐deficient mice and diverse genotype‐phenotype relationships in LGMD2B patients have prompted the development of new in vitro models for personalized studies of dysferlinopathy. Here the first 3‐D tissue‐engineered hiPSC‐derived skeletal muscle (“myobundle”) model of LGMD2B is described that exhibits compromised contractile function, calcium‐handling, and membrane repair, and transcriptomic changes indicative of impaired oxidative metabolism and mitochondrial dysfunction. In response to the fatty acid (FA) challenge, LGMD2B myobundles display mitochondrial deficits and intracellular lipid droplet (LD) accumulation. Treatment with the ryanodine receptor (RyR) inhibitor dantrolene or the dissociative glucocorticoid vamorolone restores LGMD2B contractility, improves membrane repair, and reduces LD accumulation. Lastly, it is demonstrated that chemically induced chronic RyR leak in healthy myobundles phenocopies LGMD2B contractile and metabolic deficit, but not the loss of membrane repair capacity. Together, these results implicate intramyocellular Ca2+ leak as a critical driver of dysferlinopathic phenotype and validate the myobundle system as a platform to study LGMD2B pathogenesis.
Silicon / Perovskite Tandem Solar Cells with Reverse Bias Stability down to −40 V. Unveiling the Role of Electrical and Optical Design
Authors: Di Girolamo Diego , Dupré Olivier , Giuliano Giuliana , Veirman Jordi , Bengasi Giuseppe , Foti Marina , Gerardi Cosimo
Published: June 2024

The reverse bias stability is a key concern for the commercialization and reliability of halide perovskite photovoltaics. Here, the robustness of perovskite‐silicon tandem solar cells to reverse bias electrical degradation down to −40 V is investigated. The two‐terminal tandem configuration, with the perovskite coupled to silicon, can improve the solar cell resistance to severe negative voltages when the tandem device is properly designed. While perovskite cells typically exhibit early reverse bias breakdown voltages, the serial connection with silicon cells with large shunt resistances and high voltage breakdown limits their negative polarization and prevent the passage of large current densities when reverse biased. The importance of careful optical design is illustrated, with bottom‐limited conditions required to prevent the perovskite top cell from exploring its own breakdown. This aspect is of great importance in the case of partial shading events when the solar spectrum is richer in the IR components than the standard AM1.5G. Notably, 100% of efficiency retained after polarization at −40 V in different stressing conditions is observed. The results presented suggest that standard industrial bypass diode schemes may be compatible with silicon/perovskite tandem photovoltaics and provide new guidelines for the standardization of the stressing protocols.
T Cell‐Derived Apoptotic Extracellular Vesicles Hydrolyze cGAMP to Alleviate Radiation Enteritis via Surface Enzyme ENPP1
Authors: Zhou Yang , Bao Lili , Gong Shengkai , Dou Geng , Li Zihan , Wang Zhengyan , Yu Lu , Ding Feng , Liu Huan , Li Xiayun , Liu Siying , Yang Xiaoshan , Liu Shiyu
Published: June 2024

Radiation enteritis is the most common complication of pelvic radiotherapy, but there is no effective prevention or treatment drug. Apoptotic T cells and their products play an important role in regulating inflammation and maintaining physiological immune homeostasis. Here it is shown that systemically infused T cell‐derived apoptotic extracellular vesicles (ApoEVs) can target mice irradiated intestines and alleviate radiation enteritis. Mechanistically, radiation elevates the synthesis of intestinal 2′3′ cyclic GMP‐AMP (cGAMP) and activates cyclic GMP‐AMP synthase (cGAS)‐stimulator of interferon genes (STING) proinflammatory pathway. After systemic infusion of ApoEVs, the ectonucleotide pyrophosphatase phosphodiesterase 1 (ENPP1) enriches on the surface of ApoEVs hydrolyze extracellular cGAMP, resulting in inhibition of the cGAS‐STING pathway activated by irradiation. Furthermore, after ApoEVs are phagocytosed by phagocytes, ENPP1 on ApoEVs hydrolyzed intracellular cGAMP, which serves as an intracellular cGAMP hydrolyzation mode, thereby alleviating radiation enteritis. The findings shed light on the intracellular and extracellular hydrolysis capacity of ApoEVs and their role in inflammation regulation.
A Cell Cycle‐Aware Network for Data Integration and Label Transferring of Single‐Cell RNA‐Seq and ATAC‐Seq
Authors: Liu Jiajia , Ma Jian , Wen Jianguo , Zhou Xiaobo
Published: June 2024

In recent years, the integration of single‐cell multi‐omics data has provided a more comprehensive understanding of cell functions and internal regulatory mechanisms from a non‐single omics perspective, but it still suffers many challenges, such as omics‐variance, sparsity, cell heterogeneity, and confounding factors. As it is known, the cell cycle is regarded as a confounder when analyzing other factors in single‐cell RNA‐seq data, but it is not clear how it will work on the integrated single‐cell multi‐omics data. Here, a cell cycle‐aware network (CCAN) is developed to remove cell cycle effects from the integrated single‐cell multi‐omics data while keeping the cell type‐specific variations. This is the first computational model to study the cell‐cycle effects in the integration of single‐cell multi‐omics data. Validations on several benchmark datasets show the outstanding performance of CCAN in a variety of downstream analyses and applications, including removing cell cycle effects and batch effects of scRNA‐seq datasets from different protocols, integrating paired and unpaired scRNA‐seq and scATAC‐seq data, accurately transferring cell type labels from scRNA‐seq to scATAC‐seq data, and characterizing the differentiation process from hematopoietic stem cells to different lineages in the integration of differentiation data.
Extended Berry Curvature Tail in Ferromagnetic Weyl Semimetals NiMnSb and PtMnSb
Authors: Singh Sukriti , García‐Page Ana , Noky Jonathan , Roychowdhury Subhajit , Vergniory Maia G. , Borrmann Horst , Klauss Hans‐Henning , Felser Claudia , Shekhar Chandra
Published: June 2024

Heusler compounds belong to a large family of materials and exhibit numerous physical phenomena with promising applications, particularly ferromagnetic Weyl semimetals for their use in spintronics and memory devices. Here, anomalous Hall transport is reported in the room‐temperature ferromagnets NiMnSb (half‐metal with a Curie temperature (TC) of 660 K) and PtMnSb (pseudo half‐metal with a TC of 560 K). They exhibit 4 µB/f.u. magnetic moments and non‐trivial topological states. Moreover, NiMnSb and PtMnSb are the first half‐Heusler ferromagnets to be reported as Weyl semimetals, and they exhibit anomalous Hall conductivity (AHC) due to the extended tail of the Berry curvature in these systems. The experimentally measured AHC values at 2 K are 1.8 × 102 Ω−1 cm−1 for NiMnSb and 2.2 × 103 Ω−1 cm−1 for PtMnSb. The comparatively large value between them can be explained in terms of the spin‐orbit coupling strength. The combined approach of using ab initio calculations and a simple model shows that the Weyl nodes located far from the Fermi energy act as the driving mechanism for the intrinsic AHC. This contribution of topological features at higher energies can be generalized.
Advances in Redox Flow Batteries – A Comprehensive Review on Inorganic and Organic Electrolytes and Engineering Perspectives
Authors: Shoaib Muhammad , Vallayil Priya , Jaiswal Nandini , Iyapazham Vaigunda Suba Prathap , Sankararaman Sethuraman , Ramanujam Kothandaraman , Thangadurai Venkataraman
Published: June 2024

Development and application of large‐scale energy storage systems are surging due to the increasing proportion of intermittent renewable energy sources in the global energy mix. Redox flow batteries are prime candidates for large‐scale energy storage due to their modular design and scalability, flexible operation, and ability to decouple energy and power. To date, several different redox couples are exploited in redox‐flow batteries; some are already commercialized. This battery technology is facing a lot of challenges in the science, engineering, and economic front. Issues plaguing flow batteries are low energy density, high overall cost, poor stability of electrolytes, shifting of solvent from anolyte to catholyte while using cation exchange membrane, reverse flow with anion exchange membrane, and corrosion of graphite felt in the catholyte side. Significant research efforts are ongoing to address these challenges. This comprehensive and critical review summarizes the recent progress in electrolyte technologies, including electrochemical performance and stability, strategies to enhance the energy and power densities and, in the end, the levelized and life‐cycle cost of these batteries analyzed. A comprehensive outlook on this technology with respect to practical energy storage applications is also provided.