bluuebunny/crossref_metadata_2025 huggingface dataset:
Cosmic Ray Nucleonic Intensity in Low-Amplitude Days During the Passage of High-Speed Solar Wind Streams
Authors: Agarwal Rekha , Mishra Rajesh , Tiwari Sharad
Published: June 2008

Cosmic Ray Nucleonic Intensity in Low-Amplitude Days During the Passage of High-Speed Solar Wind Streams

One of the most striking features of solar wind is its organization into high- and low- speed streams. It is now well established that the passage over the Earth of high-speed solar wind streams leads to geomagnetic disturbances. The high-speed plasma streams are thus a key element in the complex chain of events that link geomagnetic activity to the solar activity and are therefore of great interest to the solar terrestrial physics. Two types of high-speed solar wind streams - coronal-hole-associated (or corotating) and flare-generated - were studied based on magnetic field and solar wind plasma parameters. In the work, the dependence was obtained for cosmic ray (CR) depressions due to high-speed solar wind streams during low-amplitude days. The CR nucleonic intensity data were subjected to the superposed epoch analysis with respect to the start time of high-speed solar wind streams. It was found that streams of both types produce significant deviations in the CR intensity during low-amplitude anisotropic wave train events. At the onset of such streams the CR intensity reaches its minimum during low-amplitude events and then increases statistically.
Nanostructure design for surface-enhanced Raman spectroscopy – prospects and limits
Authors: Xiao Sanshui , Mortensen Niels Asger , Jauho Antti-Pekka
Published: June 2008

Surface-enhanced Raman spectroscopy (SERS) allows single-molecule detection due to the strong field localization occurring at sharp bends or kinks of the metal-vacuum interface. An important question concerns the limits of the signal enhancement that can be achieved via a judicious design of the surface. By using a specific example of a technologically realizable nanopatterned surface, we demonstrate that while very high enhancement factors (≈ 1012) can be found for an ideal surface, these are unlikely to be achieved in laboratory samples, because even a minute, inevitable rounding-off strongly suppresses the enhancement, as well as shifts the optimal frequency. Our simulations indicate that the geometric enhancement factors are unlikely to exceed ≈ 108 for real samples, and that it is necessary to consider the geometric uncertainty to reliably predict the frequency for maximum enhancement.
Editorial
Authors: Salemink Oscar
Published: June 2008

On Sunday, 23 February 2003, around twelve thousand foreign domestic workers in Hong Kong—largely, but not exclusively, Filipina “maids”—demonstrated in Victoria Park against government plans to levy a new charge on migrant labor contracts while lowering the minimum wage.
Introduction
Authors: Barber Pauline Gardiner , Lem Winnie
Published: June 2008

This issue brings together the work of researchers who seek to illuminate the class configurations of contemporary global diasporas. Contributions proceed by problematizing the relationship between political mobilization and the class locations of women and men as they negotiate and renegotiate the social conditions under which they make a living as émigrés, people who are subject to and participants in the processes of global change. Although class and culture, as well as mobility and fixity, are often presented as oppositional lenses though which to view global transformations, articles in this issue explore the possibilities for translation of particularized local or cultural concerns into broader collective mobilizations of class activism, nationalist claims, or struggles for entitlement in the circumscribed political spaces migrants seek to create. The gender, ethnic, local, national, and other cultural components of identity and class formation are made explicit as contributors question how and why political struggles and activism may, or indeed may not, be carried forward in geographic and social border crossings as well as citizenship and migration scenarios. It is the contention of each contributor that any instance of activism, and also its absence, requires sustained critical examination of the politics and economics of its production and reproduction.
Cell phones, complicity, and class politics in the Philippine labor diaspora
Authors: Barber Pauline Gardiner
Published: June 2008

This article addresses the politics of class, culture, and complicity associated with Philippine gendered-labor export. Several examples drawn from multisited ethnographic research explore two faces of class: migrant performances of subordination contrasted with militancy in the labor diaspora. With few exceptions, the literature on Philippine women in domestic service has emphasized disciplined subjectivities, the everyday dialectics of subordination. But class is also represented in these same relationships, understandings, and actions. Alternatively, the political expressions of Philippine overseas workers, and their supporters, is a feature of Philippine migration that is not often mentioned in writing concerned with migrant inequalities. This article proposes a reconciliation of these two faces of class expression by exploring how new media, primarily cell-phone technologies, enhance possibilities for organized and personal resistance by Filipino migrants, even as they facilitate migrant acquiescence, linked here to gendered subordination and class complicity, in the contentious reproduction of the migrant labor force.
Political engagement of Latin Americans in the UK
Authors: Però Davide
Published: June 2008

This article examines the political engagement of Latin Americans in the UK in the context of a mounting neo-assimilationist and anti-multicultural offensive in the public debate on integration. Assuming that migrants should have a say about their own integration in society, the article explores the extent to which the public debate is sensitive to migrants' own collective concerns. It is from this empirically informed perspective that the article criticizes assimilationist and multi-culturalist attitudes for their disregard of the exploitation and lack of social and cultural recognition that afflicts newly arrived migrants. The article helps to rebalance the prevailing trend in policy and academic circles to treat migrants as objects of policies and ignore their political agency and active collective engagement in the improvement of their conditions. It also offers a corrective to emerging alternative approaches that tend to reduce migrants' politics to their role in sustaining long-distance diasporic communities.
On the charisma, civility, and practical goodness of "modern" Christianity in post-Soviet Lithuania
Authors: Lankauskas Gediminas
Published: June 2008

This article examines The Word of Faith, one of the largest congregations of "modern" charismatic Christians in post-Soviet Lithuania. The ethnographic focus is on the church's extensive network of trust, altruistic exchange, and sociability, known as bendravimas. These networks are theorized as a kind of civil society that allows its members to claim "ethical distinction" and enables them to take a critical stance toward the surrounding social milieu, perceived to be in moral disarray. The Word of Faith is discussed in relation to the national Catholic Church (its principal religious rival) and vis-à-vis broader Lithuanian society. The article suggests that it is concrete everyday practices deemed to be moral and civil, rather than abstract Christian precepts, that motivate Word of Faith believers to be "good people." It is also argued that such practices constitute important means for engendering and reproducing the charisma of this "modern" evangelical congregation.
Living with/in and without neo-liberalism
Authors: Clarke John
Published: June 2008

This article explores some concerns about the concept of neo-liberalism, suggesting that it has been stretched too far to be productive as a critical analytical tool. Neo-liberalism suffers from promiscuity (hanging out with various theoretical perspectives), omnipresence (treated as a universal or global phenomenon), and omnipotence (identified as the cause of a wide variety of social, political and economic changes). Alternative ways of treating neo-liberalism as more contingent and contested are considered. These emphasize its mobile and flexible character, stressing processes of contextual assemblage, articulation, and translation. The article concludes by wondering whether the concept of neo-liberalism is now so overused that it should be retired.
BOOK REVIEW – CRITIQUE BIBLIOGRAPHIQUE
Authors: Oppong Richard Frimpong
Published: June 2008

Economic integration has been promoted as essential for the development of Africa. Currently, the principal vehicle for integration in the West Africa sub-region is the Economic Community of West African States [ECOWAS]. A lot has been written on ECOWAS from socio-economic and political perspectives. What has so far been missing is a comprehensive study of ECOWAS from a legal or institutional perspective. It is a defining characteristic of Africa's integration processes that the role of law, rules or institutions has not been emphasised. The process has been a political construct fortified by economic theory with the central role of law or institutions missing. Indeed, a 2006 report of the United Nations Economic Commission for Africa found the existing legal framework for Africa's integration ‘ambiguous and imprecise’. It is against this background that Dr. Kofi Oteng Kufuor's book The Institutional Transformation of the Economic Community of West African States is timely and welcomed. It is the singular contribution of Kufuor's work that while not ignoring the importance of the socio-economic and political perspectives, he brings to bear on the study of ECOWAS a legal and institutional perspective that is at once critical and rigorous.
Plural Views, Common Purpose: On How to Address Moral Failure by International Political Organisations
Authors: Dobson Lynn
Published: June 2008

International organisations are actors capable of bearing moral responsibilities and ought to be accountable for their failures in doing so. However, we should understand these responsibilities and respond to their failures in the light of fuller considerations about morality and the common good. The article argues that the international community should ensure victims are attended to, but also that defaulting institutions may themselves need rehabilitation for different kinds of international common purposes to be achievable. Further, the ways in which both goals are agreed and undertaken must recognise multiple perspectives, else the possibilities for durable peaceable cooperation internationally will be damaged. Even in a world of plural views, we can find sufficient proximity on matters of ‘good’ and ‘bad’ to move toward further agreement. Drawing on Braithwaite, Rawls, and Sunstein, the article argues we should search out and build on such ‘islands of agreement’ on wrongs in international life and on mutually respectful ways of responding to them.
The Delinquency of Anarchical Societies: Transformation, Not Punishment; Restyling, Not Rehabilitation
Authors: Frost Mervyn
Published: June 2008

This article explores the ways in which we hold participants in dispersed practices to ethical account for the accumulated consequences of their individual actions over time. This ‘holding to account’ is quite different to that found within centralised practices such as a state or a corporation. In the case of a state, for example, we hold presidents, prime ministers (and others) to account in terms of well understood norms of ethical behaviour internal to the practice. For example, we might accuse them of corruption. In such cases an actor is criticised for failing to adhere to a well understood ethical norm. In dispersed practices, the holding to account is different. Here the allegation is that the participants, through adhering to the ethical norms inherent in the practice, are collectively bringing about an unethical result. Through their doing the ethically right thing, they are bringing about a wrong. Marx's analysis of capitalism can be understood in this way. In the normal day to day activity in a capitalist system, individual buyers and sellers are not doing anything ethically wrong, but the accumulated outcome of their individual actions is ethically (on Marx's analysis) unacceptable. The wrongdoing arises from a failure to understand the structural consequences of the operation of the practice over time. It also arises from a failure to understand and act on the political possibilities of transformation that exist within the practices in question.
Influence of time-dose-relationships in therapeutic nuclear medicine applications on biological effectiveness of irradiation
Authors: Dörr W. , Wust P. , Kotzerke J. , Oehme L.
Published: June 2008

Aim: The biological effectiveness of irradiation is influenced not only by the total dose but also the rate at which this dose is administered. Tolerance dose estimates from external radiation therapy with a conventional fractionation protocol require adaptation for application in targeted radionuclide therapy. Methods: The linear-quadratic model allows for calculation of the biologically effective dose (BED) and takes into consideration tissue specific factors (recovery capacity) as well as dose rate effects (recovery kinetics). It can be applied in radionuclide therapy as well. For relevant therapeutic radionuclides (e. g. 188Re, 90Y, 177Lu, and 131I), the effect of different physical decay times and variable biological half-lives on BED was calculated for several organs. Results: BED is markedly increased using 188Re compared to longer-lived radionuclides. The effect is dose-dependent and tissue-specific, resulting, for example, in higher effects on the kidneys compared to bone marrow. Therefore, in unfavourable conditions (e. g. reduced recovery capacity due to concomitant diseases or previous therapy), the BED may exceed organ dose tolerance. Conclusion: Time-dose-relationships have to be taken into consideration by the calculation of BED for internal radionuclide therapy. The biological effectiveness depends on dose- and tissue-specific factors and is much more pronounced in 188Re than in 90Y and other longer living radionuclides. Determination of organ tolerance dose values should take into account these radiobiological differences, since it is currently not considered in dosimetry programs.
Acute Myocardial Infarction in Swine Rapidly and Selectively Releases Highly Proliferative Endothelial Colony Forming Cells (ECFCs) into Circulation
Authors: Huang Lan , Hou Dongming , Thompson Meredith A. , Baysden Sarah E. , Shelley W. Christopher , Ingram David A. , March Keith L. , Yoder Mervin C.
Published: June 2008

We have recently identified endothelial colony forming cells (ECFCs) in human blood and blood vessels, and ECFC are elevated in patients with coronary artery disease. Because pigs are a favored model for studying myocardial ischemia, we questioned whether ECFCs also exist in swine and whether myocardial ischemia would alter the number of ECFC in circulation. ECFCs were present in circulating blood and aortic endothelium of healthy pigs. In pigs with an acute myocardial infarction (AMI) (n = 9), the number of circulating ECFC was markedly increased compared to sham control pigs (15 ± 6 vs. 1 ± 1 colonies/100 cc blood, p < 0.05). Moreover, the percentage of circulating high proliferative potential ECFCs (HPP-ECFCs) was significantly increased following AMI induction compared to sham control (38.4 ± 5.8% vs. 0.4 ± 0.4%, p < 0. 05) and to baseline (38.4 ± 5.8% vs. 2.4 ± 2.4%, p < 0. 05) blood samples. This is the first study to report that ECFCs are present in blood and aorta in healthy pigs and that the number and distribution of circulating ECFCs is altered following AMI. Because circulating ECFC are also altered in human subjects with severe coronary artery disease, the pig model of AMI may be an excellent preclinical model to test the role of ECFC in the pathophysiology of AMI.
Adipose-Derived Cells
Authors: Meliga Emanuele , Strem Brian M. , Duckers H. J. , Serruys Patrick W.
Published: June 2008

Heart failure is by far the most common cause of hospitalization in Western countries, with onerous economic consequences. Cell therapy holds great promise for use in tissue regeneration and is increasingly used in an effort to improve outcomes in cardiac disease. Recently it has been shown that adipose tissue, in addition to committed adipogenic, endothelial progenitor cells and pluripotent vascular progenitor cells, also contains multipotent cell types (adipose-derived stem cells, ADSCs) that, in cell culture conditions, have shown to have an impressive developmental plasticity including the ability to undergo multilineage differentiation and self-renewal. ADSCs express multiple CD marker antigens similar to those observed on MSCs and are also capable of secreting a large number of angiogenesis-related cytokines, including vascular endothelial growth factor, granulocyte/macrophage colony stimulating factor, stromal-derived factor-1α, and hepatocyte growth factor. Adipose tissue can be harvested in large quantities with minimal morbidity in several regions of the body and, on average, 100 ml of human adipose tissue yields about 1 × 106 stem cells. Studies conducted in porcine AMI models have shown a significant LV functional improvement, with no report of any potentially fatal arrhythmias. The APOLLO trial, a prospective, double blind, randomized, placebo-controlled trial currently in the recruiting phase, is a “first-in-man” study that explores the safety and feasibility of ADSC transplantation in patients with acute MI.
Cardiac Cell-Based Therapy: Cell Types and Mechanisms of Actions
Authors: Ramos Geraldo A. , Hare Joshua M.
Published: June 2008

Over the past decade, the concept that the heart could undergo cardiac regeneration has rapidly evolved. Studies have indicated that numerous sites in the body harbor stem or progenitor cells, prompting clinical trials of these potential therapeutic cell-based approaches. Most notable are the series of trials utilizing either skeletal myoblasts or autologous whole bone marrow. More recently the quest has focused on specific bone marrow constituents, most notably the mesenchymal stem cell, which has several unique advantages including immunoprivilege, immunosuppression, and the ability to home to areas of tissue injury. Most recently, cells have been identified within the heart itself that are capable of self-replication and differentiation. The discovery of cardiac stem cells offers not only a potential therapeutic approach but also provides a plausible target for endogenous activation as a therapeutic strategy. Together the new insights obtained from studies of cell-based cardiac therapy have ushered in new biological paradigms and enormous potential for novel therapeutic strategies for cardiac disease.
Myocardial Assistance by Grafting a New Bioartificial Upgraded Myocardium (MAGNUM Clinical Trial): One Year Follow-Up
Authors: Chachques Juan C. , Trainini Jorge C. , Lago Noemi , Masoli Osvaldo H. , Barisani Jose L. , Cortes-Morichetti Miguel , Schussler Olivier , Carpentier Alain
Published: June 2008

Cell transplantation for the regeneration of ischemic myocardium is limited by poor graft viability and low cell retention. In ischemic cardiomyopathy the extracellular matrix is deeply altered; therefore, it could be important to associate a procedure aiming at regenerating myocardial cells and restoring the extracellular matrix function. We evaluated intrainfarct cell therapy associated with a cell-seeded collagen scaffold grafted onto infarcted ventricles. In 15 patients (aged 54.2 ± 3.8 years) presenting LV postischemic myocardial scars and with indication for a single OP-CABG, autologous mononuclear bone marrow cells (BMC) were implanted during surgery in the scar. A 3D collagen type I matrix seeded with the same number of BMC was added on top of the scarred area. There was no mortality and no related adverse events (follow-up 15 ± 4.2 months). NYHA FC improved from 2.3 ± 0.5 to 1.4 ± 0.3 (p = 0.005). LV end-diastolic volume evolved from 142 ± 24 to 117 ± 21 ml (p = 0.03), and LV filling deceleration time improved from 162 ± 7 to 196 ± 8 ms (p = 0.01). Scar area thickness progressed from 6 ± 1.4 to 9 ± 1.5 mm (p = 0.005). EF improved from 25 ± 7% to 33 ± 5% (p = 0.04). Simultaneous intramyocardial injection of mononuclear bone marrow cells and fixation of a BMC-seeded matrix onto the epicardium is feasible and safe. The cell-seeded collagen matrix seems to increase the thickness of the infarct scar with viable tissues and helps to normalize cardiac wall stress in injured regions, thus limiting ventricular remodeling and improving diastolic function. Patients' improvements cannot be conclusively related to the cells and matrix due to the association of CABG. Cardiac tissue engineering seems to extend the indications and benefits of stem cell therapy in cardiology, becoming a promising way for the creation of a “bioartificial myocardium.” Efficacy and safety of this approach should be evaluated in a large randomized controlled trial.
Myocyte Replacement Therapy: Skeletal Myoblasts
Authors: Sherman Warren
Published: June 2008

Skeletal myoblasts function as precursors to adult skeletal myocytes. More so than other muscle progenitors, their capacity for de novo self-renewal and their positive functional effects in the cardiac environment have been demonstrated, even though they do not attain a cardiomyocyte phenotype. Autologous skeletal myoblasts are easily procured by established methods and can be administered into diseased myocardium safely and without technical difficulty, features that at this time set them apart from any other myogenic cell. Clinical studies in patients with chronic myocardial disease have consistently reported modest improvements in ventricular function and clinical status. Data from the Myogenesis Heart efficiency and Regeneration Trial (MYOHEART) trial are currently being evaluated. Larger, randomized, placebo-controlled studies in patients with congestive heart failure due to postinfarction systolic left ventricular dysfunction are under way, such as Myoblast Autologous Grafting in Ischemic Cardiomayopathy (MAGIC) and Multicenter Study of the Safety and Cardiovascular Effects Of Myoblasts in Congestive Heart Failure (MARVEL). The future role of skeletal myoblasts in the clinical setting will be determined by the results of randomized trials as well as by the investigation of subsequent generations of myoblasts, engineered for enhanced efficacy.
Intramyocardial Delivery of Bone Marrow Mononuclear Cells and Mechanical Assist Device Implantation in Patients with End-Stage Cardiomyopathy
Authors: Nasseri Boris A. , Kukucka Marian , Dandel Michael , Knosalla Christoph , Potapov Evgenij , Lehmkuhl Hans B. , Meyer Rudolph , Ebell Wolfram , Stamm Christof , Hetzer Roland
Published: June 2008

In end-stage heart failure, mechanical ventricular assist devices (VAD) are being used as bridge-to-transplantation, as a bridge-to-recovery, or as the definitive therapy. We tested the hypothesis that myocardial implantation of autologous bone marrow mononuclear cells (BMNC) increases the likelihood of successful weaning from left VAD (LVAD) support. Ten patients (aged 14–60 years) with deteriorating heart function underwent LVAD implantation and concomitant implantation of autologous BMNC. Bone marrow was harvested prior to VAD implantation and BMNC were prepared by density centrifugation. Two patients received a pulsatile, extracorporeal LVAD and eight a nonpulsatile implantable device. Between 52 and 164 × 107 BMNC containing between 1 and 12 × 106 CD34+ cells were injected into the LV myocardium. There was one early and one late death. The median time on LVAD support was 243 days (range 24–498 days). Repeated echocardiographic examinations under increased hemodynamic load revealed a significant improvement of LV function in one patient. Three patients underwent heart transplantation, and four patients remain on LVAD support >1 year without evidence of recovery. Only one patient was successfully weaned from LVAD support after 4 months, and LV function has remained stable ever since. In patients with end-stage cardiomyopathy, intramyocardial injection of BMNC at the time of LVAD implantation does not seem to increase the likelihood of successful weaning from VAD support. Other cell-based strategies should be pursued to harness the potential of cell therapy in LVAD patients.
Improved Cell Survival in Infarcted Myocardium Using a Novel Combination Transmyocardial Laser and Cell Delivery System
Authors: Patel Amit N. , Spadaccio Cristiano , Kuzman Michael , Park Eulsoon , Fischer David W. , Stice Steven L. , Mullangi Chandra , Toma Catalin
Published: June 2008

Stem cell therapy has been used to treat ischemic cardiac disease with promising early results. However, there has been limited success using cell therapy in infarcted tissue. The cells have an inadequate microvascular environment in order to survive once implanted into scar tissue. The goal of this study was to create a microvascular environment into infarcted myocardial tissue using transmyocardial laser revascularization (TMR) as a pretreatment before cell implantation and evaluate cell survival afterwards. Balloon occlusion catheter-based myocardial infarct of the circumflex artery was created in a porcine model. The infarct was allowed to mature for 2 weeks. Three groups consisting of TMR alone (TMR), TMR + fluorescent-labeled allogeneic mesenchymal stem cells (MSCs) (TMR + Cells), and MSCs alone (Cells) were injected into the infarcted tissue using a combination TMR and cell delivery system (Phoenix™, Cardiogenesis). The hearts were explanted at 1 week after treatment for cell and tissue evaluation. The myocardial infarcts were verified in all animals using both ultrasound and direct visual imaging. All arms of the study were successful with a mean of 2.0 ± 106 MSCs injected per site into the scar tissue. All animals survived to explant at 1 week. On histological examination, 300 high-power fields were evaluated demonstrating that the TMR + Cells group had 25 ± 5 cells and the Cells group 5 ± 2 cells compared to baseline TMR alone by fluorescence. The use of TMR as a pretreatment for MSC injection increases early cell survival in infarcted tissue without increased adverse events. Further long-term functional and differentiation analysis will be required to evaluate the efficacy for future clinical translation.
SDF-1 Recruits Cardiac Stem Cell-Like Cells that Depolarize In Vivo
Authors: Unzek Samuel , Zhang Ming , Mal Niladri , Mills William R. , Laurita Kenneth R. , Penn Marc S.
Published: June 2008

Prolongation or reestablishment of stem cell homing through the expression of SDF-1 in the myocardium has been shown to lead to homing of endothelial progenitor cells to the infarct zone with a subsequent increase in vascular density and cardiac function. While the increase in vascular density is important, there could clearly be other mechanisms involved. In a recent study we demonstrated that the infusion of mesenchymal stem cells (MSC) and MSC that were engineered to overexpress SDF-1 led to significant decreases in cardiac myocyte apoptosis and increases in vascular density and cardiac function compared to control. In that study there was no evidence of cardiac regeneration from either endogenous stem cells or the infused mesenchymal stem cells. In this study we performed further detailed immunohistochemistry on these tissues and demonstrate that the overexpression of SDF-1 in the newly infracted myocardium led to recruitment of small cardiac myosin-expressing cells that had proliferated within 2 weeks of acute MI. These cells did not differentiate into mature cardiac myocytes, at least by 5 weeks after acute MI. However, based on optical mapping studies, these cells appear capable of depolarizing. We observed greater optical action potential amplitude in the infarct border in those animals that received SDF-1 overexpressing MSC than observed in noninfarcted animals and those that received control MSC. Further immunohistochemistry revealed that these proliferated cardiac myosin-positive cells did not express connexin 43, but did express connexin 45. In summary, our study suggests that the prolongation of SDF-1 expression at the time of acute MI leads to the recruitment of endogenous cardiac myosin stem cells that may represent cardiac stem cells. These cells are capable of depolarizing and thus may contribute to increased contractile function even in the absence of maturation into a mature cardiac myocyte.
Accumulation of Ambient Black Carbon Particles Within Key Memory-Related Brain Regions
Authors: Vanbrabant Kenneth , Van Dam Debby , Bongaerts Eva , Vermeiren Yannick , Bové Hannelore , Hellings Niels , Ameloot Marcel , Plusquin Michelle , De Deyn Peter Paul , Nawrot Tim S.
Published: April 2024

Importance

Ambient air pollution is a worldwide problem, not only related to respiratory and cardiovascular diseases but also to neurodegenerative disorders. Different pathways on how air pollutants could affect the brain are already known, but direct evidence of the presence of ambient particles (or nanoparticles) in the human adult brain is limited.

Objective

To examine whether ambient black carbon particles can translocate to the brain and observe their biodistribution within the different brain regions.

Design, Setting, and Participants

In this case series a label-free and biocompatible detection technique of nonincandescence-related white light generation was used to screen different regions of biobanked brains of 4 individuals from Belgium with neuropathologically confirmed Alzheimer disease for the presence of black carbon particles. The selected biological specimens were acquired and subsequently stored in a biorepository between April 2013 and April 2017. Black carbon measurements and data analysis were conducted between June 2020 and December 2022.

Main Outcomes and Measures

The black carbon load was measured in various human brain regions. A Kruskal-Wallis test was used to compare black carbon loads across these regions, followed by Dunn multiple comparison tests.

Results

Black carbon particles were directly visualized in the human brain of 4 individuals (3 women [75%]; mean [SD] age, 86 [13] years). Screening of the postmortem brain regions showed a significantly higher median (IQR) number of black carbon particles present in the thalamus (433.6 [289.5-540.2] particles per mm3), the prefrontal cortex including the olfactory bulb (420.8 [306.6-486.8] particles per mm3), and the hippocampus (364.7 [342.0-448.7] particles per mm3) compared with the cingulate cortex (192.3 [164.2-277.5] particles per mm3), amygdala (217.5 [147.3-244.5] particles per mm3), and the superior temporal gyrus (204.9 [167.9-236.8] particles per mm3).

Conclusions and Relevance

This case series provides evidence that ambient air pollution particles are able to translocate to the human brain and accumulate in multiple brain regions involved in cognitive functioning. This phenomenon may contribute to the onset and development of neurodegenerative disorders.
Structural determinants for membrane binding of the EGFR juxtamembrane domain
Authors: Wu Ziwei , Li Ling , Zhu Lina , Wang Runhan , Dong Yingkui , Zhang Yaoyao , Wang Yujuan , Wang Junfeng , Zhu Lei
Published: April 2024

Overactivation of the epidermal growth factor receptor (EGFR) is critical for the development of multiple cancers. Previous studies have shown that the cell membrane is a key regulator of EGFR kinase activity through its interaction with the EGFR juxtamembrane domain (JM). However, the lipid recognition specificity of EGFR‐JM and its interaction details remain unclear. Using lipid strip and liposome pulldown assays, we showed that EGFR‐JM could specifically interact with PI(4,5)P2‐or phosphatidylserine‐containing membranes. We further characterized the JM–membrane interaction using NMR‐titration‐based chemical shift perturbation and paramagnetic relaxation enhancement analyses, and found that residues I649 − L659 comprised the membrane‐binding site. Furthermore, the membrane‐binding region contains the predicted dimerization motif of JM, 655LRRLL659, suggesting that membrane binding may affect JM dimerization and, therefore, regulate kinase activation.
Study on the Influence of Etchant Composition and Etching Process on the Precision of Stainless‐Steel Microchannel and Etching Mechanism
Authors: Wei Yanni , Zhu Linghao , Jia Lei , Chen Yu , Li Yaru
Published: April 2024

The chemical etching method has the advantages of high precision and low cost for the preparation of steel surface microchannel, but the composition of the etching solution and the etching process have a great influence on the precision of the microstructure. In this article, the influence of etching solution composition and the etching time on the etching precision of stainless steel using a mixture of HCl and H2O2 as an etching solution is studied. The reactions and passivation processes that occur during the etching process are analyzed. The etching mechanism is revealed. The sample prepared with HCl:H2O2 = 1:2 can obtain better etching precision and high‐dimensional stability. The amount of lateral erosion and the depth of etching increases with the increase of etching time, resulting in a decrease in the etching factor and precision. Pitting and intergranular corrosion mainly occur during the etching process, and the loss of metal chloride formed in the process forms holes, which become rapid diffusion channels for corrosive Cl and O elements, and promotes the etching process. The etching reaction forms a passivation film on the surface of the substrate, which reduces the rate of the etching reaction.
Intraocular Pressure Monitoring Smart Contact Lens with High Environmental Stability
Authors: Yang Huan , Zhu Hengtian , Liu Hanwen , Mao Zhengyi , Luo Junxian , Zhu Shugeng , Hu Zizhong , Yuan Songtao , Xu Fei
Published: April 2024

Smart contact lenses (SCLs), integrating various functional components, serve as a platform for wirelessly intraocular pressure (IOP) monitoring. Accurate and dynamic measurements offer crucial clinical references for patients with ocular hypertension. Nevertheless, the complex ocular environment poses great challenges, particularly for inductor–capacitor–resistor (LCR) type IOP sensors, which suffer signal instability due to variations of ocular dielectric properties. Here, an innovative IOP monitoring sensor with robust environmental stability, achieved by integrating the ground shield, is proposed. Employing a capacitive pressure sensor with porous polydimethylsiloxane (PDMS) structure encased in a hydrogel, the study successfully demonstrates high‐sensitivity monitoring of IOP changes using in vitro porcine eyes. This optimized design empowers the wireless IOP sensor with a sensitivity of 1.15 ‰/mmHg. It exhibits exceptional frequency stability after undergoing 100 wear cycles on ten distinct porcine eyes and remains reliable across a wide range of metabolite concentrations typical of normal eyes. Notably, any observed frequency shift translates into IOP changes within a 3 mmHg range, showcasing its suitability for repeated use and daily IOP monitoring.
Stabilizing Layered‐Type K0.4V2O5 Cathode by K Site Substitution with Strontium for K‐Ion Batteries
Authors: Oh Gwangeon , Kansara Shivam , Xu Xieyu , Liu Yangyang , Xiong Shizhao , Hwang Jang‐Yeon
Published: April 2024

Developing suitable cathodes with high capacity and high power is challenging for K‐ion batteries. Herein, electrochemical K‐ion storage properties of the layered‐type K0.4V2O5 (KVO) cathode by incorporating divalent strontium ions (Sr2+) into its crystal structure are enhanced. Divalent strontium ions (1.18 Å) are preferentially incorporated into the octahedrally coordinated K (1.38 Å) layers due to the similar ionic size compared to V4+ (0.58 Å). The introduction of 3 mmol of Sr ions in the KVO crystal improves electrical conductivity and reduces K‐ion diffusion energy barriers. In addition, the strong Sr2+ and O2− interaction acts as a structural pillar, suppressing irreversible phase transition during charge–discharge process. Multi‐physics simulations clearly confirm that the K0.34Sr0.03V2O5 (KS3VO) cathode exhibits a more uniform K‐ion distribution and enhanced reactions of K‐ions compared to the KVO cathode at various depths of discharge. As a result, the KS3VO cathode demonstrates improved reversible capacity, cycling stability, and power capability over the KVO cathode in a K‐ion cell. Synchrotron X‐ray analysis reveals how Sr substitution enhances the electrochemical K‐ion storage properties of the KS3VO cathode. In addition, the KS3VO cathode exhibits superior thermal stability and cycling stability in a full cell coupled with a hard carbon anode compared to the KVO cathode.
Fully UV Modulated Artificial Synapses with Integrated Sensing, Storage and Computation
Authors: Sun Shuyi , Zhang Tao , Jin Shuoqi , Pan Xinhua , Lu Jianguo , Ye Zhizhen , Lu Bin
Published: April 2024

Optical synaptic devices are considered a preferred substitute to electrical synapses for low‐energy, high‐efficiency neuromorphic computing (NC). However, most optical synapses irreversible optical response severely restricts their application scenarios. In this study, a fully photon‐modulated synaptic device constructed from Si‐doped beta‐gallium oxide (β‐Ga2O3)/ZnO heterojunction is demonstrated. The device exhibits reversible conductance changes and mimics a range of synaptic behaviors, which are modulated by two different wavelengths (255 and 370 nm) of UV light. Owing to the device's plasticity, four types of logic functions including “AND”, “OR”, “NOR” and “NAND” are implemented in the device by optical stimulation. Furthermore, an artificial neural network (ANN) is simulated based on the device's excitatory and inhibitory characteristics, and an optical programming scheme is employed to enhance the network's performance, resulting in a high recognition rate of 95.5% for handwritten digits. The fully photon‐modulated synapse development strategy and programming scheme, as presented in this work, advance the utilization of optical artificial synapses in ANN.
Enhancing the Performance of the Mesoporous TiO2 Film in Printed Perovskite Photovoltaics through High‐Speed Imaging and Ink Rheology Techniques
Authors: Potts Sarah‐Jane , Bolton Rebecca , Dunlop Tom , Lacey Kathryn , Worsley Carys , Watson Trystan , Jewell Eifion
Published: April 2024

Mesoscopic carbon‐based perovskite solar cells (C‐PSCs) have the potential to be manufactured at an industrial scale by utilizing screen‐printing, a simple, affordable, and commercially mature process. As such, many recent publications have focused on enhancing performance through modifying cell architecture and perovskite chemistries. This work examines how ink rheology can be tuned to optimize cell performance through reducing the occurrence of common print defects to create higher quality m‐TiO2 films. Inks with different solvent dilutions and rheological profiles are assessed using high‐speed imaging through the screen‐printing visualization (SPV) technique, to investigate the impact of the viscosity and elasticity on ink separation mechanisms. The resultant film quality and its influence on device performances are then assessed. Ink separation lengths are minimized, and the formation of filaments ceases during printing, leading to improved TiO2 film topography and homogenous infiltration of the perovskite precursor. Consequently, PCE is improved by over 10% of the original efficiency in cells and 224 cm2 active area modules due to enhanced Voc and FF. These results not only provide key insights into tailoring ink rheology, to achieve improved print homogeneity and higher performing cells, but also aid further work on enhancing the performance of other screen‐printed functional films.
Inverse Magnetocaloric Effect in Altermagnetic 2D Non‐van der Waals FeX (X = S and Se) Semiconductors
Authors: Liu Qinxi , Kang Jinchao , Wang Peng , Gao Weiwei , Qi Yan , Zhao Jijun , Jiang Xue
Published: April 2024

The concept of altermagnet (AM), which is neither ferromagnet nor antiferromagnet, has recently been proposed as compensated collinear magnet. Among 2D non‐van der Waals crystals, one of the thinnest altermagnets is identified and their interesting physical phenomenon at 2D limit is investigated. According to symmetry analysis and first‐principles calculations, 2D FeX (X = S, Se) sheets with one‐unit‐cell thickness are intrinsic altermagnetic semiconductors with observable magnitude of spin splitting (103−193 meV), high magnetic transition temperature (TAM = 400 and 190 K), large out‐of‐plane magnetic anisotropy energy (0.24 and 0.74 meV per atom) and considerable metal‐like anomalous Hall conductivity (143 and 249 Ω−1 cm−1). Moreover, the spin lattices of these 2D FeX ultrathin films are formed by parallel diamond‐like chains with spin frustrated interaction through spin exchange along the b direction. Consequently, an inverse magnetocaloric effect with positive ∆Sm values of 1.7–8.2 mJ kg−1 K−1 near TAM is observed. These results enrich the database of altermagnets and provide deep insights into the spin frustration effect in 2D magnets, which paves the avenue for the next‐generation spintronics.
Spring Lock: Constructing Cluster Emitters with Colorful TADF from Non‐Conjugated Polymaleimide Helical Chains
Authors: Liu Jun , Wang Shuaiqi , Lv Wei , Wu Junyan , Ling Qidan , Lin Zhenghuan
Published: April 2024

Non‐conjugated luminescent polymers have received much attention due to their excellent flexibility, processability, and biocompatibility. However, the single emission color and low solid‐state luminescence efficiency restrict their further development. Herein, by introducing carboxyl‐terminated alkyl chains on the rigid and helical polymaleimide backbone, a series of non‐conjugated luminescent polymers are designed and synthesized. Due to the “spring lock” formed by the synergism of scalable helical main chains and flexible alkyl side chains, these polymers exhibit effective cluster luminescence with thermally activated delayed fluorescence (TADF) property, thereby significantly improving the solid‐state luminescence efficiency with the quantum yield up to 59.6%. The TADF emission wavelengths of the polymer powders can be tuned from 498 to 639 nm through changing reaction solvents, because the conformation of helical chains forming clusters is sensitive to solvent polarity. Interestingly, metal ions can induce the polymers to construct self‐repairing cluster luminescence gels, which show excellent potential applications in ammonia detection and information encryption. This work not only provides an effective design strategy for the colorful cluster luminescence with high‐efficiency TADF, but also further reveals the cluster luminescence mechanism and enlightens the promising applications of cluster luminescent gels.
High‐Density, Conformable Conducting Polymer‐Based Implantable Neural Probes for the Developing Brain
Authors: Ma Liang , Wisniewski Duncan J. , Cea Claudia , Khodagholy Dion , Gelinas Jennifer N.
Published: April 2024

Neurologic and neuropsychiatric disorders substantially impact the pediatric population, but there is a lack of dedicated devices for monitoring the developing brain in animal models, leading to gaps in mechanistic understanding of how brain functions emerge and their disruption in disease states. Due to the small size, fragility, and high water content of immature neural tissue, as well as the absence of a hardened skull to mechanically support rigid devices, conventional neural interface devices are poorly suited to acquire brain signals without inducing damage. Here, the authors design conformable, implantable, conducting polymer‐based probes (NeuroShanks) for precise targeting in the developing mouse brain without the need for skull‐attached, rigid mechanical support structures. These probes enable the acquisition of high spatiotemporal resolution neurophysiologic activity from superficial and deep brain regions across unanesthetized behavioral states without causing tissue disruption or device failure. Once implanted, probes are mechanically stable and permit precise, stable signal monitoring at the level of the local field potential and individual action potentials. These results support the translational potential of such devices for clinically indicated neurophysiologic recording in pediatric patients. Additionally, the role of organic bioelectronics as an enabling technology to address questions in developmental neuroscience is revealed.
Water Catchers within Sub‐Nano Channels Promote Step‐by‐Step Zinc‐Ion Dehydration Enable Highly Efficient Aqueous Zinc‐Metal Batteries
Authors: Xu Dongming , Wang Zhe , Liu Chengjun , Li Haoyu , Ouyang Feng , Chen Benqiang , Li Weihang , Ren Xueting , Bai Lishun , Chang Zhi , Pan Anqiang , Zhou Haoshen
Published: April 2024

Zinc metal suffers from violent and long‐lasting water‐induced side reactions and uncontrollable dendritic Zn growth, which seriously reduce the coulombic efficiency (CE) and lifespan of aqueous zinc‐metal batteries (AZMBs). To suppress the corresponding harmful effects of the highly active water, a stable zirconium‐based metal‐organic framework with water catchers decorated inside its sub‐nano channels is used to protect Zn‐metal. Water catchers within narrow channels can constantly trap water molecules from the solvated Zn‐ions and facilitate step‐by‐step desolvation/dehydration, thereby promoting the formation of an aggregative electrolyte configuration, which consequently eliminates water‐induced corrosion and side reactions. More importantly, the functionalized sub‐nano channels also act as ion rectifiers and promote fast but even Zn‐ions transport, thereby leading to a dendrite‐free Zn metal. As a result, the protected Zn metal demonstrates an unprecedented cycling stability of more than 10 000 h and an ultra‐high average CE of 99.92% during 4000 cycles. More inspiringly, a practical NH4V4O10//Zn pouch‐cell is fabricated and delivers a capacity of 98 mAh (under high cathode mass loading of 25.7 mg cm−2) and preserves 86.2% capacity retention after 150 cycles. This new strategy in promoting highly reversible Zn metal anodes would spur the practical utilization of AZMBs.
Highly Efficient Cash Sterilization with Ultrafast and Flexible Joule‐Heating Strategy by Laser Patterning
Authors: Xu Yang , Lin Jing , Chen Yi , Zhong Haosong , Lee Connie Kong Wai , Tan Min , Chen Siyu , Kim Minseong , Poon Elizabeth Wing Yan , Chan Timothy Yee Him , Yuan Aidan Qiaoyaxiao , Tang Miao , Yang Rongliang , Pan Yexin , Fu Ying , Li Mitch Guijun
Published: April 2024

Since ancient times, humans have learned to use fire and other heating methods to fight against dangerous pathogens, like cooking raw food, sterilizing surgical tools, and disinfecting other pathogen transmission media. However, it remains difficult for current heating methods to achieve extremely fast and highly efficient sterilization simultaneously. Herein, an ultrafast and uniform heating‐based strategy with outstanding bactericidal performance is proposed. Ultra‐precise laser manufacturing is used to fabricate the Joule heater which can be rapidly heated to 90 °C in 5 s with less than 1 °C fluctuation in a large area by real‐time temperature feedback control. An over 98% bactericidal efficiency on S. aureus for 30 s and on E. coli for merely 5 s is shown. The heating strategy shows a 360 times faster acceleration compared to the commonly used steam sterilization from the suggested guidelines by the Centers for Disease Control and Prevention (CDC), indicating that high temperatures with short duration can effectively disinfect microorganisms. As a proof of concept, this heating strategy can be widely applied to sterilizing cash and various objects to help protect the public from bacteria in daily life.