bluuebunny/crossref_metadata_2025 huggingface dataset:
Joint work and power associated with acceleration and deceleration in tammar wallabies (Macropus eugenii)
Authors: McGowan C. P. , Baudinette R. V. , Biewener A. A.
Published: December 2004

Measurements of joint work and power were determined using inverse dynamics analysis based on ground reaction force and high-speed video recordings of tammar wallabies as they decelerated and accelerated while hopping over a force platform on level ground. Measurements were obtained over a range of accelerations ranging from -6 m s-2 to 8 m s-2. The goal of our study was to determine which joints are used to modulate mechanical power when tammar wallabies change speed. From these measurements, we also sought to determine which hind limb muscle groups are the most important for producing changes in mechanical work. Because our previous in vivoanalyses of wallaby distal muscle function indicated that these muscle-tendon units favor elastic energy savings and perform little work during steady level and incline hopping, we hypothesized that proximal muscle groups operating at the hip and knee joint are most important for the modulation of mechanical work and power. Of the four hind limb joints examined, the ankle joint had the greatest influence on the total limb work, accounting for 89% of the variation observed with changing speed. The hip and metatarsophalageal (MP) joints also contributed to modulating whole limb work, but to a lesser degree than the ankle, accounting for 28% (energy production) and -24% (energy absorption) of the change in whole limb work versus acceleration, respectively. In contrast, the work produced at the knee joint was independent of acceleration. Based on the results of our previous in vivo studies and given that the magnitude of power produced at the ankle exceeds that which these muscles alone could produce, we conclude that the majority of power produced at the ankle joint is likely transferred from the hip and knee joints viaproximal bi-articular muscles, operating in tandem with bi-articular ankle extensors, to power changes in hopping speed of tammar wallabies. Additionally, over the observed range of performance, peak joint moments at the ankle (and resulting tendon strains) did not increase significantly with acceleration, indicating that having thin tendons favoring elastic energy storage does not necessarily limit a tammar wallaby's ability to accelerate or decelerate.
Ion-selective microelectrode analysis of salicylate transport by the Malpighian tubules and gut ofDrosophila melanogaster
Authors: O'Donnell Michael J. , Rheault Mark R.
Published: December 2004

Transport of the organic anion salicylate by the Malpighian tubules and gut of larval and adult fruit flies was studied using two salicylate-selective microelectrode methods. The first method combined the high selectivity of tridodecylmethylammonium-based electrodes for salicylate with the self-referencing ion-selective microelectrode technique for non-invasive spatial and temporal analysis of salicylate flux. Measurements with this technique revealed secretion of salicylate across the main and distal segments of the Malpighian tubule as well as the midgut, ileum and rectum. The second method used a salicylate-selective microelectrode to measure the concentration of salicylate in fluid droplets secreted by isolated DrosophilaMalpighian tubules set up in a Ramsay secretion assay. Transepithelial salicylate flux was calculated as the product of fluid secretion rate and secreted fluid salicylate concentration. Measurements with this method revealed that salicylate transport was active and saturable; the kinetic parameters Jmax and Kt were 2.72 pmol min-1 tubule-1 and 0.046 mmol l-1,respectively. Measurements of transepithelial salicylate flux determined by both microelectrode methods were in good agreement. Transepithelial flux measurements measured by microelectrodes were also validated by comparing them with measurements of radiolabelled salicylate levels in secreted droplets. Salicylate concentrations in haemolymph samples were measured with salicylate-selective microelectrodes after injection of salicylate into the haemocoel or after insects were fed salicylate-rich diets. The rate of salicylate secretion by Malpighian tubules in vitro was sufficient to account for the measured rate of decline of salicylate concentration in the haemolymph in vivo.
Dynamics and control performance of hard disk drives with passive dampers
Authors: Xu L M , Guo N , Zeng S , Lin R M , Du H
Published: December 2004

The residual vibration is one of the primary mechanical problems that affect the dynamic characteristics of the head actuator assembly in hard disk drives, and the data access speed and positioning resolution. A discrete damping device has been developed to suppress the quasi-rigid-body mode and a reduction of 10 dB in amplitude is shown possible. The servo performance of the head actuator assembly with and without the damping device is presented in this paper, together with the measurement and prediction of the dynamic characteristics. Both closed- and open-loop transfer functions of the plant are measured in the actual operating environment on a servo test stand and compared with the simulation. It is found that the use of passive damping in the structure design allows for a greater margin of error at the crossover frequency since less phase loss results when notch filters are used, thus improving the stability robustness in feedback control.
Position control of a dual-servo stage featuring an electrorheological fluid clutch and piezostack actuator
Authors: Han S-S , Choi S-B
Published: December 2004

In this work, a novel type of dual-servo stage system is proposed in order to achieve accurate position control. A bidirectional electrorheological fluid clutch is adopted for a coarse-positioning stage, and a multi-stack piezoceramic actuator associated with a displacement amplifier for a fine-positioning stage. After deriving the dynamic model of the coarse-motion stage, a sliding-mode controller associated with a friction compensator is formulated to achieve robust position control performance. In addition, a model-based feedforward compensator incorporating a conventional proportional-integral-derivative controller is designed to compensate the hysteresis non-linearity of the fine-positioning stage. These controllers are experimentally realized in a decentralized strategy and control responses such as step input response are evaluated to verify the effectiveness of the proposed dual-servo positioning system.
Elastic creep in serpentine belt drives and adopting a suitable strain measure
Authors: Schulz M
Published: December 2004

The paper deals with the transient dynamics of serpentine belt drives. A model for the rotational motion that has been proposed in the literature is extended to elastic belt creep. However, unlike previous articles, this paper adopts a logarithmic strain measure to describe elastic creep. A condition for the existence of steady state motions with constant belt tensions, as a solution of the mass conservation law, is derived. This condition is violated for the linear strain measure together with Hooke's law, whereas it holds for the logarithmic strain measure. As a consequence, only the logarithmic strain measure, together with Hooke's law, leads to system equations that cover steady operating states. In the case of linear strain, belt tensions and tensioner position do not converge towards constant values when choosing a set of external torques that balance each other out. This is illustrated by two numerical examples. Furthermore, the considerations are reinforced and anchored in the automotive field by analysing the transient belt drive behaviour during a ‘revving-up’ manoeuvre of a common rail diesel engine. The considerations are generally applicable, not only to the classical elastic creep theory but also to any other, more sophisticated theory.
Flexural motion due to laser ablation: Influence of force location on the flexural motion
Authors: Yilbas B S , Hyder J
Published: December 2004

The flexural motion of a multilayer assembly subjected to laser ablation is studied. The assembly consists of thin layers of Inconel alloy (top and bottom layers) and a steel layer (intermediate layer). The assembly resembles a stainless steel sheet with both surfaces coated. The recoil pressure generated during the ablation process results in a loading pressure force acting normal to the assembly surface. The pressure force causes flexural motion in the assembly. In order to secure a sufficiently large flexural displacement, a cantilever arrangement of the assembly is considered. The recoil pressure and the resulting force are formulated and the flexural displacement as well as the resulting stress fields are computed. The influence of the pressure force location at the assembly surface on the flexural motion is examined. It is found that the time occurrence of maximum flexural displacement is the same for all the load locations and the maximum displacement occurs at the free end of the cantilever assembly. The magnitude of normal stresses and shear stress is less than the yielding limit of the substrate material. Moreover, the maximum shear stress is almost three times the maximum normal stress in the assembly.
Abnormal direction of internal auditory canal and vestibulocochlear nerve
Authors: Kariya Shin , Nishizaki Kazunori , Akagi Hirofumi , Paparella Michael M.
Published: December 2004

Several internal auditory canal (IAC) anomalies have been reported. To our knowledge, only one case with an abnormal direction of the IAC has been reported in an infant with Pierre Robin syndrome. In this paper, we present the first report of two non-syndromic cases with abnormal IAC direction.
Consumptive coagulopathy complicating juvenile angiofibroma
Authors: Baguley Campbell , Sandhu Guri , O’Donnell James , Howard David
Published: December 2004

Objective: To investigate the incidence and clinical significance of deranged clotting results among patients with juvenile (nasopharyngeal) angiofibroma.

Methods: Twenty consecutive patients treated for juvenile angiofibroma between March 1998 and July 2002 in whom preoperative coagulation tests were performed were selected. Results were compared with normal laboratory values, and clinical and histological records were retrospectively analysed.

Results: Four out of 20 patients were found to have abnormal tests, consistent with concurrent consumptive coagulopathies. One patient was found to have a raised D-dimer level. This resolved following removal of the lesion.

Conclusions:The association between larger arterio-venous malformations and disseminated intravascular coagulopathy is well described (Kasabach–Merritt syndrome). Our findings suggest that low-grade consumptive coagulopathies may also complicate smaller juvenile angiofibromas, implying that preoperative coagulation screening tests may have a role in ensuring optimal perioperative haemostasis.
Postauricular cutaneous mastoid fistula
Authors: Choo J.C. , Shaw C.L. , Chong Y.C. S.
Published: December 2004

Postauricular cutaneous mastoid fistula is a rare condition. The cutaneous mastoid fistula is a very rare complication of chronic suppurative otitis media. The fistula tracts are typically difficult to manage because of the surrounding necrotic skin edges. We describe an unusual case of a postauricular cutaneous mastoid fistula and outline the surgical technique used for closure.
Volumetric analysis of maxillary sinuses of Zulu and European crania by helical, multislice computed tomography
Authors: Fernandes C.L.
Published: December 2004

Introduction: The volumes of the maxillary sinuses are of interest to surgeons operating endoscopically as variation in maxillary sinus volume may mean variation in anatomical landmarks. Other surgical disciplines, such as dentistry, maxillo-facial surgery and plastic surgery, may benefit from this information.

Objectives: To compare the maxillary sinus volumes of dried crania from cadavers of European and Zulu descent, with respect to ethnic group and gender.

Methodology: Helical, multislice computed tomography (CT) was performed using 1-mm coronal slices. The area
for each slice was obtained by tracing the outline of each slice. The CT machine calculated a volume by totalling the slices for each sinus.

Results: Ethnic and gender variations were found in the different groups. It was found that European crania had significantly larger antral volumes
than Zulu crania and men had larger volumes than women. Race and gender interaction was also assessed, as was maxillary sinus side.

Conclusion: A variation in maxillary sinus volume between different ethnic groups and genders exists, and surgeons operating in this region should be aware of this.
Repair of subtotal tympanic membrane perforations with Seprafilm®
Authors: Konakçi Ersin , Koyuncu Mehmet , Ünal Recep , Tekat Atilla , Uyar Melek
Published: December 2004

Objectives: We studied the experimental use of Seprafilm, a sheet-like filmform of hyaluronic acid, in the repair of subtotal perforations of the tympanic membrane (TM), and the durability of such repairs.

Method: The research was conducted on 42 Sprague–Dawley rats. Right TMs of all rats were subtotally and thermally perforated in the same fashion. Seprafilm was applied to the perforated TMs of the 21 rats comprising the experiment group. The perforated TMs of the remaining 21rats, the control group, were left to heal spontaneously.

Results: The mean healing times were recorded as 7.8 ± 0.6 days for the Seprafilm group and 14.9 ± 1.1 days for the control group (p < 0.001).

Conclusions: These results suggest that Seprafilm may be a possible first choice (before thedecision to operate) in subtotal perforations, considering its easy application and patient follow-up.
Evaluation of Drug Interaction Software to Identify Alerts for Transplant Medications
Authors: Smith Wendy D , Hatton Randy C , Fann Amy L , Baz Maher A , Kaplan Bruce
Published: December 2004

BACKGROUND:

The ability of computerized physician order entry (CPOE) systems to identify clinically significant drug interactions is dependent upon the integrity of the drug information populating the software. A CPOE system with incomplete or inaccurate drug information will fail to identify clinically important drug interactions and, therefore, fail to reduce preventable adverse drug events (pADEs).

OBJECTIVE:

To evaluate, from the prescribers' perspective, the ability of a common drug interaction database to identify clinically important drug interactions involving drugs used in transplantation.

METHODS:

The clinical significance of drug interactions involving 5 transplant drugs was evaluated by an expert panel to determine whether alerts should be generated for physicians not involved in the transplant at the time of order entry. Drug interactions included in the analysis were generated from the expert panel, a common drug interaction database, and 2 standard drug interaction references. Responses on the clinical significance were used to calculate the sensitivity, specificity, and positive and negative predictive values for each severity setting of a common electronic drug interaction database.

RESULTS:

Overall, the database failed to identify approximately 70% of interactions considered significant by the expert panel. Of the alerts that were generated, >85% were considered clinically significant. The database was most deficient in identifying interactions resulting from additive toxicity.

CONCLUSIONS:

To expect a decrease in pADEs caused by drug interactions, the information used to populate CPOE systems must be validated. Establishing consistency and integrity of this information may be a future role for pharmacists.
Nicotine Enhancement of Dopamine Release by a Calcium-Dependent Increase in the Size of the Readily Releasable Pool of Synaptic Vesicles
Authors: Turner Timothy J.
Published: December 2004

A major factor underlying compulsive tobacco use is nicotine-induced modulation of dopamine release in the mesolimbic reward pathway (Wise and Rompre, 1989). An established biochemical mechanism for nicotine-enhanced dopamine release is by activating presynaptic nicotinic acetylcholine receptors (nAChRs) (Wonnacott, 1997). Prolonged application of 10-7to 10-5mnicotine to striatal synaptosomes promoted a sustained efflux of [3H]dopamine. This nicotine effect was mediated by non-α7 nAChRs, because it was blocked by 5 μmmecamylamine but was resistant to 100 nmα-bungarotoxin (αBgTx). Dopamine release was diminished by omitting Na+or by applying peptide calcium channel blockers, indicating that nAChRs trigger release by depolarizing the nerve terminals. However, because α7 receptors rapidly desensitize in the continuous presence of agonists, a repetitive stimulation protocol was used to evaluate the possible significance of desensitization. This protocol produced a transient increase in [3H]dopamine released by depolarization and a significant increase in the response to hypertonic solutions that measure the size of the readily releasable pool (RRP) of synaptic vesicles. The nicotine-induced increase in the size of the readily releasable pool was blocked by αBgTx and by the calmodulin antagonist calmidazolium, suggesting that Ca2+entry through α7 nAChRs specifically enhances synaptic vesicle mobilization at dopamine terminals. Thus, nicotine enhances dopamine release by two complementary actions mediated by discrete nAChR subtypes and suggest that the α7 nAChR-mediated pathway is tightly and specifically coupled to refilling of the RRP of vesicles in dopamine terminals.
Role of Actin Filaments in the Axonal Transport of Microtubules
Authors: Hasaka Thomas P. , Myers Kenneth A. , Baas Peter W.
Published: December 2004

Microtubules originate at the centrosome of the neuron and are then released for transport down the axon, in which they can move both anterogradely and retrogradely during axonal growth. It has been hypothesized that these movements occur by force generation against the actin cytoskeleton. To test this, we analyzed the movement, distribution, and orientation of microtubules in neurons pharmacologically depleted of actin filaments. Actin depletion reduced but did not eliminate the anterograde movements and had no effect on the frequency of retrograde movements. Consistent with the idea that microtubules might also move against neighboring microtubules, actin depletion completely inhibited the outward transport of microtubules under experimental conditions of low microtubule density. Interestingly, visualization of microtubule assembly shows that actin depletion actually enhances the tendency of microtubules to align with one another. Such microtubule-microtubule interactions are sufficient to orient microtubules in their characteristic polarity pattern in axons grown overnight in the absence of actin filaments. In fact, microtubule behaviors were only chaotic after actin depletion in peripheral regions of the neuron in which microtubules are normally sparse and hence lack neighboring microtubules with which they could interact. On the basis of these results, we conclude that microtubules are transported against either actin filaments or neighboring microtubules in the anterograde direction but only against other microtubules in the retrograde direction. Moreover, the transport of microtubules against one another provides a surprisingly effective option for the deployment and orientation of microtubules in the absence of actin filaments.
Conversion of the Modulatory Actions of Dopamine on Spinal Reflexes from Depression to Facilitation in D3Receptor Knock-Out Mice
Authors: Clemens Stefan , Hochman Shawn
Published: December 2004

Descending monoaminergic systems modulate spinal cord function, yet spinal dopaminergic actions are poorly understood. Using thein vitrolumbar cord, we studied the effects of dopamine and D2-like receptor ligands on spinal reflexes in wild-type (WT) and D3-receptor knock-out mice (D3KO).

Low dopamine levels (1 μm) decreased the monosynaptic “stretch” reflex (MSR) amplitude in WT animals and increased it in D3KO animals. Higher dopamine concentrations (10-100 μm) decreased MSR amplitudes in both groups, but always more strongly in WT. Like low dopamine, the D3receptor agonists pergolide and PD 128907 reduced MSR amplitude in WT but not D3KO mice. Conversely, D3receptor antagonists (GR 103691 and nafadotride) increased the MSR in WT but not in D3KO mice. In comparison, D2-preferring agonists bromocriptine and quinpirole depressed the MSR in both groups. Low dopamine (1-5 μm) also depressed longer-latency (presumably polysynaptic) reflexes in WT but facilitated responses in D3KO mice. Additionally, in some experiments (e.g., during 10 μmdopamine or pergolide in WT), polysynaptic reflexes were facilitated in parallel to MSR depression, demonstrating differential modulatory control of these reflex circuits. Thus, low dopamine activates D3receptors to limit reflex excitability. Moreover, in D3ligand-insensitive mice, excitatory actions are unmasked, functionally converting the modulatory action of dopamine from depression to facilitation.

Restless legs syndrome (RLS) is a CNS disorder involving abnormal limb sensations. Because RLS symptoms peak at night when dopamine levels are lowest, are relieved by D3agonists, and likely involve increased reflex excitability, the D3KO mouse putatively explains how impaired D3activity could contribute to this sleep disorder.
Subcortical Modulation of Attention Counters Change Blindness
Authors: Cavanaugh James , Wurtz Robert H.
Published: December 2004

Change blindness is the failure to see large changes in a visual scene that occur simultaneously with a global visual transient. Such visual transients might be brief blanks between visual scenes or the blurs caused by rapid or saccadic eye movements between successive fixations. Shifting attention to the site of the change counters this “blindness” by improving change detection and reaction time. We developed a change blindness paradigm for visual motion and then showed that presenting an attentional cue diminished the blindness in both humans and old world monkeys. We then replaced the visual cue with weak electrical stimulation of an area in the monkey's brainstem, the superior colliculus, to see if activation at such a late stage in the eye movement control system contributes to the attentional shift that counters change blindness. With this stimulation, monkeys more easily detected changes and had shorter reaction times, both characteristics of a shift of attention.
Localization of Brain-Derived Neurotrophic Factor to Distinct Terminals of Mossy Fiber Axons Implies Regulation of Both Excitation and Feedforward Inhibition of CA3 Pyramidal Cells
Authors: Danzer Steve C. , McNamara James O.
Published: December 2004

Hippocampal dentate granule cells directly excite and indirectly inhibit CA3 pyramidal cells via distinct presynaptic terminal specializations of their mossy fiber axons. This mossy fiber pathway contains the highest concentration of brain-derived neurotrophic factor (BDNF) in the CNS, yet whether BDNF is positioned to regulate the excitatory and/or inhibitory pathways is unknown. To localize BDNF, confocal microscopy of green fluorescent protein transgenic mice was combined with BDNF immunohistochemistry. Approximately half of presynaptic granule cell-CA3 pyramidal cell contacts were found to contain BDNF. Moreover, enhanced neuronal activity virtually doubled the percentage of BDNF-immunoreactive terminals contacting CA3 pyramidal cells. To our surprise, BDNF was also found in mossy fiber terminals contacting inhibitory neurons. These studies demonstrate that mossy fiber BDNF is poised to regulate both direct excitatory and indirect feedforward inhibitory inputs to CA3 pyramdal cells and reveal that seizure activity increases the pool of BDNF-expressing granule cell presynaptic terminals contacting CA3 pyramidal cells.
Selectivity for the Spatial and Nonspatial Attributes of Auditory Stimuli in the Ventrolateral Prefrontal Cortex
Authors: Cohen Yale E. , Russ Brian E. , Gifford Gordon W. , Kiringoda Ruwan , MacLean Katherine A.
Published: December 2004

Spatial and nonspatial auditory processing is hypothesized to occur in parallel dorsal and ventral pathways, respectively. In this study, we tested the spatial and nonspatial sensitivity of auditory neurons in the ventrolateral prefrontal cortex (vPFC), a cortical area in the hypothetical nonspatial pathway. We found that vPFC neurons were modulated significantly by both the spatial and nonspatial attributes of an auditory stimulus. When comparing these responses with those in anterolateral belt region of the auditory cortex, which is hypothesized to be specialized for processing the nonspatial attributes of auditory stimuli, we found that the nonspatial sensitivity of vPFC neurons was poorer, whereas the spatial selectivity was better than anterolateral neurons. Also, the spatial and nonspatial sensitivity of vPFC neurons was comparable with that seen in the lateral intraparietal area, a cortical area that is a part of the dorsal pathway. These data suggest that substantial spatial and nonspatial processing occurs in both the dorsal and ventral pathways.
Hippocampal Structures Among Japanese Adolescents Before and After the COVID-19 Pandemic
Authors: Cai Lin , Maikusa Norihide , Zhu Yinghan , Nishida Atsushi , Ando Shuntaro , Okada Naohiro , Kasai Kiyoto , Nakamura Yuko , Koike Shinsuke
Published: February 2024

Importance

Few studies have used a large-sample, longitudinal, population-based cohort study to examine whether the COVID-19 pandemic as a global major life event is associated with structural plasticity of the adolescent hippocampus.

Objective

To examine whether Japan's first state of emergency (SoE) during the COVID-19 pandemic was associated with alterations in the macrostructures and microstructures of the hippocampus during its development.

Design, Setting, and Participants

The population-neuroscience Tokyo TEEN Cohort study is a prospective cohort study with 4 consecutive waves in Tokyo, Japan. Due to the SoE, data collection was suspended between March 27, 2020, and July 30, 2020. Analyzed data, comprising 1149 brain structural scans obtained from 479 participants, of whom 336 participants had undergone 2 or more scans, were collected between October 2013 and November 2021. Data were analyzed from August 2022 to December 2023.

Exposures

Japan’s first SoE (April 7 to May 25, 2020).

Main Outcomes and Measures

Hippocampal volume, 12 hippocampal subfield volumes, and 7 microstructural measures of the hippocampus.

Results

A total of 1060 brain scans from 459 participants (214 female participants [47%]) including 246 participants from wave 1 (median [IQR] age, 11.3 [11.1-11.7] years), 358 from wave 2 (median [IQR] age, 13.8 [13.3-14.5] years), 304 from wave 3 (median [IQR] age, 15.9 [15.4-16.5] years), and 152 from wave 4 (median [IQR] age, 17.9 [17.5-18.4] years) were included in the final main analysis. The generalized additive mixed model showed a significant associations of the SoE with the mean hippocampal volume (β = 102.19; 95% CI, 0.61-203.77; P = .049). The generalized linear mixed models showed the main associations of the SoE with hippocampal subfield volume (granule cell and molecular layer of the dentate gyrus: β = 18.19; 95% CI, 2.97-33.41; uncorrected P = .02; CA4: β = 12.75; 95% CI, 0.38-25.12; uncorrected P = .04; hippocampus-amygdala transition area: β = 5.67; 95% CI, 1.18-10.17; uncorrected P = .01), and fractional anisotropy (β = 0.03; 95% CI, 0.00-0.06; uncorrected P = .04).

Conclusions and Relevance

After the first SoE, a volumetric increase in the hippocampus and trend increase in 3 subfield volumes and microstructural integration of the hippocampus were observed, suggesting that the transient plasticity of the adolescent hippocampus was affected by a major life event along with the typical developmental trajectory.
Lipid droplets provide metabolic flexibility for cancer progression
Authors: Safi Rémi , Menéndez Pablo , Pol Albert
Published: February 2024

A hallmark of cancer cells is their remarkable ability to efficiently adapt to favorable and hostile environments. Due to a unique metabolic flexibility, tumor cells can grow even in the absence of extracellular nutrients or in stressful scenarios. To achieve this, cancer cells need large amounts of lipids to build membranes, synthesize lipid‐derived molecules, and generate metabolic energy in the absence of other nutrients. Tumor cells potentiate strategies to obtain lipids from other cells, metabolic pathways to synthesize new lipids, and mechanisms for efficient storage, mobilization, and utilization of these lipids. Lipid droplets (LDs) are the organelles that collect and supply lipids in eukaryotes and it is increasingly recognized that the accumulation of LDs is a new hallmark of cancer cells. Furthermore, an active role of LD proteins in processes underlying tumorigenesis has been proposed. Here, by focusing on three major classes of LD‐resident proteins (perilipins, lipases, and acyl‐CoA synthetases), we provide an overview of the contribution of LDs to cancer progression and discuss the role of LD proteins during the proliferation, invasion, metastasis, apoptosis, and stemness of cancer cells.
The ecology of online hate speech: Mapping expert perspectives on the drivers for online hate perpetration with the Delphi method
Authors: Weber Ina , Vandebosch Heidi , Poels Karolien , Pabian Sara
Published: February 2024

Online hate speech (OHS) is a prevalent issue on social media with harmful consequences for individuals and society. Counteracting this issue requires a better understanding of the factors that drive behaviors such as posting hate speech or making hateful comments. The present study contributes to this need by investigating the personal, social, and digital determinants for OHS perpetration. By conducting a two‐round Delphi study, data was collected from an interdisciplinary sample of experts. Practitioners were included in this sample to bridge gaps between research and fieldwork on OHS. The first survey collected information through open‐ended questions, which was then organized in different themes and lists of determinants in a thematic analysis. These determinants were rated for relevance in a follow‐up survey. Data analysis of the second survey used nonparametric statistics. From a total list of 129 determinants, the participants reached a consensus on 27 determinants as most relevant (median > 4) for facilitating the production and dissemination of OHS. An ecological perspective was applied to interpret these findings. As a result, we propose an ecological model of personal, social, and digital determinants for online hate perpetration to illustrate their influence on individual behavior as well as their possible connections. The model provides a comprehensive overview of factors facilitating OHS perpetration, which can help to identify points for intervention.
Biallelic variants in GTPBP3: New patients, phenotypic spectrum, and outcome
Authors: Nardecchia Francesca , Carrozzo Rosalba , Innocenti Alice , Torraco Alessandra , Zaccaria Valerio , Rizza Teresa , Pisani Francesco , Bertini Enrico , Leuzzi Vincenzo
Published: February 2024

Introduction

COXPD23 is a rare mitochondrial disease caused by biallelic pathogenic variants in GTPBP3. We report on two siblings with a mild phenotype.

Case reports

The young boy presented with global developmental delay, ataxic gait and upper limbs tremor, and the older sister with absence seizures and hypertrophic cardiomyopathy. Respiratory chain impairment was confirmed in muscle.

Discussion

Reviewed cases point toward clustering around two prevalent phenotypes: an early‐onset presentation with severe fatal encephalopathy and a late milder presentation with global developmental delay/ID and cardiopathy, with the latter as, is the main feature. Our patients showed an intermediate phenotype with intrafamilial variability.
Atomic Layer Deposition of Epitaxial Ferroelectric Hf0.5Zr0.5O2 Thin Films
Authors: Cho Jung Woo , Song Myeong Seop , Choi In Hyeok , Go Kyoung‐June , Han Jaewoo , Lee Tae Yoon , An Chihwan , Choi Hyung‐Jin , Sohn Changhee , Park Min Hyuk , Baek Seung‐Hyub , Lee Jong Seok , Choi Si‐Young , Chae Seung Chul
Published: February 2024

The groundbreaking discovery of unconventional ferroelectricity in HfO2 opens exciting prospects for next‐generation memory devices. However, the practical implementation, particularly its epitaxial stabilization and a clearer understanding of its intrinsic ferroelectricity has been a significant challenge. The study arouses the potential importance of atomic layer deposition (ALD) for mass production in modern industries, demonstrating its proficiency in achieving epitaxial growth of ferroelectric Hf0.5Zr0.5O2 (HZO) thin films on Yttria‐stabilized zirconia (YSZ) substrates. Moreover, with distinct ferroelectric switching currents, the work reveals the ferroelectric characteristics of epitaxial HZO thin films deposited through ALD on YSZ‐buffered Si substrates, which aligns well with CMOS technology. Overall, the results pave the way for a scalable synthesis system for ferroelectric HfO2‐based materials, hinting at a bright future for low‐temperature epitaxial nanoelectronics.
Structurally Stable, Low H2O Prussian Blue Analogs toward High Performance Sodium Storage
Authors: Gao Yuting , Wu Xingxing , Wang Li , Zhu Yaofeng , Sun Guoxing , Tang Yuxin , Yan Mi , Jiang Yinzhu
Published: February 2024

Prussian blue analogues (PBAs) are recognized as promising cathode materials for sodium‐ion batteries (SIBs) due to their facile synthesis, low‐cost, high capacity, and environmental friendliness. However, high water content (>10 wt%) in the framework and unsatisfactory structural stability of PBAs are still the bottlenecks for industrial applications. Herein, interstitial K‐doping is employed to minimize the interstitial water and enhance the structural stability of Na2‐xFeMn[Fe(CN)6] (FeMnPBA), thereby boosting the sodium storage performance. The 3% K‐doping (K‐FeMnPBA3) demonstrates a much‐reduced water content of 6.9%, accompanied by a notably enhanced capacity of 139.1 mAh g−1 at 100 mA g−1 and a remarkable capacity retention of 77.1% after 700 cycles. Furthermore, the K‐FeMnPBA3/hard carbon (HC) pouch cell achieves a stable cyclability with 82.6% capacity retention after 600 cycles. This research offers valuable insights into low‐water PBAs for practical applications in SIBs.
CVD Synthesis of Twisted Bilayer WS2 with Tunable Second Harmonic Generation
Authors: Xu Manzhang , Ji Hongjia , Zhang Mingwen , Zheng Lu , Li Weiwei , Luo Lei , Chen Mengdi , Liu Zheng , Gan Xuetao , Wang Xuewen , Huang Wei
Published: February 2024

The introduction of rotational freedom by twist angles in twisted bilayer (TB) transition metal dichalcogenides (TMDCs) can tailor the inherent properties of the TMDCs, which provides a promising platform to investigate the exotic physical properties. However, direct synthesis of high‐quality TB‐TMDCs with full twist angles is significantly challenging due to the substantial energy barriers during crystal growth. Here, a modified chemical vapor deposition strategy is proposed to synthesize TB‐WS2 with a wide twist angle range from 0° to 120°. Utilizing a tilted SiO2/Si substrate, a gas flow disturbance is generated in the furnace tube to create a heterogeneous concentration gradient of the metal precursor, which provides an extra driving force for the growth of TB‐WS2. The Raman and photoluminescence results confirm a weak interlayer coupling of the TB‐WS2. High‐quality periodic Moiré patterns are observed in the scanning transmission electron microscopy images. Moreover, owing to the strong correlation between the nonlinear optical response and the twisted crystal structure, tunable second harmonic generation behaviors are realized in the TB‐WS2. This approach opens up a new avenue for the direct growth of high‐crystalline‐quality and pristine TB‐TMDCs and their potential applications in nonlinear optical devices.
Photoredox‐Enabled Manganese‐Catalyzed [2+2+2] Cycloaddition of Alkynes
Authors: Zhou Yi , He Yong‐Qin , Wang Xiao‐Yu , Lu Lin , Zhou Zhao‐Zhao , Song Xian‐Rong , Tian Wan‐Fa , Xiao Qiang
Published: February 2024

Manganese (Mn) is the third most abundant transition metal on Earth and is known for its exceptional biocompatibility. The development of novel catalytic mode for Mn is of great significance to advancing organic synthesis. In this study, the first manganese (Mn)‐catalyzed [2+2+2] cycloaddition of alkynes is achieved with the aid of visible‐light photoredox catalysis. Photoredox catalysis is proposed to promote the transformation by in situ reduction of high‐valent Mn(II) complex to Mn(0) species, thereby initiating the reaction. Additionally, a photooxidation‐induced reductive ellimination step is also suggested. This system is further distinguished by its notable tolerance towards both terminal and internal alkynes as counterparts of diynes.
Back‐End‐of‐Line Integration of Synaptic Weights using HfO2/ZrO2Nanolaminates
Authors: Bégon‐Lours Laura , Slesazeck Stefan , Falcone Donato Francesco , Havel Viktor , Hamming‐Green Ruben , Fernandez Marina Martinez , Morabito Elisabetta , Mikolajick Thomas , Offrein Bert Jan
Published: February 2024

In artificial neural networks, the “synaptic weights” connecting the neurons are adjusted during the training. Beyond silicon, functionalizing the back‐end‐of‐line (BEOL) of CMOS circuits with novel materials is a key enabler for deploying neural network accelerators. The hardware implementation of the synaptic weights requires linear and reprogrammable resistive elements. In ferroelectric tunnel junctions, the resistance is programmed by controlling the configuration of the ferroelectric domains with electrical pulses. From ferroelectric HfZrO4to HfO2–ZrO2nanolaminates (NL), the crystallization temperature lowers below the upper limit of 400 °C required for CMOS BEOL. The device footprint is reduced, and the maximum‐to‐minimum conductance ratio increases from 7 to 32. Operated with pulses in the ultra‐fast (20 ns) and biological (500 µs) timescales, the synaptic plasticity exhibits several regimes. Dynamic hysteresis mode characterization after up to 1011switching cycles indicates the coexistence of ferroelectric and non‐ferroelectric effects such as defect rearrangement. Temperature‐dependent transport measurements in the Ohmic (linear) regime support these conclusions. Multi‐level resistive switching is achieved in HfO2–ZrO2NL co‐integrated to CMOS in the BEOL. 1T‐1R operation is demonstrated, paving the way for hardware implementation of synaptic weights for in‐memory neuromorphic computing.
A comparison of operator and financial characteristics of U.S. beef cow‐calf producers by race
Authors: Davis Christopher G. , Collins LaPorchia A. , Davis Gailda Pitre
Published: February 2024

This study compares financial characteristics of U.S. beef cow‐calf farms by race and highlights potential challenges faced by minority farms based on the historical context in which they operate. We find that, in 2018, factors related to farm size and inefficiencies in generating returns contributed to racial disparities in the profitability of beef cow‐calf farms. Relative to White cow‐calf farms, on average, African American and Native American farms had less acreage, value of production, and net farm income but a higher share at financial risk due to inefficiencies. More research is needed to understand racial differences in farm financial performance.
Facile Construction of Self‐Powered Electronic Textiles for Comprehensive Respiration Analysis
Authors: Zhang Jiabei , Ren Wenjuan , Chen Sitong , Wang Ruoyu , Luo Hua , Diao Yan , Han Yangyang , Gan Fangji , Wu Xiaodong
Published: February 2024

Respiration is one of the most important physiological processes of the human body. Continuous monitoring of respiration with wearable sensors can provide abundant information related to the health status of the respiratory system. However, the vast majority of the developed respiration sensors are constructed on nontextile substrates, resulting in dissatisfactory convenience, comfortness, and aesthetics. Additionally, special micro‐/nanomaterials are inevitably involved to construct the respiration sensors, which pose potential hazards to the human body due to the exfoliation and inhalation of these micro‐/nanomaterials. Here, humidity‐ and temperature‐sensitive electronic textiles (e‐Textiles) are presented, which are fabricated based on easily accessible and biofriendly materials (e.g., sodium chloride, glycerin, aluminum fiber, carbon fiber, and polyvinyl alcohol). Moreover, the proposed e‐Textiles use a potentiometric sensing mechanism, featuring self‐powered signal outputs and ultralow power consumption. The humidity and temperature‐sensing functionalities can also be in situ integrated into commercial masks for constructing full‐textile and all‐in‐one e‐Masks for comprehensive respiration monitoring. As demonstrations, both single‐point respiration monitoring (e.g., intensity, frequency, etc.) and 2D respiratory analysis (i.e., airflow distribution) can be realized with the e‐Masks. This work provides a facile and scalable approach to manufacture self‐powered and fully fabric respiration sensors for comprehensive respiratory analysis.
De Novo Designed Ru(II) Metallacycle as a Microenvironment‐Adaptive Sonosensitizer and Sonocatalyst for Multidrug‐Resistant Biofilms Eradication
Authors: Xu Yuling , Pang Yida , Luo Lishi , Sharma Amit , Yang Jingfang , Li Chonglu , Liu Shuang , Zhan Jianbo , Sun Yao
Published: February 2024

Albeit sonodynamic therapy (SDT) has achieved encouraging progress in microbial sterilization, the scarcity of guidelines for designing highly effective sonosensitizers and the intricate biofilm microenvironment (BME), substantially hamper the therapeutic efficacy against biofilm infections. To address the bottlenecks, we innovatively design a Ru(II) metallacycle‐based sonosensitizer/sonocatalyst (namedRu‐A3‐TTD) to enhance the potency of sonotherapy by employing molecular engineering strategies tailored to BME. Our approach involves augmentingRu‐A3‐TTD’s production of ultrasonic‐triggered reactive oxygen species (ROS), surpassing the performance of commercial sonosensitizers, through a straightforward but potent π‐expansion approach. Within the BME,Ru‐A3‐TTDsynergistically amplifies sonotherapeutic efficacy via triple‐modulated approaches: (i) effective alleviation of hypoxia, leading to increased ROS generation, (ii) disruption of the antioxidant defense system, which shields ROS from glutathione consumption, and (iii) enhanced biofilm penetration, enabling ROS production in deep sites. Notably,Ru‐A3‐TTDsono‐catalytically oxidizes NADPH, a critical coenzyme involved in antioxidant defenses. Consequently,Ru‐A3‐TTDdemonstrates superior biofilm eradication potency against multidrug‐resistantEscherichia colicompared to conventional clinical antibiotics, both in vitro and in vivo. To our knowledge, this study represents the pioneering instance of a supramolecular sonosensitizer/sonocatalyst. It provides valuable insights into the structure‐activity relationship of sonosensitizers and paves a promising pathway for the treatment of biofilm infections.
Patterns, processes and conservation management consequences of intraspecific diversity, illustrated by fishes from recently glaciated lakes
Authors: Koene J. Peter , Bean Colin W. , Kristjánsson Bjarni K. , Skúlason Skúli , Leblanc Camille A.‐L. , Adams Colin E.
Published: February 2024

Patterns in phenotypic and genotypic diversity within many species are becoming increasingly apparent, although there remain many species for which such patterns have yet to be described adequately.

Fishes from recently glaciated ecosystems are likely to be particularly rich in intraspecific diversity, yet current conservation management strategies are, in many parts of the world, particularly in Europe, conventionally and overwhelmingly focused on species, regardless of competing species concepts, and appropriate policies for managing diversity at a sub‐specific level still have to be developed.

Occasional attempts to protect certain vulnerable ecotypes and proposed alternative units of conservation (e.g. ‘Pragmatic Species’ or ‘Evolutionarily Significant Units’) reinforce the conventional primacy of contemporary expressed patterns of variation.

Intraspecific phenotypic and genotypic patterns are ultimately the result of complex processes of divergence; conservation approaches that focus on the products of evolution largely ignore the processes that generate and maintain those patterns. Policies that acknowledge the continuation of evolution, the derivation of novel diversity over often very short time spans and the role of environment in initiating and perpetuating these processes are poorly integrated into management strategy.

To address possible deficits, where intraspecific diversity is not addressed in management practice, we believe it to be important first to characterize hidden genetic and phenotypic diversity, which may intimate eco‐evolutionary processes, initially among species of high conservation status. A second step should be to use an approach to intraspecific diversity that illuminates the ultimate processes and mechanisms that bring about that diversity, which also concedes the central role of the environment and affords adequate protection to the ecosystems that drive these processes, such as the United Nations Convention on Biological Diversity (CBD) Ecosystems approach.
Diving into archival data: The hidden decline of the giant grouper (Epinephelus lanceolatus) in Queensland, Australia
Authors: Chong‐Montenegro Carolina , Thurstan Ruth H. , Pandolfi John M.
Published: February 2024

The giant grouper (Epinephelus lanceolatus) is the largest reef fish in the Indo‐Pacific (~2.5 m TL, >400 kg), and it is highly susceptible to overfishing. Despite regional protections and documented population declines, the species is listed by IUCN as Data Deficient due to minimal long‐term population data and a paucity of life history information. This study used historical fishing records derived from newspaper articles, fishing magazines, grey literature and naturalists' descriptions to collate life history information and reconstruct giant grouper population trends from 1854 to 1958 in Queensland, Australia. Historical recreational catch trends of four biologically distinct grouper size classes demonstrated that over 92 years, fishing disproportionately affected two size classes: immature (fish below reproductive size) and mature individuals. Changes in the probability of capturing a grouper within a recreational fishery were examined as a proxy of relative abundance. The probability of catching a giant grouper within a popular recreational fishery significantly declined from 81% in 1860 to 2% in 1958. Further analysis based on a non‐probabilistic method of giant grouper sighting records showed fluctuations in the giant grouper population trajectory, from a steady decline during the early 20th century to an increase during WWII (1939–1945) followed by a reduction in the last half of the 20th century. This study highlights the importance of archival sources to uncover population trends of rare species by combining quantitative assessments and biological inferences to determine the timing and occurrence of population declines and recoveries and inform how vulnerable fish species respond to the cumulative effects of fishing over time.