The influence of non-neural factors on BOLD signal magnitude

To what extent is the size of the blood-oxygen-level-dependent (BOLD) response influenced by factors other than neural activity? In a re-analysis of three neuroimaging datasets, we find large systematic inhomogeneities in the BOLD response magnitude in primary visual cortex (V1): stimulus-evoked BOLD responses, expressed in units of percent signal change, are up to 50% larger along the representation of the horizontal meridian than the vertical meridian. To assess whether this surprising effect can be interpreted as differences in local neural activity, we quantified several factors that potentially contribute to the size of the BOLD response. We find strong relationships between BOLD response magnitude and cortical thickness, cortical curvature, and the presence of large veins. These relationships are consistently found across subjects and suggest that variation in BOLD response magnitudes across cortical locations reflects, in part, differences in anatomy and vascularization. To compensate for these factors, we implement a regression-based correction method and show that after correction, BOLD responses become more homogeneous across V1. The correction reduces the horizontal/vertical difference by about half, indicating that some of the difference is likely not due to neural activity differences. Additionally, we find that while the cerebral sinuses overlap with the vertical meridian representation in V1, they do not explain the observed horizontal/vertical difference. We conclude that interpretation of variation in BOLD response magnitude across cortical locations should consider the influence of the potential confounding factors of cortical thickness, curvature, and vascularization.

Paradoxical facilitation alongside interhemispheric inhibition

Neurophysiological experiments using transcranial magnetic stimulation (TMS) have sought to probe the function of the motor division of the corpus callosum. Primary motor cortex sends projections via the corpus callosum with a net inhibitory influence on the homologous region of the opposite hemisphere. Interhemispheric inhibition (IHI) experiments probe this inhibitory pathway. A test stimulus (TS) delivered to the motor cortex in one hemisphere elicits motor evoked potentials (MEPs) in a target muscle, while a conditioning stimulus (CS) applied to the homologous region of the opposite hemisphere modulates the effect of the TS. We predicted that large CS MEPs would be associated with increased IHI since they should be a reliable index of how effectively contralateral motor cortex was stimulated and therefore of the magnitude of interhemispheric inhibition. However, we observed a strong tendency for larger CS MEPs to be associated with reduced interhemispheric inhibition which in the extreme lead to a net effect of facilitation. This surprising effect was large, systematic, and observed in nearly all participants. We outline several hypotheses for mechanisms which may underlie this phenomenon to guide future research.

Quasiadiabatic electron transport in room temperature nanoelectronic devices induced by hot-phonon bottleneck

Since the invention of transistors, the flow of electrons has become controllable in solid-state electronics. The flow of energy, however, remains elusive, and energy is readily dissipated to lattice via electron-phonon interactions. Hence, minimizing the energy dissipation has long been sought by eliminating phonon-emission process. Here, we report a different scenario for facilitating energy transmission at room temperature that electrons exert diffusive but quasiadiabatic transport, free from substantial energy loss. Direct nanothermometric mapping of electrons and lattice in current-carrying GaAs/AlGaAs devices exhibit remarkable discrepancies, indicating unexpected thermal isolation between the two subsystems. This surprising effect arises from the overpopulated hot longitudinal-optical (LO) phonons generated through frequent emission by hot electrons, which induce equally frequent LO-phonon reabsorption (“hot-phonon bottleneck”) cancelling the net energy loss. Our work sheds light on energy manipulation in nanoelectronics and power-electronics and provides important hints to energy-harvesting in optoelectronics (such as hot-carrier solar-cells).

A Review on Synthesis of Silver Nanoparticles and their Biomedical Applications

The silver (Ag) metal is considered a very useful metal for treating consume wound diseases, open wounds, and cuts, respectively. Nowadays, nanotechnology has created a surprising effect by changing over metallic silver into silver nanoparticles (AgNPs) for better applications. However, according to advanced technology, the synthesis of nanoparticles occurs by using organic or biological techniques rather than physical and chemical techniques. Also, the synthesis of silver nanoparticles (AgNPs) using biological or organic sources is cost-effective and eco-friendly. Silver nanoparticles (AgNPs) are broadly used as antibacterial specialists, helping us cure novel diseases and questionable sicknesses. In biomedicine, silver nanoparticles have huge points of interest because of their physical and synthetic flexibility. The uses of silver nanoparticles (AgNPs) in nano-gels, nano-fluids, silver-based coating over food and medical devices are advancing. Still, there is a need to innovate a better version of silver nanoparticles for vigorous use in an eco-friendly way. So, this review describes the methods of synthesis, activities under various conditions, and different biomedical uses of silver nanoparticles (AgNPs) in detail.

2020—Going Viral

The rapid spread of Covid-19 transformed lives all across the world, causing restrictions on individual liberties and cross-border movements. Transatlantic travel came to a virtual halt in the spring of 2020. The coronavirus caused a severe and rapid economic contraction. Its politicization exacerbated existing divides within societies and polities. Yet, in some ways the most surprising effect of the pandemic may turn out to be the limited impact it had on the structural bonds between America and Europe. Talk about NATO’s demise took a back seat and the momentum for increased transatlantic cooperation in science and innovation picked up. In November 2020, Donald Trump’s defeat in the US presidential elections—perhaps the most closely observed political event of all time—signaled a possible return to less divisive public discourse. Even when infected by a virus, Pax Transatlantica endured.

The temporary cost of dominance

In a population of wild baboons, a new way to assess biological age reveals a surprising effect of social hierarchy.

Spatial and Motor Aspects in the “Action-Sentence Compatibility Effect”

The Action-sentence Compatibility Effect (ACE) is often taken as supporting the fundamental role of the motor system in understanding sentences that describe actions. This effect would be related to an internal “simulation,” i.e., the reactivation of past perceptual and motor experiences. However, it is not easy to establish whether this simulation predominantly involves spatial imagery or motor anticipation. In the classical ACE experiments, where a real motor response is required, the direction and motor representations are mixed. In order to disentangle spatial and motor aspects involved in the ACE, we performed six experiments in different conditions, where the motor component was always reduced, asking participants to judge the sensibility of sentences by moving a mouse, thus requiring a purely spatial representation, compatible with nonmotor interpretations. In addition, our experiments had the purpose of taking into account the possible confusion of effects of practice and of compatibility (i.e., differences in reaction times simultaneously coming from block order and opposite motion conditions). Also, in contrast to the usual paradigm, we included no-transfer filler sentences in the analysis. The ACE was not found in any experiment, a result that failed to support the idea that the ACE could be related to a simulation where spatial aspects rather than motor ones prevail. Strong practice effects were always found and were carved out from results. A surprising effect was that no-transfer sentences were processed much slower than others, perhaps revealing a sort of participants’ awareness of the structure of stimuli, i.e., their finding that some of them involved motion and others did not. The relevance of these outcomes for the embodiment theory is discussed.

A case study on Antiaging property of Mandukparni as an Ayurvedic cosmetic drug

We use cosmetics for keeping and improving natural beauty. The most common problem today is premature ageing of skin. Ayurvedic cosmetics include healthy lifestyle and use of medicinal herbs. Mandukparni is one of those herbal drugs, which is frequently used in Antiaging creams. Hence, we had made attempt to explore antiaging effect of Mandukparni on skin. A female patient of 39 years old at OPD of SRC Ayurveda college, Chikhli was selected for study. She had given Mandukparni churna in the form of lepa and also internally for 30 days. After treatment Mandukparni showed improvement in Wrinkles, Blemishes, Hyperpigmentation, Blackheads, Oiliness. Hence it can be concluded that Mandukparni is an Ayurvedic cosmetic drug showing surprising effect on skin.

Research progress on individual effect of graphene oxide in cement-based materials and its synergistic effect with other nanomaterials

Poor crack resistance, high brittleness, and poor toughness are inherent limitations of traditional cement-based materials. Besides, cement-based materials have certain shortcomings in energy consumption and environmental protection. Therefore, improving the performance of cement-based materials becomes a hot topic in related research. At the same time, the development of nanomaterials and technologies provides researchers with a new research idea: to enhance the performance of cement-based materials at the nanoscale level. Graphene oxide (GO) is one of the most representative nano-reinforcements. Due to its high surface area and excellent physical properties, GO has a surprising effect on improving the performance of cement-based materials. In addition, nanosilica (NS) and carbon nanotubes (CNTs) have excellent improvement on cement-based materials, and people also hope to further improve the performance of cement-based materials through the interaction of various nanomaterials. In this paper, the influence of GO on cement-based materials is reviewed by consulting a lot of correlative literature, mainly focusing on the following aspects: (i) The dispersion of GO in cement paste. (ii) The influence of GO on the properties of cement-based materials, including working performance, mechanical strength, microstructural characteristics, and durability. (iii) The effect of nanohybrid materials of GO, NS, and CNTs on cement-based materials, and the synergistic effects of various nanomaterials are reviewed for the first time. (iv) Evaluation of current progress. This paper aims to provide guidance for the study and application of GO-modified cement-based materials and nanohybrid materials.