Paper has been present in the world of analytical chemistry for centuries, but it seems that just a few years back it was rediscovered as a valuable substrate for sensors. We can easily list some of ...the countless advantages of this simple cellulosic substrate, including mechanical properties, three-dimensional fibrous structure, biocompatibility and biodegradability, easiness of production and modification, reasonable price, and availability all over the world. Those characteristics make paper a first-choice substrate for disposable sensors and integrated sensing platforms. Nowadays, numerous examples of paper-based sensors are being presented in the literature. This review describes some of the most prominent examples classifying them by type of detection: optical (colorimetric, fluorescence, surface-enhanced Raman spectroscopy, and transmittance methods) and electrochemical (voltammetric, potentiometric, and conductivity-based methods). We take a closer look at recent advances in immunoassays fabricated on paper, excluding simple lateral flow tests assembled on nitrocellulose. This review also summarizes the main advantages and disadvantages of the use of paper as a substrate for sensors, as well as its impact on their performance and application, presents a short history of paper in analytical chemistry, and discusses fabrication methods and available sources of paper.
Paper-based sensors gained almost explosive attention during the last few years. A large number of systems, often destined to resource limited settings is based on enzymatic reactions. Choice of an ...adequate immobilization method could significantly prolong the shelf-life of such sensors, especially in applications, where exposure to high temperatures during storage and transport is more than a threat. We are seeking to compare a variety of immobilization methods based on different phenomena (adsorption, entrapment in gel, microencapsulation, covalent linkage), with total of 33 methods tested. Glucose oxidase was used as a model enzyme. Enzymatic activity of immobilized samples was accompanied for a period of 24 weeks considering two sets of samples, one stored in 4 °C and other in ambient temperature.
•Simple, easy-to-use electrochemical paper-based analytical device.•The 3D device allows fast filtration and electrochemical detection.•The paper-based electrochemical cell was constructed using ...pencil and paper.•The paper based device allows p-nitrophenol detection at the micromolar level.
We report here the fabrication and electrochemical characterization of a three-dimensional paper-based analytical device made from pencil (hard and soft) and paper as a low-cost, simple, easy-to-use device for p-nitrophenol analysis. The three-dimensional device integrates filtration and was fabricated from conventional printing paper patterned with a wax printer. A quick response code (QR) was added to the device to enable the user to rapidly assess p-nitrophenol information. The counter electrode was drawn on the paper while the working electrode consisted of a short section of graphite obtained from a pencil (30×0.3mm). p-Nitrophenol was selected as the target analyte and basic parameters such as solution pH, buffer concentration, and pulse amplitude were optimized. Under optimized conditions (0.1M acetate buffer, pH 4.0), a detection limit of 1.1μM was obtained. The devices showed high sensitivity and a linear range for p-nitrophenol, 10 to 200μM. The devices were employed to determine p-nitrophenol in water samples and the results showed recoveries ranging from 91.8 to 108.2%.
•Contact shapes brain activity when inferring mental states from different race eyes.•Greater STS activity to white vs. Black RME targets for lower contact white people.•No difference in STS activity ...by RME target race for high contact white people.•Greater STS activity for own-race mentalizing may reflect less other-race expertise.
Inferring others’ mental states, or mentalizing, is a critical social cognitive ability that underlies humans’ remarkable capacity for complex social interactions. Recent work suggests that interracial contact shapes the recruitment of brain regions involved in mentalizing during impression formation. However, it remains unclear how a target's perceived racial group and a perceiver's previous contact with that racial group shapes mental state inferences. In this study, we examined brain activity in regions of interest associated with mentalizing and race perception among self-identified White perceivers who varied in lifetime contact while they inferred secondary emotions from perceived White eyes and perceived Black eyes (i.e., the Reading the Mind in the Eyes test). The interaction between lifetime contact and perceived target race predicted activity in the superior temporal sulcus (STS), a region consistently implicated in mental state inferences from perceptual cues, tracking eye gaze, and biological motion. Low and average contact White perceivers showed more left STS activity when inferring mental states from perceived White eyes than perceived Black eyes, whereas high contact White perceivers showed similar left STS activity regardless of perceived target race. These results indicate that interracial contact decreases racial biases in the recruitment of regions involved in mentalizing when inferring mental states from perceptual cues.
A new dense and widely distributed tsunami observation network installed off northeast Japan detected millimeter‐scale tsunamis from an Mw 6.0 shallow interplate earthquake on 20 August 2016. Based ...on the fault model deduced from this data set, we obtained a stress drop of 1.5 MPa for this event, similar to those associated with typical interplate earthquakes. The rupture area was unlikely to overlap with regions where slow earthquakes occur, such as low‐frequency‐tremors and very‐low‐frequency‐earthquakes. The results demonstrated that this new network has dramatically increased the detectability of millimeter‐scale tsunamis. Some near‐source stations were contaminated by large pressure offset signals irrelevant to tsunami, and we must therefore be careful when analyzing these data. Nonetheless, the new array enables estimations of the stress drops of moderate offshore earthquakes and can be used to elucidate the spatial variation of mechanical properties along the plate interface with much higher resolution than previously possible.
Plain Language Summary
Tsunamis are generated when an earthquake occurs beneath the seafloor. Far fewer tsunami observations have been recorded from moderate earthquakes than large to giant earthquakes because tsunamis created by moderate earthquakes have been too small to be observed. On 20 August 2016, a moderate earthquake occurred off Sanriku, in northeastern Japan, and a tsunami with a height of less than 1 cm was recorded by a new seafloor tsunami observation network. This network has many tsunami sensors distributed much closer to each other and over a much wider area than any other previous network in the world. Using these data, this study estimated the source location and size, and the slip amount of the 2016 earthquake with higher accuracy, which was impossible to achieve from past observations because they were too far away from the earthquake and the signals were too small. Using this source information, we could estimate the stress drop associated with the earthquake, which is important because the stress drop information deepens our understanding of how and why earthquakes happen.
Key Points
Millimeter‐scale tsunamis from an Mw 6.0 earthquake were captured by the S‐net, a new nationwide pressure gauge array off Sanriku, Japan
Tsunami signals were identified from the pressure data adjacent to the source, which were contaminated by signals irrelevant to tsunamis
We inferred the stress drop of the earthquake from the tsunami data more reliably than could be done from seismogram analysis
Inferring the relative rank (i.e., status) of others is essential to navigating social hierarchies. A survey of the expanding social psychological and neuroscience literatures on status reveals a ...diversity of focuses (e.g., perceiver vs. agent), operationalizations (e.g., status as dominance vs. wealth), and methodologies (e.g., behavioral, neuroscientific). Accommodating this burgeoning literature on status in person perception, the present review offers a novel social neuroscientific framework that integrates existing work with theoretical clarity. This framework distinguishes between five key concepts: (1) strategic pathways to status acquisition for agents, (2) status antecedents (i.e., perceptual and knowledge-based cues that confer status rank), (3) status dimensions (i.e., domains in which an individual may be ranked, such as wealth), (4) status level (i. e., one’s rank along a given dimension), and (5) the relative importance of a given status dimension, dependent on perceiver and context characteristics. Against the backdrop of this framework, we review multiple dimensions of status in the nonhuman and human primate literatures. We then review the behavioral and neuroscientific literatures on the consequences of perceived status for attention and evaluation. Finally, after proposing a social neuroscience framework, we highlight innovative directions for future social status research in social psychology and neuroscience.
Summary
There have been many studies on the mechanisms of internalization of DNA–anti‐DNA immune complexes by cells, including the one used for rheumatoid factor‐expressing mouse B cells. In ...parallel, studies on the role of intracellular DNA sensors in the pathogenesis of systemic lupus erythematosus (SLE) have been conducted, including the one using a mouse model lacking one of the sensors. These and other data have established a framework for understanding the pathogenic role of anti‐DNA antibodies, but studies on normal cells are limited. Here, we used the monoclonal anti‐dsDNA antibody 2C10, 2‐kbp dsDNA and healthy human peripheral blood mononuclear cells (PBMCs) to test whether and how 2C10 and/or DNA cause pathology in normal cells. We found that on culture with PBMCs, 2C10 preferentially entered monocytes and that DNA enhanced this internalization. In contrast, DNA alone was not significantly internalized by monocytes, but 2C10 facilitated its internalization. This was suppressed by cytochalasin D, but not by methyl‐β‐cyclodextrin, chloroquine or an Fc blocker, suggesting the involvement of macropinocytosis in this process. Internalization of 2C10 and DNA together resulted in production of interferon (IFN)‐α, IFN‐γ, tumor necrosis factor (TNF)‐α, monocyte chemoattractant protein‐1 (MCP‐1), interleukin (IL)‐1β, IL‐6, IL‐10 and IL‐33 by PBMCs. Cytokine production was suppressed by chloroquine and shikonin, but not by RU.521, suggesting dependence on activation of the Toll‐like receptor (TLR)‐9 and absent in melanoma 2 (AIM‐2) pathways. These results established a simple model to demonstrate that anti‐DNA antibodies can cause dysregulation of cytokine network mimicking systemic lupus erythematosus in culture of normal PBMCs, and emphasize again the importance of maintaining anti‐DNA antibodies at low levels by treatment.
Fluorescence‐labeled DNA (D) entered normal monocytes with the help of anti‐DNA antibody 2C10 (2).
This article presents results of a pulsed UV laser method for the simultaneous reduction of graphite oxide (GO) and patterning of reduced graphene oxide (rGO). This direct laser writing method was ...applied to the fabrication of graphene-based, in-plane interdigitated micro-supercapacitors (μ-SCs), prepared on free-standing GO paper (10 μm thick). The electrochemical performance of μ-SCs was studied using two different electrolytes (KOH and NaCl). The results from cyclic voltammetry measurements exhibited typical electrical double layer behavior, with specific capacitances of 9.3 μF/cm2 and 13.8 μF/cm2 (at a scan rate of 10 mV/s) for KOH and NaCl electrolytes, respectively. The μ-SCs exhibited good performance, with retention of 95% of the original capacitance values after 3400 charge-discharge cycles. When compared to devices obtained by conventional lithographic techniques, the laser fabrication of planar μ-SCs is faster, cost-effective and scalable. We believe this one-step and environmentally friendly laser-assisted method to be a good alternative for the fabrication of flexible energy storage devices.
•Direct laser writing is used to design the interdigitated electrode for μ-supercapacitor.•Direct laser writing on GO paper is simple, chemical free and room temperature technique.•The laser parameters are optimized to complete photothermal reduction of GO paper.•GO paper-based μ-supercapacitors reveal excellent electrochemical performance.
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► Low cost and simple paper-based microfluidic device with electrochemical detection. ► Only two steps are necessary for the construction of the device, construction of the ...hydrophobic walls and gold sputtering. ► The substrate works as a separation platform and makes the separation of paracetamol and 4-aminophenol. ► Paper works as a filter and no sample pre treatment is necessary to perform the analysis. ► Baseline separation of the analytes can be achieved by injecting the sample at 12mm from the working electrode.
The present work describes the construction and application of a simple, low cost and sensitive microfluidic paper-based device with electrochemical detection for the detection of paracetamol and 4-aminophenol. The separation channels of a width of 2.0mm were created on paper using a wax printing process to define the regions of the device. A baseline separation level of the analytes can be obtained in 0.1molL−1 acetate buffer solution at pH 4.5 and by injecting 500nL of the standard solutions at 12mm from the working electrode. The electrochemical detection system was created at the end of the channels through a process known as sputtering. The previously separated analytes were detected at the end of the hydrophilic separation channel by applying a potential of 400mV vs. pseudo Au on the working electrode. Experimental variables such as type of paper (cation exchanger and n1), pH, sample volume, applied potential and distance of sample injection were evaluated and, under the conditions of higher response, it was possible to obtain detection limits of 25.0 and 10.0μmolL−1 for paracetamol and 4-aminophenol, respectively.
Abstract
STUDY QUESTION
Are pregnancy and neonatal outcomes following letrozole use comparable with natural and HRT cycles in patients undergoing single frozen–thawed embryo transfer (FET)?
SUMMARY ...ANSWER
Letrozole use was significantly associated with higher rates of clinical pregnancy, clinical pregnancy with fetal heart beat and live birth, and with a lower rate of miscarriage, compared with natural and HRT cycles.
WHAT IS KNOWN ALREADY
Letrozole is the most commonly used aromatase inhibitor for mild ovarian stimulation in ART. However, the effect of letrozole on pregnancy and neonatal outcomes in FET are not well known.
STUDY DESIGN SIZE, DURATION
A retrospective cohort study was conducted using data from the Japanese national ART registry between 2012 and 2013.
PARTICIPANTS/MATERIALS SETTING METHODS
A total of 110 722 single FET cycles with letrozole (n = 2409), natural (n = 41 470) or HRT cycles (n = 66 843) were included. The main outcomes were the rates of clinical pregnancy, clinical pregnancy with fetal heart beat, miscarriage and live birth. Adjusted odds ratios and relative risks (RRs) were calculated using a generalized estimating equation adjusting for correlations within clinics.
MAIN RESULTS AND THE ROLE OF CHANCE
The rates of clinical pregnancy, clinical pregnancy with fetal heart beat, and live birth were significantly higher, while the rate of miscarriage was significantly lower in the letrozole group compared with the natural and HRT groups. In blastocyst stage transfers, the adjusted RRs for clinical pregnancy with fetal heart beat of letrozole compared with natural and HRT cycles were 1.48 (95% CI: 1.41–1.55) and 1.62 (95% CI: 1.54–1.70), respectively. Similarly, the adjusted RRs of letrozole for miscarriage compared with natural and HRT cycles were 0.91 (95% CI: 0.88–0.93) and 0.84 (95% CI: 0.82–0.87), respectively. Neonatal outcomes were mostly similar in letrozole, natural and HRT cycles.
LIMITATIONS REASONS FOR CAUTION
Important limitations of this study included the lack of information concerning the reasons for selecting the specific FET method, parity, the number of previous ART failures, embryo quality and the dose and duration of letrozole intake.
WIDER IMPLICATIONS OF THE FINDINGS
These results suggest that letrozole use may improve clinical pregnancy, clinical pregnancy with fetal heart beat, and live births and reduce the risk of miscarriage in patients undergoing single FET cycles.
STUDY FUNDING/COMPETING INTEREST(S)
No external funding was used for this study. There are no conflicts of interest.
TRIAL REGISTRATION NUMBER
Not applicable.
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