Accelerated and precise identification of antioxidants and pesticides using a smartphone-based colorimetric sensor array.

The integration of smartphones with conventional analytical approaches plays a crucial role in enhancing on-site detection platforms for point-of-care testing. Here, we developed a simple, rapid, and efficient three-channel colorimetric sensor array, leveraging the peroxidase (POD)-like activity of polydopamine-decorated FeNi foam (PDFeNi foam), to identify antioxidants using both microplate readers and smartphones for signal readouts. The exceptional catalytic capacity of PDFeNi foam enabled the quick catalytic oxidation of three typical peroxidase substrates (TMB, OPD and 4-AT) within 3 min. Consequently, we constructed a colorimetric sensor array with cross-reactive responses, which was successfully applied to differentiate five antioxidants (i.e., glycine (GLY), glutathione (GSH), citric acid (CA), ascorbic acid (AA), and tannic acid (TAN)) within the concentration range of 0.1-10 µM, quantitatively analyze individual antioxidants (with AA and CA as model analytes), and assess binary mixtures of AA and GSH. The practical application was further validated by discriminating antioxidants in serum samples with a smartphone for signal readout. In addition, since pesticides could be absorbed on the surface of PDFeNi foam through π-π stacking and hydrogen bonding, the active sites were differentially masked, leading to featured modulation on POD-like activity of PDFeNi foam, thereby forming the basis for pesticides discrimination on the sensor array. The nanozyme-based sensor array provides a simple, rapid, visual and high-throughput strategy for precise identification of various analytes with a versatile platform, highlighting its potential application in point-care-of diagnostic, food safety and environmental surveillance.

High resolution acoustic sensing based on microcavity optomechanical oscillator.

In this paper, a simple sensing method based on a silicon oxide microcavity optomechanical oscillator (OMO) is proposed and demonstrated for the detection of acoustic signals. Firstly, the resonance damping was reduced by improving the optical quality factor (Qo) and increasing the sphere-to-neck ratio. After optimizing the process, a microsphere OMO was fabricated, which has an ultra-high mechanical quality factor (6.8 × 106) and greater sphere-to-neck ratio (∼11:1), based on which ultra-narrow linewidth phonon laser (∼1 Hz) is constructed. Secondly, by changing the refractive index of the coupling interval, the low-frequency acoustic pressure signal is efficiently coupled into the microcavity OMO to construct a high-resolution acoustic sensor. This sensing mechanism can not only measure the acoustic pressure, but also use the sideband signal in the modulation mechanism to measure the frequency of acoustic signals (15 Hz∼16 kHz), the sensitivity is 10.3 kHz/Pa, the minimum detectable pressure is 1.1 mPa, and noise-limited minimum detectable pressure is 28.8 µPa/Hz1/2. It is the highest detection resolution compared with the same type of low-frequency acoustic signal detection currently reported. This OMO-based acoustic sensing detection method opens up a new path for future miniaturized, ultra-high-precision, and cost-effective acoustic sensing.

Ultra-stable control near the EP in non-Hermitian systems and high-precision angular rate sensing applications.

In non-Hermitian systems, enhancing sensitivity under exceptional point (EP) conditions offers an ideal solution for reconciling the trade-off between sensitivity and size constraints in sensing applications. However, practical application is limited by undesired sensitivity to external fluctuations, noise, and errors in signal amplification synchronization. This paper presents a precisely controlled EP tracking and detection system (EPTDS) that achieves long-term rapid tracking and locking near the EP by constructing a second-order non-Hermitian optical sensing unit, employing an optical power adaptive control method, and utilizing a combinatorial demodulation-based dual-loop cascaded control (CDCC) technique to selectively suppress traditional noise at different frequencies. The system locking time is 10 ms, and in room temperature conditions, the output frequency error over 1 hour is reduced by more than 30 times compared to before locking. To assess its sensing capabilities, the EPTDS undergoes testing in a rotational experiment based on the Sagnac effect, with the output bias instability based on Allan deviation measured at 0.036 °/h. This is the best result for EP-enhanced angular rate sensing that we are aware of that has been reported. The EPTDS method can be extended to various sensing fields, providing a new path for transitioning non-Hermitian sensing from the laboratory to practical applications.

Insight into the Mechanism Underlying the Reduction of Digestibility and IgG/IgE Binding Ability in Ovalbumin during Different High-Temperature Conduction Modes-Induced Glycation.

Effects of different high-temperature conduction modes [high-temperature air conduction (HAC), high-temperature contact conduction (HCC), high-temperature steam conduction (HSC)]-induced glycation on the digestibility and IgG/IgE-binding ability of ovalbumin (OVA) were studied and the mechanisms were investigated. The conformation in OVA-HSC showed minimal structural changes based on circular dichroism, fluorescence, and ultraviolet spectroscopy. The degree of hydrolysis analysis indicated that glycated OVA was more resistant to digestive enzymes. Liquid chromatography-Orbitrap mass spectrometry identified 11, 14, and 15 glycation sites in OVA-HAC, OVA-HCC, and OVA-HSC, respectively. The IgG/IgE-binding ability of OVA was reduced during glycation and digestion, and the interactions among glycation, allergenicity, and digestibility were further investigated. Glycation sites masked the IgG/IgE epitopes resulting in a reduction in allergenicity. Digestion enzymes destroyed the IgG/IgE epitopes thus reducing allergenicity. Meanwhile, the glycation site in proximity to the digestion site of pepsin was observed to cause a reduction in digestibility.

Bridging techniques compared with direct endovascular therapy for stroke due to tandem occlusion: A systematic review and meta-analysis.

The superiority of the bridging strategy of intravenous thrombolysis (IVT) plus endovascular therapy (EVT) to EVT alone for the anterior circulation with tandem vascular occlusion (TO) has not been specifically addressed by a single randomized trial. Analysis of 15 studies (n = 1857 patients) revealed that 90 Day good functional outcomes (MRS≤2) were better for bridging therapy (IVT + EVT) than for dEVT (OR:1.39, 95%CI: 1.09-1.79, p = 0.008); 90-day mortality was lower for IVT + EVT than for dEVT (OR: 0.57; 95%CI: 0.40-0.81, p = 0.002) and rates of successful recanalization were higher for IVT + EVT than for dEVT (OR: 1.79, 95%CI: 1.36-2.36, p<0.0001). However, there was no significant difference in the incidence of symptomatic. intracranial hemorrhage (sICH) between groups (OR 0.91, 95%CI 0.64-1.31, p = 0.62).In conclusion, Patients receiving IVT + EVT have a better functional outcome, lower death rate and a higher rate of successful recanalization than those receiving dEVT but there was no difference in sICH risk between the two treatments.

Differentiating mass-forming intrahepatic cholangiocarcinoma from atypical hepatocellular carcinoma using Gd-EOB-DTPA-enhanced magnetic resonance imaging combined with serum markers in at-risk patients with hepatitis B virus.

Background: The precise differentiation of intrahepatic cholangiocarcinoma (ICC) from atypical hepatocellular carcinoma (HCC) is vital for treatment strategy and prognostic prediction. In clinical practice, nearly 40% of HCCs demonstrate atypical manifestations, particularly HCCs with rim arterial phase hyperenhancement (APHE), which is challenging to differentiate from mass-forming ICC. Thus, we aimed to develop a diagnostic regimen of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) contrast-enhanced magnetic resonance imaging (MRI) combined with serum tumor markers in differentiating mass-forming ICC from atypical HCC in at-risk patients with the hepatitis B virus (HBV). Methods: This study enrolled 129 patients with pathologically proven mass-forming ICCs (n=53) and atypical HCCs (n=76) who had undergone preoperative Gd-EOB-DTPA contrast-enhanced MRI. The clinical data and imaging findings were analyzed. Univariate and multivariate logistic analyses were performed to identify the independent predictors for differentiating mass-forming ICCs from atypical HCCs. The diagnostic performance was evaluated using receiver operating characteristic (ROC) curves, and DeLong test was used to compare the areas under curves of all independent predictors. Results: Univariate logistic regression analysis revealed normal alpha fetoprotein (AFP), elevated carbohydrate antigen 19-9 (CA19-9) level, elevated carcinoma embryonic antigen (CEA) level, central hyperintensity on T2-weighted imaging (T2WI), central hypointensity on T2WI, and targetoid sign on hepatobiliary phase (HBP) and targetoid restriction on diffusion-weighted imaging (DWI) were more likely to be significant predictors favoring mass-forming ICCs (all P values <0.05). In contrast, multifocal hyperintensity on T2WI and capsule sign were more frequently seen in patients with atypical HCC (all P values <0.05). Multivariate analysis revealed normal AFP, elevated CA19-9 level, targetoid sign on HBP, and targetoid restriction on DWI (all P=0.001) were independent predictors for differentiating mass-forming ICCs from atypical HCCs; DeLong test showed that the area under curve (AUC) increased to 0.949 when the above predictors were combined (all P values <0.05), and the sensitivity, specificity, and accuracy of the combined independent predictors were 88.7%, 93.4%, and 91.5%, respectively. Conclusions: A diagnostic regimen integrating tumor markers (AFP, CA19-9) and imaging biomarkers (targetoid restriction on DWI and/or targetoid sign on HBP) using Gd-EOB-DTPA-enhanced MRI could help to differentiate mass-forming ICCs from atypical HCCs and achieve high diagnostic performance of mass-forming ICCs in at-risk patients with the HBV. Keywords: Mass-forming intrahepatic cholangiocarcinoma (mass-forming ICC); atypical hepatocellular carcinoma (atypical HCC); magnetic resonance imaging (MRI); gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA); hepatobiliary phase (HBP).

Effects of different high-temperature conduction modes on the ovalbumin-glucose model: AGEs production and regulation of glycated ovalbumin on gut microbiota.

Food high-temperature processing frequently induces the production of advanced glycation end products (AGEs) in the food industry. In this study, the effects of three high-temperature conduction modes on the AGEs production derived from ovalbumin (OVA)-glucose model and the regulation of glycated OVA on gut microbiota were investigated. The peak time of OVA shifted maximally from 13.72 to 13.57 due to the rise in molecular weight, confirming successful coupling between OVA and glucose. The inhibition of superheated steam (SS) on AGEs was observed, with the sample treated by SS showing the lowest content among glycated OVA groups. The analysis revealed an increase in AGEs during digestion and a decrease in fermentation, suggesting the release during digestion and the availability by intestinal flora. Furthermore, an expansion of Bifidobacterium and Lactobacillus, and the inhibition of Desulfovibrio and Escherichia-Shigella were observed, indicating the prebiotic activity of glycated OVA and its potential to improve intestinal health. These results provide valuable information for controlling high-temperature processing to inhibit AGEs formation and highlight the positive effects of glycated proteins on intestinal health.

The sustained attention characteristics of flight crews on exempt and non-exempt flights.

We analyzed the characteristics of sustained attention changes in flight crews during exempt and non-exempt flights. Fourteen pilots (aged 30-43 y) participated in this study, with seven involved in each flight type, all of which were intercontinental (China to North America). Pilots completed continuous performance tests (CPT) at the required flight stages without compromising safety while on duty. No significant differences in sleep and sustained attention emerged between the exempt and non-exempt flight crews. Pilots' fatigue was highest in the early morning hours. Their general stability of efficiency increased during the day and decreased at night. Non-exempt flight crews appeared to sacrifice reaction rate to improve accuracy. Exempt crews appeared to increase their test proficiency. The task stability time of the non-exempt flight crews was better than that of the exempt ones. Short-term stability was better for exempt inbound flights rather than for outbound ones. Pilots were more prone to error runs as their total time awake increased, especially on non-exempt flights. The addition of crew members to exempt flights, allowance for more in-flight rest shifts, and over-stop rest on non-exempt flights may alleviate pilot fatigue and preserve alertness.

Evaluation of the Inhibition Potency of Nirmatrelvir against Main Protease Mutants of SARS-CoV-2 Variants.

SARS-CoV-2 continues to pose a threat to public health. Main protease (Mpro) is one of the most lucrative drug targets for developing specific antivirals against SARS-CoV-2 infection. By targeting Mpro, peptidomimetic nirmatrelvir is able to inhibit viral replication of SARS-CoV-2 and reduce the risk for progression to severe COVID-19. However, multiple mutations in the gene encoding Mpro of emerging SARS-CoV-2 variants raise a concern of drug resistance. In the present study, we expressed 16 previously reported SARS-CoV-2 Mpro mutants (G15S, T25I, T45I, S46F, S46P, D48N, M49I, L50F, L89F, K90R, P132H, N142S, V186F, R188K, T190I, and A191V). We evaluated the inhibition potency of nirmatrelvir against these Mpro mutants and solved the crystal structures of representative Mpro mutants of SARS-CoV-2 bound to nirmatrelvir. Enzymatic inhibition assays revealed that these Mpro variants remain susceptible to nirmatrelvir as the wildtype. Detailed analysis and structural comparison provided the inhibition mechanism of Mpro mutants by nirmatrelvir. These results informed the ongoing genomic surveillance of drug resistance of emerging SARS-CoV-2 variants to nirmatrelvir and facilitate the development of next-generation anticoronavirus drugs.

An ultrahigh sensitivity acoustic sensor system for weak signal detection based on an ultrahigh-Q CaF2 resonator.

Acoustic sensors with ultrahigh sensitivity, broadband response, and high resolution are essential for high-precision nondestructive weak signal detection technology. In this paper, based on the size effect of an ultrahigh-quality (Q) calcium fluoride (CaF2) resonator, a weak acoustic signal is detected by the dispersive response regime in which an acoustic, elastic wave modulates the geometry and is converted to a resonance frequency shift. Through the structural design of the resonator, the sensitivity reaches 11.54 V/Pa at 10 kHz in the experiment. To our knowledge, the result is higher than that of other optical resonator acoustic sensors. We further detected a weak signal as low as 9.4 µPa/Hz1/2, which greatly improved the detection resolution. With a good directionality of 36.4 dB and a broadband frequency response range of 20 Hz-20 kHz, the CaF2 resonator acoustic sensing system can not only acquire and reconstruct speech signals over a long distance but also accurately identify and separate multiple voices in noisy environments. This system shows high performance in weak sound detection, sound source localization, sleep monitoring, and many other voice interaction applications.

Structural basis of main proteases of HCoV-229E bound to inhibitor PF-07304814 and PF-07321332.

PF-07321332 and PF-07304814, inhibitors against SARS-CoV-2 developed by Pfizer, exhibit broad-spectrum inhibitory activity against the main protease (Mpro) from various coronaviruses. Structures of PF-07321332 or PF-07304814 in complex with Mpros of various coronaviruses reveal their inhibitory mechanisms against different Mpros. However, the structural information on the lower pathogenic coronavirus Mpro with PF-07321332 or PF-07304814 is currently scarce, which hinders our comprehensive understanding of the inhibitory mechanisms of these two inhibitors. Meanwhile, given that some immunocompromised individuals are still affected by low pathogenic coronaviruses, we determined the structures of lower pathogenic coronavirus HCoV-229E Mpro with PF-07321332 and PF-07304814, respectively, and analyzed and defined in detail the structural basis for the inhibition of HCoV-229E Mpro by both inhibitors. Further, we compared the crystal structures of multiple coronavirus Mpro complexes with PF-07321332 or PF-07304814 to illustrate the differences in the interaction of Mpros, and found that the inhibition mechanism of lower pathogenic coronavirus Mpro was more similar to that of moderately pathogenic coronaviruses. Our structural studies provide new insights into drug development for low pathogenic coronavirus Mpro, and provide theoretical basis for further optimization of both inhibitors to contain potential future coronaviruses.

Sandwich structure magnetometer with a high sensitivity and signal-to-noise ratio based on an ultrahigh-Q CaF2 resonator.

Whispering gallery mode (WGM) resonators with an ultrahigh quality (Q) factor provide an extremely high resolution for high-precision sensing. However, it is difficult to use them directly in magnetic sensors because of the transparency to the magnetic field. In this paper, a sandwich structure consisting of a neodymium iron boron magnet and calcium fluoride resonator with a Q factor of 109 is proposed. The experimental results show that, compared with the conventional magnetometer, the signal-to-noise ratio of the optical WGM magnetometer reaches 62 dB, with the direct current sensitivity of 42.59 MHz/mT and the AC sensitivity of 794p T H z -1/2 at 42 kHz.

Analysis of blood coagulation indexes, thromboelastogram and autoantibodies in patients with recurrent pregnancy loss.

Objectives: Changes in coagulation indexes, thromboelastogram(TEG) and autoantibodies in patients with recurrent pregnancy loss (RPL) with different number of abortions were analyzed. Methods: Medical records of 48 patients with recurrent abortion, treated in Quzhou people's Hospital from November 2019 to October 2020, were collected as the observation group. Based on the number of abortions, patients were divided into Group-A (Two abortions, n=21), Group-B (Three abortions, n=16) and group C (Abortion ≥ four times, n=11). Records of 50 healthy pregnant women in our hospital in the same period were selected as the control group. Coagulation indexes [prothrombin time (PT), activated partial prothrombin time (APTT), fibrinogen (FIB), D-Dimer (DD)], thromboelastogram (TEG) parameters [reaction time (R), coagulation time(K), maximum thrombus amplitude (MA), coagulation angle (α)], changes in the levels of autoantibodies [anticardiolipin antibody (ACA), anti-endometrial antibody (EmAb), anti-thyroid antibody(ATA)] were compared between the groups. Results: There were significant differences in the levels of ATPP, Pt, FIB and DD among the groups. Higher number of abortions correlated with lower the levels of ATPP and Pt, and higher levels of FIB and DD (P<0.05). Compared to the control group, R and K in Group-A,B and C decreased, while α and MA increased (P<0.05). There were significant differences in α and MA indexes. The positive rates of ACA, EmAb and ATA in Group-A were higher than those in the control group, but the difference was not statistically significant (P>0.05), while the above indexes in groups B and C were significantly higher than those in the control group (P<0.05). The positive rates of ACA and ATA in group C were significantly higher than those in Group-A (P<0.05), but there was no significant difference in the positive rate of EmAb (P>0.05). Conclusion: RPL was related to the decrease of APTT, PT, and the increase of FIB and DD levels. TEG indicated that the increase of α and MA values indicated that the risk of multiple abortion was increased. The positive rates of ACA, EmAb and ATA were closely related to multiple abortions, especially the positive rates of ACA and ATA.

Fatigue during Long-Haul Flights of Different Crew Compositions under Exemption from Layover and Flight Time during COVID-19.

Pilot fatigue and alertness are critical for civil aviation safety. Intercontinental pilots are more prone to fatigue and sleepiness due to jet lag, prolonged workdays, and disrupted rhythms. The Civil Aviation Administration of China excused enlarged flight crews from mandatory layovers and reimposed flight duration restrictions during COVID-19. This study investigates the sleep quality and attentional performance of pilots on intercontinental flights. The fifteen pilots who performed intercontinental flights in different crew compositions wore a body movement recorder, which has been proven to accurately estimate sleep duration and sleep efficiency. The crew's attentional performance and self-report were monitored at specified flight phases. In conclusion, the larger crews slept longer and more efficiently on board, particularly pilots in charge of takeoff and landing responsibilities. Crews on four-pilot layover flights were more alert before the takeoff of the inbound flights than exempt flights, but there was no significant difference towards the end of the mission. The new long-haul flight organization did not result in fatigue or decreased attention in the pilots. This study expands on the research by validating a novel intercontinental flight operation model under the COVID-19 scenario and highlighting critical spots for future fatigue management in various crew compositions.

Effects of total sleep deprivation on execution lapses during vigilance tasks.

Total sleep deprivation (TSD) results in reduced efficiency of cognitive resources. Moreover, when the available cognitive resources are less than required, individuals exhibit lapses in responsiveness. Accordingly, this study explored the effects of TSD on executive function and the characteristics of execution lapses. Functional near-infrared spectroscopy was used to monitor the prefrontal cortex's functional connections in resting and tasking states for various sleep deprivation durations. Data from participants' attentional performance test and self-reported fatigue were collected over 30 hours of wakefulness. Task performance was compared based on time of day, time on task, and reaction time. The results show that participants' arousal level significantly decreased post 14 hours (P < .05), while sleepiness increased. The prefrontal cortex connection and attentional performance dropped at the Window of Circadian Low (3:00 ~ 6:00). The number of execution lapses was higher during the initiation, inhibition, and fatigue phases and rose markedly post 14 hours of wakefulness. We conclude that maintaining better inhibition control requires a reasonable extension of the reaction time. Moreover, subjective perception is significantly correlated with task performance and right prefrontal connection strength. This study presents the scientific evidence for measures to address consistently long working hours and disrupted circadian rhythms.

The Application of Contrast-Enhanced 3D-STIR-VISTA MR Imaging of the Brachial Plexus.

Objective: To introduce contrast-enhanced 3D-STIR-VISTA sequence that would improve the image quality for the brachial plexus imaging and enhance the contrast between the brachial plexus and surrounding tissues. Methods: Thirty subjects (average age, 47.33 ± 15.15 years; 22 males and 8 females) were enrolled, including 7 patients with brachial plexus injuries, 4 patients with schwannomas, 1 patient with neurofibroma, 1 patient with thoracic outlet syndrome, 1 patient with metastasis, 1 patient with brachial plexus neuritis, and 15 patients without abnormal findings. Scores of unenhanced and contrast-enhanced 3D-STIR-VISTA images using a 5-point scale were compared by Wilcoxon's signed-rank test. The signal intensity (SI), signal to noise ratio (SNR), contrast to noise ratio (CNR) and contrast ratio (CR) between 3D-STIR-VISTA images without and with contrast agent were compared by the paired Student t-test. Results: The SNRs of the brachial plexus between 3D-STIR-VISTA without and with contrast agent were not significantly different, while SNRs of surrounding tissues were significantly decreased with contrast agent. The CNRs of 3D-STIR-VISTA images with contrast agent were significantly higher than that without contrast agent. The 3D-STIR-VISTA sequence with contrast agent exhibited a statistically higher CR than that without contrast agent. The average score for 3D-STIR-VISTA images with contrast agent was significantly higher than that without contrast agent. Conclusion: The 3D-STIR-VISTA sequence with contrast agent is qualitatively and quantitatively superior to that without a contrast agent. The contrast-enhanced 3D-STIR-VISTA sequence can provide distinct visualization of the brachial plexus and enhance the contrast between the brachial plexus and surrounding tissues.

Oxygen vacancies and interfacial iron sites in hierarchical BiOCl nanosheet microflowers cooperatively promoting photo-Fenton.

Controllable active site construction, crystal structure regulation and efficient charge separation are core issues in heterogeneous photo-Fenton. Herein, abundant oxygen vacancies and well-dispersed interfacial iron sites are simultaneously constructed in hierarchical nanosheet-assembled BiOCl microflowers. The composites exhibit superior performance in photo-Fenton oxidation of carbamazepine (10 mg L-1) with a low H2O2 concentration (1.3 mM). The high performance highly depends on the synergistic effects between oxygen vacancies and iron species. Rather than modulating the valence band, the involvements of oxygen vacancies and iron species could modify the conduction band of BiOCl. The presence of oxygen vacancies promotes the migration of photo-generated electrons and accelerates the redox cycling of ≡Fe(III)/≡Fe(II) to boost the activation of H2O2 to generate hydroxyl radicals, and oxygen vacancies can be well preserved after cyclic use. This work provides understanding on efficient utilization of oxygen vacancies and interfacial iron sites to assist photo-Fenton and the underlying electron transfer mechanism.

[Study on homeostasis and circadian rhythm of attention performance of different chronotypes in sleep deprivation].

Difference of chronotypes makes influence to cognitive performance of individuals in routine duties. In this paper, 55 subjects with different chronotypes were subjected to continuous sleep deprivation for 30 h by using the constant routine protocol, during which core body temperature was measured continuously, and subjective sleepiness self-rating and the performance of selective attention were measured hourly. The results showed that the phase difference of core body temperature has no significant difference, yet the amplitude and term difference among the three chronotypes are significant. There was an advance in phase between subjective sleepiness self-rating and core body temperature, and the self-rating sleepiness of evening type came the latest, and the self-rating sleepiness of morning type dissipated the fastest. The response time of selective attention showed a 2 h phase delay with subjective sleepiness self-rating. And the analysis of core body temperature showed that the later the chronotype was, the greater the phase delay was. The correct rate of selective attention of different chronotypes were inconsistent with delay of subjective sleepiness self-rating and core body temperature. We provide reference for industry, aviation, military, medical and other fields to make a more scientific scheduling/ shifting based on cognitive performance characteristics of different chronotypes.

Amorphous iron oxides anchored on BiOCl nanoplates as robust catalysts for high-performance photo-Fenton oxidation.

Semiconductor supported iron oxides are highly promising catalysts to remove organic pollutants in photo-Fenton. Development of robust composite catalysts with both high activity and stability is essential. In this work, amorphous iron oxide layers are uniformly and tightly anchored on two-dimensional (2D) BiOCl nanoplates through post precipitation-deposition and subsequent low-temperature thermal treatment at 150-350 °C. A low iron loading amount (1-2 wt.%) is sufficient to make the resulted composite (BiOCl-Fe) catalysts superior in photo-Fenton oxidation of phenol (10 mg/L) with high mineralization efficiency (up to about 80% in 60 min). The low-temperature thermal treatment can significantly enhance the stability of catalysts with much less iron leached and high photo-Fenton performance maintained. The intimate contact between the amorphous iron oxide layers and the 2D BiOCl nanoplates could guarantee the fluent electron transfer and efficient activation of H2O2 at interfaces. Compared with the pristine BiOCl, the BiOCl-Fe catalysts possess faster separation of the charge carriers. The predominant active species turns from O2•- in photocatalysis to HO• in the photo-Fenton catalysis. This research could provide enhanced understanding on the synthesis of robust catalysts and the structure optimization of BiOCl supported iron oxides for photo-Fenton.

A High-Sensitivity Resonant Magnetic Sensor Based on Graphene Nanomechanical Resonator.

This paper presents a novel resonant magnetic sensor consisting of a graphene nanomechanical oscillator and magnetostrictive stress coupling structure, using Si/SiO2 substrate and Fe-Ga alloy, respectively. In this device, the deformation of the Fe-Ga alloy resulting from the external magnetic field changed the surface tension of the graphene, resulting in a significant change in the resonance frequency of graphene. Using the finite element analysis, it could be found that the response of the resonance frequency revealed a good linear relationship with the external magnetic field (along the x-axis) in the range of the 1 to 1.6 mT. By optimizing the sizes of each component of the magnetic sensor, such as the thickness of the Si/SiO2 substrate and the Fe-Ga alloy, and the length of the graphene, the sensitivity could even reach 834 kHz/mT, which is three orders of magnitude higher than conventional resonant magnetic devices. This provides a new method for highly sensitive and miniaturized magnetic sensors.