Decrement In Intensity Research Articles

A general model unifying the adaptive, transient and sustained properties of ON and OFF auditory neural responses.

Sounds are temporal stimuli decomposed into numerous elementary components by the auditory nervous system. For instance, a temporal to spectro-temporal transformation modelling the frequency decomposition performed by the cochlea is a widely adopted first processing step in today's computational models of auditory neural responses. Similarly, increments and decrements in sound intensity (i.e., of the raw waveform itself or of its spectral bands) constitute critical features of the neural code, with high behavioural significance. However, despite the growing attention of the scientific community on auditory OFF responses, their relationship with transient ON, sustained responses and adaptation remains unclear. In this context, we propose a new general model, based on a pair of linear filters, named AdapTrans, that captures both sustained and transient ON and OFF responses into a unifying and easy to expand framework. We demonstrate that filtering audio cochleagrams with AdapTrans permits to accurately render known properties of neural responses measured in different mammal species such as the dependence of OFF responses on the stimulus fall time and on the preceding sound duration. Furthermore, by integrating our framework into gold standard and state-of-the-art machine learning models that predict neural responses from audio stimuli, following a supervised training on a large compilation of electrophysiology datasets (ready-to-deploy PyTorch models and pre-processed datasets shared publicly), we show that AdapTrans systematically improves the prediction accuracy of estimated responses within different cortical areas of the rat and ferret auditory brain. Together, these results motivate the use of our framework for computational and systems neuroscientists willing to increase the plausibility and performances of their models of audition.

Promoting effect of TiVC MXene on cathodic electrogenerated chemiluminescence of Ru(bpy)32+ and its application in the sensitive detection of sulfite.

The enhanced cathodic ECL of Ru(bpy)32+ at a bimetallic element MXenes (TiVC MXene) modified electrode in neutral aqueous conditionis reported. TiVC MXene significantly catalyzed the oxygen reduction reaction (ORR) as well as the electrochemical reduction of Ru(bpy)32+ to produce reactive oxygen species and Ru(bpy)3+. The obtained hydroxyl radical (OH∙) not only oxidized Ru(bpy)3+ to generate Ru(bpy)32+* and emit light through coreactant pathway, but also oxidized Ru(bpy)32+ to Ru(bpy)33+, which caused an annihilation ECL reaction. As a result, two pathways occurred simultaneously to generate strong cathodic ECL signal. Sulfite removes the dissolved oxygen in water and reduces the occurrence of ORR, which prohibits the generation of OH∙ to decrease the ECL signal. The decrement of ECL intensity varied linearly with the concentration of sulfite in the range 2nM to 50μM with a detection limit of 0.14nM (3σ). The proposed sensor exhibited good analytical performance, and could be used in the detection of sulfite in real samples. The results revealed that the electrocatalytic behavior of TiVC MXene is the key factor for strong cathodic Ru(bpy)32+ ECL, which provides new application in ECL sensing field.

An efficient fluorescence sensor based on chitosan-modified graphitic carbon nitride for selective determination of Cu2+ ions

An effective, feasible and novel fluorescence sensor based on modified graphitic carbon nitride (g-C3N4) was constructed for the detection of Cu2+ ions. Carbon nitride nanosheets were obtained by liquid exfoliation in an acid solution and then modified by chitosan with an abundance of active sites. The as-prepared material was characterized by various methods including SEM, FT-IR, XRD, Raman, UV–vis and XPS. The modification material emitted enhanced fluorescence at 433 nm under the excitation of 368 nm and exhibited fluorescence quenching behaviors in the presence of Cu2+. The fluorescence intensity decrement was proportional to the concentration of Cu2+ ions ranging from 0 to 4.0 μM and 4.0 to 50.0 μM with a detection limit as low as 9 nM under optimal conditions. As a result of the improved sensing performance, the as-prepared g-C3N4-based material presented strong affinity, sensitivity, specificity and stability for metal ions and had a promising application for fluorescence detection.

The Effect of Variation of Palm Fronds Absorbent Concentration In Adsorption Process to Reduce Free Fatty Acid Content on Tengkawang Oil

Tengkawang oil that hasn’t through purification process contains free fatty acid that can affect its quality, where this essence is the polluter that must be removed because it can caused a rancid. The removal of free fatty acid content on Tengkawang oil was done through adsorption process utilizing palm fronds adsorbent by using its cellulose content. Palm fronds went through dilegnification process using 10% of NaOH, then adsorption process was conducted with adsorbent concentration variety 5, 10, 15, 20 and 25%. Adsorbent characterized by utilizing FTIR and SAA, from FTIR result shows that palm fronds contain berlignocellulose function cluster, after delignification the C=C lignin compound function cluster still can be found on FTIR result and after adsorption O-H cluster went through intensity decrement which shows that cellulose content and hydroxyl (-OH) cluster reacted with adsorbat. Furthermore, there’s absorption on C-H function cluster that indicates the existence of free fatty acid compound and other polluter that adsorbed by palm fronds adsorbent. The characteristic of palm fronds adsorbent after delignification process was conducted shows the pore size is on micropore range with surface area of 6.480 m2/g, pore volume of 0.01138 cc/g and pore radius of 12.4 Å. The result of the research shows decreasing percentage of free fatty acid, capacity value and adsorption effectiveness of Tengkawang oil that the highest is on adsorbent concentration as much as 25% with decreasing percentage of free fatty acid as much as 4.68%, adsorption capacity as much as 207.19 mg/g and adsorption effectiveness as much as 36.28%. Keywords: adsorption; delignification; free fatty acid; tengkawang oil

The sound of Parkinson's disease: A model of audible bradykinesia

IntroductionEvaluation of bradykinesia is based on five motor tasks from the MDS-UPDRS. Visually scoring these motor tasks is subjective, resulting in significant interrater variability. Recent observations suggest that it may be easier to hear the characteristic features of bradykinesia, such as the decrement in sound intensity or force of repetitive movements. The objective is to evaluate whether audio signals derived during four MDS-UPDRS tasks can be used to detect and grade bradykinesia, using two machine learning models. Methods54 patients with Parkinson's disease and 28 healthy controls were filmed while executing the bradykinesia motor tasks. Several features were extracted from the audio signal, including number of taps, speed, sound intensity, decrement and freezes. For each motor task, two supervised machine learning models were trained, Logistic Regression (LR) and Support Vector Machine (SVM). ResultsBoth classifiers were able to separate patients from controls reasonably well for the leg agility task, area under the receiver operating characteristic curve (AUC): 0.92 (95%CI: 0.78–0.99) for LR and 0.93 (0.81–1.00) for SVM. Also, models were able to differentiate less severe bradykinesia from severe bradykinesia, particularly for the pronation-supination motor task, with AUC: 0.90 (0.62–1.00) for LR and 0.82 (0.45–0.97) for SVM. ConclusionThis audio-based approach discriminates PD from healthy controls with moderate-high accuracy and separated individuals with less severe bradykinesia from those with severe bradykinesia. Sound analysis may contribute to the identification and monitoring of bradykinesia.

Effect of single roll drive rolling on microstructure, texture, and mechanical property anisotropy of Al−5.6Zn−2.5Mg−1.4Cu aluminum alloy

The current research aimed to study the microstructure and texture development of the Al−5.6Zn−2.5Mg−1.4Cu alloy during single roll drive rolling process (SRDR). The relationship between mechanical property anisotropy and microstructure and texture was investigated in detail. The SRDR process was immediately performed on the solution-treated sample with four different thickness reductions of 10%, 20%, 40%, and 60%, respectively. Microstructural examination by optical and scanning electron microscopes, texture evaluation by X-ray diffraction, and mechanical properties evaluation by tensile tests were conducted. The results showed that the value of in-plane anisotropy was significantly reduced from 11.6% in solution-treated alloy to 2.4% and 3.1% in 40% and 60% reduction rolled samples, respectively. This was due to the formation of the Rotated Cube component, decreasing the overall texture intensity, and the formation of new grains through dynamic recrystallization. The yield strength in the rolling direction (RD) was higher than that in the transverse direction (TD), which was due to grain morphology and texture in these samples. The severity of Portevin−Le Chatelier (PLC) along the RD (0°) was much lower than that along the HD (45°) and TD (90°) owing to the presence of several strong orientations along the RD. By increasing the thickness reduction, the difference between strain hardening rates of RD, HD, and TD decreased due to the decrement of texture intensity. There was no difference between the fracture surfaces of 60% samples in the RD, HD, and TD, revealing nearly isotropic fracture behavior.

DNAzyme-Mediated Biodeposition Coupling Adjustable Cascade Electric Fields for Photoelectrochemical Telomerase Activity Monitoring.

Telomerase, as a specialized reverse transcriptase, plays a vital role in early cancer diagnostics and prognosis; thus, developing efficient sensing technologies is of vital importance. Herein, an innovative "signal-on-off" photoelectrochemical (PEC) sensing platform was developed for ultrasensitive evaluation of telomerase activity based on an electron-transfer tunneling distance regulation strategy and DNAzyme-triggerable biocatalytic precipitation. Concretely, cascade internal electric fields between CuInS2 quantum dots (QDs), graphitic carbon nitride nanosheets (g-C3N4 NSs), and TiO2 nanorod arrays (NRAs) were developed to realize cascade electron extraction and hole transfer. Enabled by such a design, an effective "signal-on" state to gain a progressively enhanced PEC output was designed by suppressing the photogenerated electron-hole pair recombination. With the introduction of hairpin probe H2 and the subsequent extension of the primer sequence driven by the target telomerase, the CuInS2 QDs labeled with hairpin probe H1 were programmatically unfolded, resulting in CuInS2 QDs' close proximity to the working electrode away from the cascade interface, accompanied by the formation of G-quadruplex/hemin complexes. The gradual undermining of tunneling distance and implantation of DNAzyme-initiating biocatalytic precipitation tremendously induced the sluggish migration kinetics of the photoinduced charge, accompanied by the photocurrent intensity decrement, leading to the "signal-off" state. Under optimized conditions, the as-prepared PEC biosensor realizes ultrasensitive detection of telomerase activity from 10 to 105 cell·mL-1 with a detection limitation of 3 cells·mL-1. As a proof of concept, this well-designed method provides new insights into signal amplification for telomerase activity evaluation and also presents promising potential for further development in drug screening, healthcare diagnostics, and biological assays.

Aggregation induced emission of surface ligand controlled gold nanoclusters employing imidazolium surface active ionic liquid and pH sensitivity

Gold nanoclusters (AuNCs) are one of the emerging materials due to their luminescence property, but their fluorescence intensity significantly gets quenched in aqueous medium due to the intramolecular vibration and rotation of the capping ligands. Herein, we have prepared long carbon chain containing mercaptan acids capped AuNCs, using 16-mercaptohexadecanoic acid (MHDA) and 11-mercaptoundecanoic acid (MUA) respectively, in aqueous medium with quantum yields (QYs) 3.01% and 6.27% respectively. These AuNCs are negatively charged particles confirmed by zeta potential measurements. After addition of positively charged long hydrocarbon chain containing imidazolium surface active ionic liquid (SAIL), 1-hexadecyl-3-methylimidazolium chloride (C16mimCl) in these aqueous AuNCs solutions, respective fluorescence intensities increase due to the formation of rigid aggregates with AuNC. The intramolecular vibration and rotation of these capping ligands (MHDA and MUA) are reduced due to the formation of these rigid aggregates and therefore, the QYs of these MHDA and MUA capped AuNCs increase to 5.78% and 6.87% respectively. Now the aggregation induced emission is strongly dependent on the concentration of added C16mimCl with the presence of three distinct regions (first turbid, precipitate and second turbid). The aggregation induced emission enhancement in case of MHDA capped AuNC becomes more prominent than MUA capped AuNC because of more hydrophobic interaction. Moreover, with decreasing the pH of the solution, the carboxylate (–COO-) groups of the capping ligands are protonated and therefore, the electrostatic interaction between AuNCs and C16mimCl no longer exist. This results the gradual decrement in emission intensity and this produces a linear relationship against pH of the solution within pH range 7.5 to 1.5.

Tuning of (E)-(4-fluorophenyl)-1,1-diamino-2,3-diazabuta-1,3-diene nanostructures for the selective detection of imidacloprid

The present work demonstrates a facile route for synthesizing the organic nanoparticles (ONPs) and the blue fluorescent Quantum Dots (QDs) based on an organic molecule named (E)-(4-fluorophenyl)-1,1-diamino-2,3-diazabuta-1,3-diene. The synthesis process possesses advantages viz green synthesis, non-toxic degraded products, and amount of organic compound. Initially, the ONPs were prepared using the nanoprecipitation method and were screened for their recognition potential against various pesticides, however, no selectivity has been observed. This motivated us to tune the ONPs into QDs. The QDs were prepared using the hydrothermal method and a color change was observed in the QDs solution under daylight and under a UV lamp. The emission wavelength was observed at 400 nm (λexcitation = 278 nm). The synthesized QDs exhibited selective sensing potential towards imidacloprid via a quenching mechanism. A normalised decrement in the luminescence intensity of QDs was observed on raising the concentration of imidacloprid and a good linear response was noticed over a concentration varies from 1 μM to 100 μM with a regression coefficient of 0.99. The detection limit was estimated to be 4.53 nM and quantification limit was calculated to be and 13.72 nM.

Fluorometric detection of trace moisture in methanol, ethanol and n-propanol using N, P-codoped carbon dots

Trace moisture was firstly measured in methanol, ethanol and n-propanol at room temperature. The N, P-codoped carbon dots (CDs) were prepared by one pot solvothermal method, which displayed solvent-dependent fluorescence. The N, P-codoped CDs exhibited green fluorescence, with the quantum yields (QY) of 27.9%, 37.4%, 26.2% and 2.3% in methanol, ethanol, n-propanol and water, respectively. Based on the hydrogen bond interactions between the protic solvents and the N, P-codoped CDs, with the water content increased, the fluorescence intensity of N, P-codoped CDs gradually decreased in methanol, ethanol and n-propanol. The decrement in the fluorescence intensity is linearly related to the water content within the content range of 2% to 8%, 0.04% to 5% and 0.04% to 1.0%, with a limit of detection of 0.22%, 0.009% and 0.021% in methanol, ethanol and n-propanol, respectively. Therefore, the present system has a prospective value for the application in the determination of trace water in the relevant fields.

Colorimetric probing and fluorescent chemosensor features of functionalized sulphonamide-azomethine derivatives

In this work, we have experimentally synthesized bromosulfonamide-based azomethine compounds through the reaction of 4-bromobenzenesulfonamide with 2-hydroxy-5-iodobenzaldehyde, 2-hydroxy-5-nitrobenzaldehyde, and 2-hydroxy-1-naphthaldehyde. We have also characterized the molecular structure of the investigated compounds with MS, 1H NMR, FTIR and UV–vis spectra. Theoretically, using DFT and TD-DFT methods, we computed frontier molecular orbitals (FMOs) energies and UV–vis spectra as well. We have also obtained the electron localization function (ELF) maps to identify electrophilic substitution sites in the molecules and density of states (DOS) diagrams to show the composition of the fragment orbitals that contribute to the molecular orbitals. We have investigatedsteady-state absorption, emission features, and excited state dynamics to better understand the photophysical process of bromosulfonamide-based azomethines. It has been demonstrated that by adding a naphthalene unit, the absorption properties of azomethine into two branches. Besides, azomethine, including heavy iodo atoms, presents a slight decrement in the fluorescence intensity. According to thorough calculations of charge transfer dynamics using femtosecond transient absorption spectra, the bromosulfonamide-based azomethines with iodo atoms and incorporating naphthalene units exhibit an intersystem crossing mechanism following photoexcitation. The colorimetric response of the compounds in DMSO to the addition of the equivalent amount of anions (F−, Br−, I−, CN−, SCN−, ClO4−, HSO4−, AcO−, H2PO4−, N3− and OH−) was investigated. In this regard, while the addition of F−, CN−, AcO−, H2PO4− and OH− anions into the solution containing the compounds resulted in a significant color change, the addition of Br−, I−, SCN−, ClO4−, HSO4− and N3−anions resulted in no color change.

Rapid and Highly Sensitive Detection of Target DNA Related to COVID-19 Virus With a Fluorescent Bio-conjugated Probe via a FRET Mechanism

A novel cyanine 3 (Cy3)-based bio-conjugated sensor has been developed to detect target DNA or extracted RNA from COVID -19 samples using the fluorescence resonance energy transfer (FRET) experiment. A special sequence of the COVID -19 genome was selected as a complementary DNA (target DNA) part. The opposite chain of this target sequence was designed in 2 parts; one part was attached to the Cy3 organic dye (capture DNA or Cy3- DNA), and the other part was attached to the BHQ2 molecule (quencher DNA or BHQ2- DNA). The Cy3 molecule acts as a donor pair, and BHQ2 acts as an acceptor pair in the FRET experiment. The capture DNA and quencher DNA can form a sandwiched complex in the presence of target DNA. The formation of the entitled sandwiched hybrid causes the decrement of emission intensity of the Cy3 donor in bio-conjugated Cy3-DNA via energy transfer from Cy3 (as a donor) to BHQ2 (as an acceptor). Indeed, in the presence of non-complementary DNA, the pairing of DNA strands does not occur, the FRET phenomenon does not exist, and therefore fluorescence intensity of Cy3 does not decrease. Moreover, this biosensor was successfully applied to analyze real samples containing extracted RNA of COVID -19 prepared for the reverse transcriptase-polymerase chain reaction (RT-PCR) test, and the results were promising.

Residual neuromuscular fatigue influences subsequent on-court activity in basketball

ABSTRACT The aim of this study was to determine if residual neuromuscular fatigue influenced subsequent match and training activity in professional women’s basketball. Prior to matches and training sessions throughout a season, players performed countermovement jumps while wearing a magnetic, angular rate and gravity (acceleration) sensor on their upper back. Flight time to contraction time ratio was used to determine neuromuscular performance and to identify neuromuscular fatigue. Average session intensity and volume, the proportion of live time spent in different intensity bands (matches), and absolute and relative time spent in different intensity bands (training) were quantified using accelerometry. Residual neuromuscular fatigue was deemed to be present when the decrement in neuromuscular performance relative to pre-season baseline was greater than the smallest worthwhile change. Players displayed residual neuromuscular fatigue before 16% of matches and 33% of training sessions. When players were fatigued prior to matches, the proportion of live time undertaking supramaximal activity was 5.7% less (p = 0.02) and moderate-vigorous activity was 3.7% more than when not fatigued (p = 0.02). When fatigued prior to training, the players displayed a 2.6% decrement in average intensity (p = 0.02), 2.8% decrement in absolute (p = 0.01) and 5.0% decrement in relative (p = 0.01) maximal activity, as well as 13.3% decrement in absolute (p < 0.01) and 6.8% decrement in relative (p < 0.01) supramaximal activity when compared to not being fatigued. These findings suggest that residual neuromuscular fatigue influences players’ ability to perform supramaximal activity, which highlights the importance of monitoring neuromuscular performance throughout a professional season. Highlights Residual neuromuscular fatigue can influence the amount of supramaximal activity players perform in a subsequent training session or match. Practices should be implemented to minimise residual neuromuscular fatigue carried into matches while maintaining a sufficient training volume to elicit physiological adaptations. MARG sensors can be used as an affordable and time-efficient tool for regularly monitoring countermovement jump-derived neuromuscular fatigue.

Utilizing Nanoparticle Catalyzed TMB/H2 O2 System for Determination of Aspirin in Exhaled Breath Condensate

Background: According to the poison center data for most countries, more than thousands of people’s exposure to aspirin or salicylate-containing products. So, this work aimed was to offer a rapid colorimetric method for monitoring aspirin concentration in exhaled breath condensate (EBC). Methods: A method based on a redox reaction catalyzed by nanoparticles was validated for the analysis of aspirin. 3,3 ,5,5 –Tetramethyl benzidine /H2 O2 and sodium dodecyl sulfate modified silver nanoparticles were used as the redox reagents and catalyst, respectively. Results: Detection mechanism of aspirin using this system is based on the inhibitory effect of aspirin on the signal intensity of the colorimetric systems. Since the decrement in signal intensity was proportional to aspirin level, a colorimetric method was proposed for its quantification in EBC samples. This method shows a linear relationship with aspirin concentration in the range of 10‒250 mg.L−1 with a relative standard deviation of &lt; 3.5%. Conclusion: This method has great potential for aspirin determination due to some features such as high reliability, and fast response time.

Effect of Al-5Ti-1B and Zr grain refiners on the solidification characteristics and microstructure of Al-6Mg alloy studied through thermal analysis

Al-Mg based alloys are widely used in industrial applications and grain refining is used for structural refinement to achieve high strength and ductility. The aim of this work is to investigate the effects of two grain refiners of Al-5Ti-1B and Zr on the solidification transformations of Al-6Mg alloy and dendrite coherency point (DCP) using two thermocouple cooling curve thermal analyses (CCTA). The microstructure and intermetallic phases were studied through scanning electron microscopy (SEM), EDS, and X-ray mapping. Microstructural evaluations showed the main secondary phases of Al-6Mg alloy are Al3Fe, Al8Mg5, and Mg2Si. The CCTA results indicated that the addition of Al-5Ti-B and Zr causes an increment of nucleation temperature, TN,α,(from 622.4 to 628.4 and 625.7 °C, respectively). The grain refining potential is an inherent property that depends on the growth restriction factor (GRF) and mostly relates to solute concentration and liquidus line slope. The refining power of Al-5Ti-1B for Al-6Mg is more effective because of its larger growth restriction factor (GRF) in comparison with Zr. Therefore, the grain size of the alloy used Al-5Ti-1B or Zr grain refiner was 105 µm and 185 µm, respectively. This phenomenon has been proved when recalescence undercooling (ΔTR,α) was calculated. It has been shown that ΔTR,α reaches zero when Al-5Ti-1B master alloy is added to Al-6Mg alloy. Zr caused the decrement in the first derivative peak intensity of eutectic phases which may be eventuated from extending the solid solubility by the addition of Zr. These grain refiners also affected the dendrite coherency point (DCP). Although Zr changed the TN-TDCP and fsDCP, Al-5Ti-1B increased the TN-TDCP interval by about 14.8 °C and delayed up the coherency solid fraction by about 89.7 pct which can decrease the casting defects.

Tracking the Temporal Footprint Effect of Thermonociception and Denervation on the Brain's Pain Matrix: fMRI and BOLD Study in Rats.

ObjectivePain constitutes an essential alarm for preserving the organism’s integrity. Damage to the nervous system produces a pathological condition known as neuropathic pain.PurposeBlood oxygenation level-dependent (BOLD) and functional magnetic resonance imaging (fMRI) have been widely used to map neuroanatomy and the active regions of interest (ROI) of nociceptive processing. Our study explored the brain’s BOLD response in rats after thermal noxious stimulation, immediately after sciatic nerve damage and during 75 minutes after surgical lesion of the sciatic nerve.MethodsNine male Wistar rats were tested; the experiments were performed on a 7-Tesla /21-cm Varian Agilent system. This approach allowed, for the first time, to measure in vivo the BOLD changes in brain regions involved with the pain process: cingulated (ACC), somatosensory (S1), and insular cortices (IC), as well as thalamus (Th) and ventral tegmental area (VTA) related with acute thermal pain and during the early stages of sciatic denervation that produce neuropathic pain.ResultsDuring thermonociception scan, all subjects showed BOLD activation in the ROIs determined as ACC, S1, Th, IC and VTA. After denervation, these regions continued to show activation with a slow decrement in intensity for the duration of the experiment. The results suggest that these brain structures are overactive during the genesis of neuropathic pain.ConclusionThe study shows for the first time continuous activation of the pain matrix following an acute thermal nociceptive stimulus followed by neuropathic damage. These results have given insight into the early stages of the development of neuropathic pain in vivo.

The steady-state hydrodynamics of a long-lived disc: planetary system architecture and prospects of observing a circumplanetary disc shadow in V4046 Sgr

ABSTRACT Recent imaging of the disc around the V4046 Sgr spectroscopic binary revealed concentric regions of dust rings and gaps. The object’s proximity and expected equilibrated state due to its old age (&amp;gt;20 Myr) make it a superb testbed for hydrodynamical studies in direct comparison to observations. We employ two-dimensional hydrodynamical simulations of gas and multiple dust species to test whether the observed structure conforms with the presence of giant planets embedded in the disc. We then perform radiative transfer (RT) calculations of sky images, which we filter for the telescope response for comparison with near-infrared (NIR) and millimetre observations. We find that the existing data are in excellent agreement with a flared disc and the presence of two giant planets, at $9$ and $20\, {\rm au}$, respectively. The different ring widths are recovered by diffusion-balanced dust trapping within the gas pressure maxima. In our RT model, the diffusion in vertical direction is reduced in comparison to the radial value by a factor of 5 to recover the spectral energy distribution. Further, we report a previously unaddressed, azimuthally confined intensity decrement on the bright inner ring in the NIR scattered light observation. Our model shows that this decrement can be explained by a shadow cast by a circumplanetary disc around the same giant planet that creates the inner cavity in the hydrodynamical simulations. We examine the shape of the intensity indentation and discuss the potential characterization of a giant planet and its associated disc by its projected shadow in scattered light observations.

Pressure‐Treated Engineering to Harvest Enhanced Green Emission in Mn‐Based Organic–Inorganic Metal Halides at Ambient Conditions

AbstractIn the pressure‐induced emission enhancement paradigms, harvesting enhanced emission on the basis of original color is still largely hampered due to the recovery or decrement of emission intensity upon decompression. Here, a pressure‐treated strategy is reported to achieve the remarkable green emission enhancement of organic–inorganic metal halide (OIMH) [PP14]2[MnBr4] (N‐butyl‐N‐methylpiperidinium [PP14]+) at ambient conditions. After a cycle of 1 atm to 15.2 GPa, the [PP14]2[MnBr4] shows a 1.67‐fold enhancement in the photoluminescence quantum yield from 54.5% to 90.8%, and green emission monochromaticity is unexpectedly retained. The restriction of motion freedom of [MnBr4]2− by increased Br···H interactions is highly responsible for the intense emission. Furthermore, [PP14]2[MnBr4] exhibits significant piezochromism that shifts from green to red, and an ultrabroad tunability of 185 nm is observed below 12.5 GPa. The enhancement of the crystal field splitting energy and the reduction of the relaxation from the low‐energy excited state 4T1 to the ground state 6A1 that is caused by the shrinkage of MnBr bond result in the red shift of emission. This work sheds light on the effects of pressure treatment in boosting emission enhancement and facilitates the design of new OIMHs with the desired emission properties.

IImproved performance of CdS powder-based hybrid solar cells through surface modification

The effects of surface modification of CdS through organic Eosin-Y, indoline D205, and Ru-based complex N719 and N3 dyes on CdS-based hybrid solar cells were studied. Chemical bath deposition (CBD) and doctor blade methods were in turn employed to fabricate the CdS specimens on Indium-Tin Oxide (ITO) covered glass substrates. P3HT material with and without dye coatings was covered through a spin-coater on the surface of CdS specimens. Ag paste was then deposited on the surface of P3HT to obtain hybrid solar cells. Structural analysis indicated that CdS powders showed a cubic growth with the preferred orientation of (111). Morphological analysis demonstrated that CdS powders exhibited hierarchical morphology and the morphology turned to granular structure with some porosity upon deposition of both N3 dye and P3HT layers. Absorption plots indicated that Eosin-Y dye loading led to a rise in the absorbance values of CdS specimens. After dye loading, photoluminescence data of CdS-based heterostructure illustrated a decrement in the luminescence intensity, implying that effective exciton dissociation was obtained. Current density-voltage (J-V) characteristics of the hybrid solar cells depicted that the best overall efficiency was observed for Eosin-Y-modified cell as 0.135%. This proved that surface modification by Eosin-Y dye led to a better interfacial contact between CdS and P3HT bilayer due to the enhancement in the charge separation.

Discrimination of pathogenic bacteria with boronic acid modified protonated g-C3N4 nanosheets at various pHs

Rapid and accurate identification of pathogenic bacteria remains a major challenge, especially for antibiotic-resistant bacteria. In this work, a novel sensing array for the discrimination of pathogenic bacteria based on the distinctive properties of boronic acid-functionalized graphitic carbon nitride nanosheets ((+)BA-g-CN) at various acidities was constructed. Bacteria cells were attached on (+)BA-g-CN either through the electrostatic interaction or the affinity between boronic acid on the nanosheets and saccharide unit on the surface of pathogenic bacteria at various pHs. Both of these interactions can lead to the sedimentation of the composites of bacteria- (+)BA-g-CN, causing the decrement in fluorescence intensity of the supernatant. For different types of bacteria, the degree of fluorescence decrement varies at various pHs, which provides a promising way for the discrimination of pathogenic bacteria. Nine types of pathogenic bacteria, i.e., six kinds of Gram-negative bacteria and three kinds of Gram-positive bacteria were well discriminated by the sensing array with linear discriminant analysis (LDA) at OD600 = 0.01. Its practical application is further demonstrated by the identification of different growth stages of bacteria and the discrimination of pathogenic bacteria in human urine.