Solution-processed NO2 gas sensor based on poly(3-hexylthiophene)-doped PbS quantum dots operable at room temperature.

The global industrial development and increase in the number of transportation vehicles, such as automobiles and ships, have led to a steady increase in the issues related to greenhouse gas emissions. NO2 is a greenhouse gas emitted in large quantities from automobiles and factories, and its emission is unavoidable in the modern world. Therefore, a sensor capable of precise detection of NO2 is required. The most commonly reported types of NO2 sensors are those based on metal oxides. However, their operation at room temperature is impossible owing to their high-temperature operating characteristics, and therefore, a heater must be designed inside or installed outside the sensor for heating. Meanwhile, NO2 sensors based on PbS quantum dots (QDs) are advantageous as they can operate at room temperature and can be easily manufactured through a solution process rather than a complicated semiconductor process. Herein, a NO2 sensor was fabricated by doping PbS QDs with poly(3-hexylthiophene) (P3HT). The as-developed sensor exhibited high responsivity to 100-0.4-ppm NO2 gas with a resolution of 200 ppb owing to the stability of the thin film and high hole mobility of P3HT.

Reducing Radiation Dermatitis for PBS Proton Therapy Breast Cancer Patients Using SpotDelete.

Purpose: The purpose of this work was to reduce the severity of radiation dermatitis for breast cancer patients receiving pencil beam scanning proton therapy. The hypothesis was that eliminating proton spots (SpotDelete) in the 0.5 cm skin rind would reduce the potentially higher relative biological effectiveness (RBE) known to occur at the Bragg Peak. Patients and Methods: Our center has been using an in-house developed Python script in RayStation since 2021 to remove spots from the skin rind of breast patients. In this work, we retrospectively reviewed the on-treatment visit data from a cohort of breast patients treated with hypofractionation (16 fractions) before this technique (MinDepth) and after (SpotDelete) to acquire the physician-reported radiation dermatitis scores. We evaluated the delivered treatment plans, calculating the linear energy transfer (LET) and applying 3 variable RBE models, Carabe-Fernandez, Wedenberg, and McNamara. An α/ß of 10 was assumed for the skin. Results: In the MinDepth cohort (n = 28), grade 1, 2, and 3 dermatitis accounted for 57%, 36%, and 7% of the cases, respectively. For SpotDelete (n = 27), the incidence rate of grade 1 and 2 acute radiation dermatitis was 67% and 37%, respectively. There were 0 instances of grade 3 dermatitis observed in the SpotDelete cohort. The onset of radiation dermatitis in the SpotDelete cohort was delayed compared to MinDepth, occurring 1 week later in the course of treatment. There was no significant difference in LET or in any of the variable RBE models when analyzing the 0.5 cm skin rind between the cohorts. Conclusion: Despite the lack of correlation in LET or RBE, SpotDelete has been shown to reduce the severity and onset of radiation dermatitis. Possibly, more research into the α/ß for skin and RBE models based on skin cell lines could provide insight into the efficacy of the SpotDelete technique.

Overcoming the EQE × Li-Fi Frequency Constraint by Modulating the PbS CQDs Distribution in Perovskite Film.

Advanced photodetectors are crucial for high-fidelity optical communication. However, the tradeoff between high external quantum efficiency (EQE) and high light fidelity (Li-Fi) frequency often limits data transmission accuracy and timeliness. Here, we report a photodetector consisting of lead sulfide (PbS) colloidal quantum dots (CQDs) with near-infrared responsiveness and perovskite frameworks responsible for the charge transport to overcome the EQE × Li-Fi constraint. Optimizing the PbS CQDs distribution and trap depth in the perovskite layer enhances charge injection, achieving a device gain of 11892% for 1200 nm photons and a response frequency of 24 kHz at -2 V. The device exhibits a record EQE × Li-Fi frequency product of 106 Hz. We have applied the detector to near-infrared optical communications at a data transfer rate of 2000 bits per second (2 kbps) to demonstrate the advances in high fidelity, the device retains over 98% of the original waveform information in its output.

Optical Transparency Windows in Near-Infrared and Short-Wave Infrared for the Skin, Skull, and Brain: Fluorescence Bioimaging Using PbS Quantum Dots.

Fluorescence imaging (FI) employing near-infrared (NIR) light within the range of ~750-1350 nm enables biomedical imaging several millimeters beneath the tissue surface. More recent investigations into the short-wave IR (SWIR) transparency windows between ~1550-1870 and 2100-2300 nm highlight their superior capabilities. This research presents a comparison of IR-FI of PbS quantum dots, emitting at 990, 1310, and 1580 nm, through the mouse scalp skin, skull, and brain. The SWIR fluorescence is the most effectively transmitted signal, showing particularly significant enhancement when passing through the skull, which causes high light scattering. For the analysis of the imaging results and light propagation through the organs, their spectra of attenuation, absorption, and scattering coefficients are measured. In view of biomedical imaging, attenuation due to light scattering is a more destructive factor. Hence, the spatial resolution and imaging contrast can be improved by operating in SWIR due to decreased light scattering.

Dual-Mode Semiconductor Device Enabling Optoelectronic Detection and Neuromorphic Processing with Extended Spectral Responsivity.

High-performance semiconductor devices capable of multiple functions are pivotal in meeting the challenges of miniaturization and integration in advanced technologies. Despite the inherent difficulties of incorporating dual functionality within a single device, a high-performance, dual-mode device is reported. This device integrates an ultra-thin Al2O3 passivation layer with a PbS/Si hybrid heterojunction, which can simultaneously enable optoelectronic detection and neuromorphic operation. In mode 1, the device efficiently separates photo-generated electron-hole pairs, exhibiting an ultra-wide spectral response from ultraviolet (265 nm) to near-infrared (1650 nm) wavelengths. It also reproduces high-quality images of 256 × 256 pixels, achieving a Q-value as low as 0.00437 µW cm- 2 at a light intensity of 8.58 µW cm- 2. Meanwhile, when in mode 2, the as-assembled device with typical persistent photoconductivity (PPC) behavior can act as a neuromorphic device, which can achieve 96.5% accuracy in classifying standard digits underscoring its efficacy in temporal information processing. It is believed that the present dual-function devices potentially advance the multifunctionality and miniaturization of chips for intelligence applications.

Graphene-PbS Quantum Dot Heterostructure for Broadband Photodetector with Enhanced Sensitivity.

Photodetectors converting light into electrical signals are crucial in various applications. The pursuit of high-performance photodetectors with high sensitivity and broad spectral range simultaneously has always been challenging in conventional semiconductor materials. Graphene, with its zero bandgap and high electron mobility, is an attractive candidate, but its low light absorption coefficient restricts its practical application in light detection. Integrating graphene with light-absorbing materials like PbS quantum dots (QDs) can potentially enhance its photodetection capabilities. Here, this work presents a broadband photodetector with enhanced sensitivity based on a graphene-PbS QD heterostructure. The device leverages the high carrier mobility of graphene and the strong light absorption of PbS QDs, achieving a wide detection range from ultraviolet to near-infrared. Employing a simple spinning method, the heterostructure demonstrates ultrahigh responsivity up to the order of 107 A/W and a specific detectivity on the order of 1013 Jones, showcasing significant potential for photoelectric applications.

In-depth analysis of isochorismate synthase-derived metabolism in plant immunity: Identification of meta-substituted benzoates and salicyloyl-malate.

Isochorismate-derived metabolism enables biosynthesis of the plant defense hormone salicylic acid (SA) and its derivatives. In Arabidopsis thaliana, the stress-induced accumulation of SA depends on ISOCHORISMATE SYNTHASE1 (ICS1) and also requires the presumed isochorismate transporter ENHANCED DISEASE SUSCEPTIBILITY5 (EDS5) and the GH3 enzyme avrPphB SUSCEPTIBLE3 (PBS3). By comparative metabolite and structural analyses, we identified several hitherto unreported ICS1- and EDS5-dependent, biotic stress-inducible Arabidopsis metabolites. These involve meta-substituted SA derivatives (5-formyl-SA, 5-carboxy-SA, 5-carboxymethyl-SA), their benzoic acid (BA) analogs (3-formyl-BA, 3-carboxy-BA, 3-carboxymethyl-BA), and besides the previously detected salicyloyl-aspartate (SA-Asp), the ester conjugate salicyloyl-malate (SA-Mal). SA functions as a biosynthetic precursor for SA-Mal and SA-Asp, but not for the meta-substituted SA- and BA-derivatives, which accumulate to moderate levels at later stages of bacterial infection. Interestingly, Arabidopsis leaves possess oxidizing activity to effectively convert meta-formyl- into meta-carboxy-SA/BAs. In contrast to SA, exogenously applied meta-substituted SA/BA-derivatives and SA-Mal exert a moderate impact on plant immunity and defence-related gene expression. While the isochorismate-derived metabolites are negatively regulated by the SA receptor NON-EXPRESSOR OF PR GENES1, SA conjugates (SA-Mal, SA-Asp, SA-glucose conjugates) and meta-substituted SA/BA-derivatives are oppositely affected by PBS3. Notably, our data indicate a PBS3-independent path to isochorismate-derived SA at later stages of bacterial infection, which does not considerably impact immune-related characteristics. Moreover, our results argue against a previously proposed role of EDS5 in the biosynthesis of the immune signal N-hydroxypipecolic acid and associated transport processes. We propose a significantly extended biochemical scheme of plant isochorismate metabolism that involves an alternative generation mode for benzoate- and salicylate-derivatives.

Synergic Surface Modifications of PbS Quantum Dots by Sodium Acetate in Solid-State Ligand Exchange toward Short-Wave Infrared Photodetectors.

PbS quantum dots (QDs) are promising for short-wave infrared (SWIR) photodetection and imaging. Solid-state ligand exchange (SSLE) is a low-fabrication-threshold QD solid fabrication method. However, QD treatment by SSLE remains challenging in seeking refined surface passivation to achieve the desired device performance. This work investigates using NaAc in the ligand exchange process to enhance the film morphology and electronic coupling configuration of QD solids. By implementing various film and photodetector device characterization studies, we confirm that adding NaAc with a prominent adding ratio of 20 wt % NaAc with tetrabutylammonium iodide (TBAI) in the SSLE leads to an improved film morphology, reduced surface roughness, and decreased trap states in the QD solid films. Moreover, compared to the devices without NaAc treatment, those fabricated with NaAc-treated QD solids exhibit an enhanced performance, including lower dark current density (<100 nA/cm2), faster response speed, higher responsivity, detectivity, and external quantum efficiency (EQE reaching 25%). The discoveries can be insightful in developing efficient, low-cost, and low-fabrication-threshold QD SWIR detection and imager applications.

Fabrication of Soft Biodegradable Foam with Improved Shrinkage Resistance and Thermal Stability.

The soft PBAT foam shows good flexibility, high elasticity, degradable nature, and it can be used as an environmental-friendly candidate for EVA and PU foams. Unfortunately, there are few reports on the application of PBAT as a soft foam. In this study, PBAT foam was fabricated by a pressure quenching method using CO2 as the blowing agent. A significant volume shrinkage of about 81% occurred, where the initial PBAT foam had an extremely high expansion ratio, of about 31 times. A 5-10 wt% PBS with high crystallinity was blended, and N2 with low gas solubility and diffusivity was mixed, with the aim of resisting foam shrinkage and preparing PBAT with a high final expansion ratio of 14.7 times. The possible mechanism behind this phenomenon was established, and the increased matrix modulus and decreased pressure difference within and outside the cell structure were the main reasons for the shrinkage resistance. The properties of PBAT and PBAT/PBS foams with a density of 0.1 g/cm3 were measured, based on the requirements for shoe applications. The 5-10 wt% PBS loading presented advantages in reducing thermal shrinkage at 75 °C/40 min, without compromising the hardness, elasticity, and the compression set, which ensures that PBAT/PBS foams have good prospects for use as soft foams.

Generation of Microplastics from Biodegradable Packaging Films Based on PLA, PBS and Their Blend in Freshwater and Seawater.

Biodegradable polymers and their blends have been advised as an eco-sustainable solution; however, the generation of microplastics (MPs) from their degradation in aquatic environments is still not fully grasped. In this study, we investigated the formation of bio-microplastics (BMPs) and the changes in the physicochemical properties of blown packaging films based on polylactic acid (PLA), polybutylene succinate (PBS) and a PBS/PLA 70/30 wt% blend after degradation in different aquatic media. The tests were carried out in two temperature/light conditions to simulate degradation in either warm water, under sunlight exposure (named Warm and Light-W&L), and cold deep water (named Cold and Dark-C&D). The pH changes in the aqueous environments were evaluated, while the formed BMPs were analyzed for their size and shape alongside with variations in polymer crystallinity, surface and mechanical properties. In W&L conditions, for all the films, the hydrolytic degradation led to the reorganization of the polymer crystalline phases, strong embrittlement and an increase in hydrophilicity. The PBS/PLA 70/30 blend exhibited increased resistance to degradation with respect to the neat PLA and PBS films. In C&D conditions, no microparticles were observed up to 12 weeks of degradation.

Laser-Induced Interference to Infrared Detector Using Continuous Wave and Short-Pulse Lasers.

The response of a DPbS3200 infrared detector irradiated by a nanosecond pulsed laser and CW laser has been investigated to study laser-induced interference. A laser interference experiment system was constructed to measure the time-varying response signal. A nanosecond pulsed laser and a CW laser of 10 Hz were used, with a 1064 nm wavelength and a millimeter-scale irradiation spot diameter. Firstly, the characteristics of transient interference signals induced by pulsed lasers were analyzed. Then, the characteristics of response signal interference by both CW laser and pulsed laser irradiation were further investigated. The results showed that the pulsed laser only produced transient interference. However, the CW laser led to a significant amplitude reduction of the response signal, which could continuously interfere in the operating time. For transient interferences, the amplitude of the interference signal increased linearly with the laser fluence. The relation between the pulse repetition rate of the incident laser and the operating frequency of the detector determined the numbers of transient interference signals in one response period; for the interference induced by both the CW laser and pulsed laser, CW laser interference played a leading role when CW laser power density increased to 4.1 W/cm2 or more. As the CW laser fluence reached 6.1 W/cm2, the PbS infrared detector was no longer able to detect any signal, which caused temporary blindness. In the end, a probit model was used to determine the interference threshold.

[Determination of ten bisphenols and five parabens in urine by solid supported liquid-liquid extraction and liquid chromatography-tandem mass spectrometry].

Bisphenols (BPs) and parabens (PBs) are of great concern for environmental pollution and human health because of their endocrine-disrupting effects and potential health hazards. Urinary biomonitoring of BPs and PBs can provide basic data for human internal exposure evaluation, which is a prerequisite for accurately assessing their health risks. In this study, we developed a new pretreatment procedure based on solid supported liquid-liquid extraction (SLE) for the simultaneous separation of ten BPs and five PBs in human urine, followed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis. In the instrumental analysis, the HPLC conditions and MS/MS parameters were comprehensively optimized. Accurate qualitative and quantitative determination of ten BPs and five PBs was achieved by introducing a ternary gradient elution system of water, methanol, and acetonitrile for LC separation. During sample pretreatment, the extraction solvent and elution volume were optimized. Specifically, urine samples were held at room temperature and centrifuged at 3000 r/min for 10 min. The supernatant (2 mL) was then transferred to a glass tube, and the pH was adjusted to 5.0 using HCl (0.5 mL; 0.1 mol/L) and NaAc-HAc buffer (1.5 mL). Thereafter, ß-glucuronidase-arylsulfatase (20 µL) and surrogate standard solutions (10 ng;13C12-BPS,13C12-BPAF,13C6-MeP, and 13C6-BuP) were added, and the mixture was incubated in a shaker bath in the dark at 37 ℃ for 16 h. After incubation, the hydrolyzed sample (4 mL) was loaded onto an SLE cartridge and equilibrated for a minimum of 5 min to ensure the solution was completely absorbed by the packing material. Subsequently, the target chemicals were eluted with a mixed ethyl acetate/n-hexane solution (3∶7, v/v; 15 mL). Separation of the targets was performed on a ZORBAX SB-C18 reversed-phase column (250 mm×4.6 mm, 5 µm) using an acetonitrile-methanol-water system as the mobile phase. The method was verified by spiking mixed urine samples at three levels (1, 5, and 50 µg/L), with the recoveries ranging from 84.3% to 119.8%. Except for bisphenols (BPS), whose matrix effect was calculated as -21.8%, the matrix effects of other analytes were lower than 20%, indicating low matrix interference. The linear ranges of the analytes varied from 0.1-500 µg/L to 1-500 µg/L, with correlation coefficients higher than 0.995. The method limits of quantification for target chemicals ranged from 0.03 to 0.30 µg/L, and the relative standard deviations of intra- and inter-day experiments were 1.4%-8.4% and 5.7%-14.6%, respectively, suggesting high stability and reproducibility. The method was successfully applied to the determination of ten BPs and five PBs in 10 urine samples from a general population. The concentrations of target chemicals in the human urine samples varied. Methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), and bisphenol A (BPA) were detected in all samples, with median mass concentrations of 1.10, 0.60, 0.21, and 0.55 µg/L, respectively. The detection rates of the other chemicals were less than 50%, which may be related to the production and use of specific chemicals, their bioavailability, and biological metabolism in humans.

Patient-specific quality assurance of dynamically-collimated proton therapy treatment plans.

BACKGROUND: The dynamic collimation system (DCS) provides energy layer-specific collimation for pencil beam scanning (PBS) proton therapy using two pairs of orthogonal nickel trimmer blades. While excellent measurement-to-calculation agreement has been demonstrated for simple cube-shaped DCS-trimmed dose distributions, no comparison of measurement and dose calculation has been made for patient-specific treatment plans. PURPOSE: To validate a patient-specific quality assurance (PSQA) process for DCS-trimmed PBS treatment plans and evaluate the agreement between measured and calculated dose distributions. METHODS: Three intracranial patient cases were considered. Standard uncollimated PBS and DCS-collimated treatment plans were generated for each patient using the Astroid treatment planning system (TPS). Plans were recalculated in a water phantom and delivered at the Miami Cancer Institute (MCI) using an Ion Beam Applications (IBA) dedicated nozzle system and prototype DCS. Planar dose measurements were acquired at two depths within low-gradient regions of the target volume using an IBA MatriXX ion chamber array. RESULTS: Measured and calculated dose distributions were compared using 2D gamma analysis with 3%/3 mm criteria and low dose threshold of 10% of the maximum dose. Median gamma pass rates across all plans and measurement depths were 99.0% (PBS) and 98.3% (DCS), with a minimum gamma pass rate of 88.5% (PBS) and 91.2% (DCS). CONCLUSIONS: The PSQA process has been validated and experimentally verified for DCS-collimated PBS. Dosimetric agreement between the measured and calculated doses was demonstrated to be similar for DCS-collimated PBS to that achievable with noncollimated PBS.

Improvement in Performance and Stability of PbS QD/IGZO Phototransistors Through the Introduction of Ga2O3 Film for Broadband Sensor Applications.

The development of broadband photosensors has become crucial in various fields. Indium-gallium-zinc oxide (IGZO, In:Ga:Zn = 1:1:1) phototransistors with PbS quantum dots (QDs) have shown promising features for such sensors, such as reasonable mobility, low leakage current, good photosensitivity, and low-cost fabrication. However, the instability of PbS QD/IGZO phototransistors under an air atmosphere and prolonged storage remain serious concerns. In this article, two concepts to improve the reliability of PbS QD/IGZO phototransistors were implemented. P-type doping in the PbS QD layer through oxidation allows increasing the built-in potential between IGZO and PbS QDs, leading to enhancement in photoinduced electron-hole pair creation. Second, agglomeration and fusion of a PbS QDs layer were controlled via thermal annealing, which facilitated the transport of photocreated carriers. The p-type doping and interconnection of a PbS QD layer can be achieved by deposition and subsequent thermal annealing of gallium oxide (Ga2O3) on PbS QD/IGZO stacks. The resulting Ga2O3/PbS QD/IGZO phototransistors exhibited high-performance switching characteristics under dark conditions. Notably, they showed a remarkable photoresponsivity of 196.69 ± 4.05 A/W and a detectivity of (5.47 ± 1.4) × 1012 Jones even at a long-wavelength illumination of 1550 nm. While the unpassivated PbS/IGZO phototransistor suffered serious degradation in optical performance after 2 weeks of storage, the Ga2O3/PbS QD/IGZO phototransistor demonstrated enhanced stability, maintaining high performance for over 5 weeks. These findings suggest that Ga2O3/PbS QD/IGZO phototransistors offer a feasible approach for the fabrication of large-scale active matrix broadband photosensor arrays, potentially revolutionizing optical sensing in various cutting-edge applications.

Inhibitors of LAMP used to detect Tenacibaculum sp. strain Pbs-1 associated with black-spot shell disease in Akoya pearl oysters, and additives to reduce the effect of the inhibitors.

Black-spot shell disease is an unresolved disease that decreases pearl quality and threatens pearl oyster survival. In previous studies, the bacterium Tenacibaculum sp. strain Pbs-1 was isolated from diseased Akoya pearl oysters Pinctada fucata, and a rapid, specific, and sensitive loop-mediated isothermal amplification (LAMP) assay for detecting this pathogen was established. This technology has considerable potential for routine diagnosis of strain Pbs-1 in oyster hatcheries and/or pearl farms; therefore, it is vital to identify substances in environmental samples that might inhibit LAMP and to find additives that can reduce the inhibition. In this study, we investigated the effects of six chemicals or proteins, otherwise known as conventional PCR inhibitors, on LAMP, using the DNA of strain Pbs-1 as template: humic acid, urea, iron (III) chloride hexahydrate, melanin, myoglobin, and Ethylenediamine-N,N,N',N'-tetraacetic acid, disodium salt, dihydrate (EDTA; pH 6.5). Next, to reduce the effects of identified inhibitors, we tested the addition of bovine serum albumin (BSA) or T4 gene 32 protein (gp32) to the LAMP assay. When 50 ng of DNA template was used, 4 ng/µL of humic acid, 0.05% melanin, and 10 mM of EDTA (pH 6.5) inhibited the LAMP reaction, whereas myoglobin, urea, and FeCl3 had no effect. When 50 pg of DNA template was used, 4 ng/µL of humic acid, 0.05% melanin, 4 µg/µL of myoglobin, 10 µg/µL of urea, and 10 mM of EDTA inhibited the LAMP reaction. Thus, it was shown that the gene-amplification inhibitory effect of melanin, humic acid, and urea could be reduced by adding BSA or gp32 to the LAMP reaction mixture. This technique could be applied as part of a protocol to prevent mass mortalities of pearl oysters; moreover, the results enhance our knowledge about substances that inhibit LAMP and methods to reduce the inhibition, which have rarely been reported.

Membrane-Free Electrocatalytic Co-Conversions of PBS Waste Plastics and Maleic Acid into High-Purity Succinic Acid Solid.

Plastic pollution, an increasingly serious global problem, can be addressed through the full lifecycle management of plastics, including plastics recycling as one of the most promising approaches. System design, catalyst development, and product separation are the keys in improving the economics of electrocatalytic plastics recycling. Here, a membrane-free co-production system was devised to produce succinic acid (SA) at both anode and cathode respectively by the co-electrolysis of polybutylene succinate (PBS) waste plastics and biomass-derived maleic acid (MA) for the first time. To this end, Cr3+-Ni(OH)2 electrocatalyst featuring much enhanced 1,4-butanediol (BDO) oxidation reaction (BOR) activity has been synthesized and the role of doped Cr has been revealed as an "electron puller" to accelerate the rate-determining step (RDS) in the Ni2+/Ni3+ cycling. Impressively, an extra-high SA production rate of 3.02 g h-1 and ultra-high apparent Faraday efficiency towards SA (FEapparent=181.5%) have been obtained. A carbon dioxide-assisted sequential precipitation approach has been developed to produce high-purity SA and byproduct NaHCO3 solids. Preliminary techno-economic analysis demonstrates that the reported system is economically profitable and promising for future industrial applications.

Advancing Dental Implant Design: A Comprehensive Study of Machining Parameters, Corrosion Behavior, and Microstructural Evaluation.

In this research, we investigate the impact of varying machining parameters [depth of cutting (mm) and spindle rotation speed (rpm)] on the microstructure and electrochemical behavior of Ti6Al4V-ELI dental implants. This comprehensive study employs an approach, leveraging potentiodynamic methods and electrochemical impedance spectroscopy, to analyze corrosion behavior in a phosphate-buffered saline solution. To further deepen our understanding of corrosion kinetics, we used an alternating current circuit model, based on a simple Randles equivalent circuit. This model elucidates the corrosion interface interactions of the Ti6Al4-V-ELI alloy implant within the PBS solution. In addition, our research delves into the microstructural implications of different machining parameters, utilizing scanning electron microscopy and X-ray diffraction (XRD) techniques to reveal significant phase changes. The changes in texture were examined qualitatively by comparing the intensities of the peaks of the XRD pattern. A detailed correlation analysis further links the machining parameters with the corrosion properties of dental implants, offering a comprehensive perspective rarely explored in the existing literature. The results obtained for the three samples showed that the corrosion resistance would be higher by increasing the machining depth and the spindle rotation and that the corrosion current would be lower. As a result, a lower corrosion rate was obtained. Finally, experimental results from electrochemical analyses are compared and discussed.

Revealing oxygen effect on efficiency and stability of quantum dot photovoltaics.

Colloidal quantum dot solar cells (CQDSCs) have received great attention in the development of scalable and stable photovoltaic devices. Despite the high power-conversion-efficiency (PCE) reported, stability investigations are still limited and the exact degradation mechanisms of CQDSCs remain unclear under different atmosphere conditions. In this study, the atmospheric influence on the ZnO electron transport layer material (ETL), halide-passivated lead sulfide CQDs (PbS-PbI2) photoactive layer material and 1,2-ethanedithiol-PbS CQDs (PbS-EDT) hole transport material on device stability in PbS CQDSCs is investigated. It was found that O2 had negligible influence on PbS-PbI2, but it did induce the increase in work function of ZnO ETL and PbS-EDT layers. Notably, the increase of the ZnO work function (WFZnO) induces the formation of interface barrier between ZnO and PbS-PbI2, leading to a deterioration in device efficiency. By further replacing ZnO ETL with SnO2, a multi-interface collaborative CQDSC was constructed to realize the PCE with high stability. This study identifies the efficiency evolution that is inherent in CQDSCs under different atmospheric conditions.

Flexible Printed Ultraviolet-to-Near-Infrared Broadband Optoelectronic Carbon Nanotube Synaptic Transistors for Fast and Energy-Efficient Neuromorphic Vision Systems.

To simulate biological visual systems and surpass their functions and performance, it is essential to develop high-performance optoelectronic neuromorphic electronics with broadband response, low power consumption, and fast response speed. Among these, optoelectronic synaptic transistors have emerged as promising candidates for constructing neuromorphic visual systems. In this work, flexible printed broadband (from 275 to 1050 nm) optoelectronic carbon nanotube synaptic transistors with good stability, high response speed (3.14 ms), and low-power consumption (as low as 0.1 fJ per event with the 1050 nm pulse illumination) using PbS quantum dots (QDs) modified semiconducting single-walled carbon nanotubes (sc-SWCNTs) as active layers are developed. In response to optical pulses within the ultraviolet to near-infrared wavelength range, the optoelectronic neuromorphic devices exhibit excitatory postsynaptic current, paired-pulse facilitation, and a transition from short-term plasticity to long-term plasticity, and other optical synaptic behaviors. Furthermore, a simplified neural morphology visual array is developed to simulate integrated functions such as image perception, memory, and preprocessing. More importantly, it can also emulate other complicated bionic functions, such as the infrared perception of salmon eyes and the warning behavior of reindeer in different environments. This work holds immense significance in advancing the development of artificial neural visual systems.

Ultrabright NIR-IIb Fluorescence Quantum Dots for Targeted Imaging-Guided Surgery.

Pioneering approaches for precise tumor removal involve fluorescence-guided surgery, while challenges persist, including the low fluorescence contrast observed at tumor boundaries and the potential for excessive damage to normal tissue at the edges. Lead/cadmium sulfide quantum dots (PbS@CdS QDs), boasting high quantum yields (QYs) and vivid fluorescence, have facilitated advancements in the second near-infrared window (NIR-II, 900-1700 nm). However, during fluorescent surgical navigation operations, hydrophilic coatings of these inorganic nanoparticles (NPs) guarantee biosafety; it also comes at the expense of losing a significant portion of QY and NIR-II fluorescence, causing heightened damage to normal tissues caused by cutting edges. Herein, we present hydrophilic core-shell PbS@CdS@PEG NPs with an exceptionally small diameter (∼8 nm) and a brilliant NIR-IIb (1500-1700 nm) emission at approximately 1600 nm. The mPEG-SH (MW: 2000) addresses the hydrophobicity and enhances the biosafety of PbS@CdS QDs. In vivo fluorescence-guided cervical tumor resection becomes achievable immediately upon injection of an aqueous solution of PbS@CdS@PEG NPs. Notably, this approach results in a significantly reduced thickness (100-500 µm) of damage to normal tissues at the margins of the resected tumors. With a high QY (∼30.2%) and robust resistance to photobleaching, NIR-IIb imaging is sustained throughout the imaging process.