Atmosphere Storage Research Articles

Abstract A034: Addressing the challenge of pre-analytical variables in circulating protein biomarker analysis for liquid biopsy

Abstract While liquid biopsy using plasma proteins is a promising avenue for early cancer detection, diagnosis, prognosis, and disease monitoring, the clinical translation of plasma proteomics has been limited due to the complexity of the proteome and the impact of pre-analytical variation on its integrity. In recent years, advancements in plasma proteomic technologies, such as Olink, have helped address the challenge of proteome complexity. However, challenges with pre- analytical variables have persisted. During blood collection and whole blood storage, ex vivo blood cell activation and lysis can occur, releasing proteins into the plasma and obscuring relevant in vivo abundances. This is especially true for cancer where many key biomarkers are expressed in white blood cells and platelets. To address these issues, Streck developed Protein Plus BCT, which stabilizes blood cells and minimizes plasma proteome changes following prolonged whole blood storage. To demonstrate its functionality and compatibility with Olink assays, blood was collected from 5 donors into EDTA, ACD-A, and Protein Plus BCT. Plasma was isolated at draw time (< 2 hours) and following 24, 72, and 120 hours of ambient whole blood storage using a double spin protocol (per Instructions for Use). Plasma samples were analyzed using an Olink Explore 384-plex panel. After just 24 hours of whole blood storage, plasma isolated from EDTA or ACD-A had 4.2 and 2.2 times more proteins that are significantly elevated in abundance relative to draw time, respectively, than plasma isolated from Protein Plus BCT. For the key cancer biomarker IL-8, which is associated with worse clinical outcomes and poor response to immunotherapy, Protein Plus BCT maintains draw-time levels such that the mean NPX difference relative to draw time never exceeds -0.18, or a 0.88-fold change for up to 120 hours. Comparatively, samples collected into EDTA and ACD-A show dramatic increases in IL-8 levels with mean NPX differences of 6.34 and 6.62, respectively, corresponding to 80.1- and 98.3-fold increases after 120 hours of whole blood storage. For Galectin-3, an inflammatory biomarker elevated in many cancer types (i.e., lung, breast, and ovarian), the mean NPX difference relative to draw time for samples drawn into EDTA is 1.46 after 24 hours and increases to 2.27 after 120 hours of whole blood storage (a 2.75-fold and 4.8-fold increase, respectively). In samples collected into Protein Plus BCT, the mean NPX difference, relative to draw time, for Galectin-3 never exceeds 0.05 (a 1.04-fold increase) even after 120 hours of whole blood storage. Taken together, these data suggest that Protein Plus BCT extends the storage of whole blood at ambient temperature without compromising the integrity of the sample or the proteomic results, providing researchers and assay developers valuable flexibility in the transport, storage, and processing of their samples. Protein Plus BCT is for Research Use Only. Not for use in diagnostic procedures. Protein Plus BCT should only be used for research or the development of new assays. Citation Format: Rachel M Miller, Jing Li. Addressing the challenge of pre-analytical variables in circulating protein biomarker analysis for liquid biopsy [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A034.

Postharvest treatment of navel oranges with fluroxypyr, 2-methyl-4-chlorophenoxyacetic acids, and 2,4-dichlorophenoxyacetic maintains physiological quality during ambient storage

Two batches of Green mature Navel oranges with calyxes attached were obtained from a farmer from Juaben Municipality in the Ashanti region of Ghana and were dipped for 2 minutes with fluroxypyr, and 2-methyl-4-chlorophenoxyacetic acid (MCPA), were assessed against the commercial 2,4-D at 0.1 and 0.2 mmol L-1 stored under ambient conditions (24±2 °C and 55-60% RH) for 4 weeks. The results showed that pre-storage dipping with fluroxypyr was the most effective in suppressing endogenous ethylene production and respiration rate, reduced calyx changes, and fruit rot, and retained fruit sensory attributes compared with MCPA 2,4-D, or untreated fruit at the end of storage life of four weeks. The effect of 2,4-D and MCPA on fruit rot, calyx browning, abscission, and fruit internal quality, was similar; which was not significantly different during storage. Dipping fruit with 0.1 mmol L-1 fluroxypyr was more effective in maintaining the quality of oranges and could be a substitute for current commercial 2,4-D.

Exploring the impact of aminoethoxyvinylglycine (AVG) on the ripening behaviour and quality of bananas under different storage conditions

ABSTRACT Bananas rapidly undergo physiological deterioration after harvest owing to their climacteric and perishable nature causing significant economic yield loss. Thus, the adoption of postharvest loss mitigation strategies becomes imperative for enhancing fruit longevity. This study aimed to assess the effect of postharvest treatment with different concentrations of aminoethoxyvinylglycine (AVG) on shelf life extension and quality sustainability of bananas, such as Grand Naine, Poovan and Ney Poovan, kept under ambient (27°C ± 2°C) and cool (17°C) conditions. The findings revealed that AVG-treated bananas reduced weight loss of banana hands (0.655–2.559 kg hand−1) and higher peel thickness (0.86–2.73 mm) and firmness (6.54–12.01 N) over untreated control at ambient storage condition, whereas under cool storage, weight loss of banana hands reduced from 0.761 to 2.579 kg hand−1, while both peel thickness (1.24–2.84 mm) and firmness (7.75–11.45 N) were retained for varieties. The physio-chemical traits of fruit, such as total chlorophyll and starch content, were improved due to AVG treatment under both storage conditions. Among the treatments, postharvest application of AVG at 700 ppm showed better performance in the morphological, physiological and quality characters irrespective of the varieties.

Effect of different packaging methods and storage conditions on postharvest quality and shelf-life of Manila Tamarind (Pithecellobium dulce (Roxb.) Benth.) var. PKM2

Manila tamarind (Pithecellobium dulce (Roxb.) Benth.), is a dry land fruit crop that belongs to the Fabaceae family commonly known Camacchile or Jungle jilebi. Pithecellobium dulce (Roxb.) has the potential to become productive under harsh climatic and edaphic conditions of dry land areas but its pods have a shorter shelf life. The most important objective was to use proper packaging methods to reduce moisture loss, slow down physiological and biochemical changes and prevent spoilage. The study evaluated 8 packaging methods, including different combinations of CFB (Corrugated Fiberboard) lined with 100-gauge polythene film with 0 %, 5 % and 10 % vents, CFB with 0 %, 5 % and 10 % vents, vacuum packing and a control, under cold storage (13-15 °C) and ambient conditions (26 ± 2 °C). On the 15th day of cold storage conditions, vacuum packing showed minimum physiological loss of weight (19.82 %), titratable acidity (0.68 %), ascorbic acid (77.20) and total sugar (8.36 %). Maximum total soluble solids (15.32 ?Brix), Anthocyanin (22.72 mg 100 g-1 m), shelf life (15 days) followed by CFB with 10 % vent. On the 12th day of ambient storage condition, vacuum packing recorded minimum physiological loss of weight (16.42 %), titratable acidity (0.42 %), ascorbic acid (76.13) and total sugar (8.53 %). Maximum total soluble solids (14.93 ?Brix), Anthocyanin (21.83 mg 100 g-1 m) and shelf life (11.5 days) followed by CFB with 10 % vent. In this study, the overall results indicated that both vacuum packaging and CFB with 10 % vent at cold storage had synergistic effect in manila tamarind fruit pods, not only in extending the shelf life but also maintained the physiological and biochemical attributes of manila tamarind.

Storage of Rabbit Meat in Vacuum Extends the Oxidative Stability of Fat

ABSTRACTMeat quality is a very important factor for both food safety and consumer acceptance, and proper storage of meat can extend the time it stays fresh. This study thus looked at the effects of the atmosphere in which rabbit meat was stored on the oxidative stability of the meat and on its volatile compounds. Not only does the formation of oxidative products adversely affect the human body, but the compounds formed during oxidative changes also typically possess unpleasant aromas, leading to deterioration in the flavor of the meat. Our study analyzed three types of storage atmosphere for rabbit meat: vacuum (VAC), a modified atmosphere (LoOxMAP) composed of 60% CO2, 25% O2, and 15% N2, and an MAP (HiOxMAP) composed of 30% CO2 and 70% O2. The results show that the MAP with 70% oxygen (HiOxMAP) is the least beneficial variant of the three. Rabbit meat packed under HiOxMAP showed the greatest oxidative changes, and volatile compounds providing an unpleasant odor were detected. The fewest changes in meat stored for 21 days occurred in samples stored in VAC.Practical Applications: For the long‐term storage of rabbit meat at refrigerated temperature, it is best to use a vacuum atmosphere to slow down the oxidative changes in the meat fat.

Evaluating serotype-specific survival of Listeria monocytogenes and Listeria innocua on wax-coated Granny Smith apples during storage

Listeria monocytogenes serotypes 1/2a, 1/2b, and 4b are implicated in over 90 % of human listeriosis cases; however, information regarding the serotype-specific survival of L. monocytogenes on apples remains limited. This study evaluated the survival dynamics of these serotypes, using two sets of strains, on Granny Smith apples (GSA) and examined the impact of wax-coating on their survivability during storage. The fate of Listeria innocua on GSA during commercial refrigerated air (RA) storage was also investigated. Results revealed distinct behaviors among L. monocytogenes serotypes. The culturable count of the serotype 4b strain on apples decreased significantly (P < 0.05) by 1.36 log CFU/apple within the first 48 h post-inoculation at ambient temperature. In contrast, counts of serotypes 1/2a and 1/2b strains significantly increased (P < 0.05) by 0.44 and 0.50 log CFU/apple, respectively, during this 48-h attachment period. Over the subsequent 12 weeks of cold storage, serotypes 1/2a and 4b remained stable on GSA, while 1/2b decreased by 1.68 log CFU/apple. Wax coating had a minor impact on L. monocytogenes survival on GSA under both cold and ambient storage conditions, regardless of serotypes. During 18 weeks of commercial RA storage, L. innocua exhibited a gradual decrease of 1.76–1.96 log CFU/apple on wax-coated GSA. Yeasts and molds showed no significant changes in populations due to wax coating, maintaining counts between 5.5 and 5.7 log CFU/apple by the end of the 18-week storage. Additionally, wax coating enhanced quality attributes, significantly preventing (P < 0.05) firmness loss and internal browning compared to unwaxed apples at the conclusion of storage. This study highlights the serotype-specific survival traits of selected L. monocytogenes produce-outbreak isolates on apples, emphasizing the importance of understanding the distinct behaviors of different serotypes.

Sustainable package design for efficient pomegranate cold chain: Enhancing storage space, sea freight efficiency, material sustainability, and energy conservation

This study evaluated the performance of a novel fabricated dual layer ventilated packaging (carton) design for pomegranate fruit. The study argues that higher process throughput, storage space usage (higher cargo density) and packaging material usage can be achieved through systematic design of packaging. The mechanical strength, fruit cooling speeds, and quality preservation characteristics of the new and existing carton designs were evaluated in a controlled laboratory environment. The new carton design achieved 22 % above minimum recommended industry compression strength, confirming its stacking safety during palletization. Fruit packed inside both carton designs attained an average respiration rate of 5.66 ± 1.23 mL CO2 kg−1 h−1 during cold storage. Fruit decay incidence (average 5.5 %), colour changes and sensory attributes were also similar in both carton designs after 12 weeks cold storage and 2 weeks ambient storage period. Finally, fresh pomegranate fruit (cv. Wonderful) were packed in the new and commercial package designs, palletized, containerized and exported from South Africa to Germany. The novel dual layer design had a higher freight density (1720 kg more fruit per reefer) compared to the commercial counterpart. It also improved the precooling process throughput (13 % faster), reduced carton material usage (40 %), and reduced energy usage (13 %). These advantages of the new dual layer ventilated packaging can be implemented with considerable sustainability benefits.

Effect of High CO2 Controlled Atmosphere Storage on Postharvest Quality of Button Mushroom (Agaricus bisporus)

Effect of High CO2 Controlled Atmosphere Storage on Postharvest Quality of Button Mushroom (Agaricus bisporus)

Nodule Associated Plant Probiotics on Seed Quality of Greengram (Vigna radiata L.) under Ambient Storage Condition

Nodule Associated Plant Probiotics on Seed Quality of Greengram (Vigna radiata L.) under Ambient Storage Condition

Drone-based warehouse inventory management of perishables

Warehouse inventory management is a complex process. When inventory includes perishables, the complexity of these processes is compounded with additional requirements such as appropriate ambient storage conditions and placement of one type of perishables (e.g., bananas) far away from another type of perishables (e.g., strawberries). With perishables spending a significant amount of time post-harvest in warehouses, appropriate management of warehouse inventory is necessary to reduce wastage due to spoilage. Drone-based warehouse inventory management is gaining popularity as seen in the increasing number of firms in this space as well as the number of research publications. RFID tags have been widely used for inventory management for more than two decades. While drones have been successfully used in warehouses with non-perishables, RFID and drone use in warehouses with perishables has not witnessed its fair share as evidenced by the lack of publications in this general area. This paper is a step in the direction to address this void in published literature. We consider object-level RFID tags and drones to automate warehouse inventory management of perishables. Results from our analytical model and simulation analysis indicate that such warehouse automation is beneficial to both the warehouse operators and their customers.

Effect of lemongrass and chili pepper oils on the quality of ripe tomato fruits stored under tropical ambient temperature

Postharvest quality of tomato (Solanum lycopersicum L.) fruits treated with lemongrass (Cymbopogon citratus L.) and chili pepper (Capsicum annuum L.) oil was evaluated. Tomato variety Roma fruits of uniform size and weight at the red stage of ripening were overlaid with lemongrass oil only (L1P0), chili pepper oil only (L0P1), or mixtures in a ratio 1:1 (L1P1), and 1:2 (L1P2 and L2P1). Control (L0P0) was not treated with any oil. Treated and untreated fruits were stored at 280±20C and 46%±2 RH for 12 days. Treatments L1P0 and L2P1 oil inhibited postharvest tomato fruit rot for 12 days, whereas L1P2, L0P1, and L1P1 oil and the control showed rot within the range of 86.6% - 100% in 12 days. L1P0 and L2P1 also slowed fruit softening and significantly reduced weight loss, though L1P0 was the most protective. Total soluble solid content of fruit was not affected by both L1P0 and L2P1 throughout storage, but the parameter reduced significantly (p&lt;0.05) in fruits treated with L1P1, L1P2, L0P1 and in control. Reduction in titratable acidity during storage was least in fruits treated with L1P0 followed by L2P1, compared to that in other treatments and the control. This study showed that lemongrass oil applied as surface coating preserved tomato fruit quality in tropical ambient storage conditions for 12 days.

Performance of Small-Scale Hermetic Storage Systems Under Periodic Access

This study characterizes the grain management performance of a novel integrated grain drying and storage system (iGDSS) adapted from 208 L drums to combat postharvest loss in developing countries through providing in situ mechanized drying and hermetic storage. The six-month storage trials of 14% moisture content maize compared different access mechanisms and two levels of pest pressure: 0 and 10 maize weevils/kg grain. This experiment allowed comparisons of differential oxygen consumption rates in small-scale hermetic systems with and without storage pests, which has not been widely reported in the literature. The iGDSS system was found to maintain grain quality parameters in dry grains with and without storage pests. After six months of storage, the results demonstrated no statistically significant difference in the moisture content, test weight, germination, proportion of broken and damaged kernels, and presence of colony-forming units between inoculated and non-inoculated systems. The iGDSS was also found to maintain oxygen intrusion rates of 0.10–0.13% O2/day, below recommended thresholds of 0.15% required to maintain benefits of modified atmosphere storage. These results indicate that the iGDSS can provide safe and reliable grain storage to smallholder farmers in developing countries, and that the drying functions of iGDSS can promote outcomes in hermetic storage.

Exogenous Melatonin as Pre- and Postharvest Application on Quality Attributes, Antioxidant Capacity, and Extension of Shelf Life of Papaya

Papaya is widely grown in tropical and subtropical climates due to its high yield potential and high returns. The vital hormone melatonin, regulating various biological processes in plants, is eco-friendly and less harmful to humans than other chemicals. This study aims to enhance the quality and antioxidant enzyme activities and lessen postharvest senescence in papaya cv. CO 8 fruits during both ambient (32 ± 2 °C and 55 ± 5% RH) and cold storage (10 ± 2 °C and 90–95% RH) as exogenous melatonin (EMT) is applied in varying concentrations. An optimum melatonin dose of 1.5 mM was applied as a pre-harvest spray 15 days before harvest and a postharvest dip proved effective in prolonging shelf life (under ambient it prolonged to day 9 and under cold storage up to 28 days) and delaying ripening and softening. Exogenous melatonin application enhanced antioxidant activity, reduced weight loss, maintained firmness, delayed ripening enzymes, and lowered ethylene and CO2 levels. For instance, control fruits had weight losses between 7.42% and 10.09%, while fruits treated with 1.5 mM melatonin showed 5.74% and 9.06% weight loss under ambient and cold storage, respectively. In conclusion, applying EMT (1.5 mM) could be an economically viable and environmentally benign way to lessen senescence after harvest and preserve the qualities of the papaya fruit during ambient and cold storage.

Bacterial Hybrid Light-Emitting Diodes.

Photon down-converting filters with fluorescent proteins (FPs) are a new frontier in the quest for rare-earth-free and non-toxic color filters for white light-emitting diodes. There are, however, concerns related to the FP purification costs and lack of FP recyclability/reuse. Here, the direct use of bacteria in photon down-converting filters can be of utmost relevance, eliminating purification and allowing in situ production of new FPs. However, their high background autofluorescence/scattering and low stability in polymer coatings have traditionally hampered the application of Engineering Living Materials (ELMs) for photon manipulation. Indeed, there are no examples of ELMs in lighting systems. This work discloses the first protocol to prepare living spheroplasts with > 90% scattering reduction, high FP expression fairly keeping their photoluminescence figures-of-merit, and excellent resilience in polymer films over 1 year under ambient storage. This unlocked the preparation of the first bacteria hybrid light-emitting diodes integrating ELMs for photon conversion. These devices feature similar stabilities to those using purified FPs, while enabling a cost-effective strategy and active FP recycling by the simple recultivation of spheroplasts. Overall, this work introduces a successful case toward bacteria-polymer photon manipulation, in general, and a new living lighting concept, in particular.

Förster Resonance Energy Transfer and Enhanced Emission in Cs4PbBr6 Nanocrystals Encapsulated in Silicon Nano-Sheets for Perovskite Light Emitting Diode Applications.

Encapsulating Cs4PbBr6 quantum dots in silicon nano-sheets not only stabilizes the halide perovskite, but also takes advantage of the nano-sheet for a compatible integration with the traditional silicon semiconductor. Here, we report the preparation of un-passivated Cs4PbBr6 ellipsoidal nanocrystals and pseudo-spherical quantum dots in silicon nano-sheets and their enhanced photoluminescence (PL). For a sample with low concentrations of quantum dots in silicon nano-sheets, the emission from Cs4PbBr6 pseudo-spherical quantum dots is quenched and is dominated with Pb2+ ion/silicene emission, which is very stable during the whole measurement period. For a high concentration of Cs4PbBr6 ellipsoidal nanocrystals in silicon nano-sheets, we have observed Förster resonance energy transfer with up to 87% efficiency through the oscillation of two PL peaks when UV excitation switches between on and off, using recorded video and PL lifetime measurements. In an area of a non-uniform sample containing both ellipsoidal nanocrystals and pseudo-spherical quantum dots, where Pb2+ ion/silicene emissions, broadband emissions from quantum dots, and bandgap edge emissions (515 nm) appear, the 515 nm peak intensity increases five times over 30 min of UV excitation, probably due to a photon recycling effect. This irradiated sample has been stable for one year of ambient storage. Cs4PbBr6 quantum dots encapsulated in silicon nano-sheets can lead to applications of halide perovskite light emitting diodes (PeLEDs) and integration with traditional semiconductor materials.

A-238 Lyophilized Bead Multiplex Assays for CT/NG/TV Detection

Abstract Background Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV) cause the three most prevalent sexually transmitted infectious diseases in developed countries, contributing to approximately 300 million new infections worldwide, annually. Due to the challenges of culturing and using immunoassays to detect these pathogens, DNA-based molecular tests have been instrumental, and current trends in molecular testing for CT/NG/TV have moved toward point-of-care tests. Lyophilization provides benefits required for point-of-care tests, such as ambient storage, extended shelf life, simplified downstream workflow, and variable formats. A lyophilized-bead format enables an assay to be placed in sealed consumables and stored at room temperature for up to two years. An additional consideration is the need for endogenous and exogenous controls. Exogenous in-process controls can be used to validate the performance of workflows culminating in a qPCR reaction and provide flexibility to test developers. An ideal exogenous in-process control is nonhomologous to human or human pathogen genome sequences and does not align with primers or probes designed for pathogen detection. The objective of the current study was to develop a lyophilized-bead-format assay containing an ideal exogenous control and establish whether it is a valid option for the accurate detection of CT, NG, and TV. Methods A synthetic DNA control containing targets for CT/NG/TV/RNase P (RP)/exogenous control was used to establish an analytical LOD by qPCR. The 5-plex assay, lyophilized in beads, was hydrated and tested for linearity over an 8-log range of the synthetic DNA control. Further, the qPCR lyophilized bead with assay was tested with a proficiency sample by extracting DNA from ZeptoMetrix NATtrol CT/NG/TV Positive Control and spiking-in the exogenous DNA control. qPCR was performed on the extracted DNA and human cDNA. Results The analytical LOD for the control DNA was determined to be 5 copies/reaction. Additionally, linearity was observed by qPCR over an 8-log range of the synthetic DNA control for all five targets in multiplex with good efficiencies and R2 values. Finally, all targets were amplified and detected by qPCR using DNA extracted from ZeptoMetrix NATtrol CT/NG/TV Positive Control with spiked-in exogenous DNA control. The detection of the exogenous sequence in the qPCR multiplex reaction indicated the extraction was successful. Conclusions We have developed a multiplex qPCR assay in lyophilized-bead format that can identify infectious agents, such as CT/NG/TV, in a single reaction. We have included RP as a human host control, plus an exogenous in-process control, for a total of 5-plex in separate fluorescent channels. We have shown that our lyophilized beads with assay produce a positive qPCR result when combined with a proficiency sample.

B-208 Room Temperature Stable PCR Reagents Preparation Using Capillary-Mediated Vitrification Process

Abstract Background Polymerase chain reaction (PCR) is a sensitive, and most used molecular technique for the disease diagnosis. Reagents used for PCR is available as a one-step and ready-to-use PCR Master Mix, which contains Taq DNA polymerase, dNTPs, MgC12, PCR reaction buffer. However, to preserve bioactivity, PCR reagents must be stored and distributed as frozen. Desiccation of PCR reagents can avoid cold storage and improper handling of wet reagents and its associated errors. We discovered capillary-mediated vitrification (CMV) processes can stabilize different biomolecules and allow them to be stored at ambient temperature. Here, we hypothesized that the CMV process can preserve and improve PCR reagents thermal stability, which will reduce PCR processing time and improve the testing throughput. Methods The CMV process was performed by mixing PCR Master Mix individual or all reagents such as Taq DNA polymerase or Hot Start Taq DNA polymerase, dNTPs, 16S rRNA primers, MgC12, and PCR reaction buffer with an excipient buffer and adding the mixture to a porous scaffold. The loaded scaffolds were placed into our vitrification chamber and dried for 30 min. After drying, the CMV-stabilized sample was tested or packed in Mylar pouches and were stored at ambient and elevated temperatures for 42 days. On the day of testing, the stabilized samples were eluted with nuclease-free water and E. coli genomic DNA was added, and the 50 uL reaction was tested by conventional PCR. The PCR product was visualized under agarose gel electrophoresis. Results To assess whether the CMV process maintains PCR reagents activity and not interfering with the assay, the individual PCR reagents and as a Master mix are preserved. The CMV stabilized polymerase enzyme, primer, or dNTPs amplified DNA similar to frozen reagents and produced comparable PCR products. Notably, CMV stabilized PCR Master Mix which contains either Taq DNA polymerase or Hot Start Taq DNA polymerase enzyme, dNTPs, primers, MgC12, and reaction buffer yielded intact amplified PCR product, which is comparable to frozen reagents. Likewise, a high intense PCR product was observed in the stabilized PCR Master Mix reagents when stored at room and elevated temperatures for 42 days. Conclusions The study results indicate that the CMV process stabilized and improved the PCR Master Mix reagents activity. The study suggests that the CMV technology has the potential to enable ambient storage and shipping of PCR reagents for molecular diagnostic and other related applications.

Long-term noninvasive cardiac monitoring via Neutralized interfacial design for noise-suppressed near-infrared organic photodetectors

Organic photodetectors (OPDs) are the prime candidates for realizing commercial photoplethysmography (PPG) sensors in the future, although their performance and stability limitations remain as challenges. This study presents a strategy for fabricating high-precision, long-term, sustainable OPDs for non-invasive cardiac monitoring. In this work, the use of appropriate amounts of heterocyclic 1,3-diazoles (solid surfactants) enhances the morphology of PEDOT:PSS films and optimizes its energy level alignment, thus directly reducing the leakage current noise and improving the stability of the OPD. The OPDs with 0.5 wt% heterocyclic 1,3-diazole demonstrate enhanced dark current suppression and detectivity enhancement in the photoconductive and self-powered modes. Improved charge recombination dynamics and optimal resistance ratios lead to better performance of the champion device under low-intensity illumination. The champion device yields a more precise Photoplethysmography (PPG) signal under normal and exercise conditions when using a near-infrared light source, and it maintains a PPG signal intensity of more than 90 % after 315 days (7560 h) of storage in a nitrogen atmosphere. Optimized PPG sensors based on flexible substrates maintain signal intensity after seven days of air storage. The low hysteresis behavior also verifies that the optimized device has higher driving stability. High-reliability, high-validity accelerated photoplethysmography (APG) demonstrated that the champion PPG sensor would be used for accurate cardiovascular diagnostics, even over an extended period.

Assessing the development of internal disorders in pome fruit with X-ray CT before, during and after controlled atmosphere storage and shelf life

Assessing the development of internal disorders in pome fruit with X-ray CT before, during and after controlled atmosphere storage and shelf life

Effect of pre-harvest application of potassium nitrate, naphthalene acetic acid and ethephon on ripening and shelf-life of guava cv. Allahabad Safeda

The current study, effect of pre-harvest application of potassium nitrate (KNO3), naphthalene acetic acid (NAA) and ethephon on ripening and shelf-life of guava (Psidium guajava L.) cv. Allahabad Safeda was undertaken at the Fruit Research Farm, Dr B R S Agri at Sri Muktsar Sahib, Punjab. The experiment was carried out on an eight-year-old guava tree of the Allahabad Safeda. The trees were sprayed with various doses of chemicals, KNO3 (1.0, 1.5, 2.0%), NAA (200, 300, 400 ppm) and ethephon (200, 400, 600 ppm) during the third week of November. The fruits were harvested at the hard ripe stage on 19 December, placed in Corrugated fibre box (CFB) of 4 kg capacity and stored at ambient temperature. In ambient storage, guava fruits were remain acceptable for up to 6 days of storage without any adverse effect on fruit quality. KNO3 (1.5 and 2.0%), NAA (300 ppm) and ethephon (200 ppm) recorded a reduction in physiological loss of weight and spoilage and KNO3 (2.0%) maintaining fruit firmness (7.64 kg/cm2), palatability rating (8.00) throughout the storage period. However, the highest storage life and good-quality fruits was recorded with the application of KNO3 (1.5, 2%) during ambient storage. At lower concentrations, ethephon also helps to enhance the ripening of fruits, contrast to this fruits treated with NAA delayed the fruit senescense.