Optimal Dilution Research Articles

Illumination optimization strategies to enhance hydrogen productivity and light conversion efficiency for photo-fermentation by Rhodobacter sphaeroides KKU-PS1 using a concentrated multi-substrate feedstock

With the use of biotechnology, hydrogen can be produced from wastewater rich in short-chain fatty acids. A previous study revealed the ability of Rhodobacter sphaeroides KKU-PS1 to produce biohydrogen from substrates mimicking succinate fermentation effluent. However, the process still requires optimization. Before illumination optimization, due to high concentration of the effluent, various effluent dilution factors ranging from 10 to 100 were compared, and the optimal dilution factor was determined to be 50. Light-emitting diode (LED) setups consisting of bands and tubes were compared, and various illuminated surface-to-volume ratios (S/V) were obtained. LED tubes were subsequently used for light intensity optimization in the range of 5–23 klux, revealing optimum light intensity at 15 klux, yielding 2202 mL H2/L and 13.8 mL H2/L/h as the cumulative hydrogen and maximum output rate, respectively. The lighting protocol at 15 klux and with a 6h–6h light-dark cycle improved the total light conversion efficiency by up to 3.1%. The study successfully optimized the process, with results rivalling those of a previous study using malate.

Tubular photobioreactor design based on mixing intensity

A novel design methodology for tubular photobioreactors (TPBRs) for the mass culture of microalgae that can account for mixing intensity is presented. To date, TPBRs have been mainly designed and operated under the assumption of perfect mixing with regard to photosynthesis performance (light integration regime). In this work we show that this simplification has been leads to significant errors in the prediction of the optimal dilution rate and biomass productivity. To this end, computational fluid dynamics and light distribution model have been employed to calculate the trajectories and light histories I(t) of a microalgal cell population represented by 50 particles of 5 μm diameter. The density of the microalgal cells was set at 1000 kg m−3 and the tube diameters (D) were 14, 24, 44, 64 and 84 mm, with the circulation velocities (v) ranging from 0.4 to 1 m s-1. This has been coupled to a dynamic photosynthesis model in order to calculate the average photosynthetic response and hence the integration factors in TPBRs. It has been demonstrated that for a generic microalgal strain, the use of the light integration simplification (Γ = 1) would result in the prediction of an optimal dilution rate of 0.0315 h−1 (for D = 14 mm and v = 0.4 m/s as an example), which would lead to an actual biomass productivity of 182.5 g biomass m−3h−1 if the predicted integration factor (Γ = 0.578) is used whereas the newly proposed method predicts an optimal dilution rate of 0.0125 h−1 and a biomass productivity of 362.3 g biomass m−3h−1. This demonstrates that simplifying the light integration regime is inadequate for TPBRs design and operation, resulting in significant inaccuracies. The estimation charts and regressions proposed in this work to estimate actual integration factors will enable the development of an optimization method for TPBRs based on mixing intensity.

A study on the performance of super duplex stainless steel cladding over mild steel using a CMT welding

Low carbon steels can be cladded with super-duplex stainless steels to enhance the surface’s mechanical and wear properties. The current study examines the impact of process parameters on weld bead geometry and dilution % during cold metal transfer (CMT) cladding of super duplex stainless steel 2507 over low carbon steel. Response Surface Methodology (RSM) with a Central Composite Design matrix was used to optimize the process parameters (welding current, welding speed, and nozzle to workpiece distance (NTD)). The adequacy of the model was checked using an ANOVA analysis. The optimal bead width, height, penetration, and dilution values were 8.05 mm, 4.52 mm, 1.56 mm and 14.64%, respectively. The ideal input parameters were 200 A of welding current, 4.64 mm/s of welding speed, and 14 mm of NTD. The welding speed is the most dominant parameter, followed by the welding current and NTD. The cladding samples were prepared from the optimal parameters. The CMT-clad layer’s microstructure, microhardness, and wear properties were also evaluated. The results indicate a dense crack-free and non-porous clad surface was obtained under optimal conditions.

First dose optimization study on freezing Anatolian buffalo semen

The main objective of sperm production centers is to produce as many straws as possible from the obtained ejaculates using the optimal dilution rate. To this end, this study is the first to evaluate the effect of different semen extender rates on Anatolian buffalo semen quality. Ejaculates were collected by artificial vagina from three Anatolian buffalo bulls. These ejaculates were divided into three aliquots and filled into 0.25 ml straws with soy-based extenders at concentrations of 35, 25, and 15 million sperm/straw (n=105). The straw samples of different sperm concentrations were frozen. The quality of sperm was evaluated after thawing (37 °C, 30 sec) and following the thermoresistance test (37 °C, 3 h). The post-thaw total motility and progressive motility values were similar between the groups. However, following the thermoresistance test, there was a significant decrease in total motility in the 35 million sperm/straw group, and the progressive motility was significantly higher in the 25 million sperm/straw group. There was no statistically significant difference between the groups in terms of sperm kinetic parameters, except for VSL after thawing, as well as VAP and LIN values following the thermoresistance test. The overall mean PMAI and STR values were the highest in the 25 million sperm/straw group. In conclusion, it is recommended to dilute the Anatolian buffalo semen at a concentration of 25 million/0.25 ml when freezing it with a soy-based semen extender. In addition, it is considered that soy-based extenders compensate for cryo-damage to sperm motility for a short time, and the thermoresistance test should be applied for objective evaluation in dose optimization studies.

Probing properties of green surfactant-based formulation by combining scattering and rheology: The case study of cocoyl methyl glucamide

Green surfactants, categorized as biobased and biosurfactants, pose formulation challenges due to their compositional variability and biodegradability. Our work addresses these challenges in formulating a hard surface cleaning spray. We utilize glucamide surfactants with a high renewable carbon index (RCI=95 %), incorporating limonene as both solvent and perfume. Additionally, the concept of formulating a concentrated "juice" is explored. A partial phase diagram guides our formulations, and rheology and small angle X-ray scattering (SAXS) pinpoint the optimal dilution line. Our concentrated formula exhibits liquid crystalline phases, offering potential applications in gel-like tablets. Performance evaluations against a market product reveal mixed results, indicating the need for further optimization. The study emphasizes a formulation minimalism approach, aligning with modern trends. It showcases the potential of green surfactants, providing insights into their behavior under varying concentrations and paving the way for environmentally friendly cleaning solutions.

Sustainable menaquinone-7 production through continuous fermentation in biofilm bioreactors.

Menaquinone-7 (MK-7), a vital vitamin with numerous health benefits, is synthesized and secreted extracellularly by the formation of biofilm, dominantly in Bacillus strains. Our team developed an innovative biofilm reactor utilizing Bacillus subtilis natto cells to foster biofilm growth on plastic composite supports to produce MK-7. Continuous fermentation in biofilm reactors offers a promising strategy for achieving sustainable and efficient production of Menaquinone-7 (MK-7). Unlike conventional batch fermentation, continuous biofilm reactors maintain a steady state of operation, which reduces resource consumption and waste generation, contributing to sustainability. By optimizing fermentation conditions, MK-7 production was significantly enhanced in this study, demonstrating the potential for sustainable industrial-scale production. To determine the optimal operational parameters, various dilution rates were tested. These rates were selected based on their potential to enhance nutrient supply and biofilm stability, thereby improving MK-7 production. By carefully considering the fermentation conditions and systematically varying the dilution rates, MK-7 production was significantly enhanced during continuous fermentation. The MK-7 productivity was found to increase from 0.12mg/L/h to 0.33mg/L/h with a dilution rate increment from 0.007 to 0.042h-1). This range was chosen to explore the impact of various nutrient supply rates on MK-7 production and to identify the optimal conditions for maximizing productivity. However, a further increase in the dilution rate to 0.084h-1 led to reduced productivity at approximately 0.16mg/L/h, likely due to insufficient retention time for effective biofilm formation. Consequently, a dilution rate of 0.042h-1 exhibited the highest productivity of 0.33mg/L/h, outperforming all investigated dilution rates and demonstrating the critical balance between nutrient supply and retention time in continuous fermentation. These findings validate the feasibility of operating continuous fermentation at a 0.084h-1 dilution rate, corresponding to a 48h retention time, to achieve the highest MK-7 productivity compared to conventional batch fermentation. The significant advancements achieved in enhancing Menaquinone-7 (MK-7) productivity through continuous fermentation at optimal dilution rates in the present work indicate promising prospects for even greater efficiency and sustainability in MK-7 production through future developments.

Seroprevalence and Endemic Status of Babesia ovis by Enzyme-Linked Immunosorbent Assay in East Azerbaijan Province, North-West of Iran.

Babesia ovis, an intraerythrocytic parasite carried by ticks and one of the most common subclinical ovine illnesses, was studied to ascertain its seroprevalence and endemic status in ram and ewe populations in East Azerbaijan Province, Iran, in lambs, yearlings, and adults of over two years of age. A total of 960 sheep from 10 cities were selected from Jan 2018 to Nov 2019. Blood samples were collected from each animal and tested for the presence of B. ovis antibodies by applying a developed enzyme-linked immunosorbent assay (ELISA) technique. Checkerboard titrations were used to determine the optimal dilution of the antigen using negative and positive control sera. To determine whether the disease is endemically stable, inoculation rates for each age group were also calculated. Correlation coefficients were calculated between age and infection rates and also between age and inoculation rates. The results revealed an average infection rate of 49.4% in East Azerbaijan Province. There was a positive correlation between the age of animals and susceptibility to infection except for lambs and yearlings, whereas there was no meaningful difference in exposure to B. ovis between rams and ewes. The negative correlation between age and inoculation rates indicates increased disease instability with age. Inoculation rate results revealed the endemically instable status of B. ovis in the studied area. High prevalence rates and endemically instable status of the disease suggest demand for vaccine development and implementation of appropriate control measures for ovine babesiosis to mitigate the associated economic losses.

Mathematical Model-Based Optimization of Continuous Flow Photobioreactor Operating at Steady State Using MATLAB Optimization Function

AbstractMicroalgae have received great attention recently due to its potential for sustainable CO2 emission reduction and production of biofuel. These applications are highly dependent on microalgae biomass productivity of photobioreactor (PBR). The objective of this work is to optimize continuous flow PBR at steady state using a mathematical model describes growth of the microalgae species Chlorella vulgaris. The operating conditions that affect the performance of PBR are determined as pH, CO2 percentage in the gas feed, light intensity, and dilution rate. The MATLAB optimization function (fmincon) is used to find the best design and operating variables in the tested region. The maximum biomass productivity is achieved at the upper-bound of the range for pH, CO2 percentage in the gas feed, and light intensity, while for dilution rate, there exists an optimum value that guarantees maximum productivity. The maximum biomass productivity and specific growth rate were estimated as 4.03 and 0.196 billion cells/L h, respectively. This is achieved at optimum dilution rates of 0.049 and 1.0 h−1, respectively. The fmincon optimization results agree well with the literature that used different optimization methods. The model-based optimization predicts the best performance of PBR without conducting experiments. Sensitivity analysis of model constants on biomass concentration showed that mass transfer coefficient KLa has the highest sensitivity followed by µmax, KCL, and KE which has the lowest sensitivity for biomass production. The obtained results are of technological significance for processes such as CO2-fixation and biofuel production. Research effort is needed to exploit optimization results in large-scale cultivation.

A Single-Step Method for Harvesting Influenza Viral Particles from MDCK Cell Culture Supernatant with High Yield and Effective Impurity Removal

Influenza vaccines, which are recommended by the World Health Organization (WHO), are the most effective preventive measure against influenza virus infection. Madin–Darby canine kidney (MDCK) cell culture is an emerging technology used to produce influenza vaccines. One challenge when purifying influenza vaccines using this cell culture system is to efficiently remove impurities, especially host cell double-stranded DNA (dsDNA) and host cell proteins (HCPs), for safety assurance. In this study, we optimized ion-exchange chromatography methods to harvest influenza viruses from an MDCK cell culture broth, the first step in influenza vaccine purification. Bind/elute was chosen as the mode of operation for simplicity. The anion-exchange Q chromatography method was able to efficiently remove dsDNA and HCPs, but the recovery rate for influenza viruses was low. However, the cation-exchange SP process was able to simultaneously achieve high dsDNA and HCP removal and high influenza virus recovery. For the SP process to work, the clarified cell culture broth needed to be diluted to reduce its ionic strength, and the optimal dilution rate was determined to be 1:2 with purified water. The SP process yielded a virus recovery rate exceeding 90%, as measured using a hemagglutination units (HAUs) assay, with removal efficiencies over 97% for HCPs and over 99% for dsDNA. Furthermore, the general applicability of the SP chromatography method was demonstrated with seven strains of influenza viruses recommended for seasonal influenza vaccine production, including H1N1, H3N2, B (Victoria), and B (Yamagata) strains, indicating that the SP process could be utilized as a platform process. The SP process developed in this study showed four advantages: (1) simple operation, (2) a high recovery rate for influenza viruses, (3) a high removal rate for major impurities, and (4) general applicability.

Study on the Short-Term Preservation of Gametes, Cross-Stimulation of Oocytes by Distant Sperm, and the Impact of Cold-Stimulated Fertilized Eggs on Eyes in the Celestial Goldfish

This study layed the groundwork for the creation of haploid and triploid celestial goldfish, presenting essential data derived from preliminary investigations. The research delved into three main areas: the short-term preservation of celestial goldfish gametes, the interaction between oocytes and foreign sperm, and the effects of temperature on fertilized eggs concerning hatching rates and late-stage ocular development. Initially, the study explored the optimal semen dilution ratio for celestial goldfish under microscopic examination. And the hybridization of the largemouth bass and celestial goldfish was investigated: largemouth bass sperm was crossbred with celestial goldfish eggs, and it was found that their sperm could not stimulate the development of celestial eye eggs. At last, celestial goldfish fertilized eggs were stimulated at 4 °C and −20 °C, respectively, to observe their impact on the hatching rate and later celestial eye rate. The results revealed no significant differences in hatching rate and celestial eye rate between the cold stimulus groups and the control group, but numerically, the 4 °C cold stimulation reduced the celestial eye rate of celestial goldfish fertilized eggs. The research provided fundamental data for artificial breeding and hybridization experiments in celestial goldfish.

Population growth of two limno-terrestrial Antarctic microinvertebrates in different aqueous soil media

Terrestrial microinvertebrates provide important carbon and nutrient cycling roles in soil environments, particularly in Antarctica where larger macroinvertebrates are absent. The environmental preferences and ecology of rotifers and tardigrades in terrestrial environments, including in Antarctica, are not as well understood as their temperate aquatic counterparts. Developing laboratory cultures is critical to provide adequate numbers of individuals for controlled laboratory experimentation. In this study, we explore aspects of optimising laboratory culturing for two terrestrially sourced Antarctic microinvertebrates, a rotifer (Habrotrocha sp.) and a tardigrade (Acutuncus antarcticus). We tested a soil elutriate and a balanced salt solution (BSS) to determine their suitability as culturing media. Substantial population growth of rotifers and tardigrades was observed in both media, with mean rotifer population size increasing from 5 to 448 ± 95 (soil elutriate) and 274 ± 78 (BSS) individuals over 60 days and mean tardigrade population size increasing from 5 to 187 ± 65 (soil elutriate) and 138 ± 37 (BSS) over 160 days. We also tested for optimal dilution of soil elutriate in rotifer cultures, with 20–80% dilutions producing the largest population growth with the least variation in the 40% dilution after 36 days. Culturing methods developed in this study are recommended for use with Antarctica microinvertebrates and may be suitable for similar limno-terrestrial microinvertebrates from other regions.

Development and application of a blocking ELISA based on a N protein monoclonal antibody for the antibody detection against porcine reproductive and respiratory syndrome virus 2

Porcine reproductive and respiratory syndrome (PRRS) is one of the most widespread illnesses in the world's swine business. To detect the antibodies against PRRSV-2, a blocking enzyme-linked immunosorbent assay (B-ELISA) was developed, utilizing a PRRSV-2 N protein monoclonal antibody as the detection antibody. A checkerboard titration test was used to determine the optimal detection antibody dilution, tested pig serum dilution and purified PRRSV coated antigen concentration. After analyzing 174 negative pig sera and 451 positive pig sera, a cutoff value of 40 % was selected to distinguish between positive and negative sera using receiver operating characteristic curve analysis. The specificity and sensitivity of the assay were evaluated to equal 99.8 % and 96 %, respectively. The method had no cross-reaction with PCV2, PRV, PPV, CSFV, PEDV, TGEV, and PRRSV-1 serum antibodies, and the coefficients of variation of intra-batch and inter-batch repeatability experiments were both <10 %. A total of 215 clinical serum samples were tested, and the relative coincidence rate with commercial ELISA kit was 99.06 %, and the kappa value was 0.989, indicating that these two detection results exhibited high consistency. Overall, the B-ELISA should serve as an ideal method for large-scale serological investigation of PRRSV-2 antibodies in domestic pigs.

Blood Flow in the Meniscus Can Be Visualized Arthroscopically Using an Intravenous Indocyanine Green Solution Diluted 10× in a Pig Model

PurposeThis study mainly aimed to determine the optimal indocyanine green (ICG) dose required for assessing vascularity in the meniscus using ICG fluorescence-guided knee arthroscopy in a pig model. MethodsA 3-month-old esculent Japanese female pig was used in this study. Intravenous injections of ICG (25 mg) were administered with 2.0 mL of 5×; 10×; 100×; and 1,000× diluted solutions. An additional experiment was conducted to assess the microvasculature within the meniscus considering the results of the optimal dilution setting. A radial tear was purposely induced in the middle-to-posterior section of the medial meniscus to observe vascularity in the cross-sectioned meniscus; the optimal ICG dilution was administered. ResultsNo fluorescence was detected in the meniscus with solutions diluted by 1,000× and 100×. Fluorescence was visualized at the anterior portion of the synovium and the anterior cruciate ligament using ICG diluted by 10×. Diluting ICG by 5×, contrast enhancement was too intense for observation. Therefore, the 10× diluted solution was considered the optimal setting for knee arthroscopy and observation of the radial tear. No fluorescence was observed in the cross-section of the medial meniscus. Arterial hemorrhage was observed by stimulating the fluorescence-dyed synovium adjacent to the tear site. Through the additional waiting time after stimulating the tear site, the hemorrhage inside the meniscus became more intense. ConclusionsThe optimal dilution and dose setting of ICG for knee arthroscopy was 10× in a 2.0-mL intravenous injection. The meniscus showed no active blood flow, even in the red-red zone. This finding might support the notion that blood flow cannot be initiated, without synovial stimulation, even in vascular areas. Clinical RelevanceThis study could determine an ICG solution suitable for ICG fluorescence-guided knee arthroscopy. This finding could be valuable in future research focusing on case-specific meniscal vascularization under arthroscopy, particularly, applying these findings to human meniscus treatment.

Effects of dilution and pretreatment on nutrient removal and biomass production of Chlorella vulgaris in kitchen wastewater

This research investigated the effect of kitchen wastewater (KWW) concentrations and pretreatment methods on Chlorella vulgaris biomass production, lipid content and nutrient removal. This study was divided into two separate experiments. The first experiment determined the appropriate dilution rate of KWW for the growth of microalgae, sterilized KWW was varied between 25%, 50%, 75%, and 100%(v/v). The result indicated that 50%(v/v) showed the highest nutrient removal by 90.23%, 85.87%, and 80.64% of sCOD, TKN, and TP, respectively. The highest biomass and lipid content were obtained with 50%(v/v) (1.447 g/L, 37.9%). The second experiment was to find an effective physical pretreatment method, which separated the biotic contaminant, non-sterilized KWW was diluted 50%(v/v) and filtered with different mesh size filters (150 μm, 50 μm, and 30 μm) compared with sterilized KWW as a control sample. The result indicated that pretreatment with 50 μm filtration was found highest nutrient removal by 90.51%, 84.74%, and 77.50% of sCOD, TKN, and TP, respectively. The highest biomass and lipid content were obtained with 50 μm filtration (1.496 g/L, 39.4%). Our results support the hypothesis that the optimal dilution and proper filtration of KWW helps create more favorable environment for microalgal growth.

A dot-blot ELISA preliminary evaluation using PvMSP1-42 recombinant protein as antigen for serological diagnosis of Plasmodium vivax infection in Thailand.

Plasmodium vivax is the most prevalent cause of malaria in Thailand and is predominant in malarial endemic areas worldwide. P. vivax infection is characterized by low parasitemia, latent liver-stage parasites, or asymptomatic infections leading to underreported P. vivax cases. These are significant challenges for controlling and eliminating P. vivax from endemic countries. This study developed and evaluated a dot-blot enzyme-linked immunosorbent assay (ELISA) using PvMSP1-42 recombinant antigen for serological diagnosis based on the detection of antibodies against P. vivax. The optimal PvMSP1-42 concentration and dilutions of anti-human IgG horseradish peroxidase (HRP)-conjugated antiserum were tested on 88 serum samples from P. vivax, Plasmodium falciparum and bacterial infection, including healthy individuals. A cut-off titer of 1:800 produced optimal values for sensitivity and specificity of 90.9 and 98.2%, respectively, with an accuracy of 95.5%. The positive and negative predictive values were 96.8 and 94.7% respectively. The results from microscopic examination and dot-blot ELISA showed strong agreement with the 0.902 kappa index. Thus, the dot-blot ELISA using PvMSP1-42 antigen provided high sensitivity and specificity suitable for serodiagnosis of P. vivax infection. The test is a simple and quick diagnostic assay suitable for field testing as it does not require specific equipment or particular skills.

Detection of CD40 Protein-Umbelliferone Interaction via Differential Scanning Fluorescence.

The investigation of interactions between different molecules is a crucial aspect of understanding disease pathogenesis and screening for drug targets. Umbelliferone, an active ingredient in Tibetan medicine Vicatia thibetica, exhibits an immunomodulatory effect with an unknown mechanism. The CD40 protein is a key target in the immune response. Therefore, this study employs the principle of differential scanning fluorescence technology to analyze the interactions between CD40 protein and umbelliferone using fluorescent enzyme markers. Initially, the stability of the protein fluorescent orange dye was experimentally verified, and the optimal dilution ratio of 1:500 was determined. Subsequently, it was observed that the temperature melting (Tm) value of CD40 protein tended to decrease with an increase in concentration. Interestingly, the interaction between CD40 protein and umbelliferone was found to enhance the thermal stability of CD40 protein. This study represents the first attempt to detect the binding potential of small molecule compounds and proteins using fluorescence microplates and fluorescent dyes. The technique is characterized by high sensitivity and accuracy, promising advancements in the fields of protein stability, protein structure, and protein-ligand interactions, thus facilitating further research and exploration.

Immunoinformatics-guided recombinant polypeptide-based enzyme-linked immunosorbent assay for seromonitoring of laboratory animals for minute virus of mice and Kilham rat virus.

Subclinical infection of laboratory animals with one or more of several pathogens affects the results of experiments on animals. Monitoring the health of laboratory animals encompasses routine surveillance for pathogens, including several viruses. This study aimed to explore the development of an alternative assay to the existing ones for detecting infection of mice and rats with the parvoviruses minute virus of mice (MVM) and Kilham rat virus (KRV), respectively. Full-length VP2 and NS1 proteins of these parvoviruses, besides fragments containing multiple predicted epitopes stitched together, were studied for serological detection. The optimal dilution of full-length proteins and antigenic regions containing predicted epitopes for coating, test sera, and conjugate was determined using a checkerboard titration at each step. The assays were evaluated vis-à-vis commercially available ELISA kits. The results showed that an engineered fusion of fragments containing multiple predicted MVM VP2 and NS1 epitopes was better than either of the full-length proteins for detecting antibodies in 90% of the tested sera samples. For KRV ELISA, full-length VP2 was better compared to other individual recombinant protein fragments or combinations thereof for the detection of antibodies in sera. This report is the first description of an ELISA for KRV and an improved assay for MVM. Importantly, our assays could be exploited with small volumes of sera. The results also demonstrate the utility of immunoinformatics-driven polypeptide engineering in the development of diagnostic assays and the potential to develop better tests for monitoring the health status of laboratory animals.

Scaling-Up of Solution-Processable Tungsten Trioxide (WO3) Nanoparticles as a Hole Transport Layer in Inverted Organic Photovoltaics

We reported the comparative studies of the optimization of solution-processable tungsten trioxide (WO3) as a hole transporting layer (HTL) in inverted organic photovoltaics (OPVs) using spin coating, slot-die coating, and spray coating technologies for scaling-up applications. To facilitate the technology’s transition into commercial manufacturing, it is necessary to explore the role of scalable technologies for low-cost and efficient device fabrication. We investigated the role of diluting WO3 with isopropanol as an HTL in inverted OPVs to solve the issue of poor wettability of the hydrophobic surface of the PBDB-T: ITIC bulk heterojunction layer. The optimal dilution ratios of WO3 with isopropanol were 1:4, 1:4 and 1:8 with spin coating, slot-die coating and spray coating techniques, respectively. We evaluated the device performance by conducting a current density–voltage (J-V) analysis, incident photon-to-current conversion efficiency (IPCE) measurements, and ultraviolet–visible (UV-Vis) absorbance spectra for various WO3 concentrations. The J-V characteristics revealed that slot-die coating resulted in the highest performance, followed by the spray coating technology. We further investigated the impact of the annealing temperature on device performance for both slot-die- and spray-coated diluted WO3. The highest device performance was achieved at an annealing temperature of 120 °C for both coating technologies. This research offers valuable insights into the scalable fabrication of inverted OPV devices, paving the way for cost-effective and efficient large-scale production.

Development and application of an indirect ELISA and nested PCR for the epidemiological analysis of Klebsiella pneumoniae among pigs in China.

Klebsiella pneumoniae (K. pneumoniae) is an important opportunistic and zoonotic pathogen which is associated with many diseases in humans and animals. However, the pathogenicity of K. pneumoniae has been neglected and the prevalence of K. pneumoniae is poorly studied due to the lack of rapid and sensitive diagnosis techniques. In this study, we infected mice and pigs with K. pneumoniae strain from a human patient. An indirect ELISA was established using the KHE protein as the coating protein for the detection of K. pneumoniae specific antibody in clinical samples. A nested PCR method to detect nuclei acids of K. pneumoniae was also developed. We showed that infection with K. pneumoniae strain from a human patient led to mild lung injury of pigs. For the ELISA, the optimal coating concentration of KHE protein was 10 µg/mL. The optimal dilutions of serum samples and secondary antibody were 1:100 and 1:2500, respectively. The analytical sensitivity was 1:800, with no cross-reaction between the coated antigen and porcine serum positive for antibodies against other bacteria. The intra-assay and inter-assay reproducibility coefficients of variation are less than 10%. Detection of 920 clinical porcine serum samples revealed a high K. pneumoniae infection rate by established indirect ELISA (27.28%) and nested PCR (19.13%). Moreover, correlation analysis demonstrated infection rate is positively correlated with gross population, Gross Domestic Product (GDP), and domestic tourists. In conclusion, K. pneumoniae is highly prevalent among pigs in China. Our study highlights the role of K. pneumoniae in pig health, which provides a reference for the prevention and control of diseases associated with K. pneumoniae.

Dissimilar welding of Cu55Ni45 alloy with Ti-6Al-4V and 316L using a continuous 1030 nm Yb:YAG laser

The welding of Cu55Ni45 alloy to titanium and stainless steel has not been reported in the scientific literature, which motivated us to perform the present weldability study of Cu55Ni45/Ti-6Al-4V and Cu55Ni45/316L combinations using a continuous Yb:YAG laser with 1030 nm wavelength. Different laser spot offsets from the joint line were tested in search of optimal dilutions. Microstructure and mechanical properties of the joints were investigated.The Cu55Ni45/Ti-6Al-4V melted zones exhibited elevated hardness due to the formation of intermetallic phases, but contained no microcracks. The highest UTS of 250 MPa was reached for the lowest titanium dilution that resulted in average melted zone hardness of ~400 HV. On the other hand, Cu55Ni45/316L melted zones exhibited a hardness similar to those of base materials for all dilutions. All Cu55Ni45/316L joints demonstrated a ductile behavior during the tensile test, with average UTS values of 446 MPa, and fractured in solid Cu55Ni45 insert.