mL Of Volume Research Articles

Remote Measurements of Tear Electrolyte Concentrations on Both Sides of an Inserted Contact Lens.

In this paper, a method is described to perform ion concentration measurements on both sides of an inserted contact lens, without physical contact with the eye or the contact lens. The outer surface of an eye is covered with a tear film that has multiple layers. The central aqueous layer contains electrolytes and proteins. When a contact lens is inserted, it becomes localized in the central layer, which creates two layers known as the pre-lens tear film (PLTF) and the post-lens tear film (PoLTF). The PoLTF is in direct contact with the sensitive corneal epithelial cells which control electrolyte concentrations in tears. It is difficult to measure the overall electrolyte concentration in tears because of the small 7 μL volume of bulk tears. No methods are known, and no method has been proposed, to selectively measure the concentrations of electrolytes in the smaller volumes of the PLTF and the PoLTF. In this paper, we demonstrate the ability to localize fluorophores on each side of a contact lens without probe mixing or diffusion across the lens. We measured the concentration of sodium in the region of the PoLTF using a sodium-sensitive fluorophore positioned on the inner surface of a contact lens. The fluorescence measurements do not require physical contact and are mostly independent of eye motion and fluorophore concentration. The method is generic and can be combined with ion-sensitive fluorophores for the other electrolytes in tears. Instrumentation for non-contact measurements is likely to be inexpensive with modern opto-electronic devices. We expect these lenses to be used for measurements of other ions in the PLTF and the PoLTF, and thus become useful for both research and in the diagnosis of infections, keratitis and biomarkers for diseases.

Conceptualisation of a novel electromechanical system for small-volume needle-free jet injection

Needle-free jet injectors are minimally invasive drug delivery systems that utilise high-velocity microjets (∼100 m/s) created by pressurising the liquid drug through a micronozzle (50–300 µm in diameter). Most of the current commercially available jet injectors use a mechanical power possessed by a compressed spring or air to pressurise the fluid inside the injection chamber to deliver the liquid drug (typically ∼100 µL in volume) into the skin matrix. However, they cannot be utilised for achieving shallow penetration depths as they lack dynamic control that can shape the real-time microjet characteristics. Recently, electrically or optically powered jet injection systems are being developed to achieve shallow penetration depth by small-volume (<5 μL) injections. However, they require complex system and have a limited injection frequency (maximum reported value is 16 Hz). Herein, we propose a novel electro-mechanical jet injection system, where a mechanically actuated source pressurises the fluid inside the injection chamber and an electrically actuated system controls the characteristics of the propelled microjet. A computational model was developed to prove the feasibility of the proposed system, and the obtained results showed that the proposed system could produce stable small-volume microjets at about 100 Hz frequency that could be utilised for drug delivery applications.

From "wet" matrices to "dry" blood spot sampling strategy: a versatile LC-MS/MS assay for simultaneous monitoring caffeine and its three primary metabolites in preterm infants.

To update traditional "wet" matrices to dried blood spot (DBS) sampling, based on the liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) technique, and develop a method for simultaneous analyzing caffeine and its three primary metabolites (theobromine, paraxanthine, and theophylline), supporting routine therapeutic drug monitoring (TDM) for preterm infants. DBS samples were prepared by a two-step quantitative sampling method, i.e.,volumetric sampling of a quantitative 10 μL volume of peripheral blood and an 8 mm diameter whole punch extraction by a methanol/water (80/20, v/v) mixture containing 125 mM formic acid. Four paired stable isotope labeled internal standards and a collision energy defect strategy were applied for the method optimization. The method was fully validated following international guidelines and industrial recommendations on DBS analysis. Cross validation with previously developed plasma method was also proceeded. The validated method was then implemented on the TDM for preterm infants. The two-step quantitative sampling strategy and ahigh recovery extraction method were developed and optimized. The method validation results were all within the acceptable criteria. Satisfactory parallelism, concordance, and correlation were observed between DBS and plasma concentrations of the four analytes. The method was applied to provide routine TDM services to 20 preterm infants. A versatile LC-MS/MS platform for simultaneous monitoring caffeine and its three primary metabolites was developed, fully validated, and successfully applied into the routine clinical TDM practices. Sampling method switching from "wet" matrices to "dry" DBS will facilitate and support the precision dosing of caffeine for preterm infants.

Comparison of microwave alone and combined with ethanol ablation for different types of benign mixed thyroid nodules.

To evaluate the efficacy and safety of microwave ablation (MWA) plus ethanol ablation (EA) for different types of benign mixed thyroid nodules. A total of 81 patients with 81 benign mixed thyroid nodules were enrolled into the study; 39 were divided to the MWA group and 42 to the combined group (MWA combined with EA). Nodule ablation rate, volume reduction rate (VRR) and surgical complications of all patients were analyzed before and after treatment. The mean ablation rate were 86.49 ± 6.68% and 90.09 ± 5.79% in the microwave and combined groups respectively, and the ablation rate of nodule decreased as the nodule volume increased. For nodules ≥15 ml in volume, the mean ablation rate of the combined group was higher than that of the microwave group (all P < 0.05). The mean VRR at 12 months postoperatively was 89.58 ± 4.32% in the microwave group and 92.92 ± 3.49% in the combined group, showing statistical significantly different between both arms (P = 0.001). The combined group decreased in volume more significantly than the microwave group for nodules with 20-50% or 50-80% cystic proportions or >15 ml in volume (all P < 0.05). The complication rate was 23.08% and 2.38% respectively. MWA combined with EA is more effective than MWA for treating mixed thyroid nodules. MWA combined with EA may be the first approach for nodules with >20% cystic proportions or volume >15 ml.

Inter-user Comparison for Quantification of Superparamagnetic Iron Oxides with Magnetic Particle Imaging Across Two Institutions Highlights a Need for Standardized Approaches.

Magnetic particle imaging (MPI) is being explored in biological contexts that require accurate and reproducible quantification of superparamagnetic iron oxide nanoparticles (SPIONs). While many groups have focused on improving imager and SPION design to improve resolution and sensitivity, a few have focused on improving quantification and reproducibility of MPI. The aim of this study was to compare MPI quantification results by two different systems and the accuracy of SPION quantification performed by multiple users at two institutions. Six users (3 from each institute) imaged a known amount of Vivotrax + (10μg Fe), diluted in a small (10 μL) or large (500 μL) volume. These samples were imaged with or without calibration standards in the field of view, to create a total of 72 images (6 users × triplicate samples × 2 sample volumes × 2 calibration methods). These images were analyzed by the respective user with two region of interest (ROI) selection methods. Image intensities, Vivotrax + quantification, and ROI selection were compared across users, within and across institutions. MPI imagers at two different institutes produce significantly different signal intensities, that differ by over 3 times for the same concentration of Vivotrax + . Overall quantification yielded measurements that were within [Formula: see text] 20% from ground truth; however, SPION quantification values obtained at each laboratory were significantly different. Results suggest that the use of different imagers had a stronger influence on SPION quantification compared to differences arising from user error. Lastly, calibration conducted from samples in the imaging field of view gave the same quantification results as separately imaged samples. This study highlights that there are many factors that contribute to the accuracy and reproducibility of MPI quantification, including variation between MPI imagers and users, despite pre-defined experimental setup, image acquisition parameters, and ROI selection analysis.

Graphene Oxide Paper Manipulation of Micro-Reactor Drops.

Digital microfluidics, which relies on the movement of drops, is relatively immune to clogging problems, making it suited for micro-reactor applications. Here, graphene oxide paper of 100 μm thickness, fabricated by blade coating sedimented dispersions onto roughened substrates, followed by drying and mechanical exfoliation, was found to be relatively free of cracks and curling. It also exhibited high wettability and elasto-capillary characteristics. Possessing low enough stiffness, it could rapidly and totally self-wrap water drops of 20 μL volume placed 2 mm from its edge when oriented between 0 and 60° to the horizontal. This complete wrapping behavior allowed drops to be translated via movement of the paper over long distances without dislodgement notwithstanding accelerations and decelerations. An amount of 2 drops that were wrapped with separate papers, when collided with each other at speeds up to 0.64 m/s, were found to eschew coalescence. This portends the development of robust digital microfluidic approaches for micro-reactors.

Term Delivery Complicated by Uterine Rupture with No Prior History of Cesarean Section or Uterine Curettage Following Oxytocin Use and Arrest in Second Stage of Labor: A Case Report.

BACKGROUND Uterine rupture during delivery in an unscarred uterus may be associated with oxytocin dose during second stage arrest and with underlying maternal factors. This report is of a 34-year-old woman, gravida 5, para 3, with no previous history of cesarean section (CS), who had a uterine rupture at term delivery following the use of oxytocin for second-stage arrest. CASE REPORT A 34-year-old Afghani woman, gravida 5, para 3 was admitted at term for delivery. The current pregnancy had been normal and the estimated birth weight was approximately 4000 g. There was no history of steroid treatment or any underlying connective tissue disease, and no history of dilation and curettage. Oxytocin was given as per protocol, starting at 20 ml/h of a dilution of 10 IU/1 L natrium chloride (NaCl). Subsequent labor progress was complicated by arrest of descent in the second stage of labor, necessitating cesarean section delivery. After opening the abdominal wall, a uterine rupture with several large blood clots was discovered, freely floating in the peritoneal space, about 500 ml in volume. The rupture stretched from the left side of the uterine body and down into the thin lower segment. The tissue in this area had diffuse hematoma. CONCLUSIONS Although uterine rupture mostly occurs in women with previous CS, this report has shown that uterine rupture can occur in pregnancy complicated by arrest in the second stage of labor.

An anthropomorphic body phantom for the determination of calibration factor in radionuclide treatment dosimetry.

The aim of this study is to create an inhomogeneous human-like phantom, whose attenuation and scattering effects are similar to the human body, as an alternative to the homogeneous phantoms traditionally used in calibration factor (CF) determination. The phantom was designed to include the thorax, abdomen and upper pelvis regions sized to represent a 75-kg male with a body mass index of 25. Measurements using Lu-177 with 50- and 100-mL lesion volumes were performed using inhomogeneous anthropomorphic body phantom (ABP) and homogeneous NEMA PET body phantom. There was a difference of 5.7% of Calibration Factor including attenuation and scatter effect between ABP and NEMA PET body phantom. Because it better reflects the attenuation and scatter effect, it is recommended to use a human-like inhomogeneous phantom for determination of CF instead of a homogeneous phantom.

Continuous-flow enzymatic synthesis of chiral lactones in a three-dimensional microfluidic reactor

A new continuous-flow process for the enzymatic synthesis of optically pure γ-lactones, which are used as flavors and fragrances in the food and cosmetic industries, was developed in a three-dimensional microfluidic reactor. The microchannels (175 mm in length, 0.9 mm in depth, and 1.72 mL in volume) were carved precisely inside a single borosilicate glass (90 mm × 75 mm × 12 mm) with ultrafast femtosecond laser micromachining. The flow field analysis and reaction simulation showed that the mixing of substrates and enzymes was enhanced, allowing the adjustment of residence time in a wide window. SmCRV4, a carbonyl reductase with excellent catalytic activity and enantioselectivity toward γ/δ-keto acids, was employed for the asymmetric synthesis of various chiral lactones. 30 mmol/L (R)-γ-decalactone (3g) can be obtained in 26 s with a space-time yield (STY) up to 16,877 g L−1 d−1, which is 14.4 times higher than the highest STY of batch reaction reported previously. This continuous-flow process was applied to the synthesis of 6 chiral lactones. In addition, the scaled-up synthesis of 3g was carried out in 6 cascade microreactors continuously for 6 h, demonstrating the feasibility and stability of the 3D continuous-flow process in enzymatic synthesis of optically pure compounds.

Immersion of debrided diabetic foot ulcer tissue in electrochemically generated pH neutral hypochlorous acid significantly reduces the microbial bioburden: whole-genome sequencing of Staphylococcus aureus, the most prevalent species recovered

Diabetic foot ulcer infections (DFUIs) are the leading cause of lower-limb amputations, mediated predominantly by Staphylococcus aureus. pH-neutral electrochemically generated hypochlorous acid (anolyte) is a non-toxic, microbiocidal agent with significant potential for wound disinfection. To investigate both the effectiveness of anolyte for microbial bioburden reduction in debrided ulcer tissues and the population of resident S.aureus. Fifty-one debrided tissues from 30 people with type II diabetes were aliquoted by wet weight and immersed in 1- or 10-mL volumes of anolyte (200parts per million) or saline for 3min. Microbial loads recovered were determined in colony forming units/g (cfu/g) of tissue following aerobic, anaerobic and staphylococcal-selective culture. Bacterial species were identified and 50S.aureus isolates from 30 tissues underwent whole-genome sequencing (WGS). The ulcers were predominantly superficial, lacking signs of infection (39/51, 76.5%). Of the 42/51 saline-treated tissues yielding ≥105cfu/g, a microbial threshold reported to impede wound-healing, only 4/42 (9.5%) were clinically diagnosed DFUIs. Microbial loads from anolyte-treated tissues were significantly lower than saline-treated tissues using 1mL (1065-fold, 2.0 log) and 10mL (8216-fold, 2.1 log) immersion volumes (P<0.0005). S.aureus was the predominant species recovered (44/51, 86.3%) and 50 isolates underwent WGS. All were meticillin susceptible and comprised 12 sequence types (STs), predominantly ST1, ST5 and ST15. Whole-genome multi-locus sequence typing identified three clusters of closely related isolates from 10 patients indicating inter-patient transmission. Short immersions of debrided ulcer tissue in anolyte significantly reduced microbial bioburden: a potential novel DFUI treatment.

Scalable cryopreservation of infectious Cryptosporidium hominis oocysts by vitrification.

Cryptosporidium hominis is a serious cause of childhood diarrhea in developing countries. The development of therapeutics is impeded by major technical roadblocks including lack of cryopreservation and simple culturing methods. This impacts the availability of optimized/standardized singular sources of infectious parasite oocysts for research and human challenge studies. The human C. hominis TU502 isolate is currently propagated in gnotobiotic piglets in only one laboratory, which limits access to oocysts. Streamlined cryopreservation could enable creation of a biobank to serve as an oocyst source for research and distribution to other investigators requiring C. hominis. Here, we report cryopreservation of C. hominis TU502 oocysts by vitrification using specially designed specimen containers scaled to 100 μL volume. Thawed oocysts exhibit ~70% viability with robust excystation and 100% infection rate in gnotobiotic piglets. The availability of optimized/standardized sources of oocysts may streamline drug and vaccine evaluation by enabling wider access to biological specimens.

Enrichment and quantification of 18 polycyclic aromatic hydrocarbons from intermediates for plastics production by a generic liquid chromatography column switching.

The polycyclic aromatic hydrocarbon concentration in plastic products is regulated in (European Union) No. 1272/2013. However, this only covers the end products and not intermediate substances. Therefore, a generic method was developed to analyze the polycyclic aromatic hydrocarbons listed by the Environmental Protection Agency and the European Union. This method is based on direct large volume injection from solutions of plastic additives followed by liquid chromatography coupled to fluorescence detection. The additives Irganox 1010, ureido methacrylate, and cetyl methacrylate 1618F were used as examples for method development. Two serially coupled columns allowed the matrix to be removed on the first column and the analytes to be separated on the second column. The columns were connected by an intermediate valve. The valve allowed the matrix to be diverted after the first column and water to be dosed upstream of the second column via an additional pump. This allowed samples in aqueous or organic media to be focused at the column head. An injection volume of 100μl and online aqueous dilution of 1:3 led to a limit of detection below 1ng/ml for 15 polycyclic aromatic hydrocarbons. Moreover, concentrations between 1.6 and 10.3ng/ml were found in the three plastic additives.

High-resolution multi-shot diffusion imaging of structural networks in healthy neurocognitive aging

Healthy neurocognitive aging has been associated with the microstructural degradation of white matter pathways that connect distributed gray matter regions, assessed by diffusion-weighted imaging (DWI). However, the relatively low spatial resolution of standard DWI has limited the examination of age-related differences in the properties of smaller, tightly curved white matter fibers, as well as the relatively more complex microstructure of gray matter. Here, we capitalize on high-resolution multi-shot DWI, which allows spatial resolutions < 1 mm3 to be achieved on clinical 3T MRI scanners. We assessed whether traditional diffusion tensor-based measures of gray matter microstructure and graph theoretical measures of white matter structural connectivity assessed by standard (1.5 mm3 voxels, 3.375 μl volume) and high-resolution (1 mm3 voxels, 1μl volume) DWI were differentially related to age and cognitive performance in 61 healthy adults 18–78 years of age. Cognitive performance was assessed using an extensive battery comprising 12 separate tests of fluid (speed-dependent) cognition. Results indicated that the high-resolution data had larger correlations between age and gray matter mean diffusivity, but smaller correlations between age and structural connectivity. Moreover, parallel mediation models including both standard and high-resolution measures revealed that only the high-resolution measures mediated age-related differences in fluid cognition. These results lay the groundwork for future studies planning to apply high-resolution DWI methodology to further assess the mechanisms of both healthy aging and cognitive impairment.

Delayed puberty: How to approach?

Disorders of puberty can profoundly impact physical and psychosocial well-being. Delayed puberty is the absence of breast development in girls by 13 years of age and absence of testicular growth to at least 4 mL in volume or 2.5 cm in length in boys by 14 years of age. Hypogonadism occurs when there is a disruption in the hypothalamic-pituitary-gonadal axis. Two categories of delayed puberty are: hypergonadotropic (primary) hypogonadism and hypogonadotropic (secondary) hypogonadism. The etiology of delayed puberty varies from relatively benign to life threatening conditions, which may be either congenital or acquired. Constitutional delay of growth and puberty is the commonest cause of delayed puberty, which is a diagnosis of exclusion. There is a notable delay in puberty but eventually progress through normal stages of puberty. History concerns about stature are often present and a familial pattern of inheritance is usually present. Delayed bone age but corresponding to height age helps in diagnosis. Reversible hypogonadotropic hypogonadism may be observed due to associated conditions including chronic malnutrition, systemic disease, untreated hypothyroidism, hyperprolactinemia, anorexia nervosa. Permanent causes include structural damage either to hypothalamic-pituitary axis or linked to the sexual organs of the individual. Complete physical examination should include proper anthropometry, pubertal staging and assessment to look for any signs of chronic illness or stigmata of syndromes. In laboratory analysis, hypogonadotropichypogonadism (pHH) showing low serum testosterone or estradiol and blunted follicle-stimulating hormones (FSH) and luteinizing hormones (LH) levels may be due to abnormalities in the central nervous system. Magnetic resonance imaging is necessary to exclude morphological abnormalities and neoplasia. Low serum testosterone in male patients and low estradiol values in female patients, associated with high serum FSH and LH levels, suggest a diagnosis of hypergonadotropic hypogonadism due to dysfunction of peripheral sex organs. Abnormal growth velocity necessitates assessment of serum thyroid function, prolactin, and insulin like growth factor-1. Karyotyping can reveal a chromosomal abnormality like Turner syndrome or Klinefelter syndrome. Beside reassurance, in cases where the adolescent with CDGP is experiencing psychological difficulties, short courses of sex hormones may be used to allow individuals to catch up with their peers. Definitive treatment for underlying cause is worthy where possible. Long-term hormone replacement therapy is recommended for permanent causes of delayed puberty. Bangladesh J Medicine 2023; Vol. 34, No. 2(1) Supplement: 192

Accelerating radiochemistry development: Automated robotic platform for performing up to 64 droplet radiochemical reactions in a morning

The growing discovery and development of novel radiopharmaceuticals and radiolabeling methods requires an increasing capacity for radiochemistry experiments. However, such studies typically rely on radiosynthesizers designed for clinical batch production rather than research, greatly limiting throughput. Two general solutions are being pursued to address this: developing new synthesis optimization algorithms to minimize how many experiments are needed, and developing apparatus with enhanced experiment throughput. We describe here a novel high-throughput system based on performing arrays of droplet-based reactions at 10 μL volume scale in parallel. The automatic robotic platform can perform a set of 64 experiments in ∼3 h (from isotope loading to crude product, plus sampling onto TLC plates), plus ∼1 h for off-line radio-TLC analysis and radioactivity measurements, rather than the weeks or months that would be needed using a conventional system. We show the high repeatability and low crosstalk of the platform and demonstrate optimization studies for two 18F-labeled tracers. This novel automated platform greatly increases the practicality of performing arrays of droplet reactions by eliminating human error, vastly reducing tedium and fatigue, minimizing radiation exposure, and freeing up radiochemist time for other intellectually valuable pursuits.

Application of a nitrifying bacterium Pseudomonas sp. HIB_D to reduce nitrogen waste in the Litopenaeus vannamei cultivation environment.

Pseudomonas sp. HIB_D has been observed to have nitrification activity that can oxidize ammonia/ammonium to nitrite and nitrate. This bacterium was isolated from the aquaculture environment with Ancol Indonesian marine water sources. Pseudomonas sp. HIB_D was applied in the rearing water of Litopenaeus vannamei to decrease nitrogen pollution levels and support a sustainable cultivation environment. This present study was set up using a completely randomized design with four treatments and three replications, i.e., control (without bacterial application) and bacterial application with a cell density of 107, 108, and 109CFUmL-1 in a volume of 100mL for 90 L seawater treatment. Thirty-six individuals of 15-day-old postlarvae L. vannamei (PL 15) (a density of 120 PL m-2) were used in this study for an 8-week rearing period. Based on the water quality analysis, the ammonia level under the bacterial applications was lower than in thecontrol after 8-week cultivation. Nitrate levels increased at week 6 and decreased at week 8, specifically in 109CFUmL-1 treatment. L. vannamei with 109CFUmL-1 bacterial application had the best production performance with a survival rate of 94.33 ± 2.78%, an absolute length gain of 10.59 ± 0.22cm, an absolute weight gain of 8.16 ± 0.33g, a specific growth rate of 14.12% ± 0.01% day-1, and a feed conversion ratio of 1.26 ± 0.03. The blood glucose level and total hemocyte count of shrimp under the bacterial application with a density of 109CFUmL-1 showed the highest level (30.71 ± 13.9mg dL-1) and the lowest level (15 × 106 cells mL-1), respectively. The results showed that all treatments performed better than the control, in which the 109CFUmL-1 bacterial application was the best treatment.

Titanium particles incorporated polymer monolith microcolumn for phosphoprotein enrichment from biological samples

In proteomic studies, selective enrichment of target phosphoproteins from biological samples is of importance. Of various enrichment methods, affinity chromatography is widely preferred method. Development of micro-affinity columns with simple strategies are in constant demand. Here in this report, for the first time, we have embedded TiO2 particles within the monolith structure in a single step. Fourier transform infrared spectroscopy and scanning electron microscope analysis has confirmed the successful incorporation of TiO2 particles within the polymer monolith. Incorporation of 3-(trimethoxy silyl) propyl methacrylate within the poly(hydroxyethyl methacrylate) based monolith composition has enhanced its rigidity and one fold phosphoprotein (α-casein) adsorption capacity. Presence of only 66.6 µg of TiO2 particles within the monolith has displayed a four-fold higher affinity to α-casein over the non-phosphoprotein i.e. bovine serum albumin. Under optimized conditions (TiO2 particle and acrylate silane), the affinity monolith has a maximum adsorption capacity of ∼ 72 mg per gram monolith. Translation of TiO2 particles-monolith into a microcolumn of 3 cm long and 19 µL volume was successful. α-casein was selectively separated from an artificial protein mixture of α-casein and BSA, α-casein spiked human plasma, and cow milk within 7 min

Facile and Scalable Synthesis of Metal- and Nitrogen-Doped Carbon Nanotubes for Efficient Electrochemical CO2 Reduction.

Metal- and nitrogen-doped carbon (M-N-C) is a promising material to catalyze electrochemical CO2 reduction reaction (CO2RR). However, most M-N-C catalysts in the literature require complicated synthesis procedures and produce small quantities per batch, limiting the commercialization potential. In this work, we developed a simple and scalable synthesis method to convert metal-impurity-containing commercial carbon nanotubes (CNTs) and nitrogen-containing organic precursors into M-N-C via one-step moderate-temperature (650 °C) pyrolysis without any other treatment nor the need to add metal precursors. Batches of catalysts in varied mass up to 10 g (150 mL in volume) per batch were synthesized, and repeatable catalytic performances were demonstrated. To the best of our knowledge, the 10 g batch is one of the largest batches of CO2RR catalysts synthesized in the literature while requiring minimal synthesis steps. The catalyst possessed single-atomic iron-nitrogen (Fe-N) sites, enabling a high performance of >95% CO product selectivity at a high current density of 400 mA/cm2 and high stability for 45 h at 100 mA/cm2 in a flow cell testing. The catalyst outperformed a benchmark noble-metal nanoparticle catalyst and achieved longer stability than many other reported M-N-C catalysts in the literature. The scalable and cost-effective synthesis developed in this work paves a pathway toward practical CO2RR applications. The direct utilization of metal impurities from raw CNTs for efficient catalyst synthesis with minimal treatment is a green and sustainable engineering approach.

Modified Ultrafiltration and Acute Kidney Injury in Patients Undergoing Open Heart Surgery Using Cardiopulmonary Bypass

Objective: To determine the incidence of acute kidney injury (AKI) in patients undergoing open heart surgery using cardiopulmonary bypass (CBP) with and without modified ultrafiltration (MUF). Materials and Methods: A total of 150 patients who underwent open heart surgery using CPB in our hospital from Jan-2022 to Dec-2022. In group A patients MUF was performed during the CPB and atleast 1000 ml of volume was removed using MUF. While in group B patients, no filtration was performed during CPB. In ICU all patients were followed till three days after surgery to determine the incidence of AKI. Results: Mean age was 53.4±10.9 years in MUF group versus 55.6±11.8 years in control group, p-value 0.23. Majority, 53 (70.7%) patients were male in MUF and 57 (76%) in control group, p-value 0.55. Mean CPB time was 101.6±45.2 mins in MUF and 96.5±39.1 mins in control group, p-value 0.46. Mean X-clamp time was 47.5±19.3 mins in MUF and 51.4±21.6 mins in control group, p-value 0.43. The incidence of AKI was comparable, with frequency rate of 3 (4.0%) in MUF group versus 1 (1.3%) in control group, p-value 0.31. Conclusion: In present study, the incidence of AKI in MUF and control group was almost similar. So according to the results of present study, the use of MUF has no role in preventing or aggravating AKI in patients undergoing CPB. Keywords: Acute kidney injury, cardiopulmonary bypass, modified ultrafiltration.

Characterization of a novel tetravalent botulism antitoxin based on receptor-binding domain of BoNTs.

Botulinum neurotoxin (BoNTs; serotypes A, B, E, and F) cause botulism disease in humans, which could be effectively treated using antitoxins. Herein, we established a novel receptor-binding domain (RBD)-based antitoxin using recombinant C terminal heavy chain (Hc) domains of BoNTs as immunogens. Immunization of horses with these recombinant Hc domains allowed the purification and digestion of IgGs from hyper-immune sera to produce high-quality and high-efficiency monovalent botulism antitoxin F(ab')2 against each BoNT (M-BATs). However, these M-BATs could not bind or neutralize other serotypes of BoNTs, and that there were no cross-protective effects among these M-BATs. This suggested the need to prepare tetravalent antitoxins to neutralize the four BoNTs simultaneously. Thus, these M-BATs were formulated into a novel tetravalent botulism antitoxin (T-BAT), in which a 10-ml volume contained 10000IU of BoNT/A and 5000IU of BoNT/B, BoNT/E, and BoNT/F antitoxins. The novel antitoxin preparation could prevent and treat the four mixed botulinum neurotoxins simultaneously in vivo, representing strong efficacy in an animal poisoning model. Moreover, these antibodies in T-BAT could bind the RBD, whereas conventional antitoxins based on inactivated toxins mainly bind the light chain or heavy chain translocation domain (HN) and weakly bind the important RBD in current experimental conditions. The high levels of RBD-specific novel antitoxins can efficiently bind the RBD and neutralize natural or recombinant toxins containing this RBD. The findings of the present study experimentally support the use of RBD-specific antitoxins to treat BoNT serotype A, B, E, and F-mediated botulism. This study demonstrated the concept of developing potent novel multivalent antitoxins against all BoNTs or other toxins, using the RBD of these toxins as an alternative antigen to inactivated toxins. KEY POINTS: • Antitoxins based on the receptor-binding domains of botulinum neurotoxins were made. • Novel antitoxin binds RBD; traditional antitoxin mainly binds light chain or HN domain. • A tetravalent antitoxin could prevent and treat the four mixed neurotoxins in vivo.