The separation membranes in artificial organs

Separation membranes play a crucial role in the functioning of artificial organs, such as hemodialysis machines, membrane oxygenators, and artificial liver models. The current COVID-19 pandemic has highlighted the importance of these technologies in the medical community. However, membrane technology in artificial organs faces significant challenges, such as the clearance of low-middle-molecule and protein-bound toxins and limited blood compatibility. In this review, we will discuss the separation mechanisms, separation performance, and biocompatibility of different types of separation membranes used in artificial organs. We will also highlight the opportunities and challenges for next-generation membrane technology in this field, including the need for improved clearance of toxins and increased blood compatibility, as well as the potential for microfluidic devices.

Numerical Investigation on Silicon based Hollow Core Photonic Crystal Fiber for sensing Multiple Virus

In recent years, spread of infection due to virus became whirlwind and creates threat to life in multiple ways. Hence there is in need to sense virus as early as possible in easier way. In this work we propose a multi virus sensor which senses IBV, H5N1, H9N2, and H4N6.Very low refractive index is sensed in this work with increased birefringence due to its elliptical core, where the samples are infiltrated. Numerical analysis is done using Finite Element Method. Among these 4 viruses, IBV has higher sensitivity, birefringence and lower confinement loss which belong to COVID family.88.56% of sensitivity is obtained at 1550nm with low confinement loss. © 2022 IEEE.

Electrospray-on-Electrospun Breathable, Biodegradable, and Robust Nanofibrous Membranes with Photocatalytic Bactericidal Activity

The increasing emergence of infectious diseases like COVID-19 has created an urgent need for filtration/purification materials coupled with multifunctional features such as mechanical integrity, excellent airflow/filtration, and antibacterial/antimicrobial properties. Polymer membranes and metal-organic frameworks (MOFs) have demonstrated high effectiveness in air filtration and purification. MOF nanoparticles have been introduced into electrospun polymer nanofibrous membranes through embedding or postsolution growth. However, the derived hybrids are still facing the issue of (1) limited MOF exposure, which leads to low efficacy;and (2) uncontrollable growth, which leads to pore blocking and low breathability. In this work, we customized an electrospray-on-electrospinning in situ process to dynamically integrate MOF nanoparticles into a robust and elastic continuous nanofibrous membrane for advanced properties including high mechanical strength and flexibility, excellent breathability, particle filtration, and good antimicrobial performance. Biodegradable polylactic acid was reinforced by the poly(hydroxybutyrate)-di-poly(DLA-CL)x copolymer (PHBR) and used as an electrospinning matrix, while MOF nanoparticles were simultaneously electrically sprayed onto the nanofibers with easily controllable MOF loading. The MOF nanoparticles were homogeneously deposited onto nanofibers without clogging the pores in the membrane. The collision of PLA and MOF under the wet status during electrospinning and the hydrogen bonding through C=O and N-H bonds strengthen the affinity between PLA nanofibers and MOF nanoparticles. Because of these factors, the MOF-incorporated PLA/PHBR nanofibrous membrane achieved over 95% particle filtration efficiency with enhanced mechanical properties while maintaining high breathability. Meanwhile, it exhibits excellent photocatalytic antibacterial performance, which is necessary to kill microbes. The electrospray-on-electrospinning in situ process provides an efficient and straightforward way to hybridize one-dimensional (1D) or two-dimensional (2D) nanomaterials into a continuous nanofibrous membrane with strong interaction and controllable loading. Upon integrating proper functionalities from the materials, the obtained hybrids are able to achieve multifunctionalities for various applications.

Prosthetic Rehabilitation of A Post-Covid Mucormycosis Maxillectomy Defect Using A Fused Two-Piece Hollow Obturator: A Fabrication Technique

Purpose: Intraoral defects in the maxilla cause communication with the nasopharyngeal complex. The surgically removed palate can have a devastating effect on the appearance and speech of the patient. Obturators allow patients to eat and drink without any suspicion of food entering the oroantral cavities/ pharynx during mastication. This clinical report describes fabrication of a closed hollow bulb obturator using the two-piece double flask technique. Method(s): After the final teeth arrangement was completed, teeth over the defect were removed and separately processed using heat cure acrylic resin. Both the segments are combined by autopolymerizing acrylic resin to form a single hollow-bodied obturator. Conclusion(s): This technique uses a double flasking method of the two segments to control the thickness of the bulb in the defect area, thus decreasing the weight of the obturator.Copyright © 2020 Ubiquity Press. All rights reserved.

Hollowing of Delayed Surgical Obturator in Maxillectomy Defects Secondary to Mucormycosis in Post-COVID-19 Era: A Case Series

During the second wave of the coronavirus disease 2019 (COVID-19) pandemic in India, there was an increase in the surge of mucormycosis cases secondary to COVID-19 infection. Aggressive surgical debridement is the most common treatment modality opted for its treatment that leads to extended maxillary defects. Obturating such defects may be very challenging from a prosthodontic point of view, as larger defect sizes and fewer retentive areas make it difficult to retain the prosthesis. A delayed surgical obturator is a prosthesis that is placed 6–10 days after the surgery, mainly used to minimize postoperative complications. It reproduces the contour of the palate and allows the patient to resume a regular diet. It also assists in normal speech. But in large surgical defects, the increased obturator's weight makes it uncomfortable and nonretentive for the patient, compromising its function. Consequently, in this case series, hollow bulb obturators are fabricated to decrease the weight of the prosthesis and to improve the function by establishing palatal contour. In case 1, hollowing was done using thermoplastic polyvinyl chloride (PVC) sheets and in case 2 acrylic shim was used. In both cases two-layer techniques were used, as in large defects if we use a single-layer technique it will either increase the weight of the prosthesis or may fail to create a palatal contour that further compromises the function. The techniques followed here are easy to use and less time-consuming. © The Author(s). 2022.

A novel photoelectrochemical immunosensor based on TiO2@Bi2WO6 hollow microspheres and Ag2S for sensitive detection of SARS-COV-2 nucleocapsid protein.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV-2) is a cluster of ß coronaviruses. The 2019 coronavirus disease (COVID-19) caused by SARS-COV-2 is emerging as a global pandemic. Thus, early diagnosis of SARS-COV-2 is essential to prevent severe outbreaks of the disease. In this experiment, a novel label-free photoelectrochemical (PEC) immunosensor was obtained based on silver sulfide (Ag2S) sensitized titanium dioxide@bismuth tungstate (TiO2@Bi2WO6) nanocomposite for quantitative detection of SARS-COV-2 nucleocapsid protein. The constructed TiO2@Bi2WO6 hollow microspheres had large specific surface area and could produce high photocurrent intensity under visible light illumination. Ag2S was in-situ grown on the surface of thioglycolic acid (TGA) modified TiO2@Bi2WO6. In particular, TiO2@Bi2WO6 and Ag2S formed a good energy level match, which could effectively enhance the photocurrent conversion efficiency and strength the photocurrent response. Ascorbic acid (AA) acted as an effective electron donor to effectively eliminate photogenerated holes. Under optimal experimental conditions, the constructed immunosensor presented a supersensitive response to SARS-COV-2 nucleocapsid protein, with a desirable linear relationship ranged from 0.001 to 50 ng/mL for nucleocapsid protein and a lower detection limit of 0.38 pg/mL. The fabricated sensor exhibited a wide linear range, excellent selectivity, specificity and stability, which provided a valuable referential idea for the detection of SARS-COV-2.

LONG-TERM SUPER HIGH-FLUX HEMODIALYSIS (OR EXPANDED HEMODIALYSIS;HDx) DOES NOT ALTER NUTRITION STATUS WITH THE SIGNIFICANTLY REDUCED MIDDLE-MOLECULE AND PROTEIN-BOUND UREMIC TOXINS IN HEMODIALYSIS PATIENTS

Introduction: Super high-flux hemodialysis (SHF-HD) provides comparable effectiveness in terms of middle-molecule and protein-bound uremic toxin removal to online hemodiafiltration in prevalent end-stage kidney disease (ESKD). However, dialysate albumin loss is raised awareness of the long-term using SHF-HD. The study aims to monitor the long-term use of SHF-HD in nutritional status change and the sustained effect of uremic toxin removal. Method(s): The present study was prospectively conducted on the 15 prevalent ESKD patients from a run-in period of standard high-flux hemodialysis (HF-HD) with ELISIO-H21 dialyzer for 4 weeks to thereafter 15 months follow-up with SHF-HD. The patients provided high-efficiency (high blood flow and dialysate flow rate) SHF-HD using PES17D alpha dialyzers for the first three months. After the amendment protocol, SHF-HD was run with the same type of dialyzer;ELISIO-17Hx (Nipro Corporation, Osaka, Japan) due to the COVID-19 pandemic. Nutritional parameters, BCM;body composition monitor (FMC, Bad Homburg, Germany), and uremic toxins were measured at baseline and every three months during SHF-HD. Result(s): Fourteen of 15 patients could complete the study. One patient was early terminated due to undergoing kidney transplantation. After 15 months of SHF-HD treatment compared to HF-HD at baseline, there was not a statistically significant change in clinical and laboratory parameters on nutritional status. The mean serum albumin levels were 4.09 (1.36) versus 4.01 (0.3) g/dL, respectively (p=0.52), and the mean difference (SE) of normalized protein catabolic rate (nPCR) was -0.04 (0.08), 95% confidence interval [CI] -0.19, 0.11. On the other hand, lean tissue mass (LTM) was significantly decreased, and fat mass was significantly increased (mean difference (SE) of -3.66 (1.07) gram, 95% CI -5.76, -1.55, and 1.79 (0.80), 95% CI 0.21, 3.36). SHF-HD sustainably and significantly removed medium to large middle-molecule uremic toxins including pre-dialysis beta-2 microglobulin, kappa-free light chain, and lambda-free light chain. In addition, protein-bound uremic toxin;indoxyl sulfate was significantly reduced during long-term follow-up using SHF-HD. SHF-HD with PES17D alpha dialyzer resulted in more dialysate albumin leaks than a newer type of SHF-HD with ELISIO-Hx17. Conclusion(s): Long-term use of SHF-HD in ESKD patients was associated with nutritional safety and effectiveness in middle-molecule and protein-bound uremic toxin removal. Although serum albumin and BMI were not changed. LTM was significantly reduced with lower levels of nPCR than in other studies but trended to increase over time. The LTM absolute levels are not below the 10 percentiles of the healthy reference range. Increasing protein intake to reach the current recommendation and physical activity was advised with long-term use of SHF-HD to avoid further reduce LTM. [Formula presented] [Formula presented] [Formula presented] No conflict of interestCopyright © 2023

Evolutions of extracorporeal membrane oxygenator (ECMO): perspectives for advanced hollow fiber membrane.

Hollow fiber membrane is incorporated into an extracorporeal membrane oxygenator (ECMO), and the function of the membrane determines the ECMO's functions, such as gas transfer rate, biocompatibility, and durability. In Japan, the membrane oxygenator to assist circulation and ventilation is approved for ECMO support. However, in all cases, the maximum use period has been only 6 h, and so-called 'off-label use' is common for ECMO support of severely ill COVID-19 patients. Under these circumstances, the HLS SET Advanced (Getinge Group Japan K.K.) was approved in 2020 for the first time in Japan as a membrane oxygenator with a two-week period of use. Following this membrane oxygenator, it is necessary to establish a domestic ECMO system that is approved for long-term use and suitable for supporting patients. Looking back on the evolution of ECMO so far, Japanese researchers and manufacturers have also contributed to the developments of ECMO globally. Currently, excellent membrane oxygenators and systems have been marketed by Japanese manufacturers and some of them are globally acclaimed, but in fact, most of the ECMO membranes are not made in Japan. Fortunately, Japan has led the world in the fields of membrane separation technology and hollow fiber membrane production. In the wake of this pandemic, from the perspective of medical and economic security, the practical use of purely domestic hollow fiber membranes and membrane oxygenators for long-term ECMO is imperative in anticipation of the next pandemic.

Efficient selective adsorption of cytokine IL-6 and other middle-macromolecular toxins in the serum of uremia patients with specially designed porous hollow carbon spheres

[Display omitted] • Porous hollow carbon spheres (HCSs) with adjustable size and pore width distribution were synthesized. • The clearance rate of HCSs to interleukin 6 (IL-6) in PBS buffer solution was up to 99.8%. • HCSs had a high adsorption rate and removal efficiency for PTH, β 2 -MG, IL-6 and TNF-α in the serum of uremic patients. • The selective adsorption of middle-macromolecular toxins or cytokines was achieved by regulating the pore structure of HCSs. Abnormally elevated middle-macromolecular toxins such as interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF- α) in human blood are fatal precipitating factors for patients suffered from immune-related diseases, especially for uremia and COVID-19 critical patients, while the effective clearance of them has always been problematic in clinic. In this work, porous hollow carbon spheres (HCSs) with different size and pore structure has been successfully prepared. The removal efficiency for IL-6 in PBS solution is about 99.8 %, even in the serum of uremic patients, HCSs could remove 94.75 % and 98.33 % of parathyroid hormone (PTH) and β 2 -microglobulin (β 2 -MG) efficiently within 5–10 min, and particularly, the adsorption of IL-6 and TNF- α is 17.6 and 11.4 times higher over that of the existing commercial hemoperfusion adsorbents. The adsorption balance can be achieved in 60 min, which would greatly shorten the current clinical treatment duration. Moreover, HCSs with different pore structure exhibit distinct adsorption selectivity for IL-6 and TNF- α, which is of special significance for modifying the middle-macromolecular cytokine level in the complicated human blood environment. [ FROM AUTHOR]

A Study of Perforative Peritonitis in a Period of One Year during Covid-19 Pandemic at a Medical College in Rajasthan

Hollow viscous perforation is one of the most common emergency dealt by general surgeons worldwide. A high degree of suspicion is required and prompt management is warranted to reduce morbidity and mortality. Here we present a study of perforative peritonitis in our medical college at the outskirt of Udaipur city in the state of Rajasthan, India during the Covid-19 pandemic. During the one year study period from September 2020 to August 2021, a total of 16 cases of hollow viscous perforation admitted and treated. The number is relatively low because of the pandemic and there was a period of total lockdown with negligible patient footfall. All patient had free gas under diaphragm in plain x-ray and all of them were scheduled for emergency laparotomy after adequate resuscitation. Emphasis given on the location of perforation, etiology, organism on culture of peritoneal fluid and procedure undertaken. Copyright © 2022, Dr Yashwant Research Labs Pvt Ltd. All rights reserved.

Why Molnupiravir Fails in Hospitalized Patients.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has radically altered daily life. Effective antiviral therapies to combat COVID-19, especially severe disease, remain scarce. Molnupiravir is an antiviral that has shown clinical efficacy against mild-to-moderate COVID-19 but failed to provide benefit to hospitalized patients with severe disease. Here, we explained the mechanism behind the failure of molnupiravir in hospitalized patients and identified alternative dosing strategies that would improve therapeutic outcomes in all patients with COVID-19. We showed that delaying therapy initiation markedly decreased the antiviral effect of molnupiravir, and these results were directly related to intracellular drug triphosphate pools and intracellular viral burden at the start of therapy. The adverse influence of therapeutic delay could be overcome by increasing drug exposure, which increased intracellular molnupiravir triphosphate concentrations that inhibited viral replication. These findings illustrated that molnupiravir must be administered as early as possible following COVID-19 symptom onset to maximize therapeutic efficacy. Higher doses may be effective in patients hospitalized with severe disease, but the safety of high-dose molnupiravir regimens is unknown. Our findings could be extended to design effective regimens with nucleoside analogs for other RNA viruses, especially those with pandemic potential. IMPORTANCE In this study, we showed that early intervention with molnupiravir resulted in a greater antiviral effect, and we explained the mechanism behind this phenomenon. Our results predicted and explained the failure of molnupiravir in hospitalized patients and highlighted the utility of preclinical pharmacodynamic studies to design optimal antiviral regimens for the treatment of viral diseases. This contrasts with the procedure that was implemented early in the pandemic in which clinical studies were conducted in the absence of preclinical experimentation. These findings are significant and demonstrated the importance of experimental approaches in antiviral development for treatments against COVID-19 as well as other viral diseases.

Efficient selective adsorption of cytokine IL-6 and other middle-macromolecular toxins in the serum of uremia patients with specially designed porous hollow carbon spheres

Abnormally elevated middle-macromolecular toxins such as interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF- α) in human blood are fatal precipitating factors for patients suffered from immune-related diseases, especially for uremia and COVID-19 critical patients, while the effective clearance of them has always been problematic in clinic. In this work, porous hollow carbon spheres (HCSs) with different size and pore structure has been successfully prepared. The removal efficiency for IL-6 in PBS solution is about 99.8%, even in the serum of uremic patients, HCSs could remove 94.75% and 98.33% of parathyroid hormone (PTH) and β2-microglobulin (β2-MG) efficiently within 5-10 min, and particularly, the adsorption of IL-6 and TNF- α is 17.6 and 11.4 times higher over that of the existing commercial hemoperfusion adsorbents. The adsorption balance can be achieved in 60 min, which would greatly shorten the current clinical treatment duration. Moreover, HCSs with different pore structure exhibit distinct adsorption selectivity for IL-6 and TNF- α, which is of special significance for modifying the middle-macromolecular cytokine level in the complicated human blood environment.

Minimal recovery of drug from extracorporeal treatment in a case of phenytoin toxicity associated with coma and hypothermia

Background: The Extracorporeal Treatments in Poisoning (EXTRIP) workgroup provides a weak conditional recommendation in support of hemodialysis (HD) for select patients with severe phenytoin poisoning. Despite this recommendation, the HD clearance of phenytoin is poorly studied. We present a patient who developed phenytoin toxicity that was treated with hemodialysis and report on the efficacy of phenytoin removal during HD. Case report: An 87-year-old man with epilepsy who was maintained on a stable dose of 300mg phenytoin extended-release daily was admitted to the hospital for treatment of Coronavirus Disease 2019 and congestive heart failure. On hospital day 14, the patient had a gradual onset of depressed mental status with hypothermia (nadir 35 degrees Celsius). At this time, he had a rising total blood phenytoin concentration (peak 49.3 mcg/mL [therapeutic 10-20mcg/mL] with an albumin of 3.8 g/dL [normal 3.4-5.4 g/dL]). The patient's other medications included furosemide, aspirin, atorvastatin, digoxin, doxycycline, metoprolol tartrate, and warfarin;he was also receiving albumin and crystalloid for hypovolemia (albumin nadir on hospital day 14: 2.5 g/dL). Free phenytoin concentrations were not available. Alternate etiologies of hypothermia (endocrine, infectious) were excluded. The Poison Control Center was consulted and recommended HD because of the concern for prolonged coma, as per EXTRIP guidelines. The patient received three sessions of HD over a period of 6 days at 2.5-3 h per session using an F160 Optiflux membrane filter (Fresenius Medical Care, Waltham, MA, USA), with a blood flow rate of 350mL/min and a dialysate flow rate of 700mL/min. After the first session of HD (2.5 h) on hospital day 21, his hypothermia resolved and his phenytoin concentration fell from 39.2mcg/mL to 34.2 mcg/mL with only mild improvement in his mental status. After 6 days (hospital day 27), his phenytoin concentration decreased to 19.5 mcg/mL and his mental status normalized. Effluent from the first HD session had phenytoin concentrations below the limit of detection (0.50mcg/mL). Thus, no greater than 52mg of phenytoin was removed during a 2.5-h session of hemodialysis. Discussion(s): The reason for the sudden increase in blood phenytoin concentrations in this patient is unclear in the absence of drug-drug interactions or dosing changes to the phenytoin. Although uncommonly reported, patients with phenytoin toxicity can experience hypothermia. In this case, the patient's hypothermia resolved during HD, although it is unclear if this was related to changes in phenytoin concentration or (more likely) direct extracorporeal warming via the HD machine. If the patient's phenytoin clearance from the first session were extrapolated to subsequent sessions an estimated maximum of 166.4mg of phenytoin would be removed in 8 total hours of HD, which is far less than previously reported phenytoin clearances on the order of grams. This difference may be related to the use of high cutoff dialysis membranes in prior studies, which are not routinely used. Conclusion(s): Although HD rapidly resolved this patient's hypothermia, a minimal amount of phenytoin was recovered in the patient's dialysate. Prior studies suggesting consequential clearance and efficacy of phenytoin removal by extracorporeal treatment may not apply to routine HD methods. Further studies on the utility of extracorporeal treatment for phenytoin toxicity are needed.

IN VITRO TO IN VIVO: COMBATING MULTIDRUG-RESISTANT ENTEROBACTERIACAE IN THE AGE OF COVID-19

SESSION TITLE: COVID-19 Co-Infections SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/19/2022 12:45 pm - 1:45 pm INTRODUCTION: The COVID-19 pandemic has highlighted the emergence of multidrug-resistant bacterial pathogens. Here we present a case of the successful treatment of a COVID-19 superinfection with Citrobacter freundii, which produced both a Klebsiella pneumoniae carbapenemase (KPC) as well as a New Delhi Metallo-Beta-Lactamase (NDM-1). CASE PRESENTATION: A 53-year-old male without significant past medical history was admitted to the intensive care unit for acute hypoxemic respiratory failure due to COVID-19 pneumonia. His hospital course was complicated by progressive hypoxia requiring intubation and mechanical ventilation. Due to persistent fevers and increased respiratory secretions, he was placed on empiric antibiotic therapy including vancomycin, cefepime, and briefly meropenem. Blood cultures were periodically drawn and ultimately demonstrated no growth. However, a respiratory culture via bronchoalveolar lavage was positive for multidrug-resistant Citrobacter freundii. Susceptibilities showed high level of resistance to meropenem, Imipenem, Ceftazidime-Avibactam as well as Aztreonam. Molecular testing confirmed the presence of both KPC and NDM-1 β-lactamases. The patient was treated with a combination of Aztreonam 2g plus Ceftazidime-Avibactam 2.5g IV every eight hours via simultaneous infusion for fourteen days, resulting in clinical improvement and discharge to a rehabilitation facility. DISCUSSION: The emergence of carbapenem-resistant enterobacteria has been identified as a major clinical problem. The high rates and high mortality of carbapenem-resistant enterobacteria complicating the course of COVID patients during the pandemic highlighted the importance of this issue. Among the Enterobacteriaceae, β-lactam resistance is primarily caused by enzymatic degradation by β-lactamases. Two carbapenemase subclasses are especially problematic: KPC and NDM-1. Horizontal gene transfer and clonal expansion have enabled KPC and NDM-1 to spread worldwide. However, coexistence of these two resistant mechanisms within the same pathogen has rarely been reported. Recently, high stability, non-inferior fitness, and transferability among patients of KPC-2-NDM-1-CRKPs have been documented, raising further concerns about the risk for further spread and increasing rates [1]. Therapeutic options are limited. We used a combination of Ceftazidime/Avibactam plus Aztreonam for treatment, based on limited in vitro studies demonstrating a synergistic effect and superior clearance rather than either antibiotic alone or administered in sequence [2,3]. CONCLUSIONS: Superinfections with carbapenem-resistant enterobacteria have increased in the context of the COVID-19 pandemic and are likely to become more prevalent in our hospitals. Prompt recognition and appropriate therapeutic selection are paramount for treating these highly resistant organisms. Reference #1: Gao H, Liu Y, Wang R, Wang Q, Jin L, Wang H. The transferability and evolution of NDM-1 and KPC-2 co-producing Klebsiella pneumoniae from clinical settings. EBioMedicine. 2020 Jan;51:102599. doi: 10.1016/j.ebiom.2019.102599. Epub 2020 Jan 3. PMID: 31911273;PMCID: PMC6948161. Reference #2: Marshall S, Hujer AM, Rojas LJ, Papp-Wallace KM, Humphries RM, Spellberg B, Hujer KM, Marshall EK, Rudin SD, Perez F, Wilson BM, Wasserman RB, Chikowski L, Paterson DL, Vila AJ, van Duin D, Kreiswirth BN, Chambers HF, Fowler VG Jr, Jacobs MR, Pulse ME, Weiss WJ, Bonomo RA. Can Ceftazidime-Avibactam and Aztreonam Overcome β-Lactam Resistance Conferred by Metallo-β-Lactamases in Enterobacteriaceae? Antimicrob Agents Chemother. 2017 Mar 24;61(4):e02243-16. doi: 10.1128/AAC.02243-16. PMID: 28167541;PMCID: PMC5365724. Reference #3: Lodise TP, Smith NM, O'Donnell N, et al. Determining the optimal dosing of a novel combination regimen of ceftazidime/avibactam with aztreonam against NDM-1-producing Enterobacteriaceae using a hollow-fibre infection model. J Antimicrob Chemother 202 ;75(9): 2622-32 DISCLOSURES: No relevant relationships by wisam daoud No relevant relationships by Christopher Walker No relevant relationships by Amanda Westbrook No relevant relationships by Nicola Zetola

RAPID, CAPILARY-DRIVEN IMMUNOASSAY FOR SARS-CoV-2 DETECTION

A rapid home-diagnostic test for SARS-CoV-2 was developed that automates the reagent delivery and washing steps required for an enzyme-linked immunosorbent assay (ELISA). The device is made of inexpensive polyethylene film and double-sided adhesive that is patterned, cut, and laminated together to create hollow channels. After sample is added, sample, reagents, and washing buffer are sequentially delivered to and washed from a detection zone on a nitrocellulose test strip, giving the end-user a visual readout in <15 minutes. A smartphone camera was used to capture images, and an analytical limit of detection of 35 PFU/mL was determined. When 22 untrained end-users were asked to visually identify a positive result, 95% correctly identified 150 PFU/mL and above as positive. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.

Public history, personal pseudohistory, and VirtHSTM.

In summer 2021, the Virtual History of Science, Technology, and Medicine group hosted two online panels on pseudoscience topics including Flat Earth, Hollow Earth, geohistory, alternate evolution, and forgeries. The panels discussed the roles of such theories in the history of science, as well as the public's understanding of both history and science.

Polypropylene Hollow Fiber Membrane by Dissolution-Inducing Pore Methods.

Plasma leakage limits the development of polypropylene membranes as oxygenated membranes. Here, a new method named the dissolution-induced pore method was adapted to prepare polypropylene hollow fiber membranes: after polypropylene and polyvinyl chloride were melt-blended and extruded, the polyvinyl chloride was removed by N, N-dimethylacetamide to obtain a porous polypropylene membrane material. The variation of membranes has been explored in detail with respect to the influence of different parameters on the flux and mechanical properties of membranes and the feasibility of the polyvinyl chloride recovery. The resulting polypropylene hollow fiber membrane shows that plasma penetration was zero within 6 h of test, gas flux can reach 189,000 L/(m2·h·0.1 MPa), and its strength at break reaches 65 MPa and the elongation at break is 890%; polyvinyl chloride recovery achieves more than 99%. This research has developed a promising and low-cost extracorporeal membrane oxygenation material, which provides benefits for patients with less capacity for medical expenditure.

State-of-the-art review of advanced electrospun nanofiber yarn-based textiles for biomedical applications.

The pandemic of the coronavirus disease 2019 (COVID-19) has made biotextiles, including face masks and protective clothing, quite familiar in our daily lives. Biotextiles are one broad category of textile products that are beyond our imagination. Currently, biotextiles have been routinely utilized in various biomedical fields, like daily protection, wound healing, tissue regeneration, drug delivery, and sensing, to improve the health and medical conditions of individuals. However, these biotextiles are commonly manufactured with fibers with diameters on the micrometer scale (> 10 µm). Recently, nanofibrous materials have aroused extensive attention in the fields of fiber science and textile engineering because the fibers with nanoscale diameters exhibited obviously superior performances, such as size and surface/interface effects as well as optical, electrical, mechanical, and biological properties, compared to microfibers. A combination of innovative electrospinning techniques and traditional textile-forming strategies opens a new window for the generation of nanofibrous biotextiles to renew and update traditional microfibrous biotextiles. In the last two decades, the conventional electrospinning device has been widely modified to generate nanofiber yarns (NYs) with the fiber diameters less than 1000 nm. The electrospun NYs can be further employed as the primary processing unit for manufacturing a new generation of nano-textiles using various textile-forming strategies. In this review, starting from the basic information of conventional electrospinning techniques, we summarize the innovative electrospinning strategies for NY fabrication and critically discuss their advantages and limitations. This review further covers the progress in the construction of electrospun NY-based nanotextiles and their recent applications in biomedical fields, mainly including surgical sutures, various scaffolds and implants for tissue engineering, smart wearable bioelectronics, and their current and potential applications in the COVID-19 pandemic. At the end, this review highlights and identifies the future needs and opportunities of electrospun NYs and NY-based nanotextiles for clinical use.

Comprehensive Characterization of PVDF Nanofibers at Macro- and Nanolevel.

This study is focused on the characterization and investigation of polyvinylidene fluoride (PVDF) nanofibers from the point of view of macro- and nanometer level. The fibers were produced using electrostatic spinning process in air. Two types of fibers were produced since the collector speed (300 rpm and 2000 rpm) differed as the only one processing parameter. Differences in fiber's properties were studied by scanning electron microscopy (SEM) with cross-sections observation utilizing focused ion beam (FIB). The phase composition was determined by Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy. The crystallinity was determined by differential scanning calorimetry (DSC), and chemical analysis of fiber's surfaces and bonding states were studied using X-ray photoelectron spectroscopy (XPS). Other methods, such as atomic force microscopy (AFM) and piezoelectric force microscopy (PFM), were employed to describe morphology and piezoelectric response of single fiber, respectively. Moreover, the wetting behavior (hydrophobicity or hydrophilicity) was also studied. It was found that collector speed significantly affects fibers alignment and wettability (directionally ordered fibers produced at 2000 rpm almost super-hydrophobic in comparison with disordered fibers spun at 300 rpm with hydrophilic behavior) as properties at macrolevel. However, it was confirmed that these differences at the macrolevel are closely connected and originate from nanolevel attributes. The study of single individual fibers revealed some protrusions on the fiber's surface, and fibers spun at 300 rpm had a core-shell design, while fibers spun at 2000 rpm were hollow.

A fiber optic-nanophotonic approach to the detection of antibodies and viral particles of COVID-19

Dr. Deborah Birx, the White House Coronavirus Task Force coordinator, told NBC News on "Meet the Press" that "[T]he U.S. needs a 'breakthrough' in coronavirus testing to help screen Americans and get a more accurate picture of the virus' spread." We have been involved with biopathogen detection since the 2001 anthrax attacks and were the first to detect anthrax in real-time. A variation on the laser spectroscopic techniques we developed for the rapid detection of anthrax can be applied to detect the Severe Acute Respiratory Syndrome-Corona Virus-2 (SARS-CoV-2 virus). In addition to detecting a single virus, this technique allows us to read its surface protein structure. In particular, we have been conducting research based on a variety of quantum optical approaches aimed at improving our ability to detect Corona Virus Disease-2019 (COVID-19) viral infection. Indeed, the detection of a small concentration of antibodies, after an infection has passed, is a challenging problem. Likewise, the early detection of disease, even before a detectible antibody population has been established, is very important. Our team is researching both aspects of this problem. The paper is written to stimulate the interest ofboth physical and biological scientists in this important problem. It is thus written as a combination of tutorial (review) and future work (preview). We join Prof. Federico Capasso and Editor Dennis Couwenberg in expressing our appreciation to all those working so heroically on all aspects of the COVTD-19 problem. And we thank Drs. Capasso and Couwenberg for their invitation to write this paper. © 2021 Walter de Gruyter GmbH, Berlin/Boston. All rights reserved.