Performance Of Strips Research Articles

Detecting Echinocandin Resistance in C. glabrata Using Commercial Methods: Are CLSI or EUCAST Breakpoints Suitable for Categorical Classification?

Previous studies correlated Sensititre YeastOne and gradient diffusion plastic strips with standard procedures for the detection of echinocandin-resistant C. glabrata isolates. However, these studies were limited by the low number of resistant isolates studied; the inclusion of sufficient numbers of mutant isolates is essential to test the procedures' capacity to detect resistance. We assessed the performance of Sensititre YeastOne and Etest strips to detect echinocandin resistance in susceptible or resistant C. glabrata isolates (n = 80) in which the FKS genes were sequenced, and MICs interpreted using EUCAST and CLSI breakpoints. Isolates were echinocandin-susceptible (n = 50) or echinocandin-resistant according to EUCAST 7.4 methodology. Echinocandin susceptibility using Sensititre YeastOne and Etest strips and categorical agreement were assessed. All except one anidulafungin-resistant isolate had an anidulafungin Sensititre YeastOne MIC ≥ 0.25 mg/L, while most micafungin-resistant isolates had a MIC ≥ 0.25 mg/L. Likewise, all anidulafungin-resistant isolates had an anidulafungin Etest strip-obtained MIC ≥ 0.03 mg/L, whereas micafungin-resistant isolates were ≥ 0.125 mg/L. Overall, these commercial methods correctly classified > 90% of isolates by using any breakpoint. Despite the low number of errors detected, these were mostly false resistance (major errors) with EUCAST breakpoints and false susceptibility (very major errors) with CLSI breakpoints. Sensititre YeastOne and Etest strips were suitable procedures to detect echinocandin resistance in C. glabrata. The high number of FKS mutants included reinforces our study and opens the door for multicentre validations.

Bidirectional "Win-Win": Asymmetrical Nanobowl-Coupled Aggregation-Induced Emissive Nanosilicon-Enhanced Immunochromatographic Strips for the Ultrasensitive Detection of Salmonella typhimurium.

The lack of nanoprobes with an efficient signal response and overlook of cooperation between nanoprobes can be responsible for the unsatisfactory analytical performance of immunochromatographic strips (ITSs). Herein, asymmetrical nanobowl-confined innumerable gold nanoparticles (AuNPs) (AuNPs@AFRNBs) to enhance the light absorption are developed for quenching the fluorescence of aggregation-induced emissive (AIE) nanosilicons, which is used for the construction of a bidirectional complementary-enhanced ITS (BC-ITS) to ultrasensitively detect Salmonella typhimurium (S. typhimurium). Briefly, density functional theory-screened AIEgens with highly fluorescent brightness are confined in nanosilicons, and the nanoconfinement has improved the fluorescent brightness by 6.78-fold compared to the free AIEgens. Moreover, the substituent group effect has also enhanced the fluorescence of the prepared fluorescent nanosilicon by 10,000-fold in ITSs. By virtue of the superior light absorption of AuNPs@AFRNBs, the BC-ITS exhibits a bidirectional "win-win" performance for the sensitive monitoring of S. typhimurium: a "turn-on" mode with a high-brightness colorimetric response and an inverse "turn-off" fluorescence response, whose limits of detection are 364 and 302 CFU mL-1, respectively, which is approximately 100-fold more sensitive than the traditional AuNPs-ITS. Furthermore, the BC-ITS can be successfully used to identify S. typhimurium in milk, illustrating the superiority of the developed BC-ITS in point-of-care diagnosis.

Strip cropping increases yield and revenue: multi-year analysis of an organic system in the Netherlands

Intercropping is proposed as a promising strategy to meet future food demand while reducing agriculture’s environmental impact by re-diversifying agricultural fields. Strip cropping, a form of intercropping, has a potential to simultaneously deliver multiple ecosystem services including productivity, while facilitating management as strip width can be adjusted to the working width of available machines. While the yield performance of strip cropping systems is influenced by the interaction between neighboring crops, to date, empirical studies on the performance of various crop combinations in strip cropping systems are limited. Here we used three-year data (2020–2022) from a 64-ha organic strip cropping system in the Netherlands to (1) evaluate the effects of crop neighbors and strip cropping on yield and (2) explore if optimizing the allocation of crop neighbors in alternative strip cropping configurations can improve yield and revenue performances. We analyzed the edge effect and strip cropping effect on yield of six crops grown in strips, each neighboring a total of five crops. The yield data was then used to evaluate the performance of the current and alternative strip configurations in terms of LER and relative revenue. Results showed that except for the positive effect observed on potato when neighboring celeriac or broccoli, edge effects lacked statistical significance. Strip cropping effect varied per crop: positive for faba bean and parsnip, neutral for celeriac and potato, and negative for oat and onion. Analysis across crops showed an overall significant positive strip cropping effect on yield. These findings highlighted the value of analysis at the cropping system level in developing designs aimed at unlocking the potential of strip cropping. The positive but variable strip cropping effects observed in the current experimental design and the two alternative configurations suggests prioritizing an overall increased crop diversity over optimizing their spatial arrangement. While we demonstrated increased productivity with strip cropping, further research is needed to expand the database on optimal crop combinations, extending the evaluation beyond yield and revenue performances to facilitate broader adoption of strip cropping in the Netherlands and Western Europe.

Impact of Nickel Strip Configurations on Resistance and Voltage Drop in Lithium Ion Battery Packs

The impact of nickel strip designs on the resistance and voltage drop in lithium ion battery packs is examined in this study. In a series parallel battery pack configuration, the effectiveness of coated and pure nickel strips is assessed, with particular attention paid to how they influence voltage drop, internal resistance, and overall efficiency. Each of the 24 series and 3 parallel cells that make up the battery pack has an internal resistance of 6 mΩ. Two configurations are analyzed: one utilizing pure nickel strips and another with coated nickel strips. The resistivity, cross sectional area, and length of the material are used to compute the equivalent resistance of the nickel strips for each arrangement. Voltage dips at a load current of 50A are determined to compare the performance of both strip. The study also looks at the voltage drop at key locations in the battery pack, including particular bent strips. The findings show that the coated nickel design displays a larger resistance (0.237Ω) and voltage drop (11.735V) than the pure nickel configuration, which has a lower total resistance (0.048Ω) and voltage drop (2.82V). Evaluation of the voltage drop during charging is also done for charging currents of 6A and 10A, demonstrating that the pure nickel arrangement allows for more efficient charging. One of the main elements affecting battery pack performance is internal resistance, which has a direct impact on the system's voltage drop and overall energy efficiency. The thickness, width, resistivity, and number of parallel strips utilized in this nickel strip material all have a major effect on the battery pack's total resistance. Because of this, the nickel strip design can improve or worsen the pack's power delivery, particularly in high load scenarios.

Pesticides trapping performance of vegetative filter strips in black soil region, Northeast China: controlled experiments and VFSMOD-W modeling

The Northeast black soil region in China is an important grain-producing area where various pesticides are extensively used to increase grain yields. However, this practice poses serious risks to the ecological health of soil and water systems, necessitating effective measures. Vegetative filter strips (VFS) are commonly used to mitigate agricultural diffuse pollutants, but their efficiency varies across different regions, requiring assessment. This study employed flume experiments, the VFSMOD-W model, and redundancy analysis (RDA) to evaluate the efficacy of VFS in runoff, sediment, and pesticide removal, as well as influencing factors. The results showed that VFS reduced outflow rate of runoff by 8 %–64 % and sediment by approximately 90 %, achieving load removal rates of 61 % and 95 % respectively. Pesticide load removal efficiency ranged from 37 % to 94 %, with higher efficiency for adsorbed pesticides like chlorpyrifos compared to water-soluble ones like atrazine. Interflow and vertical seepage were significant pathways for pesticide transport in VFS, with chlorpyrifos concentrations at 4 %–26 % and atrazine at 20 %–37 % of inflow concentrations. The VFSMOD-W model accurately predicted VFS efficiency (NSE > 0.90), and RDA results indicated that environmental factors could explain 86.7 % of the variation in VFS performance, with soil vertical saturated hydraulic conductivity (VKS) being the most influential factor, followed by rainfall intensity (T), saturated soil water content (OS), initial soil water content (OI), and filter slope for each segment (SOA). Optimizing soil moisture characteristic factors and increasing infiltration are crucial for VFS performance. Applying VFSMOD-W for precise VFS design can help reduce construction costs. In the future, long-term field monitoring and evaluation of VFS efficiency after implementation should be conducted in the black soil region of Northeast China to provide data supporting the improvement of VFSMOD-W simulation accuracy. This will also offer recommendations for the government in formulating VFS configuration schemes.

The dynamic performance of semi-infinite piezoelectric strip containing irregular boundaries based on the boundary element method

In this article, the problem of a semi-infinite piezoelectric strip with irregular boundaries is studied by boundary element method, and SH guided wave and line source loads are considered as external loads acting on piezoelectric strip. The superiority of the boundary element method is induced by two different arithmetic examples. Firstly, when the irregular boundary is not subjected to line source loads, the dynamic characteristics are analyzed in the first example, employing the image method and Graf addition theorem. Then, the Green’s identities are introduced and the Green’s function in infinite three-dimensional space is solved. When irregular boundaries are subjected to line source loads, the dynamic characteristics are investigated using the boundary element method in the second example. Finally, results clarified the influence on the dynamic stress concentration factor and electric field intensity concentration factor under proper conditions. Besides, the analytical solutions are compared with the finite element solutions to verify the accuracy of the conclusions in this article.

Development of a simple and rapid dipstick paper-based test strip for colorimetric determination of nitrate and nitrite in water and foodstuffs

A rapid user-friendly paper-based test strip using zinc microparticles in conjugation with Griess reagent was developed for nitrite and nitrate detection. Test strips were fabricated using a simple and fast method of step-by-step immersion into reagents so that each strip contained a single detection pad for nitrite detection and another separate pad for nitrate detection. To reduce nitrate to nitrite, zinc microparticles suspended in ethanolic solution of polyvinylpyrrolidone (PVP) were uniformly immobilized on the paper strips that were previously impregnated in the Griess reagent and dried. The Griess reagent components were optimized to reach the highest color intensity. The optimized test strip was able to determine both nitrite and nitrate with respective detection limits of 0.43 and 9.43 mg/kg and a detection time of 60 s. The performance of the new test strips was evaluated for the simultaneous colorimetric detection of nitrite and nitrate in water and different food samples.

Evaluation of a Diazo-Based Point-Of-Care Bilirubin Assay careSTART S1 Total Bilirubin Strip.

Neonatal jaundice (NNJ) affects a significant proportion of newborns globally, with an increased burden in low-resource settings. Effective health risk management of NNJ is hindered, particularly in resource-constrained environments, where early detection and treatment are challenging. The careSTART S1 Total Bilirubin Strip, a point-of-care testing (POCT) device based on a diazo-method, offers a potential solution by enabling onsite bilirubin measurement, thus, addressing the gap in early NNJ detection and management. The current study evaluated the analytical performance of the careSTART S1 Total Bilirubin Strip for precision, linearity, method comparison, and lot-to-lot consistency following CLSI guidelines. For method comparison, 105 residual EDTA whole blood samples were analyzed with the careSTART S1 Total Bilirubin Strip and compared with reference measurements from the Roche Cobas c702 analyzer. Additionally, statistical analyses, including Passing-Bablok regression and Bland-Altman plots, were performed. The careSTART S1 Total Bilirubin Strip showed allowable (<10%) within-laboratory imprecision of 2.5%-3.6% across all levels and demonstrated linearity over the range of 4.16-439.3 μmol/L. Method comparison revealed a constant negative bias with a mean bias -4.19 μmol/L. However, the 95% confidence interval (-7.10 to -1.28 μmol/L) of the bias is covered by the prespecified allowable bias of 8.3%, at medical decision point. Lot-to-lot variation ranged from 0.14%-6.49%, and was within the acceptable critical difference of 8.3%. The careSTART S1 Total Bilirubin Strip provided accurate and reliable bilirubin measurements that could contribute to neonatal care in settings lacking central laboratory facilities.

Evaluation of a Rapid Drug Test Device for Urine Fentanyl Compared to Mass Spectrometry and 2 Urine Fentanyl Assays.

A new Rapid Drug Test Device (RDTD) is available for analysis of urine fentanyl. With the rise in fentanyl abuse in the United States, we evaluated the analytical performance of the RDTD test strip compared to mass spectrometry and 2 urine fentanyl immunoassays. Leftover, deidentified urine samples collected from inpatients and outpatients from our psychiatric hospital and other clinics were frozen at <-70°C, thawed at room temperature, and centrifuged. Aliquots were tested with the RDTD (CLIA Waived, Inc.) test strips and 2 urine fentanyl immunoassays: the ARK Fentanyl II assay (ARK Diagnostics Inc.) and the Immunalysis SEFRIA Fentanyl assay (Immunalysis Corporation). Both assays were conducted on the Abbott Alinity c chemistry analyzer (Abbott Laboratories). Mass spectrometry analysis was performed at ARUP Laboratories. All assays had a 1 ng/mL positive cutoff. A total of 142 urine samples included 70 positive and 72 negative samples. The RDTD strips had lower sensitivity (84.3%) and efficiency (85.9%) and showed a specificity of 87.5% compared to the other assays. The ARK Fentanyl II assay showed identical sensitivity (95.7%) to the Immunalysis SEFRIA Fentanyl assay but had higher specificity (94.4% vs 81.9%) and overall efficiency (95.1% vs 88.7%). Differences were noted in the number of false negatives and positives among the assays. The RDTD demonstrated acceptable performance in detecting urine fentanyl in our patient population and would provide faster test results at point-of-care testing sites in our healthcare enterprise.

A comparison between tensile and hole expansion properties in 800 MPa tensile strength grade hot-rolled steels

Sheared edge formability can play a critical role in cold forming of high-strength hot-rolled steels due to susceptibility to edge cracking. Standardized ISO 16630 hole expansion test is currently the most widely used method to estimate sheared edge formability of steel sheets, however, there has been increasing interest in the industry to reduce the amount of required testing. The aim of this paper was to compare hole expansion performance of hot-rolled strip steels to various uniaxial tensile test results. The five investigated steels were selected to have 3 mm thickness and similar (838±10 MPa) longitudinal tensile strength level while consisting of different microstructures. Tensile properties were measured in 0°, 45°, and 90° angle relative to the rolling direction to investigate anisotropy. Plastic strain ratios were determined by digital image correlation measurement. Local ductility was evaluated with thickness strain measurements (εp_amin) on fracture surfaces of the tensile specimens. To investigate stretch-flangeability, ISO 16630 conforming hole expansion tests were performed. Test holes were produced by punching and by wire electrical discharge machining (W-EDM) to evaluate edge damage tolerance of the materials. The hole expansion ratios (HER) were not observed to correlate with majority of the investigated tensile test results, such as uniform elongation and yield strength. However, a good correlation between HER and planar anisotropy was observed. Planar anisotropy is seen to affect strain localization tendency around the hole. The HER values of neither punched nor W-EDM specimens correlated clearly with εp_amin measurement results. The results show that at a similar strength level, anisotropy is highly influencing the hole expansion performance of hot-rolled steels, and that the HER is not reliably predicted by a single local formability parameter.

Efficacy of praziquantel drug against Schistosoma haematobium and performance of urine reagent strips among pre-and-school aged children during the high transmission season in North-Western Tanzania

The World Health Organization calls for schistosomiasis endemic countries to regularly monitor the efficacy of Praziquantel (PZQ) drug, the only antischistosomal drug used for four decades in Tanzania. In response to that call, the current study investigated the efficacy of single dose of PZQ against Schistosoma haematobium during the high transmission season and further assessed, the sensitivity and specificity of urine reagent strips before and after treatment. The study recruited a total of 2,498 -children aged (4 -17 years old) who provided a single urine sample that was visually examined for macro-haematuria, then using urine dipstick and urine filtration technique for microhaematuria and the presence of S. haematobium eggs. The baseline prevalence of S. haematobium eggs positive based on urine filtration test was 29.2 % (95 %CI:27.5–31.0) and that of microhaematuria was 43.1 % (95 %CI:41.1–45.0). Of the infected participants, 40.9 % (95 %CI:37.4–44.6) had a heavy intensity of infection and the geometrical mean intensity (GMI) of infection was 33.7 eggs/10mls of urine. A single dose of PZQ reduced the prevalence of infection to 16.2 %, the GMI of infection to 18.8eggs/10mls of urine and that of microhaematuria to 27.9 %. Cure rate and egg reduction rates (ERR) were 83.8 % and 44.3 % respectively. At baseline, the sensitivity and specificity of the urine reagent strips were 59.7 % and 93.8 %, whereas at post-treatment they were 16.7 % and 93.6 %. When PZQ drug is administered during the high transmission season, its efficacy in term of ERR is poor. The urine reagent strips had low sensitivity but high specificity at pre-and-post PZQ treatment.

Pilot findings on the real-world performance of xylazine test strips for drug residue testing and the importance of secondary testing methods

BackgroundXylazine is a sedative found increasingly in the illicit fentanyl supply that can cause hypotension, bradycardia, necrosis and death. This pilot examined the real-world performance of BTNX xylazine test strips (XTS) in drug residue samples. MethodsThis study was nested within a drug checking service in Rhode Island. We tested unmeasured drug residue dissolved in 5mL of distilled water using XTS and Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry (LC-QTOF-MS). Analyses compared XTS and LC-QTOF-MS results to calculate XTS detection of xylazine in residue. ResultsAmong 41 residue samples, xylazine was detected in 11% by the XTS and 44 % by the laboratory. The LC-QTOF-MS detected xylazine in 18 samples: 4 major, 9 minor, 5 trace by volume relative to the whole sample. The XTS disagreed with the LC-QTOF-MS by indicating a negative result in 77.8 % (N=14) of the samples but never indicated a positive when the LC-QTOF-MS reported xylazine’s absence. The XTS correctly detected xylazine 22 % of the time, however, this increased to 100 % of the time if xylazine was a major active component. ConclusionsIn this study, the BTNX XTS often disagreed with LC-QTOF-MS by indicating a negative result, likely due to the dilution levels used and sample composition. The XTS may not be accurate in detecting residual amounts of xylazine, especially if xylazine is not a dominant component of the tested sample. Given the novelty of BTNX’s XTS products, we recommend XTS only be used in conjunction with other advanced drug checking modalities for residue testing.

An up-conversion fluorescence lateral-flow immunoassay for rapid detection of Daratumumab in serum protein electrophoresis clinical samples

BackgroundDaratumumab (DARA) is a commonly used monoclonal antibody (mAb) drug for the treatment of multiple myeloma (MM). Its appearance as a visible abnormal band in the γ-region of a serum protein electrophoresis (SPEP) gel may interfere with the SPEP result interpretation. With the advantages of portability and rapid testing capabilities, up-conversion fluorescence lateral-flow immunoassay (LFA) can be an ideal solution to detect DARA interference. MethodsAn up-conversion fluorescence LFA strip was designed and constructed to perform semi-quantitative DARA testing in clinical samples. The LFA strip test was evaluated for limit of detection (LOD), dynamic range, and analytical interference. ResultsTo demonstrate the clinical utility of the LFA strip, 43 SPEP-positive patient serum samples were tested for the presence of DARA, and the results exactly matched the DARA usage history in patient medical records. ConclusionsThe performance of the up-conversion fluorescence LFA strip meets the purpose of clarifying DARA interference in SPEP results. It may be used as an independent and objective confirmation of the presence of DARA in clinical samples. The LFA strip offers a cost-effective rapid on-site test to check for DARA interference alongside standard SPEP equipment, which significantly improves the interpretation of ambiguous SPEP results involving DARA, and does not intervene the current SPEP workflow in clinical laboratory practice.

Optimisation and evaluation of viral genomic sequencing of SARS-CoV-2 rapid diagnostic tests: a laboratory and cohort-based study

Sequencing of SARS-CoV-2 from rapid diagnostic tests (RDTs) can bolster viral genomic surveillance efforts; however, approaches to maximise and standardise pathogen genome recovery from RDTs remain underdeveloped. We aimed to systematically optimise the elution of genetic material from RDT components and to evaluate the efficacy of RDT sequencing for outbreak investigation. In this laboratory and cohort-based study we seeded RDTs with inactivated SARS-CoV-2 to optimise the elution of genomic material from RDT lateral flow strips. We measured the effect of changes in buffer type, time in buffer, and rotation on PCR cycle threshold (Ct) value. We recruited individuals older than 18 years residing in the greater Boston area, MA, USA, from July 18 to Nov 5, 2022, via email advertising to students and staff at Harvard University, MA, USA,and via broad social media advertising. All individuals recruited were within 5days of a positive diagnostic test for SARS-CoV-2; no other relevant exclusion criteria were applied. Each individual completed two RDTs and one PCR swab. On Dec 29, 2022, we also collected RDTs from a convenience sample of individuals who were positive for SARS-CoV-2 and associated with an outbreak at a senior housing facility in MA, USA. We extracted all returned PCR swabs and RDT components (ie, swab, strip, or buffer); samples with a Ct of less than 40 were subject to amplicon sequencing. We compared the efficacy of elution and sequencing across RDT brands and components and used RDT-derived sequences to infer transmission links within the outbreak at the senior housing facility. We conducted metagenomic sequencing of negative RDTs from symptomatic individuals living in the senior housing facility. Neither elution duration of greater than 10 min nor rotation during elution impacted viral titres. Elution in Buffer AVL (Ct=31·4) and Tris-EDTA Buffer (Ct=30·8) were equivalent (p=0·34); AVL outperformed elution in lysis buffer and 50% lysis buffer (Ct=40·0, p=0·0029 for both) as well as Universal Viral Transport Medium (Ct=36·7, p=0·079). Performance of RDT strips was poorer than that of matched PCR swabs (mean Ct difference 10·2 [SD 4·3], p<0·0001); however, RDT swabs performed similarly to PCR swabs (mean Ct difference 4·1 [5·2], p=0·055). No RDT brand significantly outperformed another. Across sample types, viral load predicted the viral genome assembly length. We assembled greater than 80% complete genomes from 12 of 17 RDT-derived swabs, three of 18 strips, and four of 11 residual buffers. We generated outbreak-associated SARS-CoV-2 genomes using both amplicon and metagenomic sequencing and identified multiple introductions of the virus that resulted in downstream transmission. RDT-derived swabs are a reasonable alternative to PCR swabs for viral genomic surveillance and outbreakinvestigation. RDT-derived lateral flow strips yield accurate, but significantly fewer, viral reads than matched PCR swabs. Metagenomic sequencing of negative RDTs can identify viruses that might underlie patient symptoms. The National Science Foundation, the Hertz Foundation, the National Institute of General Medical Sciences, Harvard Medical School, the Howard Hughes Medical Institute, the US Centers for Disease Control and Prevention, the Broad Institute and the National Institute of Allergy and Infectious Diseases.

An active-bending sheltered pathway based on bamboo strips for indoor temporary applications: Design and construction

This study explores the feasibility of employing bamboo strips to create an innovative sheltered pathway designed for indoor temporary applications. The primary design objectives encompass the development of a lightweight structure to conserve materials, ease of installation, and the use of sustainable, environmentally friendly materials. Additionally, the study places a significant emphasis on creating a structural system that can be conveniently disassembled, occupying minimal space for easy transport. The research initiative commences by investigating the mechanical properties of bamboo strips under active bending conditions, employing both bending and cantilever tests to evaluate their performance. Subsequent numerical analyses are conducted using OpenSeesPy, utilizing elastic beam elements with a corotational geometric transformation to simulate the mechanical behavior of bamboo strips. These numerical simulations are then compared with experimental results, contributing to the validation of a mechanical model for the full active bending structure. This validated model is further employed to predict deformation status and stress distribution during the substantial deformations of bamboo strips. The Employing a Particle-Spring Assembly (PSA) model, the preliminary design seamlessly evolves from a 2D bamboo strips configuration to 3D structures, showcasing the final curved form inspired by the remarkable large deformation performance of bamboo strips. Finally, the validated model guides the design of three distinct prototypes of an active-bending sheltered pathway, progressively increasing in scale and complexity. The prototypes address challenges such as lateral stiffness and employ aluminum connections for enhanced performance. The stiffness of the final sheltered pathway prototype is simulated and validated through Finite Element Modeling (FEM) simulations in ABAQUS under diverse loading conditions. The ultimate prototype represents a full-scale module of the sheltered pathway, featuring a walkway, a shelter system constructed from transparent waterproof PVC fabric, and an LED strip-based lighting system. These initial designs and prototypes demonstrate promising performance and hold considerable potential for real-world applications, establishing them as a compelling subject of study.

Comparison of carbapenem MIC for NDM-producing Enterobacterales by different AST methods.

This study compared the performance of MIC test strip (ETEST), automated AST card (Vitek 2) and broth microdilution (BMD) in determining carbapenem susceptibility and MIC values of NDM-producing Enterobacterales. NDM-producing Enterobacterales recovered from clinical specimens were included. The presence of blaNDM was confirmed by PCR. Identification of bacterial isolates was done by MALDI-TOF. Phenotypic susceptibility to three carbapenems (ertapenem, imipenem and meropenem) was tested by BMD, ETEST and Vitek 2. MIC values were interpreted in accordance with CLSI M100 (2022 edition). Using BMD as the reference standard, the essential agreement (EA), categorical agreement (CA), very major error (VME) and major error (ME) rates were evaluated. Forty-seven NDM-producing Enterobacterales isolates were included, 44 of which were Escherichia coli. The EA of Vitek 2 was 97.9% for ertapenem, 25.5% for meropenem and 42.6% for imipenem. Using Vitek 2, there were 0% VMEs across all three carbapenems tested. The EA of ETEST was 53.2% for ertapenem, 55.3% for imipenem and 36.2% for meropenem. The rates of VMEs for ETEST were high too (ertapenem 8.5%, meropenem 36.2%, imipenem 26.1%). The MIC values obtained from Vitek 2 were consistently higher than those from BMD, while MICs from ETEST were consistently lower than those from BMD. The VME rate for ETEST was unacceptably high when BMD was used as the standard for comparison. Vitek 2 had acceptable EA and CA for ertapenem when BMD was used as the standard for comparison. For meropenem and imipenem, neither of the methods (ETEST, Vitek 2) showed acceptable EA and CA when compared with BMD.

Experimental study and numerical analysis on the axial compression performance of CFRP strip reinforced round-end aluminum alloy tube concrete column

Round-end aluminum alloy tube concrete columns had good durability and were very economical, but the low strength and elastic modulus of aluminum alloy led to the need for improvement in performance. This paper proposes carbon fiber reinforced plastic (CFRP) strip reinforced round-end aluminum alloy tube concrete (CREAC) columns and investigates their mechanical properties under axial compression loads. A total of eight specimens were tested, including seven CFRP reinforced specimens and one control specimen. The effects of the width, spacing, and number of layers of CFRP strips on the axial compression performance of CREAC under the same amount of CFRP were studied. The experimental results indicate that the main failure modes of the specimen are the buckling of round-end aluminum alloy tubes and the fracture of CFRP strips. The CFRP strip can significantly improve the ultimate bearing capacity of the specimen, with a maximum increase of 15.3% in the test range. When the amount of CFRP is the same, as the number of CFRP strips decreases, the bearing capacity and ductility deteriorate. Increasing the width and thickness of CFRP strips significantly improves ductility. On the basis of the validated finite element model, parameter analysis was conducted, and the calculation method for stability coefficients was fitted. A calculation method for axial compression bearing capacity suitable for CREAC was proposed, with a maximum error of less than 1% between the predicted results and experimental results.

Testing the test strips: laboratory performance of fentanyl test strips

BackgroundThe overdose crisis driven by synthetic opioids continues to escalate in the USA. We evaluated the efficacy of multiple manufacturing lots of a fentanyl test strip (FTS) to detect fentanyl and fentanyl analogs and assessed cross-reactivity with possible interferences.MethodsDrug standards were dissolved in water in a laboratory setting and serially diluted. Drug dilutions were tested using five different manufacturing lots of BTNX Rapid Response (20 ng/mL cutoff) lateral flow chromatographic immunoassay strips to assess lot-to-lot variability for FTS sensitivity and cross-reactivity for the analytes of interest.ResultsAll five manufacturing lots cross-reacted with fentanyl and eleven fentanyl analogs. Diphenhydramine, lidocaine, MDMA, and methamphetamine were found to cause false positives with the strips. There was notable lot-to-lot variability in the sensitivity of the strips for fentanyl, fentanyl analogs, and known interferences.DiscussionFTS remains an important overdose prevention tool, but lot-to-lot variability in performance complicates robust instructions that balance the prevention of false positives and false negatives. Continued lot-to-lot performance assessment is recommended to ensure health education for FTS remains accurate. More sophisticated drug checking technologies and services are needed in the community landscape to augment personal FTS use to facilitate informed consumption and overdose risk mitigation.

Study on sealing performance and optimization design of a new type non-standard seal strip of submarine pipeline maintenance dry cabin

The submarine pipeline maintenance dry cabin can improve inspection accuracy and repair quality. However, there is no reference standard for the selection and design of the seal strip of a large underwater cabin. Therefore, in this paper, the seal strip's sealing characteristics were studied using the finite element software ABAQUS, and the structure of the non-standard seal strip is designed and optimized. The simulation results show that the D-section seal strip can provide high contact stress while maintaining low Mises stress. To further improve the sealing performance, a new type D seal strip composed of rubber and EPDM foam was designed. The ratio of the two materials affects the overall performance of the seal. Therefore, considering the contact stress integral, maximum contact stress, and maximum Mises stress, the comprehensive optimal structure was obtained based on the Response Surface Methodology. Finally, experimental results verified the accuracy of the simulation calculation.

Mechanical properties of three typical aluminum alloy strips prepared by twin-roll casting

Twin-roll casting (TRC) is a near-net shape processing technology that has found widespread application across various series of Al alloys. In this study, the process-structure-property relationships of 2099, 3003, and 6082 Al alloy strips prepared by TRC and traditional rolling (TR) methods were investigated. It shows that the tensile strength and fatigue strength of 2099-TRC are lower than 2099-TR, which is attributed to the reduced solid solubility of copper (Cu) elements resulting from the precipitation of Cu-rich micron phases and the presence of microstructure inhomogeneities. While both 3003-TRC and 3003-TR materials exhibit similar yield and tensile strength, the occurrence of casting micro-void defects in 3003-TRC leads to an accelerated accumulation of fatigue damage, consequently diminishing its fatigue strength. Conversely, 6082-TRC demonstrates an enhanced fatigue strength relative to 6082-TR. This improvement is primarily linked to the higher yield strength and comparable fatigue resistance observed in the former. In light of these findings, the TRC process holds promise for enhancing the fatigue performance of 6xxx Al alloy strips with good elongation. However, for 2xxx and 3xxx alloy strips with comparatively lower elongation, the TRC process enhancements may be necessary to realize similar benefits. The insights gleaned from this study could offer valuable reference and guidance for optimizing both the TRC process itself and the fatigue performance of Al alloy strips.