Reported Test Results Research Articles

At the mercy of the AI algorithm - discrepant PCR results.

As pathogen molecular diagnostics technology develops, the software analysis of polymerase chain reaction (PCR) sigmoidal curves, crossing threshold (Ct) values and the limit of nucleic acid detection for that assay, is not always available when reporting test results. These are critical components in interpreting results and can affect the management of patients. Our view is that all commercial assay providers must ensure users, as they can with laboratory developed tests, are able to see the curve and Ct value for all samples. Some examples demonstrating this principle are included. Regulatory bodies have a key role to play.

Substance depletion of volatile monoterpenes – A confounding factor for toxicity testing in the Ames fluctuation test

In in vitro toxicology, reported test results are typically based on nominal concentrations, i.e., the calculated amounts of a substance added to a defined volume of the test system. Consequently, if a test system does not respond to a certain endpoint, the assay is interpreted as negative and the test substance is deemed to exert no toxicity at the tested nominal concentration. However, depending on the physicochemical properties of the test substance and assay setup, the actual exposure may differ widely from nominal concentrations due to different depletion processes. (R)-(+)-Limonene (RLIM), β-myrcene (βMYR) and linalool (LIN) are naturally occurring terpenes that are permitted as flavoring agents in the European Union without limitations based on their low toxicity. Nevertheless, their hydrophobicity and high volatility classifies them as difficult to test chemicals, which has not been considered in previous in vitro tests. To exclude possible false negative results, in the present study, we assessed the cytotoxic and mutagenic potential of the latter substances toward Salmonella Typhimurium in the Ames fluctuation test using different incubation setups to minimize possible substance losses due to sorption or volatilization. Actual substance concentrations during incubation were verified analytically at different time points via headspace gas-chromatography-mass spectrometry (hs-GC-MS). Possible substance depletion due to sorption to well-plate material or volatilization was minimized using a polystyrene-free and headspace-free incubation setup, respectively. The results showed complete volatilization of the monoterpenes RLIM and βMYR in the conventional Ames fluctuation test, which may confound mutagenicity testing. The headspace-free incubation setup greatly improved substance exposure and showed cytotoxicity in low micromolar concentrations, but no signs of mutagenicity were observed.

Evidence of HARKing in mouse behavioural tests of anxiety.

Over the last decades, behavioural tests in animals, especially rodents, have been a standard screening method to determine the mechanisms of action and efficacy of psychopharmacological compounds. Yet, recently the reproducibility of some of these tests has been questioned. Based on a systematic review of the sensitivity of mouse behavioural tests to anxiolytic drugs, we analysed behavioural outcomes extracted from 206 studies testing the effect of diazepam in either the open-field test or the hole-board test. Surprisingly, we found that both the rationale given for using the test, whether to detect anxiolytic or sedative effects, and the predicted effect of diazepam, anxiolytic or sedative, strongly depended on the reported test results. The most likely explanation for such strong dependency is post hoc reasoning, also called hypothesizing after the results are known (HARKing). HARKing can invalidate study outcomes and hampers evidence synthesis by inflating effect sizes. It may also lead researchers into blind alleys, and waste animals, time and resources for inconclusive research.

Design and Implementation of an Opt-Out, End-to-End, Preemptive DPYD Testing Program for Patients Planned for a Systemic Fluoropyrimidine.

Several allelic variants of the gene DPYD encoding dihydropyrimidine dehydrogenase (DPD) are associated with impaired metabolism of the systemic fluoropyrimidine fluorouracil (5FU) and its oral prodrug, capecitabine, which elevates the risk for severe toxicity. Following a patient death related to capecitabine toxicity in which DPD deficiency was suspected, a multidisciplinary advisory panel was convened to develop an institution-wide approach to future patients planned for a systemic fluoropyrimidine. The panel selected an opt-out testing strategy which focused on developing reliable processes to collect and report test results and targeted education. An electronic health record-based automated reminder was designed to activate when a 5FU- or capecitabine-containing chemotherapy regimen was ordered for a patient without prior exposure to either agent and without a prior DPYD sequencing test result. DPYD testing was standardized across all sites of care, and a closed loop reporting system for abnormal test results was created. Before implementation, targeted education was provided to providers, pharmacists, and nurses, and a failure mode and effects analysis was performed. Program rollout was staged over a 6-month period. At 10 months, the rate of preemptive testing increased from a baseline of 26% to a sustained rate of >90%. In the six network sites, the testing rate increased from 9% to 96%. A total of 1,043 patients have been tested preemptively; allelic variants have been identified in 43 (4.1%). Among 25 evaluable patients, dose reduction or change to a non-fluoropyrimidine-based regimen was accomplished in 96%. Preemptive DPYD testing is feasible, and high rates of testing can be achieved using an opt-out, reminder-based program. We provide the details of the implementation and encourage others to emulate it.

Underuse of Antiviral Drugs to Prevent Progression to Severe COVID-19 - Veterans Health Administration, March-September 2022.

Antiviral drugs reduce the rate of progression to severe COVID-19 when given to patients with mild-to-moderate disease within 5 days of symptom onset. Despite being recommended for patients at high risk for progression to severe COVID-19 because of age or chronic conditions, reported antiviral use among the general adult population has been ≤35%. To ascertain reasons for underuse of antiviral medications to prevent severe COVID-19 and propose interventions accordingly, a detailed review was conducted of 110 Veterans Health Administration patients with mild-to-moderate infection at high risk for progression because of underlying conditions (organ transplantation or hematologic malignancies) who did not receive an antiviral drug. Among these 110 patients, all of whom had received COVID-19 vaccine, 22 (20.0%) were offered treatment but declined, and 88 (80.0%) were not offered treatment. Among the 88 patients not offered treatment, provider reasons included symptom duration of >5 days (22.7%), concern about possible drug interactions (5.7%), or absence of symptoms (22.7%); however, among nearly one half (43 of 88; 48.9%) of these patients, no reason other than mild symptoms was given. Among 24 (55.8%) of those 43 patients, follow-up was limited to telephone calls to report test results and inquire about symptom evolution, with no documentation of treatment being offered. These findings suggest that education of patients, providers, and medical personnel tasked with follow-up calls, combined with advance planning in the event of a positive test result, might improve the rate of recommended antiviral medication use to prevent severe COVID-19-associated illness, including death.

Counseling Supporting HIV Self-Testing and Linkage to Care Among Men Who Have Sex With Men: Systematic Review and Meta-Analysis.

Counseling supporting HIV self-testing (HIVST) is helpful in facilitating linkage to care and promoting behavior changes among men who have sex with men (MSM). Different levels of counseling support for MSM HIVST users may lead to variance in the linkage to care. This study aims to synthesize evidence on counseling supporting MSM HIVST users and to conduct a meta-analysis to quantify the proportion of MSM HIVST users who were linked to care. A systematic search was conducted using predefined eligibility criteria and relevant keywords to retrieve studies from the MEDLINE, Global Health, Web of Science, Embase, APA PsycINFO, and Scopus databases. This search encompassed papers and preprints published between July 3, 2012, and June 30, 2022. Studies were eligible if they reported counseling supporting HIVST or quantitative outcomes for linkage to care among MSM and were published in English. The screening process and data extraction followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The quality of the included studies was assessed by the National Institutes of Health quality assessment tool. Data were extracted using random effects models to combine the proportion of HIVST users who were linked to care. Subgroup analyses and metaregression were conducted to assess whether linkage to care varied according to study characteristics. All analyses were performed with R (version 4.2.1; R Foundation for Statistical Computing) using the metafor package. A total of 55 studies published between 2014 and 2021, including 43 observational studies and 12 randomized controlled trials, were identified. Among these studies, 50 (91%) provided active counseling support and 5 (9%) provided passive counseling support. In studies providing active counseling support, most MSM HIVST users were linked to various forms of care, including reporting test results (97.2%, 95% CI 74.3%-99.8%), laboratory confirmation (92.6%, 95% CI 86.1%-96.2%), antiretroviral therapy initiation (90.8%, 95% CI 86.7%-93.7%), and referral to physicians (96.3%, 95% CI 85%-99.2%). In studies providing passive counseling support, fewer MSM HIVST users were linked to laboratory confirmation (78.7%, 95% CI 17.8%-98.4%), antiretroviral therapy initiation (79.1%, 95% CI 48.8%-93.7%), and referral to physicians (79.1%, 95% CI 0%-100%). Multivariate metaregression indicated that a higher number of essential counseling components, a smaller sample size (<300), and the use of mobile health technology to deliver counseling support were associated with better linkage to care. The quality of the studies varied from fair to good with a low to high risk of bias. Proactively providing counseling support for all users, involving a higher number of essential components in the counseling support, and using mobile health technology could increase the linkage to care among MSM HIVST users. PROSPERO CRD42022346247; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=346247.

Prediction method for bending moment capacities and failure modes of TSOBs bolted I-beam to hollow section square column

Reported studies on T-head Square-neck One-side Bolts (TSOBs) bolted I-beam to Hollow Section Square Column (HSSC) connections demonstrated the potential of TSOB applications in terms of mechanical properties, installation construction, and cost savings [11–14]. However, existing research was limited to the connection tests and lack a systematic and complete design approach. In this paper, the method for predicting the bending moment capacities and failure modes of the connections was proposed based on the existing test researches. Besides, the Finite Element Model (FEM) of the connections was established and validated by the reported test results. A sensitive analysis on the geometric parameters of the plastic hinge line pattern for calculating the bending moment capacity of the HSSC connecting face was carried out by the validated FEM. The proposed method was compared with the numerical simulation method in terms of the predicted results of the connection structural behavior. The results show that the prediction method proposed in this paper for the connection bending moment capacities and failure modes is accurate and reliable. Moreover, the mixed patterns of Type-H bolt holes and Type-V bolt holes are recommended for the TSOBC design because of the higher bending moment capacity than the unitary bolt hole patterns.

Distribution of COVID-19 Home Testing Through Community Health Centers: Results of the COVID CoNOce MÁS Study.

To assess acceptability and feasibility of rapid at-home COVID-19 testing and reporting of test results among individuals seeking care at community health centers (CHCs) and their household members. Participants were recruited from 2 Community Health Centers during a clinic visit or a community event. Over-the-counter COVID-19 tests were distributed to participants for self-testing and to offer testing to household members. Separate surveys were administered to collect baseline information on the study participant and to collect test results on the study participant and household members. We calculated the proportion of individuals who agreed to complete COVID home testing, those who reported test results, and the test positivity. For household members, we calculated the proportion who completed and reported results and the positivity rate. We assessed reasons for undergoing COVID-19 testing and the action taken by participants who reported positive tests. A total of 2189 individuals were approached by CHC staff for participation and 1013 (46.3%) agreed to participate. Among the 959 participants with complete sociodemographic data, 88% were Hispanic and 82.6% were female. The proportion providing test results was 36.2% and the test positivity was 4.2%. Among the 1927 test reports, 35.3% for the index participant and 64.4% were for household members. The largest proportion of test results were for index participants (35.3%) and the second largest was for the participant's children (32.1%), followed by parents (16.9%), and spouse/partner (13.2%). The 2 most common reasons for testing were symptoms (29%) and attending family gatherings (26%). Among test-positive individuals (n = 80), most (83.3%) noted that they isolated but only 16.3% called their provider and 1.3% visited a clinic. Our results show interest in at-home COVID-19 testing of multiple household members, as we headed into the endemic phase of the pandemic. However, reporting of test results was modest and among test-positive individuals, reporting results to a provider was very low. These results underscore the challenges with reporting and following guidelines among people undergoing home testing for COVID-19, which may have implications for future pandemics.

Effective Communication in a Fertility Setting

Effective communication is a crucial aspect of any healthcare setting, as it directly impacts patient care, teamwork, and overall patient satisfaction. In the context of fertility treatment, clear and efficient communication is even more vital due to the complexity and sensitivity of the procedures involved. To begin with, let us discuss the importance of effective communication between doctors, nursing staff, and embryologists. In a fertility center, these professionals work closely together to provide comprehensive care to patients. Clear and open communication allows for seamless coordination of treatment plans, proper protocol adherence, timely updates on patient progress, and immediate action when complications arise. When there is effective communication among the team members, patients will experience a more streamlined and consistent care journey, ultimately improving their overall treatment outcomes and satisfaction. So, how can we ensure effective communication within this multi-disciplinary team? Here are a few strategies that can be implemented : 1. Regular team meetings: Schedule frequent team meetings to discuss patient cases, exchange information, and address any concerns or questions. These meetings should be structured, ensuring all team members have a chance to share updates and ask for clarifications. It is important to create an environment that promotes open dialogue and active participation from all team members. 2. Utilize electronic medical records (EMR) and shared systems: Implementing an EMR system or any other shared communication platform can greatly enhance communication efficiency. This allows for seamless information exchange, real-time updates, and shared access to relevant patient data. Using such platforms ensures that everyone in the team has access to the same information, reducing the chances of miscommunication or missed information. 3. Standardized protocols and guidelines: Establish consistent protocols and guidelines that outline communication expectations and procedures. This can include guidelines for reporting test results, notifying about patient progress, and communicating emergencies or critical situations. Standardized protocols minimize confusion and ensure that everyone knows what needs to be communicated and how. 4. Inter-professional training and education: Arrange regular training sessions and educational programs that involve team members from different disciplines. This facilitates mutual understanding of each other’s roles, responsibilities, and communication needs. It helps build trust and fosters a collaborative approach to patient care. 5. Feedback and evaluation: Encourage regular feedback and evaluation within the team to identify areas for improvement in communication. This can be done through surveys, colleague feedback, or self-reflection exercises. Address the feedback constructively, and work as a team to implement changes that enhance communication. In conclusion, effective communication is the cornerstone of successful teamwork and optimal patient care in a fertility setting. Clear and efficient communication between doctors, nursing staff, and embryologists ensures smooth coordination, timely interventions, and improved patient outcomes. By implementing strategies such as regular team meetings, shared communication platforms, standardized protocols, inter-professional training, and feedback mechanisms, we can enhance communication within the team.

A feature selection and ensemble learning based methodology for transformer fault diagnosis

Dissolved gas analysis (DGA) data are generally used to diagnose a transformer fault. However, the measurement errors in DGA data are inevitable and will affect the accuracy and reliability of the diagnosis results. Nevertheless, so far, only a few efforts have been devoted to addressing this issue. To provide an accurate and stable transformer fault diagnosis system, a feature selection and ensemble learning based methodology is proposed. Firstly, an Overlapping Information Feature Selection (OIFS) method is proposed to select efficient features from the given feature set for classifiers. Secondly, an Intelligent Voting Ensemble Learning (IVEL) method is proposed to generate a diagnosis model based on the feature combination from the OIFS method. The reported test results show that the OIFS method outperforms existing methods in 9 out of 10 tested classifiers. Additionally, the IVEL outperforms three popular ensemble learning methods, including random forest (RF), gradient boosting decision tree (GBDT), and LightGBM, in terms of both accuracy and robustness performances. Finally, the proposed methodology (OIFS-IVEL) is applied to diagnose the transformer faults in the IEC TC 10 database, achieving a 100% accuracy in recognizing fault types and a 92.6 % accuracy in evaluating fault severity.

Seismic behavior of irregular shaped beam-column connections

This paper reports test results and numerical analysis of special-shaped beam-column connections based on a frame-shear wall structure. Four connections of 1/5 scale ratio were tested under constant axial force and reversed lateral load on the top of column. The experiment investigated the effect of steel reinforced concrete (SRC) beam, in-plane and out of-plane reinforced concrete (RC) wall on the connections’ seismic behavior. The failure modes, hysteresis curves, ductility, strength degradation and energy-dissipating capacity of test specimens are reported. The results indicated that test joints were susceptible to suffer more brittle failure caused by formation of plastic hinge on column, which is considered unfavorable compared to conventional joint with regular shape in earthquake resisting. Adding in-plane shear walls to the connection switched column failure to beam failure mode, and significantly improved the connection’s strength, stiffness and ductility. Finite element models were detailed established and validated through experiment data. Influence of parameters including axial load ratio, concrete strength grade, section area and steel ratio of upper column, transverse hoops volumetric, RC wall of two orthogonal directions on connection’s seismic behavior were studied through modeling results.

Crossing points detection in plain weave for old paintings with deep learning

In the forensic studies of painting masterpieces, the analysis of the support is of major importance. For plain weave fabrics, the densities of vertical and horizontal threads are used as main features, while angle deviations from the vertical and horizontal axis are also of help. These features can be studied locally through the canvas. In this work, deep learning is proposed as a tool to perform these local densities and angle studies. We trained the model with samples from 36 paintings by Velázquez, Rubens or Ribera, among others. The data preparation and augmentation are dealt with at a first stage of the pipeline. We then focus on the supervised segmentation of crossing points between threads. The U-Net with inception and Dice loss are presented as good choices for this task. Densities and angles are then estimated based on the segmented crossing points. We report test results of the analysis of a few canvases and a comparison with methods in the frequency domain, widely used in this problem. We concluded that this new approach successes in some cases where the frequency analysis tools fail, while improves the results in others. Besides, our proposal does not need the labeling of part of the to be processed image. As case studies, we apply this novel algorithm to the analysis of two pairs of canvases by Velázquez and Murillo, to conclude that the fabrics used came from the same roll.

Behavior of novel steel-concrete-steel sandwich walls under low-velocity impact loading

This paper reported experimental and analytical studies on impact behaviors of steel-concrete-steel sandwich composite (SCSSC) walls using enhanced C-channels (ECs). Six SCSSC walls, designed with variations in impact energy levels and boundary columns, were tested by drop hammer and simulated by LS-DYNA. The main failure modes of the specimens after impact loading were global flexure and flexure-shear mode. As direct-link connections, the ECs provided strong interfacial shear and tensile resistances, which prevented local failure of SCSSC walls. Under three impact energy levels, boundary CSFT columns increased the ultimate impact resistance of SCSSC walls, and effectively reduces their peak displacements. Refined finite element (FE) models considering the effect of strain rate were established, and verified by reported impact test results. In addition, this study adopted modified two-degree-of-freedom (TDOF) model to estimate the impact force and displacement responses of this type of SCSSC walls. Validations against reported test results confirmed that the TDOF model provided reasonable predictions.

An empirical potential for simulating hydrogen isotope retention in highly irradiated tungsten

We describe the parameterization of a tungsten-hydrogen empirical potential designed for use with large-scale molecular dynamics simulations of highly irradiated tungsten containing hydrogen isotope atoms, and report test results. Particular attention has been paid to getting good elastic properties, including the relaxation volumes of small defect clusters, and to the interaction energy between hydrogen isotopes and typical irradiation-induced defects in tungsten. We conclude that the energy ordering of defects changes with the ratio of H atoms to point defects, indicating that this potential is suitable for exploring mechanisms of trap mutation, including vacancy loop to plate-like void transformations.

Superconducting VLSI Logic Cell Library Using DC-Powered Clockless Dynamic SFQ Gates and ASIC-Style Layout Template

We report a new approach to building an ASIC-style superconducting SFQ logic cell library for the 8-layer 0.35 μm Niobium SFQ5ee process from MIT LL. The developed library layout template supports XY routing with Passive Transmission Lines (PTLs) and targets conventional Place-and-Route assembly for the design of VLSI Random Logic Macros (RLMs). The designed library gates are based on clockless Dynamic SFQ (DSFQ) logic which allows one to directly implement deep combinational logic clouds. The full library gates communicate only via an XY PTL routing plane, while internally they are assembled from smaller self-contained subgates, connected via inductors and placed in one template row. We report test results for two chips that independently verify library subgate assemblies that are used to build DSFQ logic gates as well as active PTL interconnect; on-chip testbenches provide low-speed and high-speed (GHz) test modes. We have achieved low-speed and high-speed functionality of both the DSFQ logic gates (AND, OR, and AO21) and active interconnect circuitry (transmitters Tx and receivers Rx) used for communicating SFQ signals over 700 μm PTLs and short (∼50 μm) series inductor-resistor (LR) connections. The measured speed of the OR and AND logic circuits exceeded 10 GHz, while the speed for PTLs and LR connections was more than 10 and 30 GHz, respectively.

Results from an IFCC global survey on laboratory practices for the analysis of circulating tumor DNA

BackgroundThe clinical validity of ctDNA analysis as a diagnostic, prognostic and predictive biomarker has been demonstrated in many studies. The rapid spread of tests for the analysis of ctDNA raises questions regarding their standardization and quality assurance. The aim of this study was to provide a global overview of the test methods, laboratory procedures and quality assessment practices using ctDNA diagnostics. MethodsThe Molecular Diagnostics Committee of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC C-MD) conducted a survey among international laboratories performing ctDNA analysis. Questions on analytical techniques, test parameters, quality assurance and the reporting of findings were included. ResultsA total of 58 laboratories participated in the survey. The majority of the participating laboratories (87.7 %) performed testing for patient care. Most laboratories conducted their assays for lung cancer (71.9 %), followed by colorectal (52.6 %) and breast (40.4 %) cancer, and 55.4 % of the labs used ctDNA analysis for follow-up/monitoring of treatment-resistant alterations. The most frequent gene analysed was EGFR (75.8 %), followed by KRAS (65.5 %) and BRAF (56.9 %). Participation in external quality assessment programs was reported by only 45.6 % of laboratories. ConclusionsThe survey indicates that molecular diagnostic methods for the analysis of ctDNA are not standardized across countries and laboratories. Furthermore, it reveals a number of differences regarding sample preparation, processing and reporting test results. Our findings indicate that ctDNA testing is being conducted without sufficient attention to analytical performance between laboratories and highlights the need for standarisation of ctDNA analysis and reporting in patient care.

The impact of war on cytopathological practice in Ukraine

Aim: To investigate the impact of Russian invasion on Ukrainian healthcare services related to cytopathology screening and diagnostics.Methods: The workload and output of the cytopathological laboratory located in Kyiv before and during 8 months of Russian invasion were analyzed. The laboratory performance was assessed by the total number of cytologic cases, the turn-around time (TAT) index, and the percentage of timely reported test results. The geographic distribution of cases was also analyzed.Results: There was a significant decline in the workload of the laboratory during the first two months of the war, and the numbers of cytopathology specimens fell to less than one third of prewar levels, and the TAT was prolonged. Since May 2022, the efficiency and quality of cytopathologic testing has been largely restored in most parts of Ukraine, only to be affected again by increased Russian bombardment toward the end of summer 2022. The number of cytology specimens was reduced and the source of cytology specimens changed from the prewar conditions reflecting the relocation of the CSD Lab to western Ukraine.Conclusion: Cytolopathological screening and diagnostics were seriously disrupted in Ukraine during the Russian invasion resulting in a decreased volume of cytology specimens received in the CSD Lab during the early months of the war. By adapting to the war conditions and reorganizing the cytology services, CSD Lab has continued providing cytology services at a level of efficiency similar to those of the prewar period. However, the volume of cytology specimens remains much smaller than before war, indicating that the cytology services have been adversely affected by the war.

Obstetrical, perinatal, and genetic outcomes associated with nonreportable prenatal cell-free DNA screening results

The clinical implications of nonreportable cell-free DNA screening results are uncertain, but such results may indicate poor placental implantation in some cases and be associated with adverse obstetrical and perinatal outcomes. This study aimed to assess the outcomes of pregnancies with nonreportable cell-free DNA screening in a cohort of patients with complete genetic and obstetrical outcomes. This was a prespecified secondary analysis of a multicenter prospective observational study of prenatal cell-free DNA screening for fetal aneuploidy and 22q11.2 deletion syndrome. Participants who underwent cell-free DNA screening from April 2015 through January 2019 were offered participation. Obstetrical outcomes and neonatal genetic testing results were collected from 21 primary-care and referral centers in the United States, Europe, and Australia. The primary outcome was risk for adverse obstetrical and perinatal outcomes (aneuploidy, preterm birth at <28, <34, and <37 weeks' gestation, preeclampsia, small for gestational age or birthweight <10th percentile for gestational week, and a composite outcome that included preterm birth at <37 weeks, preeclampsia, small for gestational age, and stillbirth at >20 weeks) after nonreportable cell-free DNA screening because of low fetal fraction or other causes. Multivariable analyses were performed, adjusting for variables known to be associated with obstetrical and perinatal outcomes, nonreportable results, or fetal fraction. In total, 25,199 pregnant individuals were screened, and 20,194 were enrolled. Genetic confirmation was missing in 1165 (5.8%), 1085 (5.4%) were lost to follow-up, and 93 (0.5%) withdrew; the final study cohort included 17,851 (88.4%) participants who had cell-free DNA, fetal or newborn genetic confirmatory testing, and obstetrical and perinatal outcomes collected. Results were nonreportable in 602 (3.4%) participants. A sample was redrawn and testing attempted again in 427; in 112 (26.2%) participants, results were again nonreportable. Nonreportable results were associated with higher body mass index, chronic hypertension, later gestational age, lower fetal fraction, and Black race. Trisomy 13, 18, or 21 was confirmed in 1.6% with nonreportable tests vs 0.7% with reported results (P=.013). Rates of preterm birth at <28, 34, and 37 weeks, preeclampsia, and the composite outcome were higher among participants with nonreportable results, and further increased among those with a second nonreportable test, whereas the rate of small for gestational age infants was not increased. After adjustment for confounders, the adjusted odds ratios were 2.2 (95% confidence interval, 1.1-4.4) and 2.6 (95% confidence interval, 0.6-10.8) for aneuploidy, and 1.5 (95% confidence interval, 1.2-1.8) and 2.1 (95% confidence interval, 1.4-3.2) for the composite outcome after a first and second nonreportable test, respectively. Of the patients with nonreportable tests, 94.9% had a live birth, as opposed to 98.8% of those with reported test results (adjusted odds ratio for livebirth, 0.20 [95% confidence interval, 0.13-0.30]). Patients with nonreportable cell-free DNA results are at increased risk for a number of adverse outcomes, including aneuploidy, preeclampsia, and preterm birth. They should be offered diagnostic genetic testing, and clinicians should be aware of the increased risk of pregnancy complications.

Mechanical properties of Q690E/Q960E high-strength steels at low and ultra-low temperatures: Tests and full-range constitutive models

Mechanical properties of high-strength steels (HSSs) at varying temperatures are fundamental information for the design and numerical analysis of cold-region structures and LNG containers using HSSs. Tensile tests on 14 HSS Q690E and 17 Q960E tensile coupons were firstly carried out at six low temperatures of 20, −30, −60, −80, −120 and −165 °C. The required low-temperature environment for the tensile tests was achieved through an insulation chamber with injecting liquid nitrogen (LN) gas. Their results showed that decreasing the low temperature from 20 to −165 °C slightly affected the elastic modulus of both HSS Q690E and Q960E materials, but significantly increased their yield and ultimate strengths. In addition, ductile failure occurred to all the HSS coupons at low temperatures, and the ductility of HSS was not compromised. Finally, this paper developed full-range constitutive models to describe stress–strain laws of HSS Q690E and Q960E at a low-temperature range of −165 ∼ 20 °C. Validations against the reported test results showed that the proposed full-range constitutive model reasonably estimated the stress–strain behaviours of Q690E and Q960E HSSs at low temperatures.

Biodiesel as an alternate fuel for future energy production: A review

AbstractThere has been a significant growth in aviation industry due to the increased consumption of aviation fuel which is one of the main sources of anthropogenic CO2 emissions. As a result, using aviation fuels made from renewable resources has drawn a lot of attention. There have been significant attempts made to create renewable fuels as alternatives to petroleum‐based fuels in order to provide a conservative approach for mitigating CO2 emissions from the air transportation sector. Non‐edible oils combined with diesel are preferred as biofuels due to the growing global population and the rising need for edible oils and food crops. Various non edible oils which include candle nut, soap nut, jatropha, groundnut, canola, karanja, mahua, neem, jojoba, rubber seed oil, etc., are employed to produce biofuel. These biodiesels are prepared from the raw oil by a two‐step co‐solvent esterification process. In this study, an attempt is made to compare the important performance parameters of biodiesel blends made from both edible and non‐edible sources. Brake thermal efficiency and brake specific fuel consumption of known biodiesel samples are evaluated based on the reported test results. Emission parameters includes carbon monoxides, carbon di oxides, smoke, and nitrogen oxide emissions are also compared.