Uniform Threshold Research Articles

Computing Stabilizing Feedback Gains via a Model-Free Policy Gradient Method

In spite of the lack of convexity, convergence and sample complexity properties were recently established for the random search method applied to the linear quadratic regulator (LQR) problem. Since policy gradient approaches require an initial stabilizing controller, we propose a model-free algorithm that searches over the set of state-feedback gains and returns a stabilizing controller in a finite number of iterations. Our algorithm involves a sequence of relaxed LQR problems for which the associated domains converge to the set of stabilizing controllers for the original continuous-time linear time-invariant system. Starting from a stabilizing controller for the relaxed problem, the proposed approach alternates between updating the controller via policy gradient iterations and decreasing relaxation parameter in the LQR cost while preserving stability at all iterations. By properly tuning the relaxation parameter updates we ensure that the cost values do not exceed a uniform threshold and establish computable bounds on the total number of iterations.

Predictive value of late gadolinium enhancement cardiovascular magnetic resonance in patients with persistent atrial fibrillation: dual-centre validation of a standardized method.

With recurrence rates up to 50% after pulmonary vein isolation (PVI) in persistent atrial fibrillation (AF), predictive tools to improve patient selection are needed. Patient selection based on left atrial late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) has been proposed previously (UTAH-classification). However, this approach has not been widely established, in part owed to the lack of standardization of the LGE quantification method. We have recently established a standardized LGE-CMR method enabling reproducible LGE-quantification. Here, the ability of this method to predict outcome after PVI was evaluated. This dual-centre study (n = 219) consists of a prospective derivation cohort (n = 37, all persistent AF) and an external validation cohort (n = 182; 66 persistent, 116 paroxysmal AF). All patients received an LGE-CMR prior to first-time PVI-only ablation. LGE was quantified based on the signal-intensity-ratio relative to the blood pool, applying a uniform LGE-defining threshold of >1.2. In patients with persistent AF in the derivation cohort, left atrial LGE-extent above a cut-off value of 12% was found to best predict relevant low-voltage substrate (≥2 cm two with <0.5 mV during sinus rhythm) and arrhythmia-free survival 12 months post-PVI. When applied to the external validation cohort, this cut-off value was also predictive of arrhythmia-free survival for both, the total cohort and the subgroup with persistent AF (LGE < 12%: 80% and 76%; LGE > 12%: 55% and 44%; P = 0.007 and P = 0.029, respectively). This dual-centre study established and validated a standardized, reproducible LGE-CMR method discriminating PVI responders from non-responders, which may improve choice of therapeutic approach or ablation strategy for patients with persistent AF.

Predicting the Porosity in Selective Laser Melting Parts Using Hybrid Regression Convolutional Neural Network

Assessing the porosity in Selective Laser Melting (SLM) parts is a challenging issue, and the drawback of using the existing gray value analysis method to assess the porosity is the difficulty and subjectivity in selecting a uniform grayscale threshold to convert a single slice to binary image to highlight the porosity. This paper proposes a new approach based on the use of a Regression Convolutional Neural Network (RCNN) algorithm to predict the percent of porosity in CT scans of finished SLM parts, without the need for subjective difficult thresholding determination to convert a single slice to a binary image. In order to test the algorithm, as the training of the RCNN would require a large amount of experimental data, this paper proposed a new efficient approach of creating artificial porosity images mimicking the real CT scan slices of the finished SLM part with a similarity index of 0.9976. Applying RCNN improved porosity prediction accuracy from 68.60% for image binarization method to 75.50% using the RCNN. The algorithm was then further developed by optimizing its parameters using Bees Algorithm (BA), which is known to mimic the behavior of honeybees, and the hybrid Bees Regression Convolutional Neural Network (BA-RCNN) produced better prediction accuracy with a value of 85.33%.

Cold temperature characterization of ring triplets based on RD53A readout chip

This paper reports the Trento test setup and the cold test procedure for three triplets (ID: R4, R5, and R6) assembled with RD53A readout cheap and planar sensors. The trim and tuning of Front Ends (FE), as well as sensor I-V measurements, were made for a cold temperature (−25 °C) for an applied voltage (−30 V for R4, −10 V for R5 and R6). As a part of QC, initially, several test scans: analog, digital, threshold, ToT, noise, etc., were performed to evaluate the module response at −25 °C before applying a necessary tuning script to find a spatially uniform threshold distribution over the pixel matrix. Later, the crosstalk-based disconnected-bump and X-ray scans were made to check modules’ bump bonding quality and hits per pixel. Results reported here show a good agreement to a qualified triplet module, assuring the Trento cold test setup capacity for the ATLAS ITk QA/QC process.

The cost-effectiveness of a uniform versus age-based threshold for one-off screening for prevention of cardiovascular disease.

The objective of this article was to assess the cost-effectiveness of screening strategies for cardiovascular diseases (CVD). A decision analytic model was constructed to estimate the costs and benefits of one-off screening strategies differentiated by screening age, sex and the threshold for initiating statin therapy ("uniform" or "age-adjusted") from the Spanish NHS perspective. The age-adjusted thresholds were configured so that the same number of people at high risk would be treated as under the uniform threshold. Health benefit was measured in quality-adjusted life years (QALY). Transition rates were estimated from the European Prospective Investigation into Cancer and Nutrition (EPIC-CVD), a large multicentre nested case-cohort study with 12years of follow-up. Unit costs of primary care, hospitalizations and CVD care were taken from the Spanish health system. Univariate and probabilistic sensitivity analyses were employed. The comparator was no systematic screening program. The base case model showed that the most efficient one-off strategy is to screen both men and women at 40years old using a uniform risk threshold for initiating statin treatment (Incremental Cost-Effectiveness Ratio of €3,274/QALY and €6,085/QALY for men and women, respectively). Re-allocating statin treatment towards younger individuals at high risk for their age and sex would not offset the benefit obtained using those same resources to treat older individuals. Results are sensitive to assumptions about CVD incidence rates. To conclude, one-off screening for CVD using a uniform risk threshold appears cost-effective compared with no systematic screening. These results should be evaluated in clinical studies.

Predictive value of late gadolinium enhancement MRI in patients with persistent atrial fibrillation. Multicentric validation of a standardised method

Abstract Background With recurrence rates after PVI in persistent atrial fibrillation (AF) as high as 50%, predictive tools to improve patient selection are clearly needed. Compared to paroxysmal AF, persistent AF is more substrate-dependent. While endocardial low voltage substrate detected by invasive mapping has been shown to predict AF recurrence, to date the only non-invasive method to assess arrhythmogenic substrate is late gadolinium enhancement (LGE)-MRI. In fact, patient selection for PVI based on left atrial (LA) LGE extent according to the UTAH stages has been proposed, However, this approach has not been widely established, in part owed to the lack of standardisation and thus limited reproducibility of the MRI postprocessing method. Moreover, in the recent DECAAF-2 multicenter trial, the UTAH stages failed to predict outcome in patients with persistent AF. Purpose We have recently established a standardised MRI method that aims at reproducible quantification of LGE. Here, the ability of this method to detect arrhythmogenic substrate and to predict outcome after PVI in patients with persistent AF was evaluated by two centers independently. Methods This dual center study consisted of a prospective derivation cohort at centre1 and a validation cohort at centre 2. All patients received an LGE-MRI prior to ablation (PVI only) and were followed systematically with holter ECG at 3, 6 and 12 months. Gradient echo MR sequences were acquired in sinus rhythm and LA 3D-reconstruction performed using ADAS-3D software. LGE was quantified based on the signal intensity ratio of each voxel relative to the blood pool, applying a uniform threshold of &amp;gt;1.2 to define LGE indicative of fibrotic tissue. Invasive mapping served as a reference defining arrhythmogenic substrate (&amp;gt;2 cm2 LA area with bipolar voltage &amp;lt;0.5 mV). Results A ROC analysis of 37 consecutive patients with persistent AF in the prospective derivation cohort yielded a cutoff-value of 12% LGE to predict relevant low-voltage substrate with the highest accuracy. This cutoff-value was also predictive of AF recurrence after PVI (Fig. 1). When applied to the external validation cohort of 182 consecutive patients, the cutoff-value of 12% was also predictive of AF recurrence after PVI – both in the full cohort (odds ratio 3.3, p=0.003) and in the subgroup of 65 patients with persistent AF (odds ratio 3.7, p=0.038). Of note, among patients with persistent AF, recurrence rate was 54% in those with &amp;gt;12% LGE but only 24% in those with &amp;lt;12% (Fig. 2). Conclusion This dual center study established and validated the predicitive value of LGE as determined by a standardised MRI method in patients with persistent AF that can be reproducibly applied across different centers. A cutoff-value of 12% LGE was able to discriminate between responders and non-responders to PVI and may thus guide selection of suitable candidates that are likely to benefit from ablation. Funding Acknowledgement Type of funding sources: None.

Prior land surface reflectance-based sandstorm detection from space using deep learning

Traditional sandstorm detection methods use radiation differences among dust, underlying surface, and cloud to distinguish them by setting appropriate thresholds. Owing to the complex structure of the underlying surface, dust, and cloud, it is difficult to set a uniform threshold to achieve high-precision separation. Deep learning (DL) has powerful information mining capabilities and can fully use spectral differences between dust, land surface, and clouds. However, under the limited band information provided by satellite sensors, DL cannot easily distinguish highly heterogeneous land surfaces from multi-modal dust and cloud. This study proposes a sandstorm detection algorithm with DL supported by a land surface reflectance (LSR) dataset. The clear sky LSR dataset was obtained based on the MOD09A1 product. Based on the dataset, the difference between the reflectance observed by the satellite and the corresponding LSR is generated, which is used as a characteristic parameter of sandstorm detection with the deep learning method. The sandstorm detection of MODIS data is realized using multi-band radiation and radiation difference with DL. Results showed that the sandstorm detection algorithm used in this study was consistent with the OMI AI product with a detection accuracy of 84.6%. Compared with the detection results without the LSR dataset, this method effectively improves the accuracy of sandstorm identification.

On connectivity and robustness of random graphs with inhomogeneity

AbstractThe study of threshold functions has a long history in random graph theory. It is known that the thresholds for minimum degreek,k-connectivity, as well ask-robustness coincide for a binomial random graph. In this paper we consider an inhomogeneous random graph model, which is obtained by including each possible edge independently with an individual probability. Based on an intuitive concept of neighborhood density, we show two sufficient conditions guaranteeingk-connectivity andk-robustness, respectively, which are asymptotically equivalent. Our framework sheds some light on extending uniform threshold values in homogeneous random graphs to threshold landscapes in inhomogeneous random graphs.

Patterning an Erosion-Free Polymeric Semiconductor Channel for Reliable All-Photolithography Organic Electronics.

Reliable patterning of organic semiconductors (OSCs) with high uniformity is essential to all-photolithography organic electronics. However, the majority of cross-linked OSCs experience performance fluctuations after photolithography because of the inherent vulnerability of low-ordered regions. Herein, we develop an anti-solution penetration photolithography process to achieve the reliable patterning of the OSC layer for all-photolithography integrated organic electronics. Using a thick and highly cross-linked semiconductor film and a low-solubility developer, an erosion-free semiconductor channel is obtained with a high mobility of up to 1.254 cm2 V-1 s-1 and a uniform threshold voltage close to zero. Compared with existing all-photolithography organic circuits, the unit logic gate area consumption is lower by 1-3 orders of magnitude at 0.0069 mm2, while the transistor density is higher by 1-2 orders of magnitude at 6780 Tr cm-2. The miniaturized organic inverters maintain uncompromised voltage gains, and the 15-stage organic ring oscillators feature higher oscillation frequencies, making them promising for applications in wide-ranging integrated organic circuits.

High-Yield and Uniform NbO x -Based Threshold Switching Devices for Neuron Applications

Threshold switching (TS) devices based on NbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> materials show intriguing potential for constructing artificial neurons in a neuromorphic machine. However, the high electroforming voltage, the low TS yield, and the poor device uniformity hinder the practical application of NbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> -based TS devices. In this work, we systematically investigate the effect of film composition on device performance by adjusting the oxygen contents in the NbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> films. The electroforming voltage decreases with lowering the oxygen content, and the forming yield for activating TS behavior increases without an additional reset process. Moreover, we propose a stacked method by inserting a NbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>y</i></sub> layer with high oxygen content between the low oxygen NbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> layer and the bottom electrode. The intercalated NbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>y</i></sub> layer serves as a virtual bottom electrode after breakdown, enhancing the local electrical field and improving cycle-to-cycle stability and device-to-device uniformity. These results demonstrate that the device performances are greatly improved by optimizing the oxygen content and structure, guiding for practical applications of NbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>x</i></sub> -based TS devices in neuromorphic computing.

Abstract P102: Comparison Of Existing Cardiovascular Risk Prediction Models In Haiti: Implications For Primary Prevention In Lower-income Countries

Introduction: Cardiovascular diseases (CVD) are rapidly increasing in low-middle income countries. Accurate risk assessment is essential to reduce premature CVD by targeting primary prevention. Available CVD risk prediction models are built on predominantly Caucasian, high-income country populations, and have not been evaluated in lower-income countries. We aimed to compare six existing models for predicted 10-year risk of CVD and identify high-risk groups for targeted prevention in Haiti. Methods: We used cross-sectional data within the Haiti CVD Cohort Study, including 653 adults ≥ 40 years without known history of CVD. Six CVD risk prediction models were compared: pooled cohort equations (PCE), adjusted PCE with updated cohorts, Framingham CVD Lipids, Framingham CVD Body Mass Index (BMI), WHO Lipids, and WHO BMI. Risk factors were measured during clinical exams. Primary outcome was continuous and categorical predicted 10-year CVD risk. Secondary outcome was statin eligibility. Results: Seventy percent (460/653) were female, 65.5% (428/653) lived on a daily income of ≤1 USD, 57.0% (372/653) had hypertension, 14.5% (95/653) had hypercholesterolemia, 9.3% (61/653) had diabetes mellitus, and 5.5% (36/653) were current smokers. Predicted 10-year CVD risk ranged from 3.9% in adjusted PCE (IQR 1.7-8.4) to 9.8% in Framingham-BMI (IQR 5.0-17.8), and Spearman correlation coefficients ranged from 0.87 to 0.98. The percent of the cohort categorized as high risk using the uniform threshold of 10-year CVD risk ≥ 7.5% ranged from 28.8% in the adjusted PCE model to 62.0% in the Framingham-BMI model (χ 2 = 331, p value &lt; 0.001). Statin eligibility also varied widely. Conclusions: In the Haiti CVD Cohort, there was substantial variation in the proportion identified as high-risk and statin eligible using existing models, leading to very different treatment recommendations and public health implications depending on model choice. There is a need to design and validate CVD risk prediction tools for low-middle income countries.

Abstract P3-16-04: Estimation of willingness-to-pay for breast cancer treatments through contingent valuation method in Japanese breast cancer patients (JCOG1709A): The main study findings

Abstract Background In 2019, the Japanese government has introduced the economic valuation to healthcare system. However, the threshold for determining cost-effectiveness-analysis has yet to be adequately studied. Therefore, we have designed a study to examine the financial value of “life” and “health” based on willingness-to-pay (WTP) considered by patients with primary and metastatic breast cancer (PBC and MBC) in Japan. Methods This study is conducted by forty-five hospitals under the Breast Cancer Study Group of Japan Clinical Oncology Group (JCOG). In the preliminary study, 168 patients (84 patients with PBC and 84 patients with MBC) from 20 to 79 years of age paying medical costs were examined their WTP for setting up the dichotomous-choice method survey form for using in the main study. Virtual scenario-specific treatments to avoid the recurrence and death of breast cancer for one year for PBC patients, and to prolong the survival period for one year for the patients with MBC were presented. The patients were evaluated how much money would pay to receive the treatment in a self-written answer and the amount of WTP that would be presented in the main study was determined. In the main study, 1,620 patients (810 patients with PBC and 810 patients with MBC) were surveyed to their WTP for hypothetical scenarios using the dichotomous-choice method survey form. With the two-step dichotomous-choice method, if the first stage response was yes, a higher amount was displayed for the second stage. If the first stage response was no, a lower amount was shown for the second stage. For the main analysis, the acceptance probability curve was calculated using the parametric method. The calculation was based on the obtained responses and median WTP, which was determined by calculating the amount at which the acceptance probability curve is at 50%. The obtained amount was converted to WTP per one QALY based on the displayed question content. Results Completed surveys were collected from 716 PBC patients (88.4%) and 702 patients (86.7%). Based on the preliminary study, the amount of WTP offering in the first stage was set 5 million yen (JPY) (50,000 USD), and offering in the second stage was 7 million JPY (70,000 USD) for those who responded accepting the scenario treatment and 3 million JPY (30,000 USD) for those who responded refusing. We obtained point estimates of WTP for each virtual scenario treatments. The WTP of the two hypothetical scenarios for PBC patients were as follows; scenario 1) the treatment to gain one year without recurrence: 2.06 million JPY (20,600 USD), scenario 2) the treatment that reduces risk of recurrence by 40%: 2.40 million JPY (24,000 USD). The WTP of the two hypothetical scenarios for MBC patients were as follows; scenario 3) the treatment that can prolong survival for one year in current health condition: 2.81 million JPY (28,100 USD), scenario 4) the treatment that can prolong survival by one year in the health condition before having breast cancer: 2.92 million JPY (29,200 USD). Conclusion We created hypothetical 1-quality-adjusted survival year (QALY) scenarios for breast cancer patients with different disease status and validated them using the contingent valuation method. Our results demonstrate that WTP per 1QALY varies with the disease status of breast cancer. Therefore, we conclude that we cannot simply use a uniform threshold when examining the cost-effectiveness of medical interventions in breast cancer as a unit of cost/QALY. Citation Format: Tsuguo Iwatani, Fumikata Hara, Tadahiko Shien, Masato Takahashi, Norikazu Masuda, Yasuaki Sagara, Keita Sasaki, Junki Mizusawa, Haruhiko Fukuda, Takaru Shiroiwa, Hiroji Iwata. Estimation of willingness-to-pay for breast cancer treatments through contingent valuation method in Japanese breast cancer patients (JCOG1709A): The main study findings [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-16-04.

Threshold optimization method of single-bit quanta image sensor based on bit density

To improve the quality of reconstructed images of single-bit quanta image sensors, a self-adaptive threshold optimization method is proposed. The method can adaptively adjust the quantization threshold according to different light intensities, making the quality of the reconstructed image improved. First, the bitstream data from the quantization of real images are obtained by sensor model. Second, the optimal threshold value of each row is determined by calculating the bit-density, followed by the threshold value updated according to the deviation value between the bit-density of a single-pixel and 0.5. Finally, the optimal threshold matrix obtained by this method is used to reconstruct the image to improve imaging quality. Four identical test images were processed by the proposed method, the traditional method, and Elgendy’s variable threshold method, respectively. The results show that the proposed method can improve the peak signal-to-noise ratio of the reconstructed image in comparison with the traditional uniform threshold method. Compared with Elgendy’s method, the proposed method can effectively reduce the number of iterations under the same parameter conditions. These experiments prove that the proposed method can effectively improve the quality of reconstructed images with fewer iterations.

Dose-dependent strain localization and embrittlement in ferritic materials: A predictive approach based on sub-grain plasticity modelling

This paper presents a theoretical approach addressing plastic-strain spreading in post-irradiated BCC materials accounting for crucial sub-grain scale, dislocation-mediated plasticity mechanisms. The proposed model explicitly provides the number of shear-bands developed in irradiated ( N i r r ) versus non-irradiated ( N 00 d p a ) grain cases, for fixed amounts of plastic deformation. Calculations carried out under various irradiation defect size and number density cases, which helps it appraising important material properties, in particular the dose-dependent, grain-scale uniform elongation threshold. The model ability to handle macro-scale effects is then evaluated using a simple stochastic calculation procedure, taking advantage of actual grain size and orientation maps. The dose-dependent embrittlement amplitude appears to critically depend on the shear band thickness and spacing variations, existing near the fracture surface of failing specimens. That perception allows comparing our predictions with adapted test results, for validation.

A low-g omnidirectional MEMS inertial switch with load direction identification

In order to solve the problem that the low-g omnidirectional MEMS inertial switches cannot recognize the load direction, a nickel omnidirectional MEMS inertial switch with identifiable load direction and uniform in-plane threshold distribution was designed. The switch is mainly composed of a spring–mass system, four independent flexible radial electrodes and an axial electrode. The function of identifying the direction of acceleration is realized by detecting the closed states of different electrodes. According to the design results of MEMS inertial switch, the dynamic performance of the switch was analyzed by ANSYS software. The results show that the designed switch meets the functional requirements of load direction identification. Based on UV-LIGA multilayer photolithography, the nickel MEMS inertial switch was fabricated on a steel substrate. In the process of fabrication, the line width compensation method was used to reduce the dimensional error caused by swelling phenomenon and removal process of the photoresist. What's more, the thickness compensation method was used to reduce the process error caused by flattening treatment. The overall dimension of the switch is 5300 × 5300 × 270 μm and the smallest line-width is 20 μm. Ultimately, the fabricated switch was tested by the centrifuge device and dropping hammer in XOY plane and Z-axis direction. The dynamic threshold of the switch is between 7.9 and 11.3 g, and the response time in each direction is less than 2 ms. The switch can recognize the direction of acceleration in XOY plane and Z-axis. The switch has an excellent anti-overload performance.

CKD Progression From the Time of Estimated GFR-Based Waitlist Eligibility and Racial Disparities in Transplant Access

Equations for estimated glomerular filtration rate (eGFR) that incorporate a term for race assign a higher value to Black individuals compared to non-Black individuals for the same sex, age, and serum creatinine concentration. This difference may contribute to racial disparities in kidney transplant access. We sought to (1) compare time from meeting a transplant eligibility threshold of eGFR≤20 mL/min/1.73 m2 to kidney failure with replacement therapy (KFRT) among Black, Hispanic, and White patients, and (2) assess the impact of incorporation of race into eGFR expressions on establishment of waitlist eligibility and time from eligibility to KFRT. Retrospective cohort. Using the OptumLabs Data Warehouse, we assembled a cohort of 40,042 White, 8,519 Black, and 3,569 Hispanic patients having at least one eGFR value between 20 and 60 mL/min/1.73 m2 within the preceding 2 years and an incident outpatient eGFR of≤20 mL/min/1.73 m2 between 2008-2018, using the CKD-EPI creatinine equation that includes a term for race coded as Black or non-Black. We then reassembled a Black patient cohort based on incident eGFR≤20 mL/min/1.73 m2 (n= 11,269) estimated using the same CKD-EPI equation but coding Black patients as non-Black. Race/ethnicity. Time to KFRT. Unadjusted and adjusted Fine-Gray models; linear regression to compute eGFR slopes. By 3 years, the cumulative incidence of KFRT was 20.5% among White patients, 40.9% among Hispanic patients, 36% among Black patients whose GFR was estimated using a race term coded as Black, and 28.7% among Black patients whose GFR was estimated using a race term coded as non-Black. In fully adjusted analyses including 11,269 Black patients with an eGFR≤20 mL/min/1.73 m2 based on coding them as non-Black, KFRT risk remained greater among Black (HR, 1.28 [95% CI, 1.15-1.43]) and Hispanic (HR, 1.66 [95% CI, 1.18-2.31]) patients than among White patients. Based on slopes of eGFR decline, coding Black patients as non-Black would allow earlier waitlist activation by an estimated median of 0.5 [interquartile range, 0.27-1.23] years. Inability to exclude individuals who would not be kidney transplant candidates if comprehensively evaluated. A uniform eGFR threshold provides less opportunity for being placed on the transplant waitlist among Black and Hispanic patients. For many Black patients, estimation of GFR as if their race category were non-Black would allow substantially earlier waitlisting but would not eliminate their shorter time to KFRT and reduced opportunity for preemptive transplantation compared with White patients.

Common iliac vein stenting for May-Thurner syndrome and subsequent pregnancy

BackgroundFor women with left common iliac vein compression (ie, May-Thurner syndrome) who undergo venous stenting and subsequently become pregnant, concerns have been raised regarding a possible compromise of stent patency due to compression from the gravid uterus and the hypercoagulability induced by pregnancy. Only a small body of literature exists on this subject, and limited management guidelines are available. The present study was designed to evaluate the safety of iliac vein stenting for May-Thurner syndrome (MTS) with subsequent pregnancy. MethodsFemale patients who had undergone common iliac vein stenting at our center who were aged 18 to 45 years and had subsequently become pregnant were identified. A retrospective medical record review of eight eligible patients was conducted, recording the demographics, procedural characteristics, and anticoagulation strategies. The primary outcome evaluated was stent patency. ResultsAll eight patients had undergone left common iliac vein stenting for MTS. A total of eight stents were placed, and all demonstrated duplex ultrasound patency throughout pregnancy and postpartum. Seven patients delivered healthy pregnancies, and one experienced a stillbirth. The clinical CEAP (clinical, etiologic, anatomic, pathophysiologic) class remained unchanged or improved from pregnancy to postpartum for all patients. The average age at stent placement was 31 ± 5 years, and the average interval from stent placement to pregnancy was 28 ± 19 months. One patient developed nonobstructive deep vein thrombosis (DVT) of the left femoral vein during pregnancy and was treated with therapeutic enoxaparin. The nonobstructive DVT did not compromise the iliac vein stent. Two patients received low-dose aspirin and prophylactic doses of enoxaparin, one for a history of DVT and factor V Leiden and one for a recent history of fertility treatment. The five remaining patients received no anticoagulation, three received low-dose aspirin, and two received no antiplatelet therapy. ConclusionsCommon iliac vein stent patency was not compromised by subsequent pregnancy in our eight patients with MTS. Furthermore, the stents remained patent throughout pregnancy in patients receiving a wide range of anticoagulation and antiplatelet treatments, suggesting that no uniform therapeutic threshold exists and treatment should be individualized. For most patients, low-dose aspirin alone or no treatment was adequate. This could have implications for counseling women who require intervention for MTS and are of child-bearing age.

Individualized faecal immunochemical test cut-off based on age and sex in colorectal cancer screening.

The risk of having colorectal cancer (CRC) or its precursors vary with age and sex. Yet, most CRC screening programs using the quantitative faecal immunochemical test (FIT) use a uniform FIT cut-off. We aimed to calculate individualized FIT cut-offs based on age and sex. Data from a study of 1,112 asymptomatic average-risk screening participants undergoing colonoscopy without preselection were used to build a logistic regression model to calculate the risk of having advanced neoplasia (AN) at colonoscopy using age, sex, and FIT concentration as variables. We calculated age- and sex-adjusted FIT cut-off concentrations based on a uniform risk threshold. In a total of 101 of the 1,112 participants AN was detected at colonoscopy. We selected a risk threshold that would produce a specificity of 96.9% in the study group, matching the specificity of FIT at a cut-off of 20µg Hb/g faeces. At this threshold, age- and sex-adjusted FIT cut-off concentrations ranged from 36.9µg Hb/g faeces for 50-year-old women to 9.5µg Hb/g faeces for 75-year old men. At this level of specificity, the risk-based model reached a sensitivity for AN of 28.7% (95%CI: 20.8 to 38.2) versus 27.7% (95%CI: 19.9 to 37.1) for FIT only. Using a risk threshold instead of a uniform FIT-based threshold for inviting screening participants to follow-up colonoscopy ensures that everyone has a comparable risk of AN prior to colonoscopy and may improve the detection of advanced neoplasia, although the absolute magnitude of the increase is likely to be limited.

Optimal cumulative cisplatin dose during concurrent chemoradiotherapy among children and adolescents with locoregionally advanced nasopharyngeal carcinoma: A real-world data study

PurposeTo identify an optimal cumulative cisplatin dose along with concurrent chemoradiotherapy (CC-CCD) for children and adolescents with locoregionally advanced nasopharyngeal carcinoma (CALANPC) using real-world data. Materials and MethodsUsing an NPC-specific database at our center, 157 patients younger than 19 years old with non-disseminated CALANPC and receiving neoadjuvant chemotherapy (NAC) plus cisplatin-based concurrent chemoradiotherapy (CCRT) were enrolled. Confounding factors were controlled by conducting propensity score matching analysis. Primary endpoints include disease-free survival (DFS) and distant metastasis-free survival (DMFS). ResultsThe optimal threshold for CC-CCD with respect to DFS was 160 mg/m2 based on recursive partitioning analyses (RPA). Therefore, a uniform threshold of 160 mg/m2 (≥160 vs. <160 mg/m2) was selected to classify patients between high and low CC-CCD groups for survival analysis. Patients receiving low CC-CCD showed a significant decrease in 5-year DFS (76.6% vs 91.3%; P = 0.006) and DMFS (81.3% vs 93.5%; P = 0.009) compared to those receiving high CC-CCD. Multivariate analyses indicated that high CC-CCD as an favorable prognostic influence for DFS (P = 0.007) and DMFS (P = 0.008). Further matched analysis identified 65 pairs in both high and low CC-CCD groups. In the matched cohort, high CC-CCD was still identified as a favorable factor for prognosis in DFS (HR, 0.23; 95% CI, 0.08–0.70; P = 0.010) and DMFS (HR, 0.23; 95% CI, 0.06–0.82; P = 0.023). ConclusionCC-CCD exerts significant treatment effects and 160 mg/m2 CC-CCD may be adequate to provide antitumor effects for CALANPC receiving NAC plus CCRT.

Hydrological management strategies for the control of algal blooms in regulated lowland rivers

AbstractReservoirs of lowland floodplain rivers with eutrophic backgrounds cause variations in the hydrological and hydraulic conditions of estuaries and low‐dam reservoir areas, which can promote planktonic algae to proliferate and algal bloom outbreaks. Understanding the ecological effects of variations in hydrological and hydraulic processes in lowland rivers is important for algal bloom control. In this study, the middle and lower reaches of the Han River, China, a typical regulated lowland river with a eutrophic background, are selected. Based on the effect of hydrological and hydraulic variability on algal blooms, a hydrological management strategy for river algal bloom control is proposed. The results showed that (a) differences in river morphology and background nutrient levels cause significant differences in the critical threshold flow velocities for algal bloom outbreaks between natural river and low‐dam reservoir sections; there is no uniform threshold flow velocity for algal bloom control. (b) There are significant differences in the river hydrological/hydraulic conditions between years with and without algal blooms. The average river flow, water level and velocity in years with algal blooms are significantly lower than those in years without algal blooms. (c) For different river sections where algal blooms occur and to meet the threshold flow velocities, the joint operation of cascade reservoirs and diversion projects is an effective method to prevent and control algal blooms in regulated lowland rivers. This study is expected to deepen our understanding of the ecological significance of special hydrological processes and guide algal bloom management in regulated lowland rivers.