Nearest Method Research Articles

Heavy Menstrual Bleeding in Adolescents on Direct Oral Anticoagulants

Background Direct oral anticoagulants (DOACs) - Dabigatran, Rivaroxaban, and Apixaban - are increasingly being used in the pediatric and adolescent population. DOACs have been shown to increase the likelihood of heavy menstrual bleeding (HMB) in adult women of childbearing age, when compared to vitamin K antagonists or low molecular weight heparins (LMWH). There are limited data regarding the prevalence of HMB in the adolescent population on DOACs. Pivotal trials leading up to the approval of DOACs in the adolescent and pediatric populations also failed to prespecify prospective analyses on the impact of DOACs on HMB. The effect of HMB and its treatment burden can contribute to the compliance rates of DOACs in this population, adding to the recurrence rates of venous thromboembolism. Our study aims to assess the rate of HMB with DOAC use in adolescents by comparing the rate of HMB and its associated healthcare burden to patients on other anticoagulants. Methods This is a retrospective cohort study conducted with deidentified data obtained from the Pediatric Health Information System (PHIS) database after IRB approval. The PHIS is a comparative database with clinical and resource utilization data for inpatient, ambulatory surgery, ED, and observation unit encounters from more than 49 children's hospitals. ICD-10 codes were used to query the data for pediatric patients between the ages of 9-18 years on anticoagulant therapy from January 2020-December 2022. DOAC group was defined as patients on Rivaroxaban, Dabigatran, or Apixaban at any point in their care. The control group was defined as patients on anticoagulants other than DOACs, such as LMWH, unfractionated heparin, coumadin, and bivalirudin. Data extracted included any episode of HMB (diagnosis codes for abnormal uterine bleeding, dysfunctional uterine bleeding, menorrhagia, or heavy menstrual bleeding), risk factors for HMB other than anticoagulants, and healthcare utilization data for HMB such as number of ED visits, hospital admission and length of stay, and ICU admission. For the Descriptive statistics, demographics and clinical characteristics of the patients were described using median and interquartile range (25th percentile, 75th percentile) for continuous variables, and frequency and percentages for categorical variables, as appropriate. Control group was matched to the DOAC group by propensity score matching using nearest method with the ratio 1:5 to generate the similar pairwise comparison. Categorical variables were analyzed with the chi-square test; continuous variables were assessed by Mann Whitney U test or Kruskal-Wallis rank sum test. P-value of less than 0.05 was considered as statistically significant for the analysis. All the analysis were performed using SAS software, version 9.4 (SAS Institute, Cary, NC) and R software, version 4.2.2 Results Of the total sample size of 87,119 patients on any anticoagulant, 84,411 (96.8%) patients were in the control group and 2,708 (3.1%) in the DOAC group before propensity matching. Of the three DOACs studied, 2013 were in Rivaroxaban group (74%), followed by Apixaban (671 or 25%) and Dabigatran (24 or 1%). Rates of HMB in patients on the largest DOAC group, Rivaroxaban vs the control group, and Rivaroxaban vs Apixaban are as shown in table 1.There was no significant difference in healthcare burden between the DOAC and control groups (p-value 0.954) with no difference in length of stay between the two groups (5 days for both groups). The rate of HMB with the use of DOACs or with known risk factors of HMB on any anticoagulant is as shown in table 2. Conclusion In contrast to adult patients, our study suggests similar rates of HMB in adolescents on DOACs when compared to the control group. Rivaroxaban was the most commonly used DOAC in our data set. Though the number of patients on Apixaban was small, there was no difference in the rate of HMB between Rivaroxaban and Apixaban groups. Patients with known risk factors of HMB had an increased rate of HMB with all anticoagulants. Prospective studies are needed to further elucidate the impact of DOACs and other anticoagulants on HMB in adolescents.

Experimental Design of an Adaptive LQG Controller for Battery Charger/Dischargers Featuring Low Computational Requirements

The growing use of DC/DC power converters has resulted in the requirement that their complex controllers be cheaper and smaller, thus using cost-effective implementations. For this purpose, it is necessary to decrease the computational burden in controller implementation to minimize the hardware requirements. This manuscript presents two methods for tuning an adaptive linear–quadratic–Gaussian voltage controller for a battery charger/discharger, implemented with a Sepic/Zeta converter, to work at any operating point. The first method is based on a lookup table to select, using the nearest method, both the state feedback vector and the observer gain vector, solving the Riccati’s differential equation offline for each practical operating point. The second method defines a polynomial function for each controller element that is based on the previous data corresponding to the system operating points. The adaptability of the two controllers to fixed voltage regulation and reference tracking was validated using simulations and experimental tests. The overshoot and settling time results were lower than 11% and 3.7 ms, which are in the same orders of magnitude of a control approach in which the equations are solved online. Likewise, three indices were evaluated: central processing unit capacity, cost, and performance. This evaluation confirms that the controller based on polynomial interpolation is the best option of the two examined methods due to the satisfactory balance between dynamic performance and cost. Despite the advantages of the controllers in being based on a lookup table and polynomial interpolation, the adaptive linear–quadratic–Gaussian has the benefit of not requiring an offline training campaign; however, the cost saving obtained with the lookup table controllers and polynomial interpolation controllers, due to the possible implementation on small-size microcontrollers with development tool simple and easy maintenance, will surely be desirable for a large number of deployed units, ensuring that those solutions are highly cost-effective.

Retrospective Comparative Analysis of KRAS G12C vs. Other KRAS Mutations in mCRC Patients Treated With First-Line Chemotherapy Doublet + Bevacizumab.

BackgroundKRAS mutations in metastatic colorectal cancer (mCRC) define a subset of tumors that have primary resistance to anti-EGFR-based therapy. Data concerning whether different KRAS mutations may also have a prognostic value are lacking. Furthermore, novel KRAS G12C inhibitors are currently in development. The aim of our analysis was to compare response rates in patients treated with first-line chemotherapy doublet + Bevacizumab among different KRAS variants. Secondary end-points were progression free survival (PFS) and overall survival (OS).MethodsPatients with KRAS mutated mCRC treated with either FOLFIRI/FOLFOX/XELOX + Bevacizumab were eligible for enrollment. Patients whose tumor harbored NRAS mutations or that coexpressed also BRAF mutations were excluded from this retrospective analysis. Patients’ individual data were collected from patients’ records. Propensity score matching (nearest method, 1:2 ratio) was used to define the two different groups of patients for comparison (KRAS G12C mutated vs other KRAS variants). Eastern Cooperative Oncology Group Performance Status (ECOG PS), sex, metastatic site of involvement, synchronous vs metachronous metastatic disease, tumor sidedness, mucinous histology, primary tumor surgery, more than two lines of treatment for metastatic disease, and radical surgery of metastases were used as matching factors. Response rate (RR) was calculated by RECIST 1.1 criteria. Both progression free-survival and overall survival were calculated by Kaplan–Meier method. Categorical variables were compared by Fisher exact test for binomial variables and by chi-square test for all other instances. The level of statistical significance p was set at 0.05 for all tests.ResultsA total of 120 patients were assessed in the final analysis. Out of the 120 patients, 15 (12%) were KRAS G12C mutated. In the whole cohort of patients, 59/120 (49%) had partial response (PR), 42/120 (35%) had stable disease (SD), and 19/120 (16%) had progressive disease (PD) as the best response. In KRAS G12C patients, 4/15 (27%) had PR, 6/15 (40%) had SD, and the remaining 5/15 (33%) had PD as the best response. In patients with other KRAS mutations, 55/105 (52%) had PR, 37/105 (35%) had SD, and the remaining 13/105 (12%) had PD as the best response. The difference in RR between the two groups of patients was statistically significant (p=0.017). On the other hand, no difference in PFS (p=0.76) and OS (p=0.56) was observed. After matching procedures, the difference in response rates between KRAS G12C mutated patients vs the matched cohort of patients with other KRAS mutations remained statistically significant (p=0.016). KRAS G12C mutations were not associated with differences in sites of metastatic involvement, sex, and ECOG PS. On the other hand, synchronous vs metachronous metastatic disease (p=0.039), age > 75 years (p=0.043), and mucinous histology (p=0.008) were more frequent in G12C mutated tumors.ConclusionsIn our cohort of patients, it was observed that KRAS G12C mutations are associated with worse response rates compared to other KRAS variants when treated with standard chemotherapy doublet + Bevacizumab. On the other hand, both PFS and OS were not significantly different. Based on these findings, we believe that new treatment options focused on KRAS G12C inhibition should be tested mainly in first-line setting and in addition to standard chemotherapy doublet + Bevacizumab for mCRC patients, as they might “fill the gap” in response rates that was seen in our study.

Impact of primary tumor resection on the survival of patients with unresectable colon cancer liver metastasis at different colonic subsites: a propensity score matching analysis

Objective To investigate the effect of primary tumor resection (PTR) on the prognosis of patients with unresectable colon cancer liver metastasis (UCCLM) at seven colonic subsites using the Surveillance, Epidemiology, and End Results (SEER) database. Methods Propensity score matching (PSM) was performed to balance selection bias using all available variables that could be of potential relevance. After matching, the groups were redefined in a 1:1 ratio using the nearest method. Cancer-specific survival (CSS) was compared among the patients of PTR and non-PTR groups. Cox regression models were used to identify the prognostic factors for CSS. Results CSS was significantly different between all groups. Cox regression analysis showed that PTR was an independent prognostic factor for all groups. After PSM, PTR significantly prolonged CSS for all groups. Subgroup analysis showed that PTR did not improve the prognosis of N2 stage patients in the cecum, ascending colon, and descending colon groups; T1 + T2 stage patients in the hepatic flexure group; and patients with a tumor size ≤5 cm in the splenic flexure group. Segmental colectomy could prolong CSS of patients in the cecum, ascending colon, transverse colon, splenic flexure, and sigmoid colon groups, while extended colectomy could prolong CSS of patients in the hepatic flexure and descending colon groups. Conclusion At different colonic subsites, UCCLM patients had different CSS. PTR could improve their prognosis, however, N stage, T stage, and tumor size are important reference indicators. In addition to patients in the hepatic flexure and descending colon groups, we suggested that patients in other groups should choose segmental colectomy.

Technical note: Evaluation of interval between measurements and calculation method for the quantification of enteric methane emissions measured by respiration chamber

Respiration chambers share one analyzer working in parallel, and methane (CH4) concentrations have to be measured at certain intervals. The maximum and minimum values in the kinetics of CH4 emissions can be missed during the interval between measurements, which may influence the quantification of CH4 emissions. Chambers must be opened for morning feeding and cleaning, which causes a loss of CH4 data. Calculation methods are needed to estimate the lost CH4 emission data, which may influence the estimated amount of daily CH4 emissions. In this study, we measured the CH4 emissions of 10 growing Chinese Holstein dairy heifers in respiration chambers. Methane concentrations were measured every 0.5 min to obtain the 23-h kinetics of CH4 emissions, which were further selected at different intervals between measurements (i.e., 5, 30, 60, 120, 180, and 240 min) to evaluate the effects of interval on quantification of CH4 emissions. The missing 1-h kinetics of CH4 emissions before feeding were not measured, and 2 calculation methods were used to estimate the missing 1-h kinetics of CH4 emissions: mean value of measuring period (the mean method) and the nearest value of measurement just before chamber opening (the nearest method). The results showed that the rates of CH4 emission from 10 heifers varied from 4.56 to 11.42 g/h. The increment of intervals decreased maximum rate of CH4 emission and increased minimum rate of CH4 emission. Interval caused less than 5% of the difference in measuring CH4 emissions. Although the mean method had greater estimated daily CH4 emission than the nearest method, the difference was within 3%. The interval between measurements (≤3 h) and calculation method had little influence on enteric CH4 emission measurements.

Application and numerical error analysis of multiscale method for air flow, heat and pollutant transfer through different scale urban areas

There is an increasing concern on the effect of the outdoor environment on the indoor air quality (IAQ) through ventilation. In urban areas, the physical phenomenon that the air pollutants pass over the neighborhood scale–street scale–indoor scale, and affect the health of the residents belongs to multiscale problems. The adopted multiscale method models the problem in nesting grid system approach by solving from top (entire domain with relative coarse grids) to down (subsequent sub-domains with finer grid). In this paper, a 3-D multiscale model with Richardson number (Ri) equal to 0.85 was firstly established to investigate the above multiscale phenomenon, then evaluated by comparing with the full-scale intensive simulation, since our previous study showed that when Ri ≤ 0.85 the standard k-ɛ turbulence model can better predict the flow and temperature fields. The numerical error analysis of the multiscale method was conducted by considering the effects of two aspects (boundary condition interpolation schemes and sub-domain partitioning) on the regularity of error production and transfer. Results show that the applied multiscale method can save 83.8% computing time. Furthermore, it can be concluded that among the three interpolation schemes for the boundary reconstruction the linear and spline interpolation methods are appropriate while the nearest method should not be applied because of its 1st-order accuracy. If insensitive interfaces are chosen as the partitioning interfaces of the lower-scale domain the computational accuracy of the multiscale method can be greatly improved.

Using Image Processing In Security

Using image stitching and image steganography security can be provided to any image which has to be sent over the network or transferred using any electronic mode. There is a message and a secret image that has to be sent. The secret image is divided into parts. The first phase is the Encrypting Phase, which deals with the process of converting the actual secret message into cipher text using the AES algorithm. In the second phase which is the Embedding Phase, the cipher text is embedded into any part of the secret image that is to be sent. Third phase is the Hiding Phase, where steganography is performed on the output image of Embedding Phase and other parts of the image where the parts are camouflaged by another image using least significant bit replacement. These individual parts are sent to the concerned receiver. At the receivers end decryption of Hiding phase and Embedding Phase takes place respectively. The parts obtained are stitched together using k nearest method. Using SIFT features the quality of the image is improved.

Minimization of classification samples for supercritical and subcritical patterns of supersonic inlet

In order to investigate sample minimization for classification of supercritical and subcritical patterns in supersonic inlet, three optimization methods, namely, opposite one towards nearest method, closest one towards the hyper-plane method and random selection method, are proposed for investigation on minimization of classification samples for supercritical and subcritical patterns of supersonic inlet. The study has been carried out to analyze wind tunnel test data and to compare the classification accuracy based on those three methods with or without priori knowledge. Those three methods are different from each other by different selecting methods for samples. The results show that one of the optimization methods needs the minimization samples to get the highest classification accuracy without priori knowledge. Meanwhile, the number of minimization samples needed to get highest classification accuracy can be further reduced by introducing priori knowledge. Furthermore, it demonstrates that the best optimization method has been found by comparing all cases studied with or without introducing priori knowledge. This method can be applied to reduce the number of wind tunnel tests to obtain the inlet performance and to identify the supercritical/subcritical modes for supersonic inlet.

Security Using Image Processing

Using image stitching and image steganography security can be provided to any image which has to be sent over the network or transferred using any electronic mode. There is a message and a secret image that has to be sent. The secret image is divided into parts.The first phase is the Encrypting Phase, which deals with the process of converting the actual secret message into ciphertext using the AES algorithm. In the second phase which is the Embedding Phase, the cipher text is embedded into any part of the secret image that is to be sent. Third phase is the Hiding Phase, where steganography is performed on the output image of Embedding Phase and other parts of the image where the parts are camouflaged by another image using least significant bit replacement. These individual parts are sent to the concerned receiver. At the receivers end decryption of Hiding phase and Embedding Phase takes place respectively. The parts obtained are stitched together using k nearest method. Using SIFT features the quality of the image is improved.

Security Using Image Processing

Using image stitching and image steganography security can be provided to any image which has to be sent over the network or transferred using any electronic mode. There is a message and a secret image that has to be sent. The secret image is divided into parts.The first phase is the Encrypting Phase, which deals with the process of converting the actual secret message into ciphertext using the AES algorithm. In the second phase which is the Embedding Phase, the cipher text is embedded into any part of the secret image that is to be sent. Third phase is the Hiding Phase, where steganography is performed on the output image of Embedding Phase and other parts of the image where the parts are camouflaged by another image using least significant bit replacement. These individual parts are sent to the concerned receiver. At the receivers end decryption of Hiding phase and Embedding Phase takes place respectively. The parts obtained are stitched together using k nearest method. Using SIFT features the quality of the image is improved.

복수객체의 윤곽추출을 위한 스네이크 분리 및 연결 알고리즘의 실험적 분석

복수객체의 윤곽추출을 위해 스네이크를 분리하고 연결하는 대표적인 방법이 스네이크 포인트의 거리를 이용한 최소거리방법이다. 이 방법은 객체 위상에 따라 스네이크를 분리하지 못하는 경우가 발생한다. 본 논문에서는 스네이크를 분리하지 못하는 경우를 실험적으로 증명하고 스네이크 세그먼트의 벡터를 이용한 새로운 방법이 스네이크를 성공적으로 분리 및 연결함을 실험적으로 보임으로써 최소거리방법의 문제점을 해결하였다. 하나의 영상 안에 3개 및 5개 객체가 있는 실험영상에 실험을 하여 제안한 방법이 우수하다는 것을 보여준다. The most famous algorithm of splitting and connecting Snake for extracting the boundary of multiple objects is the nearest method using the distance between snake points. It often can't split and connect Snake due to object topology. In this paper, its problem was discussed experimentally. The new algorithm using vector between Snake segment is proposed in order to split and connect Snake with complicated topology of objects. It is shown by experiment of two test images with 3 and 5 objects that the proposed one works better than the nearest one.

A distributed water-heat coupled model for mountainous watershed of an inland river basin in Northwest China (III) using the outputs from Mesoscale model version 5

The distributed water-heat coupled (DWHC) model is calibrated, with the help of the Mesoscale model version 5 (MM5), by calculating the daily precipitation, the daily average air temperature at the 2.0 m heights and the daily potential evaporation in Heihe mountainous watershed area and its vicinity (96.786°∼102.284°E, 37.328°∼40.601°N, 17 × 104 km2), from February 11 to June 30, 2003. The MM5 model periodically ran every 10 days in 3 km × 3 km grid resolution with an integral time step of 3 s. In the MM5 model, many scheme or options are consulted or adopted, such as the Grell scheme cumulus parameterization method, the Dudhia option, the cloud-radiation scheme, MRF PBL option and the modified Oregon State University Land-surface model (OSULSM). According to the projection transform methods, the MM5 outputs are interpolated to the 1 km × 1 km grid in Alberts projection by using triangle-based cubic interpolation (Cubic) and nearest neighbor interpolation (Nearest) methods, with which the DWHC model shares the same method. The result shows that, when the Nearest method is used, the Nash-Sutcliffe equation value of the daily average runoff is 0.79, the balance error is −0.79% and the goodness of fit R 2 value is 0.81. Meanwhile, when the Cubic method is used, the Nash-Sutcliffe equation value, the balance error and the R 2 value are 0.79, −0.65% and 0.80, respectively. Though the runoff simulation result is not favorable, it is still better than that using measured data at the meteorological and hydrological stations; the latter has a Nash-Sutcliffe equation value of 0.61. The MM5-DWHC model results also show that runoff mainly occurs on land surfaces and from shallow soil layers. According to model calibration results, certain outputs of MM5 are singular to some extent and the DWHC model is very sensitive to the initial values.