Exact Method Research Articles

Edge modes in finite-size systems with different edge terminals

Abstract We investigate the behavior of edge modes in the presence of different edge terminations and long-range (LR) hopping. Here, we mainly focus on such model crystals with two different types of structures (type I: “…–P–Q–P–Q–…” and type II: “… = P–Q = P–Q = …”), where P and Q represent crystal lines (CLs), while the symbols “–” and “=” denote the distance between the nearest neighbor (NN) CLs. Based on the lattice model Hamiltonian with LR hopping, the existence of edge modes is determined analytically by using the transfer matrix method (TMM) when different edge terminals are taken into consideration. Our findings are consistent with the numerical results obtained by the exact diagonalization method. We also notice that edge modes can exhibit different behaviors under different edge terminals. Our result is helpful in solving novel edge modes in honeycomb crystalline graphene and transition metal dichalcogenides with different edge terminals.

Zoledronic acid-treated rats show altered jaw histology and gene expression in non-exposed MRONJ

BackgroundDiagnosis and management of medication-related osteonecrosis of the jaws (MRONJ) prior to clinical exposure induced by trauma may lead to improved patient management. Currently, few studies have examined early histologic and molecular MRONJ-related changes in the jaws. PurposeThis study aimed to identify histological and gene expression changes in the maxilla and mandible of Sprague-Dawley (SD) rats after zoledronic acid (ZA) treatment. Study Design, Setting, and SampleThis was an in-vivo animal study. The experiments were conducted in the laboratory at the Stomatology Hospital of Tianjin Medical University. A total of 12 SD rats were included. Predictor variableThe predictor variable was ZA exposure. Twelve SD rats were divided into two groups: experimental (n = 6) and control (n = 6), and they were intraperitoneally injected with ZA and saline, respectively. Main outcome variableThe outcome variables were histological and molecular changes. The maxilla, mandible, and ilium bone tissue samples were examined using Masson's trichrome and hematoxylin-eosin staining. Gene expression changes were identified using transcriptome sequencing, Kyoto encyclopedia of genes and genomes (KEGG), and gene interactome network analysis. The key changes were validated using the quantitative real-time polymerase chain reaction and immunohistochemistry. CovariatesNone. AnalysesThe t-test, Chi-square test, and Fisher's exact probability method were used for statistical analyses using the Statistical package for the social sciences software (version 26.0). ResultsAll animals remained healthy during the experiments. Histological staining revealed that the percentage of empty bone lacunae in the maxilla and mandible was significantly higher than that in the ilium (P < 0.01). In total, 552 genes were screened using transcriptome sequencing. The sonic hedgehog (Shh) signaling pathway was highly enriched. The key gene for the Shh interaction was distal-less homeobox 5 (Dlx-5). The Shh, Dlx-5, and bone morphogenetic protein 2 genes and protein expression levels in the maxilla and mandible were higher in the experimental group than in the control group (P < 0.05). Conclusions and RelevanceMRONJ-induced osteonecrosis and gene expression changes precede trauma-induced clinical changes in the SD rat model. These findings may provide additional support for timely and clinically early diagnosis and intervention.

A Multi-Center Study on the Implementation and Challenges of Nursing Three-Level Ward Rounds in Tertiary Hospitals in Shanxi Province.

The "Key Points of the Core System of Medical Quality and Safety" (hereinafter referred to as the "Key Points") was promulgated by the National Health Commission of China in 2018, requiring that nursing ward rounds should be carried out with reference to the three-level ward round system; In 2020 and 2022 editions of the "Evaluation Standards for Tertiary Hospitals", which were implemented in China, required that nursing ward rounds should be carried out with reference to the "Key Points". Additionally, the Action Plan for Comprehensively Improving Medical Quality (2023-2025) also mentions the need to improve the quality of three-level ward rounds. However, there are no detailed guidelines regarding implementing "Nursing Three-level Ward Rounds". This study aimed to investigate the current situation of nursing three-level ward rounds in tertiary hospitals after the promulgation of the "Key Points of the Core System of Medical Quality and Safety" to provide insights and guidelines regarding relevant standards, so as to better implement of the requirements of "nursing ward rounds" in the "Evaluation Standards for Tertiary Hospitals" and "improving the quality of three-level ward rounds" in the "Action Plan". A multi-center study was conducted in February 2024, including all tertiary public hospitals in the Shanxi Province, China. A questionnaire survey using the self-designed "Questionnaire on the Implementation of Nursing Three-level Ward Rounds" was carried out. The questionnaire included the basic information of the hospital and the implementation of the three-level (namely I, II, and III) rounds (including "five aspects": ward round personnel, object, content, frequency, and record), which is expressed by quantity and composition ratio. Next is the text analysis method. First, the "five aspects" of the hospital that filled in the questionnaire survey with "nursing three-level ward rounds have been carried out" were assessed. Second, the five aspects of each hospital were assessed for consistency with the "Nursing Three-level Ward Rounds System" (hereinafter referred to as the "System") of their respective hospitals.Third, the consistency of the "System" of the hospital with the "Key Points" was assessed. The results of the analysis of the former are expressed in terms of quantity and composition ratio; the results of the latter two were analyzed using Fisher's exact test method to compare any differences. Notably, 14 of the 67 tertiary public hospitals (20.9%) carried out nursing three-level ward rounds. There were 4-10 situations in the five aspects of I, II, and III ward rounds filled in by the hospitals. The five aspects of the I, II, III ward rounds in 14 hospitals were significantly comparable with the "System", which, in turn, was comparable with the "Key Points" (P < 0.05). Not all tertiary public hospitals in the Shanxi Province have not all carried out nursing three-level ward rounds. Furthermore, the five aspects of the hospitals that carried out nursing three-level ward rounds were not entirely consistent in terms of ward round personnel, object, content, frequency, and record. The filling in of the nursing three-level ward rounds carried out by the hospitals is inconsistent with the respective "System"; the "System" of the hospital is not in line with the "Key Points". Nursing administrators should be aware of the newly issued norms and requirements in their workplace, and revise the relevant systems in accordance with the norms and requirements in a timely manner. Additionally, the revision of the system should cover the core requirements of the norms and be practicable. The system should be supervised to ensure that 100% of the implementation is in accordance with the system.

Multi-objective optimization for a green forward-reverse meat supply chain network design under uncertainty: Utilizing waste and by-products

The essential requirement for food stands as a pivotal human need, exerting significant ecological impact from production to consumption. Meat, a key dietary component, offers essential nutrients vital for human health. This paper presents a bi-objective two-stage stochastic optimization model for a green forward-reverse meat supply chain network design, addressing both economic and environmental concerns throughout the chain. In the forward flow, the supply chain manages various meat products consist of fresh, processed, and frozen meat products, ensuring their eco-efficient production and distribution. Meanwhile, in the reverse flow, waste and by-products generated during the production process are repurposed and reused. The study promotes environmental sustainability by repurposing waste, utilizing by-products, and minimizing carbon emissions. The proposed model is solved using popular exact ε-constraint method for smaller instances and Non-dominated Sorting Genetic Algorithm II (NSGA-II), Multi-Objective Particle Swarm Optimization (MOPSO), and Strength Pareto Evolutionary Algorithm 2 (SPEA2) meta-heuristic algorithms are employed for larger instances. SPEA2 outperforms both MOPSO and NASG-II, demonstrating less average gap that is 0.38% and 0.76%, respectively. Additionally, the findings reveals that an average 2.5% reduction in environmental impacts associated with an average 5% decrease in profit. The noteworthy outcomes of the research empower managers to navigate the implications of fluctuating demand effectively. Moreover, it is crucial to underscore the effects of conversion rates, particularly those associated with the manufacturing process. An excessively high conversion rate can negatively impact profitability and worsen environmental issues. Conversely, lowering the conversion rate can enhance profitability and mitigate environmental impacts.

Analgesic Characteristics of Ultrasound-guided Great Auricular Nerve Block in Middle Ear Surgery: A Prospective Randomized Controlled Preliminary Trial

PurposeTo explore the analgesic characteristics of ultrasound-guided great auricular nerve (GAN) block to further improve pain management. DesignSingle-center, prospective, randomized, controlled, and double-blind preliminary clinical trial. MethodsThirty-seven patients who underwent middle ear surgery were included in this study: 15 in the GAN block group (the large ear nerve block [NB] group) and 22 in the traditional anesthesia group (control [CON] group). After induction of anesthesia, the NB group was given an ultrasound-guided GAN block (0.25 % Ropivacaine 2 mL), while the CON group was exempt from the GAN block. The patient’s basic information, perioperative information, the region, and numeric rating scale of postoperative pain (at 1 hour, 6 hours, 12 hours, and 24 hours), and adverse reactions were recorded. Repeated measurement analysis, t test, and Fisher exact probability method were used for statistical analysis. FindingsCompared with the CON group, the numeric rating scale in the NB group was lower after surgery (1 hour: 1.18 ± 0.35 vs 0.27 ± 0.20, P = .023; 6 hours: 1.82 ± 0.37 vs 1.13 ± 0.39, P = .203; 12 hours: 1.05 ± 0.19 vs 0.20 ± 0.10, P < .001; 24 hours: 0.55 ± 0.17 vs 0.13 ± 0.09, P = .029). In the NB group, the region of pain was merely concentrated in the ear canal. In the CON group, the pain extended to areas outside the ear canal, such as tragus and mastoid (at 12 hours, P = .006). There was no significant difference in the risk of postoperative adverse reactions between the two groups. ConclusionsUltrasound-guided GAN block can relieve patients’ pain after middle ear surgery, especially in the area outside the ear canal.

An exact method for the two-echelon split-delivery vehicle routing problem for liquefied natural gas delivery with the boil-off phenomenon

In this paper we investigate a two-echelon vehicle routing problem for liquefied natural gas (LNG) delivery to determine how to transport LNG from an overseas production terminal to a set of import terminals by vessels, and transport the LNG from the import terminals to a set of filling stations either by tanker trucks or bunker barges. Some important features of this problem are that part of LNG will be evaporated during delivery and split deliveries are allowed at both import terminals and filling stations, which render the problem more intractable than those considered in most of the existing two-echelon vehicle routing studies. The objective is to find the optimal first-echelon and second-echelon delivery schemes to minimize the sum of the routing cost and boil-off cost. To solve the problem, we develop a customized branch-and-price-and-cut (BPC) algorithm incorporating a specialized labeling algorithm tailored to address the issues of LNG evaporation and split deliveries in solving the challenging pricing subproblems. To speed up the solution algorithm, we introduce some heuristic pricing strategies to quickly solve the pricing subproblems, and explore the (strong) k-path inequalities and subset-row inequalities to tighten the lower bound obtained by column generation. We conduct extensive numerical studies on simulation instances and a case study of LNG delivery in region along the Yangtze river, China to verify the effectiveness of the model and proposed algorithm. The numerical results demonstrate that our algorithm significantly outperforms CPLEX and the existing BPC algorithm on related topic, confirm the superiority of our integrated two-echelon solution method over its sequential solution counterpart, and illustrate that the locations of the production terminal and import terminals are highly related to the solution performance.

Machine Learning based Algorithm Selection and Genetic Algorithms for serial-batch scheduling

Whenever combinatorial optimization problems cannot be solved by exact solution methods in reasonable time, tailor-made algorithms (heuristics, meta-heuristics) are developed. Often, these heuristics exploit structural properties and perform well on selected subsets of the problem space. For example, this is how the two best-known construction heuristics solve the scheduling problem investigated in this study (i.e., the scheduling of parallel serial-batch processing machines with incompatible job families, restricted batch capacities, arbitrary batch capacity demands, and sequence-dependent setup times). However, when the properties change, the performance of one algorithm might decrease, and another algorithm might have been the better choice. To resolve this issue, we propose using Machine Learning to exploit the strengths of different algorithms and to select the probably best-performing algorithm for each problem instance individually. To that, we investigate a variety of methods from the “learning-to-rank” literature and propose several adaptations. Furthermore, because there is no algorithm for the considered scheduling problem that is capable to explore the entire solution space, we developed two Genetic Algorithms for the improvement of initial solutions computed by the selected algorithms. Here, we put special emphasis on ensuring that the solution representation (encoding) reflects the entire solution space and that the operators (e.g., for recombination and mutation) are appropriate to explore and exploit this space completely. Our computational experiments show an average increase of 39.19% in solution quality.

Inference about a Common Mean Vector from Several Independent Multinormal Populations with Unequal and Unknown Dispersion Matrices

This paper addresses the problem of making inferences about a common mean vector from several independent multivariate normal populations with unknown and unequal dispersion matrices. We propose an unbiased estimator of the common mean vector, along with its asymptotic estimated variance, which can be used to test hypotheses and construct confidence ellipsoids, both of which are valid for large samples. Additionally, we discuss an approximate method based on generalized p-values. The paper also presents exact test procedures and methods for constructing exact confidence sets for the common mean vector, with a comparison of the local power of these exact tests. The performance of the proposed methods is demonstrated through a simulation study and an application to data from the Current Population Survey (CPS) Annual Social and Economic (ASEC) Supplement 2021 conducted by the U.S. Census Bureau for the Bureau of Labor Statistics.

Asymptotically exact fit for linear mixed model in genetic association studies.

The linear mixed model (LMM) has become a standard in genetic association studies to account for population stratification and relatedness in the samples to reduce false positives. Much recent progresses in LMM focused on approximate computations. Exact methods remained computationally demanding and without theoretical assurance. The computation is particularly challenging for multiomics studies where tens of thousands of phenotypes are tested for association with millions of genetic markers. We present IDUL and IDUL† that use iterative dispersion updates to fit LMMs, where IDUL† is a modified version of IDUL that guarantees likelihood increase between updates. Practically, IDUL and IDUL† produced identical results, both are markedly more efficient than the state-of-the-art Newton-Raphson method, and in particular, both are highly efficient for additional phenotypes, making them ideal to study genetic determinants of multiomics phenotypes. Theoretically, the LMM likelihood is asymptotically unimodal, and therefore the gradient ascent algorithm IDUL† is asymptotically exact. A software package implementing IDUL and IDUL† for genetic association studies is freely available at https://github.com/haplotype/IDUL.

Bracing systems for three-ribbed arch bridges against out-of-plane buckling

This paper is concerned with the design of bracing systems for three-ribbed parabolic arch bridges against out-of-plane buckling. Typical bracing systems for the three-ribbed arch bridges include K-bracing system and X-bracing system as well as transverse bracing system. The buckling criterion of the braced funicular three-ribbed arch bridge is derived from an exact matrix stiffness method (MSM) with a 14 × 14 s-order element stiffness matrix of three-dimensional beam-column elements that allows for torsional and warping deformations. The lateral torsional buckling load and mode are given by the lowest eigenvalue and eigenvector associated with the assembled structural stability stiffness matrix. A comparison study between different bracing system configurations suggests that the three-ribbed arches with the integral K- or X-bracing system (a K/X-bracing across the three arch ribs) have lower lateral torsional buckling loads than their arch counterparts with the independent K- or X-bracing system (the adjacent arch ribs are connected by K/X-bracing respectively), because the latter ones could provide more restraint on the middle arch rib to avoid early lateral torsional instability. Further, a bracing utilization efficiency index (defined as the normalized buckling capacity over material usage for bracing system) is proposed to quantify the effect of bracing systems in improving the lateral torsional buckling capacity of arch bridges. Highly efficient bracing systems that maximize the lateral torsional buckling load of three-ribbed arch structures with the lowest bracing material usage are then recommended.

Quantitative analysis of heat and mass transfer in MoS2-Al2O3/EG hybrid flow between parallel surfaces with suction/injection by numerical modeling of HPM method

This description focuses on how the magnetic field affects mass and heat transfer in a hybrid nanofluid (Hnf) between two parallel, rotating plates. By dispersing aluminum oxide (Al2O3) and molybdenum disulfide (MoS2) nanoparticles (NPs) in ethylene glycol (EG), a hybrid nanofluid (Hnf) is created. This research aims to analyze the heat and mass transfer characteristics in the flow of a hybrid nanofluid (MoS2-Al2O3/EG) between two rotating parallel plates under the influence of a magnetic field. Furthermore, the statistical technique of response surface methodology (RSM) has been employed to optimize the parameters of velocity, temperature, and concentration of the nanofluid within the flow region bounded by the rotating plates. Dimensionless differential equations have been calculated and checked using the Homotopy perturbation method. This study introduces a novel approach by utilizing the RSM method to identify optimal points for velocity and temperature parameters of nanofluids between two stretching plates for the first time. Additionally, the article innovatively applies the exact HPM method to validate dimensionless linear and non-linear coupling equations. As the Reynolds number and the suction/injection coefficient of nanofluids flowing between two plates under tension increase, the results indicate a decrease in the velocity field. This decrease in velocity field can be attributed to the reduction in fluid diffusion as viscous forces diminish with varying Reynolds numbers. The ideal temperature distribution for nanofluids flowing between two parallel plates occurs when they are uniformly dispersed at the midpoint between them. As the distance from the initial point of nanofluid entry to the end of the plates increases, along with the vertical distance from the bottom plate, the temperature gradient diminishes, reducing the thickness of the thermal boundary layer. The velocity gradient and the rate of heat flux transfer between the nanofluid and plate rise by 34 % when the volume percentage is raised from 1 % to 5 %.

Two atoms in a harmonic trap with spin-orbital-angular-momentum coupling

We study the problem of two harmonically trapped atoms in the presence of spin-orbital-angular-momentum (SOAM) coupling. The two-body energy spectrum is numerically calculated by utilizing the exact diagonalization method. We analyze how the degeneracy of energy levels is lifted under the interplay between the interatomic interaction and SOAM coupling. The exact numerical results show excellent agreement with that of perturbation theory in the weak-interaction limit as well as that in the absence of SOAM coupling. The properties of correlations between the two atoms are also discussed with respect to the interaction strength. The findings in this paper may provide valuable insights into few-body physics subjected to SOAM coupling and the possible experimental detection of spectrum functions in many-body systems, such as radiofrequency spectroscopy. Published by the American Physical Society 2024

Practical and analytical considerations when performing interim analyses in diagnostic test accuracy studies

Interim analysis is a common methodology in randomised clinical trials but has received less attention in studies of diagnostic test accuracy. In such studies, early termination for futility may be beneficial if early evidence indicates that a diagnostic test is unlikely to achieve a clinically useful level of diagnostic performance, as measured by the sensitivity and specificity. In this paper, we describe relevant practical and analytical considerations when planning and performing interim analysis in diagnostic accuracy studies, focusing on stopping rules for futility. We present an adaptation of the exact group sequential method for diagnostic testing, with R code provided for implementing this method in practice. The method is illustrated using two simulated data sets and data from a published diagnostic accuracy study for point-of-care testing for SARS-CoV-2. The considerations described in this paper can be used to guide decisions as to when an interim analysis in a diagnostic accuracy study is suitable and highlight areas for further methodological development.

The application of cut-umbilical cord milking in term cesarean deliveries for preventing anemia and iron deficiency of newborns

Objective: To anlysis the efficacy and safety of cut-umbilical cord milking (C-UCM) compared with immediate cord clamping in preventing anemia and iron deficiency among term cesarean-delivered newborns. Methods: A total of 485 pregnant women planning to deliver by cesarean section were recruited in this randomized controlled trial in Hunan Maternal and Child Health Hospital and Liuyang Maternal and Child Health Care Hospital from July 2016 to April 2019. A block randomization was conducted to evenly allocate them to the controlled group and the C-UCM group. In the controlled group, the cord was clamped within 30 seconds as routine. In the C-UCM group, the cord was first clamped at 25 cm from the newborn's navel, and then the blood in the cord was gently squeezed into the newborn's body until the cord became white and shriveled. The cord was clamped twice at 2-3 cm from the newborn's navel subsequently. Neonatal jaundice, hyperbilirubinemia and polycythemia were monitored before discharge. After the newborns discharged, their hemoglobin, red blood cell count, hematocrit (at the age of 1, 6 and 12 months) and serum ferritin (at the age of 6 and 12 months) were followed up; body length and weight were measured; and information about their feeding and iron supplementation were collected (at the age of 1, 6, 12 and 18 months). The two groups were compared by t test, Mann-Whitney U test, χ² test, or Fisher exact probability method. The hospital was set as a random item, and the mixed effects regression model was used to evaluate the effect of C-UCM on relevant indicators of cesarean-delivered newborns. Results: There were 244 women in the C-UCM group with an average age of (31.9±4.4) years, and 241 in the control group with an average age of (31.8±4.2) years (P>0.05). There was no statistically significant difference between the C-UCM group and the control group at 1, 6 and 12 months of age in hemoglobin [(123.6±14.5) vs (122.2±14.5) g/L, (115.3±9.4) vs (114.1±8.5) g/L, (115.6±9.6) vs (116.1±12.6) g/L] or anemia incidence rate [15.2% (17/112) vs 18.4% (19/103), 22.7% (34/150) vs 26.8% (44/164), 22.3% (25/112) vs 19.5% (22/113)] (all P>0.05). There was no statistically significant difference between the two groups at 6 and 12 months of age in serum ferritin [M (Q1, Q3), 39.9 (24.9, 61.8) vs 43.6 (25.2, 100.9) μg/L, 40.3 (25.4, 259.2) vs 40.3 (26.4, 167.6) μg/L)] or iron deficiency incidence rate [6.1% (5/82) vs 4.2% (3/72), 6.7% (5/75) vs 3.8% (3/80)] (all P>0.05). There were also no significant difference between the two groups in other indicators, such as the Z-score of weight-for-length, the incidence of neonatal jaundice, and the incidence of neonatal hyperbilirubinemia (all P>0.05). After adjusting for the relevant covariates, there were still no significant effects of C-UCM on these outcomes above. Conclusions: Compared to immediate cord clamping, the intervention of gently squeezing 25 cm of the cord does not significantly reduce the risk of anemia or iron deficiency in term cesarean-delivered newborns, nor does it have a significant impact on infant growth and development. Yet this intervention does not increase the risk of jaundice or hyperbilirubinemia in newborns as well.

Thermomechanical buckling and vibration of composite sandwich doubly curved shells with carbon nanotube‐reinforced face layers

AbstractIn this paper, the thermomechanical buckling and vibration analysis are investigated for carbon nanotube‐reinforced composite sandwich doubly curved shells (CNCSDS) under the action of both thermal loads and in‐plane compressive loads. Based on the von‐Karman non‐linear kinematic relations, First Order Shear Theory, and Hamilton's principle, the vibration and stability equations for CNCSDS under thermomechanical loads are deduced. For obtaining the critical thermomechanical buckling load and vibration frequency, an exact method is adopted. Subsequently, the results are validated by comparing with the finding in published literature and simulation results. At last, the influence of system parameters on critical thermomechanical buckling load and vibration frequency is studied and displayed graphically. Meanwhile, some new results about thermomechanical buckling and vibration analysis of CNCSDS are proposed for the first time.Highlights Thermomechanical buckling and vibration of carbon nanotube‐reinforced composite sandwich doubly curved shells was studied. Vibration and stability equations under thermomechanical loads was deduced. The change rules of thermomechanical buckling load and frequency were obtained.

Investigation on dynamic modelling and nonlinear vibration behaviors of composite structures: A case of cable-beam model

This paper conducts a nonlinear analysis of cable-beam model of cable-stayed bridges by using the exact mode superposition method (EMSM) and the cable-beam dragging method (CBDM), respectively, comparing and exploring their theoretical foundations and practical implications. The EMSM is based on the global mode function of the cable-beam structure for nonlinear analysis, yet it requires more computational resources. The CBDM is based on the cable-beam dragging equations for nonlinear analysis, which can quickly obtain the static equilibrium state and dynamic response of the cable-beam system, but it requires some simplifying assumptions on the cable-beam connection conditions. Research results demonstrate qualitative and quantitative differences between these two methods through parametric analysis on dynamic behaviors, which provide a significant methodological study and a reference for the design and dynamics of composite structures.

Exciton energy transfer inside cavity-A benchmark study of polaritonic dynamics using the surface hopping method.

Strong coupling between the molecular system and photon inside the cavity generates polaritons, which can alter reaction rates by orders of magnitude. In this work, we benchmark the surface hopping method to simulate non-adiabatic dynamics in a cavity. The comparison is made against a numerically exact method (the hierarchical equations of motion) for a model system investigating excitonic energy transfer for a broad range of parameters. Surface hopping captures the effects of the radiation mode well, both at resonance and off-resonance. We have further investigated parameters that can increase or decrease the rate of population transfer, and we find that surface hopping in general can capture both effects well. Finally, we show that the dipole self-energy term within our parameter regime does not significantly affect the system's dynamics.

An efficient exact method with polynomial time-complexity to achieve [formula omitted]-strong barrier coverage in heterogeneous wireless multimedia sensor networks

Barrier coverage in Wireless Sensor Networks (WSNs) plays a pivotal role in surveillance and security applications. It serves as a fundamental mechanism for identifying and detecting potential intruders who endeavor to infiltrate a sensor barrier. Achieving k-strong barrier coverage is a vital indicator of a WSN’s capability to detect unauthorized intrusions. This paper establishes efficient k-strong barrier coverage in hybrid wireless multimedia sensor networks, referred to as MMS-KSB. The primary goal is to identify a minimal number of mobile sensors to obtain k-barrier coverage. Exhibiting the combinatorial structure, previous research on building k-strong barrier has failed to provide a polynomial time solution for the considered problem and resorted to approximation algorithms. We, therefore, introduce a precise algorithm, named ExA-KSB, and provide theoretical analysis to substantiate that our proposed method achieves an exact solution with polynomial time complexity. Furthermore, we conduct comprehensive experiments to evaluate the efficacy of our algorithm by comparing it with existing approaches. Numerical results demonstrate that ExA-KSB surpasses previous algorithms, and offers superior solution quality with competitive computational efficiency.

Analysis of genetic etiology of 234 deaths in the pediatric intensive care unit with suspected genetic diseases

Objective: To explore the genetic etiology of pediatric intensive care unit (PICU) mortality cases and summarize their clinical characteristics. Methods: This was a retrospective cohort study. The study population consisted of 234 children who died within 7 d after admitted to the PICU of Children's Hospital of Fudan University from January 2017 to December 2021. The clinical diagnoses, laboratory test results, and genetic testing results were collected. These patients were divided into the pathogenic gene variation positive (PGVP) group and the pathogenic gene variation negative (PGVN) group according to the results of genetic testing. The Mann-Whitney U test and Pearson's chi-square test or Fisher's exact probability method were used to compare the clinical characteristics between the groups. Results: A total of 234 cases were enrolled, including 139 (59.4%) males and 95 (40.6%) females. The age at death was 1.0 (0.4, 3.7) years old and the length of PICU stay was 16 (6, 33) days. There were 62 cases (26.5%) PGVP, and the mutated pathogenic genes included immune genes (23 cases (37.1%)), metabolic genes (11 cases (17.7%)), neuromuscular genes (11 cases (17.7%)), cardiovascular genes (4 cases (6.5%)), and genes of other systems (13 cases (21.0%)). The age at death in PGVP cases was significantly lower than in PGVN cases (0.6 (0.3, 1.4) vs. 1.3(0.5, 4.3) years old, Z=3.85, P<0.001). Compared with the PGVN group, the PGVP group had a higher incidence of family history and chronic complex conditions (CCC) than the PGVN group (6.5% (4/62) vs. 0.6% (1/172) and 93.5% (58/62) vs. 76.2% (131/172), χ2=8.87, P=0.018 and 0.003, respectively). Children in the PGVP group were admitted with higher incidence of severe infection, decreased consciousness or coma, moderate-to-severe anemia, thrombocytopenia, protracted diarrhea, and abnormalities in muscle strength or tone than those in the PGVN group (74.2%(46/62) vs. 45.9%(79/172), 50.0%(31/62) vs. 35.5%(61/172), 32.3%(20/62) vs. 18.0%(31/172), 21.0%(13/62) vs. 10.5%(18/172), 25.8%(16/62) vs. 4.1%(7/172), 16.1%(10/62) vs. 5.2%(9/172), χ2=14.63, 4.04, 5.41, 4.37, 24.30, 7.25, all P<0.05). Pathogenic genes that occurred more than twice included IL2RG (5 cases), SMN1 (4 cases), and SH2D1A (3 cases, including 2 single gene varients and 1 copy number varient). Conclusions: Among the deceased cases in the PICU, the main genetic causes are immune-related, metabolic, and neuromuscular genetic disorders. Critically ill children with a family history, CCC, and early features such as severe infections, decreased consciousness or coma, moderate to severe anemia, thrombocytopenia, protracted diarrhea, or abnormalities in muscle strength or tone should be closely monitored and undergo early genetic testing.

Sample size calculation for the sequential parallel comparison design with binary endpoint using exact methods

High placebo responses in clinical trial could reduce the treatment effect leading to the failure of a promising drug. Several strategies have been developed to minimize high placebo responses, including the sequential parallel comparison design (SPCD). For a study with binary outcome, the existing statistical methods to test the drug effectiveness always rely on the asymptotic limiting distribution. When a study's sample size is small to medium, the asymptotic approaches do not have satisfactory performance with regard to type I error rate and statistical power. For that reason, we propose utilizing exact conditional approach to calculate sample size based on the existing test statistics to order the sample space. The proposed method controls the type I error rate under the unconditional framework. We compare the proposed exact sample sizes using different test statistics and the sample size for a randomized parallel study. We would recommend using exact sample sizes for the SPCD with small- to medium sample sizes and the SPCD with extreme response rates.