Article
Mathematics, Interdisciplinary Applications
John J. Dziak, Daniel Almirall, Walter Dempsey, Catherine Stanger, Inbal Nahum-Shani
Summary: Sequential Multiple-Assignment Randomized Trials (SMARTs) are increasingly important in psychological and behavioral health research, allowing researchers to answer scientific questions about sequencing and matching interventions to individual needs. This study addresses the limited attention given to planning SMARTs with binary outcomes and provides sample size planning simulation procedures and formulas for two-wave repeated measures binary outcomes.
MULTIVARIATE BEHAVIORAL RESEARCH
(2023)
Article
Mathematical & Computational Biology
Marta Bofill Roig, Guadalupe Gomez Melis, Martin Posch, Franz Koenig
Summary: This article discusses the challenges in choosing and designing composite endpoints in randomized clinical trials and proposes a trial design that allows adaptive modification of the primary endpoint. Through simulations, it is shown that the adaptive design is effective in achieving statistical power and maintaining the significance level.
Article
Mathematical & Computational Biology
Richard D. Riley, Thomas P. A. Debray, Gary S. Collins, Lucinda Archer, Joie Ensor, Maarten van Smeden, Kym I. E. Snell
Summary: External validation is crucial in examining the performance of prediction models, but current studies often face issues with small sample sizes. To address this, determining the minimum sample size needed for a new external validation study with precise estimation calculations is proposed, taking into account calibration, discrimination, and clinical utility measures.
STATISTICS IN MEDICINE
(2021)
Article
Mathematical & Computational Biology
Maximilian Pilz
Summary: The formula of Fleiss and Cuzick (1979) is utilized to estimate the intraclass correlation coefficient and simplify the sample size calculation for clustered data with binary outcome. This approach reduces the complexity by focusing on the null and alternative hypothesis and the quantitative impact of belonging to the same cluster on the therapy success probability.
BIOMETRICAL JOURNAL
(2023)
Review
Medicine, General & Internal
Xinlian Zhang, Phillipp Hartmann
Summary: The calculation of required sample size is crucial in designing both animal and human studies. This review defines key terms related to sample size determination, such as mean, standard deviation, statistical hypothesis testing, type I/II error, power, direction of effect, effect size, expected attrition, corrected sample size, and allocation ratio. It also provides practical examples of sample size calculations based on pilot studies, similar larger studies, or estimated effect sizes per Cohen and Sawilowsky if no previous studies are available.
FRONTIERS IN MEDICINE
(2023)
Review
Geriatrics & Gerontology
Graziella D'Arrigo, Stefanos Roumeliotis, Claudia Torino, Giovanni Tripepi
Summary: A crucial step in planning a randomized clinical trial (RCT) is the calculation of sample size, which determines the optimal number of patients needed to ensure the study has enough power to detect differences in specific endpoints between study arms. This calculation involves inputting variables such as the expected effect size, alpha error (α), beta error (β), and the allocation ratio in order to determine the number of participants allocated to each arm of the RCT.
AGING CLINICAL AND EXPERIMENTAL RESEARCH
(2021)
Article
Computer Science, Interdisciplinary Applications
Lilian Golzarri-Arroyo, Stephanie L. Dickinson, Yasaman Jamshidi-Naeini, Roger S. Zoh, Andrew W. Brown, Arthur H. Owora, Peng Li, J. Michael Oakes, David B. Allison
Summary: This study simulated a cluster randomized controlled trial with binary outcomes and a small number of clusters, and evaluated the validity of the parametric bootstrap approach. The results showed that using the parametric bootstrap resulted in inflated error rates, indicating that it is not a valid method.
COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE
(2022)
Article
Health Care Sciences & Services
Menelaos Pavlou, Chen Qu, Rumana Z. Omar, Shaun R. Seaman, Ewout W. Steyerberg, Ian R. White, Gareth Ambler
Summary: This paper investigates the sample size requirements for validation studies with binary outcomes to estimate measures of predictive performance, providing various estimators which perform well even when normality assumptions are violated. Our estimators show good performance, even when normality assumptions are violated.
STATISTICAL METHODS IN MEDICAL RESEARCH
(2021)
Article
Mathematical & Computational Biology
Eric R. Cohn, Tianchen Qian, Susan A. Murphy
Summary: Micro-randomized trials (MRTs) are a new experimental design for developing mobile health interventions that repeatedly randomize participants, resulting in longitudinal data with time-varying treatments. The focus of MRT primary and secondary analyses is causal excursion effects. A sample size formula is developed for detecting a nonzero marginal excursion effect, which guarantees power under certain working assumptions. Practical guidelines are proposed for using the sample size formula, and an illustration is given on sizing an MRT for interventions on excessive drinking. The sample size calculator is implemented in R package MRTSampleSizeBinary and an interactive R Shiny app.
STATISTICS IN MEDICINE
(2023)
Article
Neurosciences
Jan Willem de Gee, Camile M. C. Correa, Matthew Weaver, Tobias H. Donner, Simon van Gaal
Summary: The study demonstrates that pupil responses and slow wave event-related potential, as physiological markers of phasic arousal, both reflect surprise in decision-making under uncertainty. Furthermore, these two variables are unrelated to each other, and prediction error computations depend on feedback awareness.
Article
Health Care Sciences & Services
Fan Li, Guangyu Tong
Summary: The study shows that using modified Poisson regression is more efficient than log-binomial regression for estimating marginal relative risk in cluster randomized trials. The sample size formulas developed for log-binomial regression naturally apply to modified Poisson regression in cluster randomized trials, and using an exchangeable working correlation is recommended for both design and analysis. The proposed sample size formulas have satisfactory performance across different cluster size variations.
STATISTICAL METHODS IN MEDICAL RESEARCH
(2021)
Article
Mathematical & Computational Biology
Rebecca. M. M. Turner, Michelle. N. N. Clements, Matteo Quartagno, Victoria Cornelius, Suzie Cro, Deborah Ford, Conor. D. D. Tweed, A. Sarah Walker, Ian. R. R. White
Summary: Bayesian analysis in non-inferiority trials allows for direct probability statements about treatment differences, without relying on arbitrary non-inferiority margins. Three Bayesian approaches for determining sample size in non-inferiority trials with binary outcomes are presented, along with their advantages and disadvantages. These approaches include a predictive power approach, an expected posterior probability approach, and a precision-based approach. Applying these methods to an antiretroviral therapy trial for HIV-infected children, the predictive power approach is most accessible, but sample sizes are larger than with frequentist calculations. The expected posterior probability approach leads to smaller sample sizes and is suitable for estimating posterior probability. The precision-based approach is useful when recruitment or cost limitations exist, but may be difficult to decide on sample size alone using this approach.
STATISTICS IN MEDICINE
(2023)
Article
Public, Environmental & Occupational Health
Nishma P. Vias, Caitlin A. Cassidy, Jessie K. Edwards, Khou Xiong, Cherese Beatty Parker, Allison E. Aiello, Ross M. Boyce, Bonnie E. Shook-Sa
Summary: This study presents a method for adjusting seroprevalence estimates for the sensitivity and specificity of diagnostic tests in complex sample designs. The method is applied to a longitudinal seroprevalence study conducted in Chatham County, North Carolina, and provides estimates of SARS-CoV-2 seroprevalence over time.
Article
Engineering, Civil
Peter Horbachov, Oleksandr Makarichev, Stanislav Svichynskyi, Ihor Ivanov
Summary: This study proposes a new method for determining the number of sample observations needed to obtain travel characteristics with a given precision. It shows that existing guidelines allow trip characteristics to be defined with an error of 20-40%, and that the required number of observations can be decreased by up to 56%.
Article
Mathematical & Computational Biology
Richard D. Riley, Ben Van Calster, Gary S. Collins
Summary: The articles describe how to calculate the minimum sample size for developing a multivariable prediction model and propose a method for identifying a plausible value for R-2 in advance. Researchers are advised to determine the value of R-2 from closely related models already published in their field.
STATISTICS IN MEDICINE
(2021)
Article
Obstetrics & Gynecology
Linli Hu, Jieqiang Lv, Qianhong Ma, Xiujuan Chen, Xiaohong Wang, Xiaoyan Liang, Dingfei Xu, Yanping Li, Yuanhua Huang, Lina Hu, Xiaohui Deng, Jing Wei, Feng Zhou, Songying Zhang, Jie Wang, Fang Ma, Yingpu Sun
Summary: The study aimed to compare the equivalence of QL1012 and Gonal-f((R)) in ovarian stimulation for assisted reproductive technology. The results showed that there were no significant differences between QL1012 and Gonal-f((R)) in the primary endpoint of oocytes retrieved, and they had similar safety profiles.
REPRODUCTIVE BIOMEDICINE ONLINE
(2023)
Article
Materials Science, Ceramics
Rong Tu, Jiaojiao Li, Mingpu Jia, Qizhong Li, Meijun Yang, Song Zhang, Takashi Goto
Summary: B4C-CrB2 composites were prepared by arc-melting using B4C and CrB2 powders as raw materials. The eutectic composition of B4C-CrB2 system was 30B(4)C-70CrB(2) (mol%) with a labyrinth-like irregularly layered eutectic microstructure. The composites exhibited maximum Vickers hardness (24.6 GPa) and fracture toughness (4.3 MPa m(1/2)) at room temperature.
INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY
(2023)
Review
Endocrinology & Metabolism
Hanjing Zhou, Chenqiong Zhao, Peixin Wang, Weijie Yang, Haiyan Zhu, Songying Zhang
Summary: Placental dysfunction refers to impaired placental function and inadequate supply of oxygen and nutrients to the fetus, resulting in fetal growth restriction. Deficient trophoblast syncytialization, inadequate trophoblast invasion, and impaired vascular remodeling contribute to placental dysfunction. Abnormal expression of proteins and signaling pathways involved in trophoblast syncytialization has been found in the placentas of pregnancies complicated by intrauterine growth restriction (IUGR).
FRONTIERS IN ENDOCRINOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Wenchao Hu, Wanyi Huang, Ying Sun, Wen Zhang, Lili Tan, Song Zhang, Guangcai Ma, Dan Zhang, Qiang Wang
Summary: In this study, fatigue properties of Mg-2Zn-0.5Zr-0.5Nd alloy were tested and it was found that the fatigue life varies with different frequencies. It was also observed that the alloy exhibits poorer fatigue resistance in 0.9 wt% NaCl solution.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Surgery
Ling-Ying Jiang, Fei-Fei Kong, Lv Yao, Fu-Xing Zhang, Sha-Sha Wang, Xiao-Ying Jin, Xiao-Mei Tong, Song-Ying Zhang
Summary: The study aimed to investigate whether using testicular sperm reduces embryo fragmentation and improves cycle outcomes. The results showed that patients who underwent intracytoplasmic sperm injection (ICSI) with testicular sperm had significantly lower fragmented embryo rate, higher transferable embryo rate, and higher implantation rate compared to those who used ejaculated sperm.
FRONTIERS IN SURGERY
(2023)
Article
Chemistry, Multidisciplinary
Liuyang Wang, Xuan Lin, Yanan Sheng, Hongyu Zhu, Zhengjun Li, Zhiguo Su, Rong Yu, Songping Zhang
Summary: The encapsulation of antigens with ZIF-8 provides advantages in vaccine development, but the synthesis conditions of ZIF-8 can be too harsh for sensitive viral antigens. This study explores the synthesis of ZIF-8 on an environment-sensitive antigen and demonstrates the importance of size and morphology in exerting adjuvant effects.
NANOSCALE ADVANCES
(2023)
Article
Chemistry, Applied
Zhen-Mei Zheng, Ning Chen, Ming-Suo Dai, Song-Lin Zhang
Summary: This study reports the reactivity properties of Cu(III)-CF3 compounds with anilines, showing distinct reactivities based on their basicity, resulting in the formation of formamides or hydrazines. This is achieved through the competing generation of difluorocarbene and N-centered radicals, controlled by the basicity of the reaction solution. The study demonstrates the unusual use of high-valent Cu(III) trifluoromethyl compounds as hydrogen-abstracting reagents for dehydrogenative reactions.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Applied
Dou-Dou Chen, Song-Lin Zhang
Summary: This study reports the geminal amino- and oxy-trifluoromethylation of ortho-ethynyl anilines/ phenols using phenCu(III)(CF3)(3), which provides a concise and controllable synthesis of valuable trifluoromethylated N and O-heterocyclic compounds. The method circumvents the regioselectivity issue often encountered in C H trifluoromethylation of arenes/heteroarenes and suppresses the competing vicinal fluoro-trifluoromethylation of terminal alkynes. The synthetic value of Cu(III) CF3 compounds in medicinal chemistry is highlighted.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Physical
Xiaole Song, Long Zheng, Rong Tu, Baifeng Ji, Jun Li, Song Zhang
Summary: V/LiF is an important window material for investigating phase transition of materials under ultra-high pressure, which is a fundamental issue in condensed matter physics. However, the large mismatch in lattice and thermal properties makes vanadium growth on LiF a big challenge. In this study, over 1.5 μm thick vanadium films were successfully grown on LiF using facing target sputtering (FTS), and transmission electron microscopy (TEM) observation revealed vertically well-aligned columnar crystals with numerous micro-sized gaps in the grown vanadium films. Particle-in-cell Monte Carlo collision (PIC-MCC) and Kinetic Monte Carlo (KMC) methods were used to simulate plasma discharge behavior, sputtered atom transport, and film growth to understand the deposition mechanism. A growth model of the vanadium film was established based on experimental and simulation results, and the micro-sized gaps in the columnar crystals were found to contribute to the release of residual stresses caused by the large mismatch, which can be explained by the grain boundary relaxation model.
APPLIED SURFACE SCIENCE
(2023)
Article
Fisheries
Felix Gyawu Addo, Songhe Zhang, Benjamin Manirakiza, Yu Ma, Shudong Yuan, Salah Alden Alklaf, Shaozhuang Guo, Godwin Abakari
Summary: In this study, a 30-day culture trial was conducted to investigate the effects of brown sugar addition on nutrient removal, feed conversion ratio, growth performance, and microbial community in a rice straw-based biofloc shrimp system. The results showed that the addition of brown sugar significantly reduced ammonium and nitrite nitrogen concentrations and improved nutrient removal rates. Furthermore, the addition of brown sugar also resulted in lower feed conversion ratio and higher shrimp survival rates. The dominant microbial phyla identified in all treatments played a crucial role in nutrient cycling and promoting water quality.
Article
Environmental Sciences
Xin He, Songhe Zhang, Xin Lv, Min Liu, Yu Ma, Shaozhuang Guo
Summary: This study investigated the role of rhizospheric biofilms on methane release in wastewater stabilization ponds (WSPs) with floating plants. The results showed that E. crassipes effectively reduced methane release and nutrients, with a higher inhibition effect on CH4 fluxes in treatments with high nutrients. Additionally, the rhizospheric bacterial community contributed to nutrients removal. In conclusion, E. crassipes plants play an important role in reducing methane release and nutrients removal.
Article
Multidisciplinary Sciences
Jue Zhou, Zhou Jiang, Leyi Fu, Fan Qu, Minchen Dai, Ningning Xie, Songying Zhang, Fangfang Wang
Summary: The study aimed to identify molecular subtypes and related genes associated with preterm labor risk in women with polycystic ovary syndrome (PCOS). Through analysis of multiple gene expression datasets, two molecular subtypes were identified in PCOS patients, and key genes related to preterm labor were determined. These findings help uncover the heterogeneity of clinical pregnancy complications in women with PCOS.
Article
Engineering, Manufacturing
Binxun Li, Song Zhang, Yujing Sun, Jin Du
Summary: In this paper, a systematic investigation was conducted on the correlation of processing parameters, plastic deformation, and mechanical properties of the machined surface layer for hardened H13 steel. The results indicate that edge micro-geometry significantly influences the depth of the plastic deformation layer, and the automated ball indentation (ABI) technique was used to assess the mechanical properties of the machined surface layers. The study reveals the relationship between processing parameters, depth of plastic deformation, and mechanical properties.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART B-JOURNAL OF ENGINEERING MANUFACTURE
(2023)
Article
Chemistry, Multidisciplinary
Rong Tu, Xinyu Li, Qingfang Xu, Bao-Wen Li, Tenghua Gao, Xian Zhang, Song Zhang, Takashi Goto, Lianmeng Zhang
Summary: This study reports the first growth of uniquely <010>-oriented ss-Ga2O3 films on quartz substrates by laser chemical vapor deposition (LCVD). The <010> orientation is closely related to the higher stability of oxygen close-packed planes under O-rich condition. The <010>-oriented ss-Ga2O3 film-based MSM type detector exhibits ultra-fast response speed.
Article
Materials Science, Coatings & Films
Qizhong Li, Tao Huang, Mai Yang, Tenghua Gao, Baifeng Ji, Song Zhang, Lianmeng Zhang, Rong Tu
Summary: Hard coatings with gradient and multilayer structures were prepared by high-power pulsed magnetron sputtering. The modulation period was found to significantly affect the microstructure, mechanical, and tribological properties of the coatings. Shorter modulation periods improved the adhesion strength and resulted in higher hardness and lower friction coefficients.
SURFACE & COATINGS TECHNOLOGY
(2023)