44 research outputs found
Integration of an On-Axis General Sun-Tracking Formula in the Algorithm of an Open-Loop Sun-Tracking System
A novel on-axis general sun-tracking formula has been integrated in the algorithm of an open-loop sun-tracking system in order to track the sun accurately and cost effectively. Sun-tracking errors due to installation defects of the 25 m2 prototype solar concentrator have been analyzed from recorded solar images with the use of a CCD camera. With the recorded data, misaligned angles from ideal azimuth-elevation axes have been determined and corrected by a straightforward changing of the parameters' values in the general formula of the tracking algorithm to improve the tracking accuracy to 2.99 mrad, which falls below the encoder resolution limit of 4.13 mrad
Risk factors associated with low anterior resection syndrome: a cross-sectional study
Purpose Oncological outcomes following rectal cancer surgery have improved significantly over recent decades with lower recurrences and longer overall survival. However, many of the patients experienced low anterior resection syndrome (LARS). This study identified the prevalence and risk factors associated with the development of LARS. Methods This cross-sectional study involved patients who were diagnosed with rectal cancer and had undergone sphincter-preserving low anterior resection from January 2011 to December 2020. Upon clinic follow-up, patients were asked to complete an interviewed based questionnaire (LARS score) designed to assess bowel dysfunction after rectal cancer surgery. Results Out of 76 patients, 25 patients (32.9%) had major LARS, 10 patients (13.2%) had minor LARS, and 41 patients (53.9%) had no LARS. The height of tumor from anal verge showed an association with the development of major LARS (P=0.039). Those patients with less than 8 cm tumor from anal verge had an increased risk of LARS by 3 times compared to those with 8 cm and above (adjusted odds ratio, 3.11; 95% confidence interval, 1.06–9.13). Conclusion Results from our study show that low tumor height was a significant risk factor that has a negative impact on bowel function after surgery. The high prevalence of LARS emphasizes the need for study regarding risk factors and the importance of understanding the pathophysiology of LARS, in order for us to improve patient bowel function and quality of life after rectal cancer surgery
Network Modeling Identifies Molecular Functions Targeted by miR-204 to Suppress Head and Neck Tumor Metastasis
Due to the large number of putative microRNA gene targets predicted by sequence-alignment databases and the relative low accuracy of such predictions which are conducted independently of biological context by design, systematic experimental identification and validation of every functional microRNA target is currently challenging. Consequently, biological studies have yet to identify, on a genome scale, key regulatory networks perturbed by altered microRNA functions in the context of cancer. In this report, we demonstrate for the first time how phenotypic knowledge of inheritable cancer traits and of risk factor loci can be utilized jointly with gene expression analysis to efficiently prioritize deregulated microRNAs for biological characterization. Using this approach we characterize miR-204 as a tumor suppressor microRNA and uncover previously unknown connections between microRNA regulation, network topology, and expression dynamics. Specifically, we validate 18 gene targets of miR-204 that show elevated mRNA expression and are enriched in biological processes associated with tumor progression in squamous cell carcinoma of the head and neck (HNSCC). We further demonstrate the enrichment of bottleneckness, a key molecular network topology, among miR-204 gene targets. Restoration of miR-204 function in HNSCC cell lines inhibits the expression of its functionally related gene targets, leads to the reduced adhesion, migration and invasion in vitro and attenuates experimental lung metastasis in vivo. As importantly, our investigation also provides experimental evidence linking the function of microRNAs that are located in the cancer-associated genomic regions (CAGRs) to the observed predisposition to human cancers. Specifically, we show miR-204 may serve as a tumor suppressor gene at the 9q21.1–22.3 CAGR locus, a well established risk factor locus in head and neck cancers for which tumor suppressor genes have not been identified. This new strategy that integrates expression profiling, genetics and novel computational biology approaches provides for improved efficiency in characterization and modeling of microRNA functions in cancer as compared to the state of art and is applicable to the investigation of microRNA functions in other biological processes and diseases
Use of anticoagulants and antiplatelet agents in stable outpatients with coronary artery disease and atrial fibrillation. International CLARIFY registry
Risk Factors Associated with Low Anterior Resection Syndrome: A Cross-Sectional Study
Introduction: Oncological outcomes following rectal cancer surgery have improved
significantly over recent decades with lower recurrences and longer overall survival.
However, these survival advantages have greatly overshadowed functional outcomes of
surgery, which are poor for many patients and consistently under-reported. Many of the
patients experienced several bowel symptoms after surgery, which include flatus and
faeces incontinence, frequent bowel opening, urgency or sense of incomplete
defecation. This combination of such symptoms after sphincter preserving surgery is
referred as Low Anterior Resection Syndrome (LARS).
Aim: The aim of this study is to identify the prevalence and risk factors associated with
development of LARS.
Methods: This is a cross-sectional study from 2 tertiary hospitals with colorectal unit in
Kelantan. All patients who were diagnosed with rectal cancer and had undergone
sphincter-preserving low anterior resection at the participating hospitals between
January 2011 and December 2020 were eligible. Upon clinic follow up, patients were
asked to complete an interviewed based simple questionnaire (LARS score) designed to
assess bowel dysfunction after rectal cancer surgery. Patients were grouped into two
separate cohorts—those with major LARS scores and those with mild/no LARS
symptoms. Categorical outcomes were compared for the major LARS group. Results: A total of 76 patients who fulfilled subject criteria recruited from clinic from
those who had sphincter preserving rectal surgery for rectal cancer in participating
hospital. There were 25 (32.8%) patients with major LARS, 10 (13.1%) patients minor
LARS, and 41 (53.9%) patients with no LARS. Height of tumour from anal verge
showed the association (P value =0.039) with development of major LARS. Those patients with less than 8cm tumour from anal verge increased risk of LARS by three
times compared to those with 8cm and above (Adjusted OR (95% CI) = 3.11
(1.06,9.13)).
Conclusion: We identified low tumour height as a significant risk factor which has
negative impact on bowel function after surgery. The high prevalence of LARS
emphasizes the need of study regarding risk factor and importance of understanding
pathophysiology of LARS, in order for us to improve patient bowel function and
quality of life after rectal cancer surger
A novel state-of-health estimation for the lithium-ion battery using a convolutional neural network and transformer model
State-of-health (SOH) estimation of lithium-ion batteries is crucial for ensuring the reliability and safety of battery operation while keeping maintenance and service costs down in the long run. This study suggests a novel SOH estimation based on data pre-processing methods and a convolutional neural network (CNN)-Transformer framework. In data pre-processing, highly related features are selected by the Pearson correlation coefficient (PCC). Principal correlation analysis (PCA) is also employed to minimize the computational burden of the estimation model by eliminating redundant feature information. Then, all the features are normalized by the min-max feature scaling method, which will speed up the training process to reach the minimum cost function. After pre-processing, all the features are fed into the CNN-Transformer model. The dataset of the battery from the NASA is employed as a training and testing dataset to build the proposed model. The simulations indicate that the proposed performance, proven by absolute estimation errors for each dataset, is within 1%. The estimation performance index is proven by mean absolute error (MAE), mean absolute percentage error (MAPE), and root mean square error (RMSE) are held within 0.55%. These show that the proposed model can estimate the battery SOH with high accuracy and stability
Dosage-dependent reduction of macular pigment optical density in female breast cancer patients receiving tamoxifen adjuvant therapy
It is now increasingly common for breast cancer patients to receive adjuvant tamoxifen therapy for a period of up to 10 years. As survival rate increases, managing tamoxifen ocular toxicities is important for patients' quality of life. Macular pigments in photoreceptor cells protect against free radical damage, which can cause macular degeneration. By reducing macular pigment concentration, tamoxifen may increase the risk of macular degeneration. Here, we compared macular pigment optical density (MPOD) and central macular thickness between breast cancer patients on tamoxifen adjuvant therapy (n = 70), and a control group (n = 72). Multiple regression analysis indicated that MPOD decreases with increasing tamoxifen dosage, up to a threshold of about 20 g, after which MPOD plateaus out. Mean MPOD in the treatment group (mean = 0.40) was significantly lower (p-value = 0.02) compared to the control group (mean = 0.47) for the left eye, and for the right eye (treatment mean = 0.39; control mean = 0.48; p-value = 0.009). No significant difference in mean central macular thickness was found between the treatment and the control group (p-values > 0.4). In the control group, MPOD and central macular thickness showed significant correlation (r∼0.30; p-values < 0.01) for both eyes. However, in the treatment group, loss of significant correlation was observed in the left eye (r = 0.21; p-value = 0.08). The present results show that MPOD decreases non-linearly as a function of tamoxifen dosage, and highlight the potential of tamoxifen to reduce macular pigment concentration through an unknown mechanism that does not depend on macular thinning solely