Simple Measures Research Articles

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Simplified measurement and verification combined with quality assurance instruments: a more practical and accessible method for M&V of energy savings

Energy efficiency (EE) is our “first fuel” and an essential resource in reaching climate goals, reducing dependence on fossil fuels, increasing security of supply, and many other “Multiple Benefits.” However, by their nature, savings are intangible. Demand-side EE measures are typically decentralized, heterogeneous, and small-scale opportunities. The difficulties in measurement and verification (M&V) of “Negawatts” are an important and often overlooked barrier to their greater application. M&V is a prerequisite to assess the performance of any energy, water, or CO2-saving measure, and to quantify the savings into physical and monetary units for reporting, re-financing, GHG accounting, or other purposes. However, in practice, M&V is often perceived (particularly by clients) as cumbersome, incomprehensible, and costly. In the broader context, energy cost savings alone are often not a sufficiently strong project driver because they lack strategic relevance for decision makers. As “Multiple Benefits” of EE become better understood, the value of quantifying savings to a high degree of accuracy may be declining, creating opportunities for more flexible M&V standards. As a new methodology, this conceptual paper proposes to combine simplified M&V (sM&V) for individual EE measures with quality assurance instruments (QAIs) to verify functionality. This “sM&V + QAI” approach is less cumbersome, less costly, and easier to comprehend than standard M&V approaches, particularly by clients, financiers, and other non-M&V experts. It has been reviewed by international experts and successfully tested and evaluated in the field. Multiple case studies are reported to verify its practical feasibility.

The Emerging Role of AI in Patient Education: A Comparative Analysis of the Accuracy of Large Language Models for Pelvic Organ Prolapse

Introduction: This study aimed to evaluate the accuracy, completeness, precision, and readability of outputs generated by three large language models (LLMs); these are GPT by OpenAI, BARD by Google, and Bing by Microsoft, in comparison to patient education material on pelvic organ prolapse (POP) provided by the Royal College of Obstetricians and Gynecologists (RCOG). Methods: A total of 15 questions were retrieved from the RCOG website and input into the three LLMs. Two independent reviewers evaluated the outputs for accuracy, completeness, and precision. Readability was assessed using the Simplified Measure of Gobbledygook (SMOG) score and the Flesch-Kincaid Grade Level (FKGL) score. Results: Significant differences were observed in completeness and precision metrics. ChatGPT ranked highest in completeness (66.7%), while Bing led in precision (100%). No significant differences were observed in accuracy across all models. In terms of readability, ChatGPT exhibited higher difficulty than BARD, Bing, and the original RCOG answers. Conclusion: While all models displayed a variable degree of correctness, ChatGPT excelled in completeness, significantly surpassing BARD and Bing. However, Bing led in precision, providing the most relevant and concise answers. Regarding readability, ChatGPT exhibited higher difficulty. We observed that while all LLMs showed varying degrees of correctness in answering RCOG questions on patient information for POP, ChatGPT was the most comprehensive, but its answers were harder to read. Bing, on the other hand, was the most precise. The findings highlight the potential of LLMs in health information dissemination and the need for careful interpretation of their outputs.

Abstract 2323: Deciphering RNA degradation: Insights from a comparative analysis of paired fresh frozen/FFPE total RNA-seq

Abstract Background: Fresh frozen (FF) and formalin-fixed paraffin-embedded (FFPE) samples are primary resources for archival tissues in cancer studies. Despite the advantages of easy storage and cost-effectiveness, FFPE samples have the disadvantage of inevitable chemical-induced RNA degradation. Although, in mRNA-seq data, the 3' bias due to the characteristics of the mRNA-seq platform allows the measure of RNA degradation levels, for total RNA-seq and FFPE samples, there is still no clear measure for RNA degradation. Methods: Our study, utilizing The Cancer Genome Atlas (TCGA) pilot data comprised of 26 paired samples of fresh frozen mRNA-seq [FFM], fresh frozen total RNA-seq [FFT], and FFPE total RNA-seq [PET], investigated RNA degradation patterns in FFPE samples. Upon investigating the read coverage of transcripts in FFPE data, we observed increased noise parameters in selected samples compared to others, suggesting a method for assessment of RNA degradation in FFPE. To measure these noise patterns, we developed a method called windowCV (wCV) utilizing coefficient of variance (CV) along the transcript length. Also, based on reports that membrane-surrounded RNA such as lncRNA and mitochondrial RNA (mtRNA) might be less affected by formalin fixation, we developed the simple measure dividing expression value of other proteins with certain lncRNA or mtRNA inferring the degree of RNA degradation. Results: We first compared the shape of transcript read coverage from 3 different RNA-seq data and observed 3’bias pattern in FFM which was not observed in FFT and PET. For FFT and PET, we applied wCV and executed hierarchical clustering. We observed that a subset of samples and genes were clustered by high wCV value suggesting notable RNA degradation. To support the hypothesis of RNA degradation, we utilized Trimmed Mean of M values (TMM) expression ratio of paired FFT and PET to determine which samples and genes were associated with underestimation of expression in PET. Interestingly, we observed that PET/FFT TMM ratio showed negative correlation with wCV. Additionally, when we investigated hierarchical clustering result of PET/FFT TMM ratio, we found that lncRNA and mtRNA were less affected by FFPE. We then calculated expression ratio between membrane-surrounded RNA and a set of protein coding genes largely affected by FFPE. As a result, we found that this ratio positively correlated with paired PET/FFT TMM ratio. We conclude that this simple measurement can provide information of FFPE induced underestimated expression with limited transcriptome data as well as RNA degradation. Conclusion: Our method can provide gene-level CV while avoiding false positive variance signal originating from transcript model and simple way to detect the degree of RNA degradation across FFPE samples. Citation Format: Wonyoung Choi, Miyeon Yeon, Hyo Young Choi, David Neil Hayes. Deciphering RNA degradation: Insights from a comparative analysis of paired fresh frozen/FFPE total RNA-seq [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2323.

Risk Assessment for Linear Regression Models in Metrology

The conformity assessment of products or a measured value with the given standards is carried out based on the global risk of producers and consumers’ calculations. A product may conform to specifications but be falsely rejected as non-conforming. This is about the producer’s risk. If a product does not meet the requirements but is falsely accepted as conforming, that poses a risk to the consumer. The conventional approach to risk assessment, which yields only a single numerical value for the global risk of producers and consumers, is naturally extended and utilized for assessing risk in measurement models with linear regression. The outcomes of the two-dimensional extension, along a moderate scale, are the parabolas with upwards openings. Risk surfaces were obtained through three-dimensional extension over the area limited by the moderate scale and guard band axes. Four models with different ranges of tolerance intervals were used to test this innovative method of risk assessment in linear regression. The corresponding standard measurement uncertainties were determined by applying a simplified measurement model with the use of comprehensive data on the measurement performance and by determining measurement uncertainty derived from consideration of the functional relationship obtained by linear regression analysis. Models that utilize information from linear regression analysis to determine measurement uncertainty are biased towards risks at the edges of the moderate scale. Testing the model’s performances with metrics related to the confusion matrix, such as the F1 score, further substantiated this assertion. The diagnostic odds ratio has been proven to be extremely effective in identifying the curve along the guard band axis, along which the global risks of producers and consumers are at their lowest.

On the effect of pressure coefficient source on the energy demand of an isolated cross-ventilated building

Natural ventilation is a simple and effective measure to both reduce the cooling demand of buildings and improve the indoor air quality. In the prediction of heating and cooling demands by means of building energy simulations (BES), the use of pressure coefficients (Cp) from databases as input for the airflow network model is the common approach. Cp values for the same building typology may differ according to the adopted database and are generally unavailable for buildings with complex geometry. Employed Cp values may lead to differences in BES results. This manuscript presents a comparison, for different wind directions, between the Cp distributions and mean values on the facades of a detached building obtained with full-scale CFD – Reynolds-averaged Navier-Stokes (RANS) and large eddy simulation (LES) – simulations, from a database and from wind-tunnel experiments. The obtained pressure coefficients are used in the BES of a naturally ventilated building and the energy demand difference between the four approaches is quantified. Four climate zones (tropical, dry/desertic, temperate, continental) are considered. Although, in terms of accuracy of Cp prediction, LES outperforms RANS for all the wind directions considered, annual cooling energy demand is found to be relatively insensitive to the source of Cp for the current case study, while predicted peak cooling values differ up to 10.8%. On the other hand, the prediction of annual heating energy demand in cold climates varies up to 3% depending on the Cp source employed for BES simulations.

A proposal for a simplified measure of HIV preexposure prophylaxis prevention-effective adherence in self-report questionnaires.

Evaluating HIV preexposure prophylaxis (PrEP) use and HIV risk events concurrently remains challenging. We developed a single question method for measuring prevention-effective adherence with PrEP in self-report questionnaires. In a questionnaire completed by 409 gay and bisexual men, 46% reported condomless anal sex that was not covered by their own PrEP use, and this was more common among younger, lower-income participants. Refining this questionnaire item could improve measurement of prevention-effective adherence.

Low Geriatric Nutritional Risk Index Predicts Early Complications following Distal Radius Fracture Open Reduction Internal Fixation

Abstract Background While previous studies have investigated the association between the Geriatric Nutritional Risk Index (GNRI) and functional outcomes following distal radius fracture (DRF), no large-scale studies have investigated the associations between GNRI and postoperative outcomes following DRFs. Objectives The purpose of this study is to investigate the association between GNRI, a simple multifaceted measure of malnutrition risk, and 30-day postoperative complications following DRF open reduction internal fixation (ORIF). Materials and Methods The American College of Surgeons National Surgical Quality Improvement Program database was queried for patients who underwent DRF ORIF from 2015 to 2021. Patients were organized into three groups based on preoperative GNRI: normal/reference (GNRI > 98), moderate malnutrition (92 ≤ GNRI ≤ 98), and severe malnutrition (GNRI < 92). Logistic regression analysis was conducted to investigate the relationship between preoperative GNRI and postoperative complications. Results Severe malnutrition was independently associated with a greater likelihood of any complication (odds ratio [OR]: 3.22, 95% confidence interval [CI]: 2.48–4.17; p < 0.001), sepsis (OR: 15.41, 95% CI: 1.66–143.32; p = 0.016), cardiac arrest or myocardial infarction (OR: 20.58, 95% CI: 1.62–261.26; p = 0.020), pulmonary embolism (OR: 9.40, 95% CI: 1.76–50.11; p = 0.009), surgical site infection (OR: 7.73, 95% CI: 1.99–30.02; p = 0.003), nonhome discharge (OR: 2.55, 95% CI: 1.87–3.49; p < 0.001), readmission (OR: 2.47, 95% CI: 1.47–4.14; p < 0.001), and length of stay > 2 days (OR: 3.51, 95% CI: 2.67–4.62; p < 0.001). Conclusions Malnutrition is an independent significant predictor of early complications following DRF ORIF. Level of Evidence Level III; retrospective cohort comparison; prognosis study.

Wireless Strain Gauge for Monitoring Bituminous Pavements

This paper introduces the implementation of a new device for measuring deformations at the surface layers of bituminous pavement. Using wireless technology, rechargeable remotely, low cost, and easily positioned in a layer by coring after pavement construction, this sensor makes it possible to obtain measurements of the deformation when a vehicle passes by. The development of the wireless sensor is presented as well as its advantages and limitations. It was then tested in the laboratory under a hydraulic press and in situ using a full-scale test of the mobile load simulator (MLS10 type). This system allows simple measurement, gives reliable results, and could be a useful device for the structural monitoring of pavement structures.

Crisis averted: Cross‐market reallocation during the great trade collapse

AbstractThis article investigates cross‐market reallocation of trade to mitigate negative effects of large economic shocks. We propose a simple measure of trade reallocation and apply it to Norwegian exports during the great trade collapse following the financial crisis in 2008–2009. The results indicate statistically significant cross‐market reallocation of trade away from markets hit hard by the crisis as measured by GDP/growth. Norwegian exports declined by 16.9% from 2008 and 2009. Without reallocation, the decline would have been between 1.6 and 3.8 percentage points greater. Successful reallocation at the firm level is done primarily along the intensive margin, by shifting physical products towards less affected markets within their pre‐crisis trade networks.

Prediction of Cancer Symptom Trajectory Using Longitudinal Electronic Health Record Data and Long Short-Term Memory Neural Network.

Ability to predict symptom severity and progression across treatment trajectories would allow clinicians to provide timely intervention and treatment planning. However, such predictions are difficult because of sparse and inconsistent assessment, and simplistic measures such as the last observed symptom severity are often used. The purpose of this study is to develop a model for predicting future cancer symptom experiences on the basis of past symptom experiences. We performed a retrospective, longitudinal analysis using records of patients with cancer (n = 208) hospitalized between 2008 and 2014. A long short-term memory (LSTM)-based recurrent neural network, a linear regression, and random forest models were trained on previous symptoms experienced and used to predict future symptom trajectories. We found that at least one of three tested models (LSTM, linear regression, and random forest) outperform predictions based solely on the previous clinical observation. LSTM models significantly outperformed linear regression and random forest models in predicting nausea (P < .1) and psychosocial status (P < .01). Linear regression outperformed all models when predicting oral health (P < .01), while random forest outperformed all models when predicting mobility (P < .01) and nutrition (P < .01). We can successfully predict patients' symptom trajectories with a prediction model, built with sparse assessment data, using routinely collected nursing documentation. The results of this project can be applied to better individualize symptom management to support cancer patients' quality of life.

The identification of an optimal body size parameter to adjust skeletal muscle area on chest CT in COVID-19 patients.

The most efficient way to adjust skeletal muscle area (SMA) derived from chest CT to body size remains unclear. We hypothesized that vertebral body area (VBA) measurement would allow such efficient adjustment. We conducted a retrospective observational study of chest CT imaging in a cohort of critically ill COVID-19 patients. We measured paravertebral SMA at T5 level and T5 vertebral body anteroposterior length, width, and area. We used linear regression and multivariable modelling to assess the association of VBA with SMA. In 48 COVID-19 patients in ICU, T5 VBA could be easily derived from simple width and anteroposterior length linear measurements. T5 VBA (measured manually or estimated from width and length) performed similarly to height (R2 of 0.22) as an adjustment variable for SMA, with R2 of 0.23 and 0.22, respectively. Gender had the strongest correlation with SMA (R2 = 0.28). Adding height or age to a model using gender and VBA did not improve correlation. Gender and estimated VBA from simple linear measurements at T5 level on CT images can be utilized for adjustment of SMA without the need for height. Validation of these findings in larger cohorts of critically ill patients is now needed.

Electrochemical DNA-based sensors for measuring cell-generated forces

Mechanical forces play an important role in cellular communication and signaling. We developed in this study novel electrochemical DNA-based force sensors for measuring cell-generated adhesion forces. Two types of DNA probes, i.e., tension gauge tether and DNA hairpin, were constructed on the surface of a smartphone-based electrochemical device to detect piconewton-scale cellular forces at tunable levels. Upon experiencing cellular tension, the unfolding of DNA probes induces the separation of redox reporters from the surface of the electrode, which results in detectable electrochemical signals. Using integrin-mediated cell adhesion as an example, our results indicated that these electrochemical sensors can be used for highly sensitive, robust, simple, and portable measurements of cell-generated forces.

Shape reconstruction of axisymmetric Taylor bubbles using conductivity probes through a scheme of combined experiment and theory.

A simple measurement scheme is proposed to reconstruct the geometry of an axisymmetric void propagating through a conducting liquid using a pair of parallel wire conductivity probes. An experimental study allows for obtaining the time variation of the resistance of the film surrounding the void. Analytical modeling and numerical simulation has been adopted to correlate the resistance between the wire electrodes and the film thickness. Finally, the shape of the void can be estimated by combining the predicted resistance-film thickness relationship and the measured time variation of resistance. For validation, this scheme has been used to reconstruct the shape of a rising Taylor bubble. There is a fair match between the reconstructed shape of the bubble and its photographic image. The probable errors in the measurement scheme have been discussed and assessed mathematically.

Artificial intelligence compared with human-derived patient educational materials on cirrhosis.

The study compared the readability, grade level, understandability, actionability, and accuracy of standard patient educational material against artificial intelligence chatbot-derived patient educational material regarding cirrhosis. An identical standardized phrase was used to generate patient educational materials on cirrhosis from 4 large language model-derived chatbots (ChatGPT, DocsGPT, Google Bard, and Bing Chat), and the outputs were compared against a pre-existing human-derived educational material (Epic). Objective scores for readability and grade level were determined using Flesch-Kincaid and Simple Measure of Gobbledygook scoring systems. 14 patients/caregivers and 8 transplant hepatologists were blinded and independently scored the materials on understandability and actionability and indicated whether they believed the material was human or artificial intelligence-generated. Understandability and actionability were determined using the Patient Education Materials Assessment Tool for Printable Materials. Transplant hepatologists also provided medical accuracy scores. Most educational materials scored similarly in readability and grade level but were above the desired sixth-grade reading level. All educational materials were deemed understandable by both groups, while only the human-derived educational material (Epic) was considered actionable by both groups. No significant difference in perceived actionability or understandability among the educational materials was identified. Both groups poorly identified which materials were human-derived versus artificial intelligence-derived. Chatbot-derived patient educational materials have comparable readability, grade level, understandability, and accuracy to human-derived materials. Readability, grade level, and actionability may be appropriate targets for improvement across educational materials on cirrhosis. Chatbot-derived patient educational materials show promise, and further studies should assess their usefulness in clinical practice.

Evaluating the Use of ChatGPT to Accurately Simplify Patient-centered Information about Breast Cancer Prevention and Screening.

Purpose To evaluate the use of ChatGPT as a tool to simplify answers to common questions about breast cancer prevention and screening. Materials and Methods In this retrospective, exploratory study, ChatGPT was requested to simplify responses to 25 questions about breast cancer to a sixth-grade reading level in March and August 2023. Simplified responses were evaluated for clinical appropriateness. All original and simplified responses were assessed for reading ease on the Flesch Reading Ease Index and for readability on five scales: Flesch-Kincaid Grade Level, Gunning Fog Index, Coleman-Liau Index, Automated Readability Index, and the Simple Measure of Gobbledygook (ie, SMOG) Index. Mean reading ease, readability, and word count were compared between original and simplified responses using paired t tests. McNemar test was used to compare the proportion of responses with adequate reading ease (score of 60 or greater) and readability (sixth-grade level). Results ChatGPT improved mean reading ease (original responses, 46 vs simplified responses, 70; P < .001) and readability (original, grade 13 vs simplified, grade 8.9; P < .001) and decreased word count (original, 193 vs simplified, 173; P < .001). Ninety-two percent (23 of 25) of simplified responses were considered clinically appropriate. All 25 (100%) simplified responses met criteria for adequate reading ease, compared with only two of 25 original responses (P < .001). Two of the 25 simplified responses (8%) met criteria for adequate readability. Conclusion ChatGPT simplified answers to common breast cancer screening and prevention questions by improving the readability by four grade levels, though the potential to produce incorrect information necessitates physician oversight when using this tool. Keywords: Mammography, Screening, Informatics, Breast, Education, Health Policy and Practice, Oncology, Technology Assessment Supplemental material is available for this article. © RSNA, 2023.

The Breakfast and Dressing Conflict Task: Preliminary Evidence of Its Validity to Measure Online Self-Awareness After Acquired Brain Injury.

Impaired self-awareness (SA) of deficits after an acquired brain injury (ABI) severely affects patients' independence in activities of daily living (ADLs). However, any assessment tool permits an exhaustive evaluation of SA in the context of ADLs. To study the validity of the Breakfast and Dressing Conflict Task (BD Conflict Task) to assess online SA (awareness of performance in the context of a given task) in patients with ABI; to study its interactions with offline SA (general awareness); and to test the validity of a simplified measure of performance monitoring, the ADL Conflict-Monitoring Index. Convergent validity and correlational study. Research laboratory, hospitals, and homes. Thirty patients with ABI and 28 neurologically healthy controls. Using the BD Conflict Task, measures of emergent awareness, self-regulation, anticipatory awareness, and self-evaluation were assessed and their convergent validity and relationship with offline SA were analyzed. The ADL Conflict-Monitoring Index was calculated, and its convergent validity was tested. The online SA variables of the BD Conflict Task showed convergent validity with traditional online SA measures. Offline SA correlated with emergent and anticipatory awareness in the Breakfast Task. The ADL Conflict-Monitoring Index proved to be a valid measure of patients' performance monitoring. These preliminary findings suggest that the BD Conflict Task is a valid tool to assess online SA in patients with ABI and provide further understanding of the online SA-offline SA interaction. Furthermore, the ADL Conflict-Monitoring Index may be a valid and easy-to-use monitoring measure in clinical settings. Plain-Language Summary: Patients with acquired brain injury (ABI) and reduced awareness of their cognitive deficits face problems performing activities of daily living (ADLs) and may show signs of unsafe behaviors. Being aware of one's own abilities involves anticipating problems before starting a task, detecting and correcting errors during the task, and evaluating performance afterward. This study provides preliminary validity for the Breakfast and Dressing Conflict Task, a new tool that assesses aspects of self-awareness simultaneously in the context of familiar and significant ADLs. Furthermore, the tool simplifies the assessment of detecting and correcting errors with an easy-to-use index, making it suitable for use in clinical settings.

A rapid method for the determination of stable hydrogen isotope ratios of acetic acid in vinegar.

Vinegar is an everyday condiment made from fermented grains or fruits. It contains acetic acid which is the main organic material produced by fermentation. Vinegar suffers from the authenticity problem of exogenous adulteration due to the indistinguishability of low-cost chemical sources of synthetic acetic acid from acetic acid produced by fermentation. It is necessary to establish a simple and rapid measurement technique. Determination was according to the total acid content of vinegar diluted with acetone to a certain concentration. Online separation and determination of acetic acid δD in vinegar were carried out using gas chromatography-pyrolysis-isotope ratio mass spectrometry. An HP-Plot/U column was selected for online separation of acetic acid and water with molecular sieve characteristics. At the same time, combined with the instrument blowback function to remove water. Dilute solvent acetone was treated with a molecular sieve to remove trace water. The reproducibility of this method is less than 3‰. The long-term stability is within a reasonable error range. The accuracy correlation coefficient is greater than 0.99. The δD values of acetic acid in vinegar (-264.5 ± 20.3‰) and from chemical sources (-30.5 ± 90.8‰) were obtained. A rapid method was developed for identification of different sources of acetic acid. These different sources of acetic acid exhibited significant hydrogen isotope distribution characteristics. Additionally, it was observed that the carboxyl hydrogen of acetic acid exhibited facile exchange with water. In future investigations, we aim to mitigate this interference.

PENGARUH HUMAS TERHADAP KEGIATAN COMMUNITY RELATIONS PADA PT KERETA COMMUTER INDONESIA AREA JABODETABEK

Erecting good connections with the girding community through enforcing community conditioning is one of the places of public relations. thus, experimenters conducted exploration with the title" The Influence of Public Relations on Community Relations Conditioning at PT Keret Commuter Indonesia Jabodetabek Area". The aimBuilding good connections with the girding community through enforcing community conditioning is one of the places of public relations. thus, experimenters conducted exploration with the title" The Influence of Public Relations on Community Relations Conditioning at PT Kereta Commuter Indonesia Jabodetabek Area". The end of this exploration is to empirically test the influence of public relations on community relations conditioning at PT Kereta Commuter Indonesia Jabodetabek Area. The methodology used is quantitative. The population of this exploration is people who took part in PT KCI's public relations conditioning in January- February 2023. The slice system used in this exploration was impregnated slice with a aggregate of 50 repliers. The data analysis styles are validity test, trustability test, normalcy test, linearity test, simple direct retrogression test, section test( T) and measure of determination test( R) using the SPSS 25 operation. The exploration results show t- number&gt; t- table( 16,823&gt; 1,677). The t- test results also give a significance of lower than0.1 or 10(0.000&lt;0.1). therefore it can be concluded that PT KCI's public relations has a positive and significant influence on community conditioning. crucial words Public relations, communication, public relations, social responsibility of this exploration is to empirically test the influence of public relations on community relations conditioning at PT Kereta Commuter Indonesia Jabodetabek Area. The methodology used is quantitative. The population of this exploration is people who took part in PT KCI's public relations conditioning in January- February 2023. The slice system used in this exploration was impregnated slice with a aggregate of 50 repliers. The data analysis styles are validity test, trustability test, normalcy test, linearity test, simple direct retrogression test, section test( T) and measure of determination test( R) using the SPSS 25 operation. The exploration results show t- number&gt; t- table( 16,823&gt; 1,677). The t- test results also give a significance of lower than0.1 or 10(0.000&lt;0.1). therefore it can be concluded that PT KCI's public relations has a positive and significant influence on community conditioning. crucial words Public relations, communication, public relations, social responsibility

Biocatalytic cascade to polysaccharide amination

BackgroundChitin, the main form of aminated polysaccharide in nature, is a biocompatible, polycationic, and antimicrobial biopolymer used extensively in industrial processes. Despite the abundance of chitin, applications thereof are hampered by difficulties in feedstock harvesting and limited structural versatility. To address these problems, we proposed a two-step cascade employing carbohydrate oxidoreductases and amine transaminases for plant polysaccharide aminations via one-pot reactions. Using a galactose oxidase from Fusarium graminearum for oxidation, this study compared the performance of CvATA (from Chromobacterium violaceum) and SpATA (from Silicibacter pomeroyi) on a range of oxidized carbohydrates with various structures and sizes. Using a rational enzyme engineering approach, four point mutations were introduced on the SpATA surface, and their effects on enzyme activity were evaluated.ResultsHerein, a quantitative colorimetric assay was developed to enable simple and accurate time-course measurement of the yield of transamination reactions. With higher operational stability, SpATA produced higher product yields in 36 h reactions despite its lower initial activity. Successful amination of oxidized galactomannan by SpATA was confirmed using a deuterium labeling method; higher aminated carbohydrate yields achieved with SpATA compared to CvATA were verified using HPLC and XPS. By balancing the oxidase and transaminase loadings, improved operating conditions were identified where the side product formation was largely suppressed without negatively impacting the product yield. SpATA mutants with multiple alanine substitutions besides E407A showed improved product yield. The E407A mutation reduced SpATA activity substantially, supporting its predicted role in maintaining the dimeric enzyme structure.ConclusionsUsing oxidase–amine transaminase cascades, the study demonstrated a fully enzymatic route to polysaccharide amination. Although the activity of SpATA may be further improved via enzyme engineering, the low operational stability of characterized amine transaminases, as a result of low retention of PMP cofactors, was identified as a key factor limiting the yield of the designed cascade. To increase the process feasibility, future efforts to engineer improved SpATA variants should focus on improving the cofactor affinity, and thus the operational stability of the enzyme.Graphical