DIG-Mol: A Contrastive Dual-Interaction Graph Neural Network for Molecular Property Prediction.

Molecular property prediction is a key component of AI-driven drug discovery and molecular characterization learning. Despite recent advances, existing methods still face challenges such as limited ability to generalize, and inadequate representation of learning from unlabeled data, especially for tasks specific to molecular structures. To address these limitations, we introduce DIG-Mol, a novel self-supervised graph neural network framework for molecular property prediction. This architecture leverages the power of contrast learning with dual interaction mechanisms and unique molecular graph enhancement strategies. DIG-Mol integrates a momentum distillation network with two interconnected networks to efficiently improve molecular characterization. The framework's ability to extract key information about molecular structure and higher-order semantics is supported by minimizing loss of contrast. We have established DIG-Mol's state-of-the-art performance through extensive experimental evaluation in a variety of molecular property prediction tasks. In addition to demonstrating superior transferability in a small number of learning scenarios, our visualizations highlight DIG-Mol's enhanced interpretability and representation capabilities. These findings confirm the effectiveness of our approach in overcoming challenges faced by traditional methods and mark a significant advance in molecular property prediction. The code for this project is now available at https://github.com/ZeXingZ/DIG-Mol.

Mechanisms of hydrogel-based microRNA delivery systems and its application strategies in targeting inflammatory diseases.

Hydrogels, composed of three-dimensional polymer networks, are excellent delivery carriers and have been extensively employed in the biomedical field. Inflammation acts as a protective mechanism to prevent harmful substances from entering living organisms, but chronic, long-lasting inflammation can cause oxidative stress, which damages tissue and organs and adversely affects patients' quality of life. The aberrant expression of microRNAs (miRNAs) has been found to play a significant part in the etiology and progression of inflammatory diseases, as suggested by growing evidence. Numerous hydrogels that can act as gene carriers for the intracellular delivery of miRNA have been described during ongoing research into innovative hydrogel materials. MiRNA hydrogel delivery systems, which are loaded with exogenous miRNA inhibitors or mimics, enable targeted miRNA intervention in inflammatory diseases and effectively prevent environmental stressors from degrading or inactivating miRNA. In this review, we summarize the classification of miRNA hydrogel delivery systems, the basic strategies and mechanisms for loading miRNAs into hydrogels, highlight the biomedical applications of miRNA hydrogel delivery systems in inflammatory diseases, and share our viewpoints on potential opportunities and challenges in the promising region of miRNA delivery systems. These findings may provide a new theoretical basis for the prevention and treatment of inflammation-related diseases and lay the foundation for clinical translation.

Development of a new environmentally friendly and efficient centrifugal variable diameter metering device.

Introduction: The design of the maize metering device involves centrifugal variable diameter pneumatic and cleaning mechanisms, aiming to enhance the performance and power efficiency of pneumatic maize metering devices. Leveraging the impact of changes in centrifugal diameter and the guidance and positioning of airflow, we optimize the hole insert, seeding plate, seed limit board, and integrated front shell. This optimization facilitates the adjustment of both the quantity and posture of seed filling. As a result, seeds can form a uniform flow within the annular cavity, reducing the wind pressure necessary for regular operation and decreasing power consumption. Methods: A quadratic regression orthogonal rotation combination experiment is conducted using a self-made experiment bench, considering ground speed, wind pressure, and seeding rate as the experiment factors. Furthermore, a comparative experiment involving a novel centrifugal variable-diameter type metering device. Results: The results indicate optimal seeding performance when the ground speed is 13.2 km/h, the wind pressure is 1.2 kPa, and the feeding rate is 25 seeds/s. Under these conditions, the quality of feed index reaches 95.20%, the multi-index is 3.87%, and the miss index is 0.93%. Findings reveal that the developed seed metering device achieved a quality of feed index exceeding 93.00% across varying speeds of 12~18 km/h, aligning with the production requirements. Moreover, the actual power consumption of Type B and C is about 85.00% and 98.00% lower than Type A, standing at only 32.90 W at 18 km/h. The COP of Type C is about 86 times and 12 times that of Type A and B, respectively, meeting the demands for efficient production of maize seed metering devices. Discussion: In comparison to traditional design and structural parameter optimization methods for maize seed metering device, this study is helpful to the sustainable development of maize industry and reduce environmental pollution.

Platelet dysfunction caused by differentially expressed genes as key pathogenic mechanisms in COVID-19.

At the end of 2019, the novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) became prevalent worldwide, which brought a heavy medical burden and tremendous economic losses to the world population. In addition to the common clinical respiratory symptoms such as fever, cough and headache, patients with COVID-19 often have hematological diseases, especially platelet dysfunction. Platelet dysfunction usually leads to multiple organ dysfunction, which is closely related to patient severity or mortality. In addition, studies have confirmed significant changes in the gene expression profile of circulating platelets under SARS-CoV-2 infection, which will further lead to changes in platelet function. At the same time, studies have shown that platelets may absorb SARS-COV-2 mRNA independently of ACE2, which further emphasizes the importance of the stability of platelet function in defense against SARS-CoV-2 infection. This study reviewed the relationship between COVID-19 and platelet and SARS-CoV-2 damage to the circulatory system, and further analyzed the significantly differentially expressed mRNA in platelets after infection with SARS-CoV-2 on the basis of previous studies. The top eight hub genes were identified as NLRP3, MT-CO1, CD86, ICAM1, MT-CYB, CASP8, CXCL8 and CXCR4. Subsequently, the effects of SARS-CoV-2 infection on platelet transcript abnormalities and platelet dysfunction were further explored on the basis of 8 hub genes. Finally, the treatment measures of complications caused by platelet dysfunction in patients with COVID-19 were discussed in detail, so as to provide reference for the prevention, diagnosis and treatment of COVID-19.

Association between preoperative frailty and myocardial injury after noncardiac surgery in geriatric patients: study protocol for a prospective, multicentre, real-world observational, cohort trial.

INTRODUCTION: Frailty has become a worldwide health burden that has a large influence on public health and clinical practice. The incidence of frailty is anticipated to increase as the ageing population increases. Myocardial injury after noncardiac surgery (MINS) is associated with short-term and long-term mortality. However, the incidence of MINS in frail geriatric patients is unknown. METHODS AND ANALYSIS: This prospective, multicentre, real-world observational cohort study will be conducted at 18 designated centres in China from January 2023 to December 2024, with an anticipated sample size of 856 patients aged 65 years and older who are scheduled to undergo noncardiac surgery. The primary outcome will be the incidence of MINS. MINS is defined as a fourth-generation plasma cardiac troponin T (cTnT) concentration ≥ 0.03 ng/mL exhibited at least once within 30 days after surgery, with or without symptoms of myocardial ischaemia. All data will be collected via electronic data acquisition. DISCUSSION: This study will explore the incidence of MINS in frail patients. The characteristics, predictive factors and 30-day outcomes of MINS in frail patients will be further investigated to lay the foundation for identifying clinical interventions. CLINICAL TRIAL REGISTRATION: https://beta. CLINICALTRIALS: gov/study/NCT05635877 , NCT05635877.

Correlation of preoperative frailty with postoperative delirium and one-year mortality in Chinese geriatric patients undergoing noncardiac surgery: Study protocol for a prospective observational cohort study.

BACKGROUND: To Frailty is associated with postoperative delirium (POD) but is rarely assessed in patients undergoing noncardiac surgery. In this study, the correlation between preoperative frailty and POD, one-year mortality will be investigated in noncardiac Chinese geriatric surgery patients. METHODS: This study is a prospective, observational, cohort study conducted at a single center with Chinese geriatric patients. Patients who undergo noncardiac surgery and are older than 70 years will be included. A total of 536 noncardiac surgery patients will be recruited from the First Affiliated Hospital of Shandong First Medical University for this study. The Barthel Index (BI) rating will be used to assess the patient's ability to carry out everyday activities on the 1st preoperative day. The modified frailty index (mFI) will be used to assess frailty. Patients in the nonfrailty group will have an mFI < 0.21, and patients in the frailty group will have an mFI ≥ 0.21. The primary outcome is the incidence of POD. Three-Minute Diagnostic Interview for CAM-defined Delirium (3D-CAM) will be conducted twice daily during the 1st-7th postoperative days, or just before discharge. The secondary outcomes will include one-year mortality, in-hospital cardiopulmonary events, infections, acute renal injury, and cerebrovascular events. DISCUSSION: This study will clarify the correlation of preoperative frailty with POD and one-year all-cause mortality in Chinese geriatric patients undergoing noncardiac surgery. Can preoperative frailty predict POD or one-year mortality? In the face of China's serious aging social problems, this result may have important clinical value for the surgical treatment of geriatric patients. TRIAL REGISTRATION: This protocol has been registered with ClinicalTrials. Gov on 12 January 2022 (https://clinicaltrials.gov/ct2/show/NCT05189678).

Preliminary investigation of the effect of non-cardiac surgery on intraoperative islet and renal function: a single-center prospective cohort study.

Background: The effect of different non-cardiac surgical methods on islet and renal function remains unclear. We conducted a preliminary investigation to determine whether different surgical methods affect islet function or cause further damage to renal function. Methods: In this prospective cohort study, the clinical data of 63 adult patients who underwent non-cardiac surgery under general anesthesia were evaluated from February 2019 to January 2020. Patients were divided into the abdominal surgery group, the laparoscopic surgery group, and the breast cancer surgery group. The primary outcome was the difference between the effects of different surgical methods on renal function. Results: Islet and renal function were not significantly different between the groups. The correlation analysis showed that hematocrit (HCT) and hemoglobin (HB) were negatively correlated with fasting plasma glucose (FPG) (p < 0.05), MAP was positively correlated with C-peptide (p < 0.05), and HCT and Hb were positively correlated with serum creatinine (SCr) (p < 0.05). Fasting insulin (FINS) and C-peptide were negatively correlated with SCr (p < 0.05), and the homeostatic model assessment of insulin resistance (HOMA-IR) was positively correlated with SCr (p < 0.05). FINS, C-peptide, HOMA-IR, and the homeostatic model assessment of ß-cell function (HOMA-ß) were positively correlated with cystatin C (Cys C) (p < 0.05). Conclusion: FINS, C-peptide, and HOMA-IR had positive effects on beta-2-microglobulin (ß2-MG). FINS, C-peptide, and HOMA-IR were positively correlated with Cys C and ß2-Mg. While FINS and C-peptide were negatively correlated with SCr, HOMA-IR was positively correlated with SCr.

Effect of the new video laryngeal mask airway SaCoVLM on airway management in lateral laparoscopic urological surgery: A single center randomized controlled trial.

There are few pertinent studies about the application of laryngeal mask airways (LMAs) in lateral decubitus surgery. Therefore, the aim of our study was to evaluate the effects of lateral position and pneumoperitoneum on oropharyngeal leak pressure (OLP) and ventilation efficiency for the LMA SaCoVLM. Patients undergoing elective retroperitoneal laparoscopic urological surgery were randomized 1:1 to the Supreme group or SaCoVLM group. The primary outcome was the OLP with LMA insertion. The secondary outcomes were the first-attempt success rate, insertion time, adjustment times, gastric tube success rate, LMA alignment accuracy, LMA removal time, regurgitation or aspiration, LMA blood staining, and incidence of adverse events 24 h after surgery. We recruited 70 patients to complete the study. Regardless of lateral position and pneumoperitoneum, the OLP was greater in the SaCoVLM group (n = 35) than in the Supreme group (n = 35), with a median difference of 4-7 cmH2O. The first-attempt success rate of the SaCoVLM group was higher than that of the Supreme group (91.4% vs. 77.1%, risk ratio (RR): 1.19; 95% CI 0.96 to 1.46, P = 0.188). Thus, in the lateral position with pneumoperitoneum, although the new video LMA SaCoVLM has a higher OLP than the LMA Supreme, both devices provide sufficient ventilation efficiency.

MicroRNA regulation of phenotypic transformations in vascular smooth muscle: relevance to vascular remodeling.

Alterations in the vascular smooth muscle cells (VSMC) phenotype play a critical role in the pathogenesis of several cardiovascular diseases, including hypertension, atherosclerosis, and restenosis after angioplasty. MicroRNAs (miRNAs) are a class of endogenous noncoding RNAs (approximately 19-25 nucleotides in length) that function as regulators in various physiological and pathophysiological events. Recent studies have suggested that aberrant miRNAs' expression might underlie VSMC phenotypic transformation, appearing to regulate the phenotypic transformations of VSMCs by targeting specific genes that either participate in the maintenance of the contractile phenotype or contribute to the transformation to alternate phenotypes, and affecting atherosclerosis, hypertension, and coronary artery disease by altering VSMC proliferation, migration, differentiation, inflammation, calcification, oxidative stress, and apoptosis, suggesting an important regulatory role in vascular remodeling for maintaining vascular homeostasis. This review outlines recent progress in the discovery of miRNAs and elucidation of their mechanisms of action and functions in VSMC phenotypic regulation. Importantly, as the literature supports roles for miRNAs in modulating vascular remodeling and for maintaining vascular homeostasis, this area of research will likely provide new insights into clinical diagnosis and prognosis and ultimately facilitate the identification of novel therapeutic targets.

Preliminary Testing of A Web-Based Lung Cancer Screening Decision Coaching Tool for Older Chinese American Smokers and Their Providers.

OBJECTIVES: To examine the acceptability of a culturally targeted lung cancer screening decision aid developed for older Chinese Americans with a smoking history and primary care providers serving this patient population. METHODS: Study participants reviewed a web-based decision aid (DA) for lung cancer screening named "Lung Decisions Coaching Tool (LDC-T)." Participants completed a baseline survey and were invited to join an interview. During the interview, participants engaged with the Lung Decisions Coaching Tool and then completed standardized measures of acceptability, usability, and satisfaction. RESULTS: Chinese American smokers (N =22) and Chinese American physicians (N=10) rated the acceptability and usability of a patient version and provider versions of the LDC-T, respectively. Patient version demonstrated high levels of acceptability, usability and satisfaction. Most participants rated the information provided as good or excellent, the amount of tool information was just right, and they thought the tool would be useful for making a screening decision. The tool was well received by participants for ease of use and well-integrated functions. Furthermore, participants indicated they would like to use the tool to help prepare for lung cancer screening shared decision-making with their provider. Similar results were found for the provider version of the LDC-T. CONCLUSIONS: Lung cancer screening represents an evidence-based approach to reducing lung cancer morbidity and mortality among chronic high-frequency smokers. Study results suggest the acceptability of a culturally targeted lung cancer screening decision aid for Chinese American smokers and providers. Additional research is needed to determine the effectiveness of the DA in increasing appropriate levels of screening in this underserved population.

Circulating microRNAs as emerging regulators of COVID-19.

Coronavirus disease 2019 (COVID-19), an infectious disease caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a global pandemic that has high incidence rates, spreads rapidly, and has caused more than 6.5 million deaths globally to date. Currently, several drugs have been used in the clinical treatment of COVID-19, including antivirals (e.g., molnupiravir, baricitinib, and remdesivir), monoclonal antibodies (e.g., etesevimab and tocilizumab), protease inhibitors (e.g., paxlovid), and glucocorticoids (e.g., dexamethasone). Increasing evidence suggests that circulating microRNAs (miRNAs) are important regulators of viral infection and antiviral immune responses, including the biological processes involved in regulating COVID-19 infection and subsequent complications. During viral infection, both viral genes and host cytokines regulate transcriptional and posttranscriptional steps affecting viral replication. Virus-encoded miRNAs are a component of the immune evasion repertoire and function by directly targeting immune functions. Moreover, several host circulating miRNAs can contribute to viral immune escape and play an antiviral role by not only promoting nonstructural protein (nsp) 10 expression in SARS coronavirus, but among others inhibiting NOD-like receptor pyrin domain-containing (NLRP) 3 and IL-1ß transcription. Consequently, understanding the expression and mechanism of action of circulating miRNAs during SARS-CoV-2 infection will provide unexpected insights into circulating miRNA-based studies. In this review, we examined the recent progress of circulating miRNAs in the regulation of severe inflammatory response, immune dysfunction, and thrombosis caused by SARS-CoV-2 infection, discussed the mechanisms of action, and highlighted the therapeutic challenges involving miRNA and future research directions in the treatment of COVID-19.

Comparison of a polyvinyl chloride tube with a wire-reinforced tube for tracheal intubation through the SaCoVLM video laryngeal mask airway: protocol for a randomised controlled study.

INTRODUCTION: The SaCoVLM is a new type of video intubating laryngeal mask airway (LMA), and it is the first LMA to realise continuous visual monitoring. There is a lack of studies on intubation using the SaCoVLM. The aim of this study is to compare the success rate of intubation with polyvinyl chloride (PVC) tubes and wire-reinforced (WR) tubes using the SaCoVLM. METHODS AND ANALYSIS: This prospective, single-centre, single-blind, parallel-arm, randomised controlled study will be conducted in a tertiary university hospital in China. We will include 104 patients undergoing elective laparoscopic surgery under general anaesthesia. Patients will be randomly assigned to the PVC tracheal tube group (n=52, PVC group) or the WR tracheal tube group (n=52, WR group). The primary outcome is the total success rate of intubation. The secondary outcomes are the first success rate of intubation, the time of tracheal intubation, the site of the first contact, the adjustment action for tracheal intubation, haemodynamic fluctuation during intubation and extubation, incidence of trauma as evidenced by blood, and the incidence rates of postoperative sore throat, hoarseness, and dysphagia. ETHICS AND DISSEMINATION: This study was approved by the Ethics Committee of the First Affiliated Hospital of Shandong First Medical University (YXLL-KY-2022 (008)). All participants will provide written informed consent. The results will be disseminated through peer-reviewed publications and at conferences or congresses. TRIAL REGISTRATION NUMBER: NCT05338827.

Is esketamine-based opioid-free anesthesia more superior for postoperative analgesia in obstructive sleep apnea patients undergoing bariatric surgery? A study protocol.

Introduction: Opioid-free anesthesia (OFA) can certainly prevent nausea and vomiting after bariatric surgery (BS), but its postoperative analgesic effect is still controversial. Obstructive sleep apnea (OSA) is a prominent feature of morbid obesity in BS and accounts for a very high proportion, which significantly increases the difficulty of patients' airway management. Those patients will be more representative and highlight the advantages of OFA. It is not clear whether esketamine can play a more prominent role in OFA for postoperative analgesia. Therefore, this study aims to explore the postoperative analgesic effect of esketamine-based OFA on BS patients with OSA. Methods and analysis: This single-center, prospective, randomized, controlled, single-blind study is planned to recruit 48 participants to undergo BS from May 2022 to April 2023. Patients will be randomly assigned to the OFA group and opioid-based anesthesia (OBA) group in a ratio of 1:1. The primary outcome is the Numeric Rating Scale (NRS) at different times postoperatively. Secondary outcomes include analgesic intake, the incidence and severity of postoperative nausea and vomiting (PONV), Leiden Surgical Rating Scale (L-SRS), postoperative agitation and chills, PACU stay time, EuroQol five-dimensional questionnaire (EQ-5D), length of hospital stay, intraoperative awareness, and hemodynamically unstable treatments. Discussion: The results of this study may explain the analgesic effect of esketamine-based OFA on patients undergoing BS combined with OSA, and provide evidence and insight for perioperative pain management. Ethics and dissemination: This study is initiated by the Ethics Committee of The First Affiliated Hospital of Shandong First Medical University [YXLL-KY-2022(035)]. The trial results will be published in peer-reviewed journals and at conferences. Clinical trial registration: [https://clinicaltrials.gov/ct2/show/NCT05386979], identifier [NCT05386979].

Circular RNAs as emerging regulators in COVID-19 pathogenesis and progression.

Coronavirus disease 2019 (COVID-19), an infectious acute respiratory disease caused by a newly emerging RNA virus, is a still-growing pandemic that has caused more than 6 million deaths globally and has seriously threatened the lives and health of people across the world. Currently, several drugs have been used in the clinical treatment of COVID-19, such as small molecules, neutralizing antibodies, and monoclonal antibodies. In addition, several vaccines have been used to prevent the spread of the pandemic, such as adenovirus vector vaccines, inactivated vaccines, recombinant subunit vaccines, and nucleic acid vaccines. However, the efficacy of vaccines and the onset of adverse reactions vary among individuals. Accumulating evidence has demonstrated that circular RNAs (circRNAs) are crucial regulators of viral infections and antiviral immune responses and are heavily involved in COVID-19 pathologies. During novel coronavirus infection, circRNAs not only directly affect the transcription process and interfere with viral replication but also indirectly regulate biological processes, including virus-host receptor binding and the immune response. Consequently, understanding the expression and function of circRNAs during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection will provide novel insights into the development of circRNA-based methods. In this review, we summarize recent progress on the roles and underlying mechanisms of circRNAs that regulate the inflammatory response, viral replication, immune evasion, and cytokines induced by SARS-CoV-2 infection, and thus highlighting the diagnostic and therapeutic challenges in the treatment of COVID-19 and future research directions.

The role of MicroRNA networks in tissue-specific direct and indirect effects of metformin and its application.

Metformin is a first-line oral antidiabetic agent that results in clear benefits in relation to glucose metabolism and diabetes-related complications. The specific regulatory details and mechanisms underlying these benefits are still unclear and require further investigation. There is recent mounting evidence that metformin has pleiotropic effects on the target tissue development in metabolic organs, including adipose tissue, the gastrointestinal tract and the liver. The mechanism of actions of metformin are divided into direct effects on target tissues and indirect effects via non-targeted tissues. MicroRNAs (miRNAs) are a class of endogenous, noncoding, negative gene regulators that have emerged as important regulators of a number of diseases, including type 2 diabetes mellitus (T2DM). Metformin is involved in many aspects of miRNA regulation, and metformin treatment in T2DM should be associated with other miRNA targets. A large number of miRNAs regulation by metformin in target tissues with either direct or indirect effects has gradually been revealed in the context of numerous diseases and has gradually received increasing attention. This paper thoroughly reviews the current knowledge about the role of miRNA networks in the tissue-specific direct and indirect effects of metformin. Furthermore, this knowledge provides a novel theoretical basis and suggests therapeutic targets for the clinical treatment of metformin and miRNA regulators in the prevention and treatment of cancer, cardiovascular disorders, diabetes and its complications.

Amyloid fibril formation by casein and fatty acid composition in breast milk of mastitis patients.

Mastitis can cause changes in the nutrient composition of breast milk, which may be harmful to both newborns and lactating mothers. In this study we preliminarily evaluated amyloid fibrils formation by casein and fatty acids (FA), as well as their potential relation with each other in the breast milk of mastitis patients. Six healthy volunteers and six mastitis patients were recruited from the Maternal and Child Health Care Hospital in Changchun were enrolled. Amyloid fibril content was assessed by thioflavin T fluorescence analysis, transmission electron microscope, circular dichroism, and proton nuclear magnetic resonance. FA contents were measured by gas chromatography. Healthy breast milk contained no amyloid fibrils but inflammatory breast milk did. Several FAs (hendecanoic acid, myristolenic acid, pentadecenoic acid, eicosatrienoic acid) differed significantly between the two groups (p < .05). The concentrations of the eicosatrienoic acid and eleven carbonic acids in the inflammatory groups were lower than those in the healthy groups, but the myristolenic acid and pentadecenoic acid were the opposite trend. Early detection of amyloid fibrils should be performed in lactating mothers with mastitis. Changes in FAs may reflect the importance of abnormal metabolism in amyloid fibril formation. PRACTICAL APPLICATIONS: The work preliminarily clarified the relationship between inflammation, fibril content, and fatty acid (FA) composition in breast milk. Healthy milk contained no amyloid fibril formed by casein but the inflammatory milk did. FAs were also significantly different between the two groups. Thus, an early determination of amyloid fibrils in milk should be considered for lactating women with mastitis to avoid the further malignant development. Additionally, the changes in FAs may reflect the importance of abnormal metabolism and oxidative pathways in amyloid fibril formation in the breast. Therefore, this study provided foundations for further investigation on the association between inflammation, fibril content and FA composition in breast milk.

Effect of moisture, protein, starch, soluble sugar contents and microstructure on mechanical properties of maize kernels.

The relationships between components contents and mechanical properties of maize kernels were studied. The relationships were analyzed by gray relation analysis (GRA), correlation analysis (CA), and multiple linear regression (MLR). Furthermore, Scanning Electron Microscope (SEM) was utilized for interpreting mechanical properties. The results of GRA and CA indicated that soluble sugar content was not an important factor that can affect mechanical properties compared with the moisture, starch and protein contents. The results of MLR indicated that the regression models can be used to access the hardness, rupture force and apparent elastic modulus (R greater than 0.75), but cannot be used to access rupture energy and viscoelastic parameters. The microstructure observation illustrated that high protein content could increase hardness, rupture force, rupture energy, and elastic properties, while high starch content could increase viscous properties. This study can provide technical references for transportation, processing and harvest processes.

Determination of hardness for maize kernels based on hyperspectral imaging.

In order to realize rapid and non-destructive detection of hardness for maize kernels, a method for quantitative hardness measurement was proposed based on hyperspectral imaging technology. Firstly, the regression model of hardness and moisture content was established. Then, based on reflectance hyperspectral imaging at wavelengths within 399.75-1005.80 nm, the prediction model of the moisture content was studied by the partial least squares regression (PLSR) based on the characteristic wavelengths, which was selected through successive projection algorithm (SPA). Finally, the hardness prediction model was validated by combing the prediction model of moisture content with the regression model of hardness. The coefficient of determination (R2), the root mean square error (RMSE) the ratio of performance-to-deviation (RPD) and the ratio of error range (RER) of hardness prediction were 0.912, 17.76 MPa, 3.41 and 14, respectively. Therefore, this study provided a method for rapid and non-destructive detection of hardness of maize kernels.