Calibrating contact parameters of typical rotary tillage components cutting soil based on different simulation methods.

This report analyzes the problem of complex soil movement patterns under the action of coupled forces, such as tension and shear, in agricultural processes and aims to improve the accuracy of contact parameters used in discrete element simulation studies of rototiller-soil interactions. This study focuses on the soil of Shihezi cotton field in the 8th division of Xinjiang and investigates the rotating tiller roller as a soil-touching component of tillage machinery. A combination of simulations and physical testing is used. We perform angle of repose tests and use edge detection, fitting, and other image processing methods to automatically, quickly, and accurately detect the soil accumulation and angle calibration of the contact parameters with soil particles. Additionally, soil slip tests are conducted to calibrate the contact parameters between the soil and the rotary blades. Optimization is achieved based on orthogonal simulations and the Box-Behnken response surface method using physically measured values as the target. A regression model of the stacking angle and rolling friction angle is established to determine the optimal combination of simulation contact parameters: between soil and soil, the recovery coefficient is 0.402, static friction coefficient is 0.621, and rolling friction coefficient is 0.078; between soil contact parts and soil, the recovery coefficient is 0.508, static friction coefficient is 0.401, and rolling friction coefficient is 0.2. Furthermore, the calibration parameters are selected as contact parameters for the discrete element simulation. By combining the above two simulation methods to analyze and compare the simulation process of cutting soil from rototiller roller parts to rototiller single blade parts, we obtained the changes in energy, cutting resistance, and soil particle movement at different depths of the soil cutting process. Finally, the average cutting resistance was used as an index for validation in the field tests. The measured value is 0.96 kN and the error of the discrete element simulation is 13%. This demonstrates the validity of the calibrated contact parameters and the accuracy of the simulation, which can provide a theoretical reference and technical support for the study of the interaction mechanisms between of tillage equipment parts and soil, as well as the design and optimization of these interactions in the future.

Development and external validation of prognostic nomograms for liver disease-free and overall survival in locally advanced rectal cancer with neoadjuvant therapy: a post cohort study based on the FOWARC trial.

Background: There is still a lack of nomograms that can accurately predict liver metastasis and poor prognosis after neoadjuvant therapy for locally advanced rectal cancer (LARC). Effective nomograms may help clinicians better identify LARC patients with potential high-risk risks, so as to carry out more targeted monitoring, treatment and follow-up. Methods: The nomograms were based on the FOWARC trial (NCT01211210), which included 302 LARC patients who underwent neoadjuvant treatment before surgery at the Sixth Affiliated Hospital of Sun Yat-sen University from 2011 to 2014. The predictive accuracy and discriminative ability of the nomograms were determined by the concordance index (C-index) and calibration curve. The results were validated using bootstrap resampling and a prospective study on 100 patients in 2017. Results: The 3-year liver disease-free survival (LDFS) rate after neoadjuvant treatment for LARC was 91.65% (training cohort 92.22%, validation cohort 90.01%). Factors associated with LDFS were hepatitis B virus (HBV) infection, anemia, lymph node number, postoperative T stage and tumor nodule, which were all included in the nomogram for LDFS. The C-indies of the nomogram for LDFS were 0.828 and 0.845 in the training and validation cohorts. The 3-year overall survival (OS) rate was 94.14% (training cohort 94.13%, validation cohort 94.05%). Factors in the nomogram for OS were mesorectal fascia involvement (MRF), postoperative N stage, pathological differentiation, tumor nodule and neural invasion. The C-indies of the nomogram for predicting OS were 0.73 and 0.774 in the training and validation cohorts. The calibration curve for the survival probability showed good agreement between the nomogram predictions and the actual observations. Conclusions: The nomograms established in this study can effectively predict LDFS and has good clinical application potential for OS in LARC patients treated with neoadjuvant therapy.

Dietary Protein From Different Sources Exerted a Great Impact on Lipid Metabolism and Mitochondrial Oxidative Phosphorylation in Rat Liver.

Associations between meat diets and human health have been widely considered. In this study, we focused on long-term effects of different sources of meat protein on liver metabolic enzymes. For 90 days, rats were fed with semisynthetic diets that differed only with protein source. Casein was used as a reference and isolated soybean, fish, chicken, pork, and beef proteins were compared. Changes in liver proteome were determined by isobaric tag for relative and absolute quantitation (iTRAQ) labeling and liquid chromatography electrospray ionization tandem mass spectrometry/mass spectrometry (LC-ESI-MS/MS). Fish and pork protein diets upregulated the gene expression involved in cholesterol synthesis and esterification, and pork protein diet also upregulated the gene expression of high-density lipoprotein receptor and low-density lipoprotein receptor. Chicken, pork, and beef protein diets upregulated the gene expression involved in cholesterol reverse transport and bile acid production, which increased the total cholesterol level in the fish protein diet group. Total cholesterol levels in liver were lower in the pork and beef protein diet groups. Triglyceride levels in liver were lower in chicken, pork, and beef protein diet groups. Peroxisomal proliferator-activated receptor-gamma coactivator-1 was upregulated by chicken, pork and beef protein diets, and promoted the degradation and metabolism of triglyceride, resulting in lower triglyceride in the three diet groups. Meat proteins at a recommended level could be more conducive to cholesterol degradation, triglyceride decomposition, and energy balance maintenance at a healthy level. The findings give a new insight into the associations between meat diet intake and human health.

Dietary soy, pork and chicken proteins induce distinct nitrogen metabolism in rat liver.

Diets have been shown to alter metabolism and gene expression. However, few data are available about changes in gene expression in liver after intake of different meat protein diets. This work aimed to explore the long-term effects of protein source on liver metabolic enzymes. Rats were fed protein diets for 90 days to study whether intake of chicken and pork protein diets promoted gene expression involved in hepatic metabolism. Liver proteome profiles were measured by iTRAQ labeling and LC-ESI-MS/MS. Chicken protein diet induced higher level of serum amino acids in rats than soy protein. Amino acid metabolizing enzymes were downregulated by pork and chicken protein diets compared with soy protein diet. Intake of meat protein diets downregulated enzymes involved in protein synthesis, disulfide bond formation, signal peptide addition, transport, localization, degradation and glycosylation modification, but upregulated enzymes involved in prolyl cis-trans isomerization for protein synthesis. Protein diets from different sources affected the amino acid supply, and further influenced ribosome assembly and protein synthesis through mTOR signaling pathway.

Effects of Dietary Protein from Different Sources on Biotransformation, Antioxidation, and Inflammation in the Rat Liver.

In this work, the effects of different sources of meat protein on liver metabolic enzymes were investigated. Rats were fed for 90 days with semisynthetic diets in which casein was fully replaced by isolated soybean, fish, chicken, pork, or beef proteins. Then, liver proteomics was performed using iTRAQ and LC-ESI-MS/MS. The results indicated that intake of meat protein diets significantly reduced the protein levels of CYP450s, GSTs, UGTs, and SULTs compared to those of the casein and soybean protein diet groups. The total antioxidant capacity and lipid peroxidation values did not differ between four meat protein diet groups and the casein diet group. However, GSH activity in the fish, chicken, and beef protein groups was significantly higher than those of the casein and soybean protein groups. The beef protein diet significantly upregulated the expression of immune-related proteins. The Keap1-Nrf2-ARE signaling pathway was suggested to involve the diet-mediated regulation of biotransformation, inflammation, and redox status.

Beef, Chicken, and Soy Proteins in Diets Induce Different Gut Microbiota and Metabolites in Rats.

Previous studies have paid much attention to the associations between high intake of meat and host health. Our previous study showed that the intake of meat proteins can maintain a more balanced composition of gut bacteria as compared to soy protein diet. However, the associations between dietary protein source, gut bacteria, and host health were still unclear. In this study, we collected colonic contents from the growing rats fed with casein, beef, chicken or soy proteins for 90 days, and analyzed the compositions of gut microbiota and metabolites. Compared to the casein group (control), the chicken protein group showed the highest relative abundance of Lactobacillus and the highest levels of organic acids, including lactate, which can in turn promote the growth of Lactobacillus. The soy protein group had the highest relative abundance of Ruminococcus but the lowest relative abundance of Lactobacillus. Long-term intake of soy protein led to the up-regulation of transcription factor CD14 receptor and lipopolysaccharide-binding protein (LBP) in liver, an indicator for elevated bacterial endotoxins. In addition, the intake of soy protein also increased the levels of glutathione S-transferases in liver, which implicates elevated defense and stress responses. These results confirmed that meat protein intake may maintain a more balanced composition of gut bacteria and reduce the antigen load and inflammatory response from gut bacteria to the host.

Fish oil diet may reduce inflammatory levels in the liver of middle-aged rats.

The impact of dietary soybean oil, lard and fish oil on physiological responses in middle age is little studied. In this study, we investigated the changes of oxidative stress, inflammatory cytokines, telomere length, and age-related gene expression in the liver of middle-aged rats in response to the above three fat diets. Male Sprague Dawley rats (12 months old) were fed AIN-93M diets for 3 months, in which soybean oil was equivalently replaced by lard or fish oil. As compared to the lard diet, intake of fish oil diet significantly decreased body weight gain, white blood cell count, and levels of hepatic triacylglycerol, total cholesterol, fat accumulation, low-density lipoprotein, oxidative stress and inflammatory cytokines (P < 0.05), but increased telomere length (P < 0.05). On the other hand, lard diet and soybean oil diet showed great similarity in the above variables. PCR array analysis further indicated that fish oil diet significantly down-regulated gene expression related to inflammatory response, apoptosis, DNA binding, proteostasis and telomere attrition. Differentially expressed genes were enriched in the complement and coagulation cascades pathways. Such physiological and molecular responses could be due to different fatty acid composition in fish oil, lard and soybean oil.

Intake of Meat Proteins Substantially Increased the Relative Abundance of Genus Lactobacillus in Rat Feces.

Diet has been shown to have a critical influence on gut bacteria and host health, and high levels of red meat in diet have been shown to increase colonic DNA damage and thus be harmful to gut health. However, previous studies focused more on the effects of meat than of meat proteins. In order to investigate whether intake of meat proteins affects the composition and metabolic activities of gut microbiota, feces were collected from growing rats that were fed with either meat proteins (from beef, pork or fish) or non-meat proteins (casein or soy) for 14 days. The resulting composition of gut microbiota was profiled by sequencing the V4-V5 region of the 16S ribosomal RNA genes and the short chain fatty acids (SCFAs) were analyzed using gas chromatography. The composition of gut microbiota and SCFA levels were significantly different between the five diet groups. At a recommended dose of 20% protein in the diet, meat protein-fed rats had a higher relative abundance of the beneficial genus Lactobacillus, but lower levels of SCFAs and SCFA-producing bacteria including Fusobacterium, Bacteroides and Prevotella, compared with the soy protein-fed group. Further work is needed on the regulatory pathways linking dietary protein intake to gut microbiota.

Comparative proteomic analysis of longissimus dorsi muscle in immuno- and surgically castrated male pigs.

We compared proteomic profiles of male pig muscles after active immunization against gonadotropin releasing hormone (GnRH) and surgical castration. Longissimus dorsi samples were collected from immunocastration (IC) and surgical castration (SC) groups (n=15 each). Muscle proteins were extracted and then identified by data-independent label-free nano LC-MS/MS. A total of 610 proteins were identified, 50 of which were differentially expressed (P<0.05) between immuno- and surgical castration. Twenty-two of 50 differentially expressed proteins were higher in abundance for IC group and 27 proteins with abundance change folds greater than 1.5 differed with castration methods. Proteins involved in cytoskeleton and immunity were abundant in IC group. Several heat shock proteins (HSPs) and laminins were abundant in SC group.

Meat, dairy and plant proteins alter bacterial composition of rat gut bacteria.

Long-term consumption of red meat has been considered a potential risk to gut health, but this is based on clinic investigations, excessive intake of fat, heme and some injurious compounds formed during cooking or additions to processed meat products. Whether intake of red meat protein affects gut bacteria and the health of the host remains unclear. In this work, we compared the composition of gut bacteria in the caecum, by sequencing the V4-V5 region of 16S ribosomal RNA gene, obtained from rats fed with proteins from red meat (beef and pork), white meat (chicken and fish) and other sources (casein and soy). The results showed significant differences in profiles of gut bacteria between the six diet groups. Rats fed with meat proteins had a similar overall structure of caecal bacterial communities separated from those fed non-meat proteins. The beneficial genus Lactobacillus was higher in the white meat than in the red meat or non-meat protein groups. Also, rats fed with meat proteins and casein had significantly lower levels of lipopolysaccharide-binding proteins, suggesting that the intake of meat proteins may maintain a more balanced composition of gut bacteria, thereby reducing the antigen load and inflammatory response in the host.

Human Tudor staphylococcal nuclease (Tudor-SN) protein modulates the kinetics of AGTR1-3'UTR granule formation.

Human Tudor staphylococcal nuclease (Tudor-SN) interacts with the G3BP protein and is recruited into stress granules (SGs), the main type of discrete RNA-containing cytoplasmic foci structure that is formed under stress conditions. Here, we further demonstrate that Tudor-SN binds and co-localizes with AGTR1-3'UTR (3'-untranslated region of angiotensin II receptor, type 1 mRNA) into SG. Tudor-SN plays an important role in the assembly of AGTR1-3'UTR granules. Moreover, endogenous Tudor-SN knockdown can decrease the recovery kinetics of AGTR1-3'UTR granules. Collectively, our data indicate that Tudor-SN modulates the kinetics of AGTR1-3'UTR granule formation, which provides an additional biological role of Tudor-SN in RNA metabolism during stress.

SND1 affects proliferation of hepatocellular carcinoma cell line SMMC-7721 by regulating IGFBP3 expression.

Staphylococcal nuclease domain containing 1 (SND1) is a ubiquitously expressed multifunctional protein involved in transcriptional regulation, RNA splicing and RNA metabolism. Ectopic expression of SND1 has been observed in various tumors including colon cancer, breast cancer, prostate cancer and hepatocellular carcinoma (HCC), indicating a positive role of SND1 in tumor initiation and progression. However, the exact role of SND1 in cancers has not been thoroughly investigated. In the present study, we investigated the role of SND1 in HCC. Immunohistochemistry analysis revealed that the expression level of SND1 was higher in HCC tissues than in adjacent nontumor tissues. Stable knock-down of SND1, performed on the HCC cell line SMMC-7721 using shRNA lentiviral expression system, led to reduced cell proliferation, clone formation and tumor formation in nude mice. The insulin-like growth factor (IGF) signaling pathway was frequently dysregulated in HCC, which could facilitate tumor progression. Screening of gene expression levels of the IGF pathway, using real-time PCR, revealed that a decrease in SND1 expression could increase the expression of IGF-binding protein 3 (IGFBP3), which can negatively regulate activation of the IGF pathway by restricting interactions between IGF and IGF receptors. Results from previous studies showed that the downregulation of IGFBP3 expression is a common feature in HCC, and the upregulation of IGFBP3 expression could suppress HCC cells proliferation. We further confirmed that stable knock-down of IGFBP3 could promote SMMC-7721 cells proliferation. Therefore, we concluded that SND1 could affect SMMC-7721 cells proliferation by regulating IGFBP3 expression and IGF signaling pathway.