Unveiling the potential of novel recyclable deep eutectic solvent pretreatment: Effective separation of lignin from poplar hydrolyzed residue.

To effectively convert the fermentable sugars present in lignocellulosic biomass into biofuels and additional value-added products, it is crucial to remove lignin from the biomass. With the intention of expeditiously remove lignin from poplar wood and improve cellulose saccharification, an innovative ternary deep eutectic solvent (DES) benzyl triethyl ammonium chloride-ethylene glycol-FeCl3 (T-EG-F) was studied for the pretreatment of poplar hydrolyzed residue (PHR). The results revealed that following T-EG-F DES pretreatment at 130 °C for 4 h, the lignin removal rate reached 91.88 %. The effect of DES on PHR and regenerated lignin was comprehensively investigated using X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), Thermogravimetric (TG) and other characterization methods, providing valuable insights into the mechanism of this innovative biomass pretreatment. Moreover, there was a significant improvement in the enzyme digestibility of the DES pretreatment residue. At 48 h, the enzyme load of 30 FPU/g cellulose achieved a remarkable enzyme digestibility of 97.31 %, and this value exhibited a notable increase of 6.56 times compared to the untreated poplar sample. In addition, the T-EG-F could be recycled and reused. This study demonstrates that the potential of T-EG-F DES pretreatment as a green and efficient method for lignin dissociation from lignocellulosic biomass, offering a promising approach for biomass component separation.

Thigh muscle fat fraction is independently associated with impaired glucose metabolism in individuals with obesity.

Background: The aim of this study was to address the intramuscular adipose tissue (IMAT) accumulation in the lower extremities and further detect the relationship between adipose tissue (AT) distribution in the muscle and glucose metabolism in subjects with obesity. Methods: We conducted a cross-sectional study in 120 Chinese obese adults (80 male and 40 female) with BMI ≥ 28 kg/m2. MRI was applied to access the IMAT content in lower extremities. The oral glucose tolerance test was used to evaluate the glucose metabolism and insulin secretion in all individuals. The correlations between glucose metabolism and the fat content of the lower extremities were further assessed. Results: Among 120 included subjects, 54 were classified as subjects with normal glucose tolerance (NGT) and 66 with impaired glucose regulation (IGR). We presented that those with IGR had higher fat accumulation in semitendinosus, adductor magnus, gracilis and sartorius than those with NGT (all P < 0.05). In sex-specific analyses, females have higher IMAT in adductor magnus than males (P < 0.001). Males with IGR had higher fat fraction of semitendinosus and sartorius than those with NGT (P = 0.020, P = 0.014, respectively). Logistic regression analyses revealed that IMAT content in semitendinosus was the independent factor of IGR in individuals with obesity after adjustment for age, gender, triglycerides, creatinine and albumin (odds ratio: 1.13, 95% CI: 1.02-1.26, P = 0.024). Conclusions: Increased adipose tissue accumulation in thigh muscles was associated with glucose dysregulation in patients with obesity. IMAT content in semitendinosus may serve as a possible risk factor for impaired glucose metabolism.

Enhancing biomass conversion: Efficient hemicellulose removal and cellulose saccharification in poplar with FeCl3 coupled with acidic electrolyzed water pretreatment.

Due to the recalcitrant structure of woody biomass such as poplar, the efficient disassembly and separation of hemicellulose component from woody biomass is crucial for green biomass processing and full component utilization. This study presented an environmentally friendly approach to utilize acidic electrolyzed water (AEW) combined with metal salts and investigated its pretreatment effects on hemicellulose removal and cellulose and lignin retention under different conditions. Meanwhile, the structural properties and enzymatic hydrolysis performance of the pretreated residues were also characterized. As a result, under the optimized pretreatment conditions (0.03 mol/L FeCl3 with AEW at 180 °C for 10 min), hemicellulose removal from poplar wood reached 98.64 %, accompanied by xylose recovery rate of 98.46 %, cellulose retention rate of 93.43 % and lignin retention rate of 94.29 %. Enzymatic hydrolysis rate of the pretreated cellulose-enriched substrate reached 97.65 %. Furthermore, comprehensive structural characterizations revealed that FeCl3 coupled with AEW pretreatment resulted in surface damage to the poplar wood, effective removal of the amorphous hemicellulose component, and partial destruction of the cellulose crystallinity. In conclusion, FeCl3 coupled with AEW pretreatment effectively separates hemicellulose, leading to significant alterations in biomass composition and structure, ultimately resulting in improved enzymatic digestion. These results provide theoretical support for targeted dissociation of hemicellulose and full component utilization of woody biomass.

A prediction model of liver fat fraction and presence of non-alcoholic fatty liver disease (NAFLD) among patients with overweight or obesity.

The global prevalence of non-alcoholic fatty liver disease (NAFLD) has attained a level of 25.24%. The prevalence of NAFLD in China has exhibited an upward trajectory in parallel with the increasing incidence of obesity over the preceding decade. In order to comprehensively assess hepatic lipid deposition in individuals with overweight or obesity, we have devised a pioneering prognostic formula that capitalizes on clinical parameters. To this end, we have conducted a cross-sectional cohort study involving 149 overweight or obese subjects. Magnetic resonance imaging proton density fat fraction (MRI-PDFF) has been employed to evaluate the extent of liver fat accumulation. Through univariate analysis, we have identified potential factors, and the definitive elements in the prediction model were selected utilizing the forward stepwise regression algorithm. The Shang Hai Steatosis Index (SHSI) incorporates alanine aminotransferase (ALT), aspartate aminotransferase (AST), fasting insulin, and 1-h postload glycaemic levels, thereby furnishing the capability to predict NAFLD with an area under the receiver operator characteristic (AUROC) of 0.87. By establishing a threshold value of 10.96, determined through Youden's index, we have achieved a sensitivity of 69.57% and a specificity of 88.24%. The Spearman correlation coefficient between liver fat fraction ascertained by MRI-PDFF and that predicted by the SHSI equation amounts to 0.74. Consequently, the SHSI equation affords a dependable means of predicting the presence of NAFLD and liver fat accumulation within the overweight and obese population.

Magnetic metal-organic frameworks containing abundant carboxylic groups for highly effective enrichment of glycopeptides in breast cancer serum.

A mercaptosuccinic acid functionalized hydrophilic magnetic metal-organic framework nanocomposite (denoted as mMOF@Au-MSA) was proposed and synthesized to provide an excellent platform for glycopeptide analysis. The novel nanomaterial integrated favorable advantages such as robust magnetic response from Fe3O4 magnetic nanoparticles, large surface area contributed by MOF, abundant ultra-high hydrophilic carboxylic groups from mercaptosuccinic acid, as well as unbiased affinity toward different types of glycopeptides. This nanocomposite was successfully utilized to capture glycopeptides from standard protein digests with the high selectivity and great sensitivity of 0.5 fmol µL-1. Notably, 307 glycopeptides assigned to 96 glycoproteins were identified from only 2 µL serum of breast cancer patient. The satisfying achievement indicated that the as-prepared nanopartical had promising potential in exploring the knowledge of glycoproteins in breast cancer.

l-cysteine-modified metal-organic frameworks as multifunctional probes for efficient identification of N-linked glycopeptides and phosphopeptides in human crystalline lens.

Highly selective enrichment of N-linked glycopeptides and phosphopeptides from complex biological samples is extremely important prior to mass spectrometry analysis due to their low abundance as well as numerous extrinsic interferences. In this work, l-cysteine (L-Cys)-modified multifunctional metal-organic frameworks denoted as Fe3O4@PDA@MIL-125@Au@L-Cys (mMIL-125@Au@L-Cys) were prepared by modifications step by step. By combining hydrophilic interaction chromatography (HILIC) with metal oxide affinity chromatography (MOAC), the as-prepared material was firstly utilized to identify N-linked glycopeptides and phosphopeptides from tryptic digests of horseradish peroxidase (HRP) and beta-casein (ß-casein), respectively, with the help of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and exhibited outstanding sensitivity (0.1 fmol µL-1), great reusability (5 circles) and high selectivity (1: 100). Based on this, it was further applied into the enrichment of glycopeptides and phosphopeptides from tryptic digests of 100 µg human crystalline lens proteins. In the end, 81 N-linked glycopeptides corresponding to 35 glycoproteins and 175 phosphopeptides ascribed to 55 phosphorylated proteins were identified, respectively. The remarkable results were benefitted from the merits of improved hydrophilicity from L-Cys, strong affinity of TiO centers, numerous reaction sites on the large surface of MOFs and superparamagnetism from Fe3O4 cores. The design of mMIL-125@Au@L-Cys not only served as a multifunctional probe for efficient identification of N-linked glycopeptides and phosphopeptides in human crystalline lens, but also set a precedent for fabricating more MOFs with post-modifications for further proteomics research.

Magnetic metal-organic framework nanocomposites for enrichment and direct detection of environmental pollutants by negative-ion matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Nowadays, the detection and removal of environmental pollutants are particularly important, owing to their harmful influence on human beings' health. Specifically, metal-organic frameworks (MOFs) as the hot materials with great potential have been widely employed as adsorbents for pollutants removal, as well as matrixes for mass spectrometry detection. In this work, magnetic Zr-based MOF (denoted as Fe3O4@PDA@ZrMOF) with outstanding properties, such as low background interference, high desorption/ionization efficiency, excellent signal reproducibility, ultrahigh surface area and strong magnetic responsiveness, was synthesized by a modified thermal annealing method. The Fe3O4@PDA@ZrMOF not only can be utilized as adsorbent towards small molecules by π-π stacking interaction between nitrophenols and ZrMOF, but also can serve as a matrix for detection of small molecules under the negative ion mode of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). As a result, with the use of Fe3O4@PDA@ZrMOF, the detection limits of 4-nitrocatechol and 4-nitroguaiacol were estimated to be about 68 µg/ml and 25 µg/ml, respectively. In addition, enrichment of nitrophenols from PM2.5 was investigated. The detected mass concentrations of 4-nitrocatechol and 4-nitroguaiacol in collected PM2.5 samples were 0.11 ng/m3 and 0.15 ng/m3, respectively, indicating the highly efficient enrichment performance of Fe3O4@PDA@ZrMOF for low-abundance nitrophenol compounds in the environment.

Core-shell structured magnetic metal-organic framework composites for highly selective enrichment of endogenous N-linked glycopeptides and phosphopeptides.

In this work, core-shell structured magnetic metal-organic framework composites denoted as Fe3O4 @MIL-100(Fe) were synthesized by means of a layer-by-layer assembly method selecting Fe as metal center and 1,3,5-benzenetricarboxylic acid as organic ligand. The as-prepared material exhibited outstanding sensitivity (0.1 fmol/µL), good selectivity (1:20 and 1:50 respectively), excellent ability of size-exclusion (1: 500), fine reusability (six cycles) and great stability (two months) in enriching N-linked glycopeptides and phosphopeptides from tryptic digests of standard proteins by combining HILIC and IMAC. Moreover, it was applied into the enrichment of endogenous N-linked glycopeptides and phosphopeptides in human saliva and achieved great results (43 phosphopeptides and 39 N-linked glycopeptides), revealing its promising potential in enrichment of low-abundance endogenous N-linked glycopeptides and phosphopeptides in practical samples.

Hydrophilic tripeptide-functionalized magnetic metal-organic frameworks for the highly efficient enrichment of N-linked glycopeptides.

Hydrophilic interaction liquid chromatography (HILIC) is a useful tool in glycoproteomic analysis. Glutathione (GSH) is a well-known zwitterionic tripeptide with great hydrophilicity and biocompatibility and is ubiquitous in biological activities. In this study, a hydrophilic metal-organic framework (denoted as mMOF@Au@GSH) was synthesized by grafting glutathione on Au-immobilized magnetic MOFs via the affinity between the thiol group in glutathione and Au. Endowed with the high hydrophilicity of glutathione, the large surface area of the MOF and strong magnetic responsiveness of magnetic nanoparticles, the as-prepared mMOF@Au@GSH exhibited high selectivity (1 : 100) and great sensitivity (0.5 fmol µL-1) towards glycopeptides. Furthermore, it also achieved outstanding performance in enriching glycopeptides from complex biological samples. In all, 273 glycopeptides corresponding to 94 glycoproteins were identified from only 2 µL human serum.

Core-shell structured magnetic metal-organic framework composites for highly selective detection of N-glycopeptides based on boronic acid affinity chromatography.

Boronic acid affinity chromatography (BAAC) is one of the most significant methods in glycoproteomics research due to its low bias towards glycopeptides and easy enrichment process. In this work, core-shell structured magnetic metal-organic framework (MOF) composites with abundant boronic acid groups were designed and synthesized for selective glycopeptide enrichment based on BAAC. The as-prepared core-shell structured magnetic MOF composites (denoted as Fe3O4@PVP/PEI@MOF (B)) inherited strong magnetic responsiveness from the Fe3O4 core as well as ultrahigh surface area and abundant boronic acid sites from the MOF shell. The affinity between boronic acid and cis-diols groups endowed the composites with improved sensitivity (0.5 fmol/µL) and selectivity (1:100) towards glycopeptides, achieving remarkable results in glycopeptides detection from standard glycoprotein digests as well as complex bio-samples. As a result, a total of 209 N-glycosylation peptides from 89 different glycoproteins were identified from human serum digests, indicating its broad prospect in glycoproteome study.

Expression of sweet taste receptor and gut hormone secretion in modelled type 2 diabetes.

Sweet taste receptors (STRs) are expressed in L cells which secret glucagon-like peptide-1 (GLP-1) in the gut. The STR blocker lactisole reduces GLP-1 secretion and increases blood glucose levels. Therefore, we investigated the expression of sweet taste molecules in the proximal and distal small intestine, and gut hormone secretion, in healthy control and type 2 diabetic rats. Two groups of rats (Sprague Dawley (SD), and Zucker diabetic fatty (ZDF)) were involved in the study. Each group (n=10) received an intragastric glucose infusion (50% glucose solution, 2g/kg body weight). Blood samples were taken for measurement of blood glucose, plasma insulin, and GLP-1 concentrations. One week later, we obtained small intestinal tissue and detected the expression of STRs and glucose transporters (GTs) by real time polymerase chain reaction (Real Time-PCR). Sweet taste molecules of T1R2, T1R3, α-gustducin and TRPM5 in ileum were dramatically higher than those in duodenum (P<0.01 for each). T1R3, α-gustducin and TRPM5 expression were less in the ileum of ZDF than those in SD (P<0.05 for each), while expression of glucose transporter 2 (GLUT-2) in ileum was significantly higher in ZDF rats. Plasma GLP-1 levels were higher in ZDF rats than SD rats at t=0, 15, 30, 60 and 120min (P<0.01). In conclusion, transcript levels of ileal T1R3 and GLUT-2 are disordered in ZDF rats suggesting that intestinal sweet taste receptor expression is associated with altered glucose metabolism. The mechanism needs further investigation, but might provide a potential therapy in the treatment of type 2 diabetes.

One-step synthesis of carboxyl-functionalized metal-organic framework with binary ligands for highly selective enrichment of N-linked glycopeptides.

Highly efficient and selective enrichment of glycopeptides from complex biosamples is vital prior to mass spectrometry analysis. In this work, a hydrophilic metal organic framework with free carboxylic groups (denoted as UiO-66-COOH) was synthesized in one step with binary ligands. Compared with pure UiO-66 with one ligand, UiO-66-COOH containing binary ligands demonstrated greater hydrophilicity and performed much better in selective enrichment of glycopeptides. The as-prepared material demonstrated excellent performance for selective enrichment of glycopeptides from tryptic digests of standard glycoproteins and practical biological samples.

The Initial Assessment of Daily Insulin Dose in Chinese Newly Diagnosed Type 2 Diabetes.

BACKGROUND: It has been well accepted that insulin therapy is the ideal treatment for newly diagnosed diabetic patients. However, there was no study about assessment of the initial insulin dosage in new onset Chinese patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: 65 newly diagnosed patients with type 2 diabetes (39 males/26 females; HbA1c ≥ 11.80 ± 0.22%) were investigated. All patients had random hyperglycaemia (at 21.8 ± 3.9 mmol/L) on the first day of admission and received insulin infusion intravenously (5 U/per hour). When the blood glucose level dropped to around 10 mmol/L, patients were then transferred to continuous subcutaneous insulin infusion (CSII). The reduction of blood glucose levels in response to per unit of insulin (RBG/RI) was recorded. The target glucose level was achieved in about 3 days. The total daily insulin dose (TDD) and basal insulin dose (TBD) were calculated. RESULTS: TDD was 45.97 ± 1.28 units and TBD was 19.00 ± 0.54 units. TBD was about 40% of the total daily insulin requirement. There was a negative correlation between the ratio of RBG/RI and TDD. CONCLUSIONS: TDD was correlated with blood glucose reduction in response to intravenous insulin infusion in Chinese new onset patients with type 2 diabetes.