Electrochemical Bioconjugation of Tryptophan Residues: A Strategy for Peptide Modification.

Interest in electrocatalytic bioconjugation reactions has surged, particularly for modifying tryptophan and tyrosine residues in proteins. We used a cost-effective graphite felt electrode and low-current methodology to achieve selective bioconjugation of tryptophan with thiophenols, yielding up to 92%. This method exclusively labeled tryptophan residues and incorporated fluorinated tryptophan for NMR analysis. Eight polypeptides, including lanreotide and leuprorelin, were effectively coupled, demonstrating the method's versatility and potential for novel diagnostic and therapeutic agents.

Matrix measure-based distributed impulsive consensus on nonlinear multi-agent systems with mixed time-varying delays.

This paper concentrates on researching the global and exponential leader-following consensus issue for an array of nonlinear multi-agent systems with the system time-varying delay and the distributed time-varying delay. An innovative distributed impulsive controller is proposed to force the states of all agents to track the trajectories of leader agent. By jointly introducing the matrix measure protocol, the comparison principle for impulsive systems, and the average impulsive interval, sufficient criteria for the realization of leader-following consensus are derived. In addition, considering different functions of impulsive signal, two different convergence rates are precisely estimated by utilizing the parameter variation formula, respectively. Finally, two numerical examples are given to demonstrate the effectiveness of proposed control strategy and the rightness of theoretical analysis.

Methylboronic acid MIDA ester (ADM) as an effective additive in electrolyte to improve cathode electrolyte interlayer performance of LiNi0.8Co0.15Al0.05O2 electrode.

We investigated the effectiveness of using methylboronic acid MIDA ester (ADM) as an additive in an electrolyte to enhance the overall electrochemical and material properties of an LNCAO (LiNi0.8Co0.15Al0.05O2) cathode. The cyclic stability of the cathode material measured at 40 °C (@ 0.2 C) showed an enhanced capacity of 144.28 mAh g-1 (@ 100 cycles), a capacity retention of 80%, and a high coulombic efficiency (99.5%), in contrast to these same properties without the electrolyte additive (37.5 mAh g-1, ~ 20%, and 90.4%), thus confirming the effectiveness of the additive. A Fourier transform infrared spectroscopy (FTIR) analysis distinctly showed that the ADM additive suppressed the EC-Li+ ion coordination (1197 cm-1 and 728 cm-1) in the electrolyte, thereby improving the cyclic performance of the LNCAO cathode. The cathode after 100 charge/discharge cycles revealed that the ADM-containing system exhibited better surface stability of the grains in the LNCAO cathode, whereas distinct cracks were observed in the system without the ADM in the electrolyte. A transmission electron microscopy (TEM) analysis revealed the presence of a thin, uniform and dense cathode electrolyte interface (CEI) film on the surface of LNCAO cathode. An operando synchrotron X-ray diffraction (XRD) test identified the high structural reversibility of the LNCAO cathode with a CEI layer formed by the ADM, which effectively maintained the structural stability of the layered material. The additive effectively inhibited the decomposition of electrolyte compositions, as confirmed by X-ray photoelectron spectroscopy (XPS).

Expression and change of miR-199b-5p, s HLA-G in thyroid carcinoma.

OBJECTIVE: This research aims to investigate the relationship between the expression of microRNA-199b-5p (miR-199b-5p) and soluble human leukocyte antigen G (sHLA-G) in thyroid cancer tissues and its clinicopathological characteristics, as well as its impact on prognosis. METHODS: Frozen tissues and serum from 85 patients with thyroid cancer, 27 with thyroid adenoma, 19 with Hashimoto's thyroiditis and 14 with nodular goiter from February 2014 to March 2016 were sampled. The miR-199b-5pmRNA expression in tissues was analyzed by real-time quantitative PCR. Serum HLA-G expression was detected by ELISA, and the relationship between s HLA-G expression and clinicopathological characteristics of thyroid cancer was analyzed. The relationship between 1- and 3-year survival rates of all patients and the expression of both detection indexes was observed. RESULTS: Compared with normal thyroid specimens, nodular goiter, Hashimoto's thyroiditis, thyroid adenoma and thyroid cancer patients, the relative expression of miR-199b-5pmRNA in thyroid cancer tissues was the lowest, while that of s HLA-G was the highest in serum of patients (P < 0.05). The levels of miR-199b-5pmRNA and serum s HLA-G in tumor tissues were correlated with clinical pathological features such as tumor size, differentiation degree, capsule invasion, lymph node metastasis, etc. (all P < 0.05). The expression of miR-199b-5pmRNA and s HLA-G were negatively correlated. ROC curve identified that miR-199b-5pmRNA and HLA-g had obvious diagnostic value for thyroid cancer patients. Kaplan-Meier survival analysis manifested that the 1- and 3-year survival rates of the miR-199b-5p low expression group in thyroid cancer tissues were lower than the miR-199b-5p high expression group, and the rates of the s HLA-G low expression group were higher than the s HLA-G high expression group. CONCLUSION: The miR-199b-5p expression in thyroid cancer tissues and HLA-g in serum were related to tumor size, differentiation degree, capsular invasion, lymph node metastasis and other characteristics. MiR-199b-5p may jointly affect the progression of thyroid cancer with s HLA-G.

Application value of 18F-FDG PETCT imaging in the clinical initial diagnosis and follow-up of primary lesions of cervical cancer.

BACKGROUND: Cervical cancer is a common malignant tumor in gynecology with a high death rate. his study aims to analyze the application value of 18F-fluorodeoxyglucose imaging examination (18F-FDG PETCT) imaging in the initial clinical diagnosis and follow-up examination of cervical cancer. METHODS: The clinical data of 71 patients with cervical lesions who were admitted to our hospital from March 2017 to March 2019 were retrospectively collected all patients underwent 18F-FDG PETCT examination. The results of the pathological examination were a benchmark to calculate the sensitivity, specificity, and accuracy of 18F-FDG PETCT imaging in the diagnosis of primary lesions of cervical cancer and the diagnosis of postoperative recurrence, residual, and metastasis. RESULTS: There were 39 patients initially suspected, and 30 cases were diagnosed as cervical cancer by pathological examination, including 22 cases with squamous cell carcinoma, 4 cases with adenocarcinoma, 3 cases with carcinoma in situ, and 1 case with adenosquamous carcinoma. The maximum standard uptake (SUVmax) value was (10.36±5.22), and the patient's lesions showed different degrees of increase of 18F-FDG metabolism. The necrotic area in the patient's lesion showed reduced/defect metabolism. The sensitivity of 18F-FDG PETCT imaging in the diagnosis of primary lesions of cervical cancer was 86.66%, specificity was 44.44%, and accuracy was 76.92%. In the 32 cases followed up for monitoring after the operation, 16 cases showed recurrence, metastasis, residual and other conditions, and 7 cases showed local recurrence/metastasis. 18F-FDG PETCT images showed: abnormal widening of the cervix, stump nodules/mass in the vagina, and rectal and bladder infiltration. All patients with local recurrence were treated with local tissue biopsy or surgical resection under 18F-FDG PETCT image localization. The diagnostic sensitivity, specificity and diagnostic coincidence rate of 18F-FDG PETCT imaging for postoperative follow-up of cervical cancer patients were 100%, 75.00% and 87.50%, respectively. CONCLUSIONS: For patients with cervical cancer who are initially diagnosed or followed up, they can all be tested by 18F-FDG PETCT imaging, which can provide a reference for the formulation of diagnosis and treatment plan and the evaluation of prognosis.

A multidimensional micro gas chromatograph employing a parallel separation multi-column chip and stop-flow µGC × µGCs configuration.

A dual-chip, multidimensional micro gas chromatographic module was designed, built and evaluated. Column chips were fabricated on a silicon wafer with an etched rectangular channel 100 µm (width) × 250 µm (depth) using a deep reactive ion etching (DRIE) process. The column chip for the first GC dimension was 3 m long and was coated with polydimethylsiloxane (DB-1) as the stationary phase. The columns on the second dimensional chip were etched with the same width and depth as the first chip, but the flow channel was split into three parallel columns, 1 m long, on the same sized silicon chip (i.e., 3 cm × 3 cm). These three parallel columns on the second chip were coated with polyethylene oxide (DB-Wax), trifluoropropylpolymethylsilicone (OV-210) and cyanopropylmethylphenylmethylpolysilicone (OV-225), accordingly, in order to provide diversified chromatographic retention. These two chips were connected via a stop-flow configuration to simultaneously generate multiple two-dimensional gas chromatograms for every analysis. This stop-flow µGC × µGCs design allowed the first column to function as a pre-separator and as a sequencing injector for the second parallel-separation chip. Fifteen volatile organic compounds with boiling points that ranged from 80-131 °C with various functional groups were tested using this µGC × µGCs module. Three discrete 2-D chromatograms were generated simultaneously, which demonstrated the advantages of simultaneously combining GC × GC with parallel separation GCs in microchip chromatography. The total traveling length in the column was only 4 m for each eluted peak and fully resolved separation was achieved through the cross reference among triplet 2-D chromatograms.