The Evolution of Lipidomics during Oil Accumulation of Plukenetia volubilis Seeds.

Sacha inchi (Plukenetia volubilis) is a valuable oilseed crop with a high content of polyunsaturated fatty acids (PUFAs). However, there is a lack of in-depth understanding of the lipidomics in Sacha inchi seeds (SIDs). Saturated fatty acids occupied more than half of the proportion (59.31%) in early development, while PUFAs accounted for 78.92% at maturation. The main triacylglycerols were TAG(18:3/18:3/18:3), TAG(18:2/18:2/18:3), and TAG(16:0/18:2/18:2). The corresponding species (18:3/18:3, 18:2/18:2, and 16:0/18:2) were also the main ingredients in diacylglycerol and phosphatidic acid, indicating high PUFA composition in the sn-1 and sn-2 positions of TAG. Only LPC(18:3), LPC(18:2), and LPC(16:0) were identified in SIDs, implying that those PUFAs on the sn-2 positions of the PC(18:3/-), PC(18:2/-), and PC(16:0/-) categories were released into the acyl-CoA pool for the Kennedy pathway. Conversely, the PC(18:1/-) and PC(18:0/-) categories might be responsible for the generation of PC-derived DAG and TAG. The lipidomics data will contribute to understanding the TAG assembly in developing SIDs, especially for PUFAs.

Unveiling the Catalytic Roles of DsBBS1 and DsBBS2 in the Bibenzyl Biosynthesis of Dendrobium sinense.

Dendrobium sinense, an endemic medicinal herb in Hainan Island, is rich in bibenzyl compounds. However, few studies have explored the molecular mechanisms of bibenzyl biosynthesis. This study presents a comprehensive analysis of DsBBS1 and DsBBS2 function in D. sinense. A molecular docking simulation revealed high-resolution three-dimensional structural models with minor domain orientation differences. Expression analyses of DsBBS1 and DsBBS2 across various tissues indicated a consistent pattern, with the highest expression being found in the roots, implying that they play a pivotal role in bibenzyl biosynthesis. Protein expression studies identified optimal conditions for DsBBS2-HisTag expression and purification, resulting in a soluble protein with a molecular weight of approximately 45 kDa. Enzyme activity assays confirmed DsBBS2's capacity to synthesize resveratrol, exhibiting higher Vmax and lower Km values than DsBBS1. Functional analyses in transgenic Arabidopsis demonstrated that both DsBBS1 and DsBBS2 could complement the Atchs mutant phenotype. The total flavonoid content in the DsBBS1 and DsBBS2 transgenic lines was restored to wild-type levels, while the total bibenzyl content increased. DsBBS1 and DsBBS2 are capable of catalyzing both bibenzyl and flavonoid biosynthesis in Arabidopsis. This study provides valuable insights into the molecular mechanisms underlying the biosynthesis of bibenzyl compounds in D. sinense.

Abnormal expression of LCA and CD43 in SCLC: a rare case report and brief literature review.

BACKGROUND: To present an unusual case of abnormal LCA expression and CD43 in SCLC and to review the reported literature to avoid potential diagnostic pitfalls. CASE PRESENTATION: A 73-year-old male patient suffered from persistent back pain for more than one month. MRI revealed a compression fracture of the L1-L5 vertebra. A CT scan revealed multiple nodules and masses at the left root of the neck, lung hilum and mediastinum, and multiple areas of bony destruction of the ribs. Histology of the tumor revealed that small and round cells were arranged in nests with areas of necrosis. The tumor cells were round to ovoid with scant cytoplasm and indistinct cell borders. The nuclear chromatin was finely granular, and the nucleoli were absent or inconspicuous. Immunohistochemically, the tumor cells were positive for cytokeratin, TTF-1, POU2F3, LCA, and CD43. CONCLUSION: This report highlights a potential diagnostic pitfall in the diagnosis of SCLC, urges pathologists to exercise caution in cases of LCA and CD43 positivity and illustrates the need for further immunohistochemical studies to avoid misdiagnosis.

Melan-A expression in non-melanocytic carcinoma: A potential diagnostic pitfall.

BACKGROUND: Melan-A/MART-1 is a melanocytic differentiation marker recognized as an antigen on melanoma cells. It is a useful diagnostic marker for pathologists in the diagnosis of melanocytic tumors. However, we recently found that Melan-A can be expressed in some non-melanocytic carcinomas that are rarely reported in the literature. METHODS: We analyzed the expression of Melan-A in 87 non-melanocytic carcinoma tissue samples by immunohistochemistry. Marker positivity was defined as ≥10% positive tumor cells. RESULTS: In 87 non-melanocytic carcinoma tissue samples, Melan-A was positive in six (6.89%) cases, of which four (66.7%) were male and two (33.3%) were female, with a mean age of 60 years (range 21-82 years). Five (83.3%) of the Melan-A-positive cases had distant metastases. Compared with Melan-A negative cases, Melan-A positive non-melanocytic carcinomas were significantly associated with poor prognosis (P=0.0023). CONCLUSIONS: Melan-A expression is relatively rare in non-melanocytic carcinoma cases. This report highlights a potential diagnostic pitfall in the diagnosis of melanoma, urges pathologists to exercise caution in cases of Melan-A positivity, and illustrates the need for an immunohistochemical marker panel to avoid misdiagnosis.

A cysteine-selective fluorescent probe for monitoring stress response cysteine fluctuations.

Rare studies provided evidence for the real-time monitoring of stress response cysteine fluctuations. Here, we have successfully designed and synthesized a cysteine-selective fluorescent probe 1 to monitor stress response Cys fluctuations, providing visual evidence of Hg2+ regulated cysteine fluctuations for the first time, which may open a new way to help researchers to reveal the mechanism of heavy metal ion poisoning.

A twin enrichment method based on dispersive liquid-liquid microextraction and field-amplified sample injection for the simultaneous determination of sulfonamides.

A twin enrichment method based on offline dispersive liquid-liquid microextraction (DLLME) coupled with online field-amplified sample injection (FASI) was developed for the simultaneous determination of four sulfonamide (SA) antibiotics, including sulfamethazine (SMZ), sulfamerazine (SMR), sulfadizine (SDZ) and sulfacetamide (SFA), in different environmental waters, followed by capillary electrophoresis (CE). Various parameters that affected the separation performance of CE and the enrichment efficiencies of DLLME and FASI were optimized in detail, and excellent CE separation was attained within 6 min. The DLLME-FASI-CE offered high sensitivity enrichment factors of 206, 166, 185 and 150 for SMZ, SMR, SDZ and SFA, respectively. Highly sensitive detection was realized with low limits of detection (LODs), which ranged from 2.0-23.0, 2.2-26.0 and 4.3-63.0 ng mL-1 in tap water, lake water and seawater, respectively, as well as limits of quantification (LOQs) within 6.0-63.0, 7.4-96.0 and 14.0-201.0 ng mL-1, respectively. Satisfactory recoveries in the range of 91-108% were obtained with the three spiked environmental water samples, and the relative standard deviations were from 1.09-7.45%. The simple effective twin enrichment method provided promising perspective for CE determination of SAs in complicated aqueous matrices, with rapidity, sensitivity, and accuracy.

Dispersive liquid-liquid microextraction coupled with pressure-assisted electrokinetic injection for simultaneous enrichment of seven phenolic compounds in water samples followed by determination using capillary electrophoresis.

Offline dispersive liquid-liquid microextraction combined with online pressure-assisted electrokinetic injection was developed to simultaneously enrich seven phenolic compounds in water samples, followed by determination using capillary electrophoresis, namely phenol, 4-chlorophenol, pentachlorophenol, 2,4,6-trichlorophenol, 2,4-dichlorophenol, 2-chlorophenol, and 2,6-dichlorophenol. Several parameters affecting separation performance of capillary electrophoresis and the enrichment efficiency of pressure-assisted electrokinetic injection and dispersive liquid-liquid microextraction were systematically investigated. Under the optimal conditions, seven phenolic compounds were completely separated within 14 min and good enrichment factors were obtained of 61, 236, 3705, 3288, 920, 86, and 1807 for phenol, 4-chlorophenol, pentachlorophenol, 2,4,6-trichlorophenol, 2,4-dichlorophenol, 2-chlorophenol, and 2,6-dichlorophenol, respectively. Good linearity was attained in the range of 0.1-200 µg/L for 2,4-dichlorophenol, 0.5-200 µg/L for 4-chlorophenol, pentachlorophenol, 2,4,6-trichlorophenol, 2-chlorophenol, and 2,6-dichlorophenol, as well as 1-200 µg/L for phenol, with correlation coefficients (r) over 0.9905. The limits of detection and quantification ranging from 0.03-0.28 and 0.07-0.94 µg/L were attained. This two step enrichment method was potentially applicable for the rapid and simultaneous determination of phenolic compounds in water samples.

A near-infrared fluorescent probe for evaluating endogenous hydrogen peroxide during ischemia/reperfusion injury.

Hydrogen peroxide (H2O2), as a major component of reactive oxygen species (ROS), plays an important role in normal physiological processes. A H2O2 burst also occurs in the ischemia/reperfusion (I/R) process and causes a series of physiological and pathological injuries. Therefore, it is important to determine concentration fluctuations of H2O2. Here we develop a ratiometric fluorescent probe, Cy-ArB, which shows high selectivity and sensitivity toward H2O2. The fluorescence response of the probe is triggered by the reaction of borate esters with H2O2, and this process releases a near-infrared heptamethine cyanine fluorophore which has the ability of mitochondrial tracing. Hence, the probe can be used for real-time monitoring of H2O2 fluctuations in the mitochondrial respiration chain. Finally, we explore the fluctuations of H2O2 in cells and in vivo during the I/R process using the probe Cy-ArB. The results of our experiments prove that our probe is a potential candidate for clinical surgery pre-evaluation.

[Preparation of Au@4-nitrothiophenol@Ag@bovine serum albumin internal surface-enhanced Raman scattering tags and its application in cell Raman imaging].

This study explored a strategy of replacing the surface stabilizer of cetyltrimethylammonium bromide (CTAB) on the tag surface with bovine serum albumin (BSA) and developed a BSA coated Au@4-nitrothiophenol(NT)@Ag internal surface-enhanced Raman scattering (SERS) tag Au@NT@Ag@BSA. The Au@NT@Ag@BSA tag retained the monodispersity and high sensitivity of the original tag, while significantly improving the signal stability and biocompatibility. Furthermore, labeling and Raman spectroscopic imaging of SMMC7721 lung cancer cells were realized by the incubation of the cells with the Au@NT@Ag@BSA SERS tags. The results demonstrated that the proposed Au@NT@Ag@BSA internal SERS tags had good potential for in vivo imaging applications.

Water-compatible temperature and magnetic dual-responsive molecularly imprinted polymers for recognition and extraction of bisphenol A.

Versatile molecularly imprinted polymers (MIPs) have been widely applied to various sample matrices, however, molecular recognition in aqueous media is still difficult. Stimuli-responsive MIPs have received increasing attentions due to their unique feature that the molecular recognition is regulated by specific external stimuli. Herein, water-compatible temperature and magnetic dual-responsive MIPs (WC-TMMIPs) with hydrophilic brushes were prepared via reversible addition-fragmentation chain transfer precipitation polymerization for reversible and selective recognition and extraction of bisphenol A (BPA). Transmission electron microscopy (TEM), Fourier transform infrared spectrometer (FT-IR) and vibrating sample magnetometry (VSM) as characterization methods were used to examine the successful synthesis of polymers, and the resultant WC-TMMIPs showed excellent thermosensitivity and simple rapid magnetic separation. Controlled adsorption and release of BPA by temperature regulation were investigated systematically, and the maximum adsorption and removal efficiency toward BPA in aqueous solutions were attained at 35 °C and 45 °C, respectively, as well as a good recoverability was exhibited with the precision less than 5% through five adsorption-desorption cycles. Phenolic structural analogs were tested and good recognition specificity for BPA was displayed. Accordingly, the WC-TMMIPs were employed as adsorbents for magnetic solid-phase extraction (MSPE) and packed SPE of BPA from seawater samples. Using the two modes followed by HPLC-UV determination, excellent linearity was attained in the range of 0.1-14.5 µM and 1.3-125 nM, with low detection limits of 0.02 µM and 0.18 nM, respectively. Satisfactory recoveries for spiked seawater samples were achieved ranging from 86.3-103.5% and 96.2-104.3% with RSD within 2.12-4.33%. The intelligent WC-TMMIPs combining water-compatibility, molecular recognition, magnetic separation, and temperature regulation proved potentially applicable for selective identification, controlled adsorption/release and high-efficiency enrichment/removal of trace targets in complicated aqueous media.

Open fermentative production of L-lactic acid with high optical purity by thermophilic Bacillus coagulans using excess sludge as nutrient.

The development of a low-cost polymer-grade L-lactic acid production process was achieved in this study. Excess sludge hydrolyzate (ESH) was chosen as nutrient source for the objective of reducing nutrient cost in lactic acid production. 1% of ESH had high performance in lactic acid production relative to 2g/l yeast extract (YE) while the production cost of ESH was much lower than that of YE, indicating ESH was a promising substitute of YE. By employing a thermophilic strain of Bacillus coagulans (NBRC 12583), non-sterilized batch and repeated batch L-lactic acid fermentation was successfully performed, and the optical purity of L-lactic acid accumulated was more than 99%. Moreover, the factors associated with cell growth and lactic acid fermentation was investigated through a two-stage lactic acid production strategy. Oxygen played an important role in cell growth, and the optimal condition for cell growth and fermentation was pH 7.0 and 50°C.

Label-free colorimetric sensor for ultrasensitive detection of heparin based on color quenching of gold nanorods by graphene oxide.

A novel label-free colorimetric strategy was developed for ultrasensitive detection of heparin by using the super color quenching capacity of graphene oxide (GO). Hexadecyltrimethylammonium bromide (CTAB)-stabilized gold nanorods (AuNRs) could easily self-assembly onto the surface of GO through electrostatic interaction, resulting in decrease of the surface plasmon resonance (SPR) absorption and consequent color quenching change of the AuNRs from deep to light. Polycationic protamine was used as a medium for disturbing the electrostatic interaction between AuNRs and GO. The AuNRs were prevented from being adsorbed onto the surface of GO because of the stronger interaction between protamine and GO, showing a native color of the AuNRs. On the contrary, in the presence of heparin, which was more easily to combine with protamine, the AuNRs could self-assembly onto the surface of GO, resulting in the native color disappearing of AuNRs. As the concentration of heparin increased, the color of AuNRs would gradually fade until almost colorless. The amounts of self-assembly AuNRs were proportional to the concentration of heparin, and thereby the changes in the SPR absorption and color had been used to monitor heparin levels. Under optimized conditions, good linearity was obtained in a range of 0.02-0.28 µg/mL (R=0.9957), and a limit of detection was 5 ng/mL. The simultaneous possession of high sensitivity and selectivity, simplicity, rapidity, and visualization enabled this sensor to be potentially applicable for ultrasensitive and rapid on-site detection toward trace heparin.

[Preparation of strong cation-exchange monolithic column and its application in polypeptide separation by capillary electrochromatography].

A strong cation-exchange monolithic column was prepared by polymerization inside the fused-silica capillary. The solution consisted of acrylic acid and 2-acrylamido-2-methyl-1-propanesulfonic acid as functional monomers, N,N'-methylenebisacrylamide as a cross-linking agent, dimethyl suiphoxide and dodecanol, 1 , 4-butanediol as organic porogenic solvents and azobisisobutyronitrile as a suitable initiator. The effects of the applied voltage, concentrations of organic modifier and salt solution, pH value on the electroosmotic flow were investigated. The experimental results showed that there existed a good linear relationship between the applied voltage and electroosmotic flow with a correlation coefficient of 0.9981; When the concentration of organic modifier (acetonitrile, ACN) was less than 70%, the swelling degree of stationary phase played a main role and the electroosmotic flow was decreased abnormally with the increase of ACN concentration; The electroosmotic flow was decreased with the increase of the concentration of phosphate. When the pH value was in the range of 3-9, it did not exert a significant change in electroosmotic flow. These results were consistent with the theoretical role. At the same time, five peptides were separated successfully under the optimal experimental conditions on the monolithic column for capillary electrochromatography. The column has obvious advantages in polypeptide separation and will be favorable for the protein investigation.

[Fast separation and analysis of water-soluble vitamins in spinach by capillary electrophoresis with high voltage].

In capillary electrophoresis, 0-40 kV (even higher) voltage can be reached by a connecting double-model high voltage power supply. In the article, water-soluble vitamins, VB1, VB2, VB6, VC, calcium D-pantothenate, D-biotin, nicotinic acid and folic acid in vegetable, were separated by using the high voltage power supply under the condition of electrolyte water solution as running buffer. The separation conditions, such as voltage, the concentration of buffer and pH value etc. , were optimized during the experiments. The results showed that eight water-soluble vitamins could be baseline separated in 2.2 min at 40 kV applied voltage, 25 mmol/L sodium tetraborate buffer solution (pH 8.8). The water-soluble vitamins in spinach were quantified and the results were satisfied. The linear correlation coefficients of the water-soluble vitamins ranged from 0.9981 to 0.9999. The detection limits ranged from 0.2 to 0.3 mg/L. The average recoveries ranged from 88.0% to 100.6% with the relative standard deviations (RSD) range of 1.15%-4.13% for the spinach samples.

[Advances in packing capillary electrochromatographic columns].

The columns in capillary electrochromatography can be classified into three classes: open tubular, packed and monolithic columns. The monolithic columns can be divided into three categories: organic polymer-based monolithic columns made from the polymerization of acrylamide, styrene, acrylate or methacrylate monomers, silica-based monolithic columns generally prepared by using sol-gel technology, and packed particulate-based monolithic columns. Monolithic columns are receiving quite remarkable attention and developing rapidly with a focus on monolithic stationary phases prepared from synthetic polymers. The preparation methods for various types of capillary electrochromatographic columns and their advantages and disadvantages are reviewed according to 100 research articles. In particular, recent advances in the preparation methods of monolithic columns and their applications are discussed in details.

[Investigation of separation mechanism for neutral solutes on cyano column in capillary electrochromatography].

The separation mechanism for neutral solutes on a cyano column in capillary electrochromatography (CEC) was investigated and the effects of components of mobile phases and the kinds of buffers on retention of samples were studied. In comparing the separation behavior of samples on CN column with reversed-phase ODS column and normal phase SI column, the peak order was different on CN column under different experimental conditions, and the characteristics of CN column having both reversed and normal phase mechanisms were obvious. The migration velocities for neutral solutes of different polarity on CN column were very different by the effects of two mechanisms under different operating conditions. It is easy to change peak order and to adjust selectivity.