Accurate Boron Determination in Tourmaline by Inductively Coupled Plasma Mass Spectrometry: An Insight into the Boron-Mannitol Complex-Based Wet Acid Digestion Method.

Tourmaline, a boron-bearing mineral, has been extensively applied as a geothermometer, provenance indicator, and fluid-composition recorder in geological studies. In this paper, the decomposition capability of an HF-HNO3-mannitol mixture for a tourmaline sample was investigated in detail for the first time, and a wet acid digestion method based on the boron-mannitol complex for accurate boron determination in tourmaline by inductively coupled plasma mass spectrometry (ICP-MS) was proposed. With a digestion temperature of 140 °C, tourmaline samples of 25 mg (±0.5 mg) can be completely decomposed by a ternary mixture, which consisted of 0.6 mL of HF, 0.6 mL of HNO3, and 0.7 mL of 2% mannitol (wt.), via a continuous heating treatment of 36 h. Following gentle evaporation at 100 °C, the sample residues were re-dissolved using 2 mL of 40% HNO3 solution (wt.) and diluted to about 2.0 × 105-fold by a two-step method using 2% HNO3 solution (wt.). The boron contents in a batch of parallel tourmaline samples were then determined by ICP-MS, and results showed that the boron concentration levels were in a range of 3.20-3.44% with determination RSDs less than 4.0% (n = 5). It was found that the boron concentrations obtained at the mass of 10B were comparable with results from the measurements at the mass of 11B. This revealed that the usage of 2% mannitol with a quantity as high as 0.7 mL in this developed approach did not exhibit significant effect on the quantification accuracy of boron at the mass of 11B. It was also found that the processes including fluoride-forming prevention and fluoride decomposition deteriorated the boron-reserving efficiency of mannitol for tourmaline, causing the averaged boron contents to vary from 2.25% to 3.57% (n = 5). Furthermore, the stability of the boron-mannitol complex under 185 °C by applying the laboratory high pressure-closed digestion method was evaluated, which showed that there existed a 60.36% loss of boron compared to that under 140 °C by using this proposed approach. For this ternary mixture, the tourmaline decomposing efficiency was found to be weakened prominently using 100 °C as the digestion temperature, and tourmaline powders can be observed even after 72 h of continuous heating with B contents within 1.09-1.23% (n = 5). To assess the accuracy of this developed method, the boron recovery of anhydrous lithium tetraborate was studied. It was found that the boron recoveries were within 96.59-102.12% (RSD < 1%, n = 5), demonstrating the accuracy and reliability of this proposed method, which exhibits advantages of high B preserving efficiency, and giving concentration information of both B and trace elements simultaneously. By applying such a boron-mannitol complex-based wet acid digestion method, the chemical composition of boron and trace elements in three tourmaline samples from different pegmatites were quantified, which provided valuable information to distinguish regional deposits and the associated evolution stages.

Laparoscopic resection of a giant choledochal cyst: A rare case report.

Giant choledochal cysts are rare, and so little data exist on the best surgical treatment method. We present here, a case of a giant choledochal cyst that was successfully excised by laparoscopic resection. A 37-year-old female presented with right upper abdominal pain and mild jaundice. On examination she had a right upper abdominal mass which on imaging was observed to be a giant choledochal cyst of type IVa, measuring approximately 129 mm × 190 mm. Her blood test results showed abnormal liver function. We successfully performed laparoscopic resection of the cyst, the patient recovered well and was discharged from hospital eight days post-operation without any complications. We wish to share the experience of this rare case and provide some clinical basis for future diagnosis and use of laparoscopic resection in the treatment of giant choledochal cysts.

LINC00707 impairs the Natural Killer cell antitumour activity in hepatocellular carcinoma through decreasing YTHDF2 stability.

Hepatocellular carcinoma (HCC) is the fifth most frequently diagnosed cancer and ranks third in cancer-related fatalities. The recognized involvement of long noncoding RNAs (lncRNAs) in several cancer types, including HCC, inspired this study to explore a novel lncRNA's functional importance in the progression of HCC. To achieve this, lncRNA microarray analysis was conducted on three distinct sets of HCC tissues, revealing LINC00707 as the most significantly upregulated lncRNA. Further research into its biological functions has revealed that LINC00707 acts as an oncogene, driving HCC progression by enhancing the proliferation, migration and invasion of HCC cells. Mechanistic insights were provided, demonstrating that LINC00707 interacts with YTH N6-methyladenosine RNA-binding protein 2 (YTHDF2), thus facilitating the ubiquitination-dependent degradation of the YTHDF2 protein. Furthermore, LINC00707 was found to influence the cytotoxicity of NK-92MI cells against HCC cells through its interactions with YTHDF2. These findings significantly contribute to a deeper understanding of the role played by LINC00707 in the progression of HCC.

Identification of metabolism terms significantly affecting hepatocellular carcinoma immune microenvironment and immunotherapy response.

Metabolic pathways exert a significant influence on the onset and progression of cancer. Public data on hepatocellular carcinoma (HCC) patients were obtained from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) databases. Analysis was performed in R software using different R packages. Here, we integrated the data from multiple independent HCC cohorts, including TCGA-LIHC, ICGC-FR and ICGC-JP. Then, the enrichment score of 21 metabolism-related pathways was quantified using the ssGSEA algorithm. Next, univariate Cox regression analysis was applied to identify the metabolic terms with significant correlation to patient survival. Finally, a prognosis model based on linoleic acid metabolism, sphingolipid metabolism and regulation of lipolysis in adipocytes was established, which showed good performance in predicting patients' survival. Furthermore, we conducted a biological enrichment analysis to delineate the biological disparities between high- and low-risk patients. Notably, we discerned differences in the microenvironments between these two patient groups. We also found that low-risk patients could potentially respond better to immunotherapy. Drug sensitivity analysis suggested that low-risk patients are more susceptible to bexarotene and erlotinib, yet exhibit resistance to ATRA and bleomycin. Furthermore, through the use of LASSO logistic regression analysis, we identified 19 characteristic genes, which could robustly indicate the risk groups. Our research underscores the role of linoleic acid metabolism, sphingolipid metabolism and the regulation of lipolysis in adipocytes in HCC, pointing towards potential avenues for future research.

In-Depth Method Investigation for Determination of Boron in Silicate Samples Using an Improved Boron-Mannitol Complex Digestion Method by Inductively Coupled Plasma Mass Spectrometry.

In this paper, a boron-mannitol complex wet acid digestion method proposed for the accurate determination of boron in silicate samples by inductively coupled plasma mass spectrometry (ICP-MS) was investigated in detail for the first time. With the addition of 50 µL of mannitol (2% wt.) into the mixture of 0.6 mL of concentrated HF and 30 µL of concentrated HNO3, the 50 mg of silicate sample was effectively decomposed after being heated overnight with optional pre-ultrasonic treatment. Following fluoride formation prevention by 8% HNO3 (wt.) and fluoride decomposition using 6% HCl (wt.), the samples were fluxed in 2.0 mL of 40% HNO3 (wt.) for 4 h and aged overnight. By diluting 1000-fold using 2% HNO3 (wt.) solution, the samples were directly quantified by an ICP-MS, showing boron recoveries of the standard materials including diabase W-2, basalt JB-2a, and rhyolite JR-2 in the range of 95.5-105.5% (n = 5). For this wet acid method, it was found that the contents of boron had no obvious difference under digestion temperatures of 65, 100, and 140 °C. It was also found that the ICP-MS quantification accuracy deteriorated at the mass of 11B when boron content was about 7250 ng yielding positive bias with average recoveries of 115.5-119.8% (n = 5), while the determination results remained unaffected at the mass of 10B. Furthermore, the digestion efficiency of boron by laboratory high-pressure closed digestion method was assessed. The boron recoveries with samples treated by the high-pressure closed digestion method were found to vary within 49.5-98.0% (n = 5) and even lowered down to 31.1% when skipping pressure relief procedure. The long-term quantification stability study showed that the boron content generally declined in one month for the high-pressure closed digestion method and exhibited no significant changes for the proposed method. By applying such an improved boron-mannitol complex digestion method, the boron concentration in the studied silicate standard materials were accurately determined, providing critical data for further boron isotope analyses and associated geochemical studies. This in-depth method investigation for silicate boron determination demonstrates the feasibility of this boron-mannitol complex strategy under a wide digestion temperature of 65-140 °C, and also sheds light on the extensive applications of boron as a geological tracer.

A Non-Matrix-Matched Calibration Method for In Situ Major and Trace Element Analysis of Scheelite by Nanosecond LA-ICP-MS.

In this work, a reliable and robust in situ non-matrix-matched calibration method is proposed for element composition determination in scheelite samples. With external calibration against the silicate glass standard reference material NIST SRM 610, the concentrations of both major elements (Ca and W) and trace elements (Si, Fe, Mo, Y, rare earth elements, etc.) in scheelite are determined using an ArF 193 nm excimer nanosecond laser ablation-inductively coupled plasma mass spectrometer (LA-ICP-MS). Here, the ablation was performed by hole drilling under a helium (He) environment using a laser spot size of 35 µm and a laser repetition of 5 Hz, and the aerosols were then transported to a quadrupole ICP-MS by a mixture of He and make-up gas argon (Ar) with a total gas flow rate of 1.6 L/min. Results showed that there was no apparent matrix effect between the NIST SRM 610 and scheelite by this proposed method. With internal standardization against W, the obtained concentrations of CaO and WO3 were found to yield an average matrix CaO/WO3 mass fraction ratio of 0.245 (2σ = 0.003, n = 19), which agreed well with the value of 0.243 (2σ = 0.002, n = 15) from electron probe microanalysis (EPMA). Furthermore, the accuracy of trace element analyses with this proposed non-matrix-matched calibration in situ method was evaluated by comparing the concentration results with those from bulk analysis by solution nebulizer ICP-MS (SN-ICP-MS). It was found that the quantification results from LA-ICP-MS and SN-ICP-MS were comparable, in particular showing a relative concentration bias of the total ∑REE+Y contents of less than 2%. This confirmed that scheelites can be accurately analyzed in situ by LA-ICP-MS without matrix-matched calibration standards. By using this developed in situ method, the element compositions in a series of scheelite samples from different W-associated deposits in China were successfully quantified, promising further genetic process investigation and associated geologic activities of the polymetallic resources.

Study of Long-Term Determination Accuracy for REEs in Geological Samples by Inductively Coupled Plasma Quadrupole Mass Spectrometry.

This work presents the long-term determination accuracy study of ICP-QMS for rare earth elements (REEs) in geological matrices. Following high-pressure closed acidic decomposition, REEs are measured repetitively across seven months by ICP-QMS. Under optimum experimental conditions (including spray chamber temperature, gas flow rate, sampling depth, etc.), the REE contents in geological standard materials from basic (basalt BCR-2 and BE-N) to intermediate (andesite AGV-2) and up to acidic (granite GSR-1) show good agreement with the certified values, giving relative errors below 10%. Here, the influence of two storage materials (perfluoroalkoxy PFA and polypropylene PP) on the long-term determination accuracy of REEs has also been monitored. It is found that the relative errors of REEs using a PFA container range from -6.6 to 6.3% (RSDs < 6.0%), while that using a PP container are within -4.0 to 3.9% (RSDs < 4.6%). By using PP material as a solution storage container, the accuracy of REEs quantification in a series of real geological samples are checked, showing the RSDs of less than 5.0%. This work first clarifies the long-term stability of REEs quantification by ICP-QMS covering two types of storage materials, confirming the reasonability of PP material as a daily storage container in terms of higher data precision and lower cost.

Study on the interaction of catalase with pesticides by flow injection chemiluminescence and molecular docking.

The interaction mechanisms of catalase (CAT) with pesticides (including organophosphates: disulfoton, isofenphos-methyl, malathion, isocarbophos, dimethoate, dipterex, methamidophos and acephate; carbamates: carbaryl and methomyl; pyrethroids: fenvalerate and deltamethrin) were first investigated by flow injection (FI) chemiluminescence (CL) analysis and molecular docking. By homemade FI-CL model of lg[(I0-I)/I]=lgK+nlg[D], it was found that the binding processes of pesticides to CAT were spontaneous with the apparent binding constants K of 10(3)-10(5) L mol(-1) and the numbers of binding sites about 1.0. The binding abilities of pesticides to CAT followed the order: fenvalerate>deltamethrin>disulfoton>isofenphos-methyl>carbaryl>malathion>isocarbophos>dimethoate>dipterex>acephate>methomyl>methamidophos, which was generally similar to the order of determination sensitivity of pesticides. The thermodynamic parameters revealed that CAT bound with hydrophobic pesticides by hydrophobic interaction force, and with hydrophilic pesticides by hydrogen bond and van der Waals force. The pesticides to CAT molecular docking study showed that pesticides could enter into the cavity locating among the four subdomains of CAT, giving the specific amino acid residues and hydrogen bonds involved in CAT-pesticides interaction. It was also found that the lgK values of pesticides to CAT increased regularly with increasing lgP, Mr, MR and MV, suggesting that the hydrophobicity and steric property of pesticide played essential roles in its binding to CAT.

Ultrasensitive determination of diphacinone by flow injection chemiluminescence: application to quantification in biofluids and photodegradation monitoring in water samples.

An ultrasensitive, quick, and simple approach for the determination of pg levels of diphacinone (DPN) by flow injection chemiluminescence (CL) analysis is proposed for the first time. It is based on the quenching effect of DPN on the CL intensity from a luminol-bovine serum albumin (BSA) CL system, for which the CL intensity decrease was linearly proportional to the logarithm of DPN concentration in the range of 5.0 to 5000 pg/mL. The LOD for DPN determination was as low as 2.0 pg/mL (3α a), and the RSD values were less than 5.0%. One determination cycle that included sampling and washing could be performed in 0.5 min with a sample throughput of 120/h under the optimum experimental conditions. This proposed method was successfully applied to determining DPN in human gastric juice and serum samples with recoveries from 91.8 to 114.3%, and to continuous monitoring of the degradation of DPN in water samples exposed to sunlight during 43 h with a variation ratio of 99.99%. The possible interaction behavior of BSA-DPN is briefly discussed.

Human saliva-based quantitative monitoring of clarithromycin by flow injection chemiluminescence analysis: a pharmacokinetic study.

Human saliva quantitative monitoring of clarithromycin (CLA) by chemiluminescence (CL) with flow injection analysis was proposed for the first time, which was based on the quenching effect of CLA on luminol-bovine serum albumin (BSA) CL system with a linear range from 7.5 × 10(-4) to 2.0 ng/ml. This proposed approach, offering a maximum sample throughput of 100 h(-1), was successfully applied to the quantitative monitoring of CLA levels in human saliva during 24 h after a single oral dose of 250 mg intake, with recoveries of 95.2 ∼ 109.0% and relative standard deviations lower than 6.5 % (N = 7). Results showed that CLA reached maximum concentration of 2.28 ± 0.02 µg/ml at approximately 3 h, and the total elimination ratio was 99.6 % in 24 h. The pharmacokinetic parameters including absorption rate constant (0.058 ± 0.006 h(-1)), elimination rate constant (0.149 ± 0.009 h(-1)) and elimination half-life time (4.66 ± 0.08 h) were obtained. A comparison of human saliva and urine monitoring was also given. The mechanism study of BSA-CLA interaction revealed the binding of CLA to BSA is an entropy driven and spontaneous process through hydrophobic interaction, with binding constant K BSA-CLA of 4.78 × 10(6) l/mol and the number of binding sites n of 0.82 by flow injection-chemiluminescence model. Molecular docking analysis further showed CLA might be in subdomain IIA of BSA, with K BSA-CLA of 6.82 × 10(5) l/mol and ΔG of -33.28 kJ/mol.

Comparison of uric Acid quantity with different food in human urine by flow injection chemiluminescence analysis.

Based on the inhibitory effect of uric acid (UA) on luminol-Co(2+) chemiluminescence (CL) system, a sensitive method for the determination of UA at nanomolar level by flow injection (FI) CL was proposed. The proposed method was successfully applied to real-time monitoring of UA excretion in human 24 h urine with different food intake, showing that meats, vegetables, and porridge intake caused differential UA excretions of 879, 798, and 742 mg, respectively. It was also found that UA concentrations in urine under the three kinds of food intake simultaneously reached maximum at 2 h after meals with the values of 417, 318, and 288 µg mL(-1), respectively. The UA concentration in human serum was also determined by this approach, and the possible mechanism of luminol-Co(2+)-UA CL reaction was discussed in detail.

Continuous, quantitative monitoring of roxithromycin in human saliva by flow injection chemiluminescence analysis.

Human saliva quantitative monitoring of roxithromycin (ROX) at picomolar-level by flow injection (FI) chemiluminescence (CL) analysis is described for the first time, to our knowledge. Monitoring was based on the CL intensity from luminol-BSA reaction, which can be quenched in the presence of ROX, with the decreasing CL intensity linearly proportional to the logarithm of the ROX concentration, ranging from 0.6 to 1000 pmol·L(-1). The detection limit of the proposed method for the determination of ROX was as low as 0.2 pmol·L(-1) (3σ), and the relative standard deviations were less than 4.0% (n = 7). A complete analytical process, including sampling and washing for ROX determination, conducted at a flow rate of 2.0 mL·min(-1), was performed completely within 30 s, yielding a sample efficiency of 120 h(-1). The proposed method was successfully applied to the determination of ROX in human saliva and serum samples with recoveries from 90.9% to 110.1%. The continuous monitoring of ROX in human saliva after oral intake showed that the total elimination ratio was 87.1% during 24 h, and the pharmacokinetic parameters were 0.97 ± 0.18 h(-1) for the absorption rate constant K(a), 0.082 ± 0.010 h(-1) for the elimination rate constant K(e), and 8.56 ± 1.11 h for the elimination half-life time t(1/2). It was also found that ROX in human saliva and urine simultaneously reached the maximum at 2 h with the concentration correlate ratio of 0.97.

Study on the chemiluminescence behavior of bovine serum albumin with luminol and its analytical application.

In this paper, the luminescence behavior of bovine serum albumin (BSA) and luminol was first studied by flow injection chemiluminescence (CL). It was found that the hyperchromic effect of luminol in the presence of BSA led to the acceleration of the electrons transferring rate of excited 3-aminophthalate, which greatly enhanced the CL intensity of luminol/dissolved oxygen reaction. The increments of CL intensity were proportional to the concentrations of BSA with a linear range from 0.01 to 7 nmol L(-1). It was also found that azithromycin could inhibit the CL intensity of luminol/BSA reaction. The decrements of CL intensity were logarithm over the concentrations of azithromycin ranging from 0.1 to 700 ng mL(-1). At a flow rate of 2.0 mL min(-1), a complete analytical process, which included sampling and washing, could be performed within 30s with relative standard deviations of less than 3.1%. This proposed method was successfully applied in assaying azithromycin in pharmaceutical and human serum samples with recoveries from 91.0 to 104.3%. The possible luminescence mechanism of luminol/BSA/azithromycin reaction was discussed in detail by CL, UV and fluorescence methods.

Study on the binding behavior of lysozyme with cephalosporin analogues by fluorescence spectroscopy.

It was first found that the intrinsic fluorescence of lysozyme at 340 nm can be quenched by cephalosporin analogues through the static quenching and non-radiative energy transferring procedure. In the acetate buffer solution with pH 7.0 and 298 K, the quenching fluorescence intensity was in a good linearity over the concentration of drugs in the range of 1-100 micromol L(-1), 0.1-100 micromol L(-1), 0.5-100 micromol L(-1) and 0.05-100 micromol L(-1) for cefradine, cefuroxime, cefotaxime and ceftriaxone, respectively. The quenching ability or the binding ability of the studied drugs followed the pattern: ceftriaxone > cefotaxime > cefuroxime > cefradine, which was close to the order of their antibacterial ability. The binding parameters including the association constant and the number of binding potential point were calculated at different temperatures (288, 298 and 308 K), and thermodynamic parameters DeltaH degrees, DeltaS degrees and DeltaG degrees were given. The binding mode of lysozyme with cephalosporins showed that the hydrophobic effect might play a major role. The binding distance between cephalosporin and tryptophan residue in lysozyme was obtained. The results provided the quantitative information for the binding of cephalosporin to lysozyme, and it was suggested that the drugs probably bound to the active site near Trp62 in lysozyme.