[Clinical value of TDI combined with 2D-STI on evaluating the microcirculation dysfunction and left ventricular dysfunction in patients with non-obstructive coronary angina].

Objective: To explore the value of tissue Doppler imaging (TDI) combined with two-dimensional speckle tracking imaging (2D-STI) at rest on evaluating microcirculation dysfunction and left ventricular dysfunction in patients with angina and no obstructive coronary artery disease(ANOCA). Methods: This retrospective study recruited 78 ANOCA patients, who hospitalized in the People's Hospital of Liaoning Province from August 2019 to July 2021. These patients underwent conventional echocardiography examination, including TDI and 2D-STI, to evaluate the left ventricular dysfunction, and adenosine stress echocardiography (SE) to evaluate the coronary flow velocity reserve (CFVR). ANOCA patients were divided into coronary microcirculation dysfunction CMD group (CFVR<2) and control group (CFVR≥2) according to CFVR. Clinical data, routine echocardiographic parameters, TDI parameters including isovolumic contraction time (IVCT), isovolumic relaxation time (IVRT), ejection time (ET), and STI parameters including global longitudinal peak strain (GLS), time to peak (TTP); peak strain dispersion (PSD) were compared between the two groups. Binary logistic regression was used to analyze the risk factors of CMD and the predictive value of each parameter to construct a joint prediction model for the diagnosis of CMD in this patient cohort. Results: The mean age was (55.5±11.2) years, 43 (55%) patients were females in this patient cohort, 38 (49%) patienst were didvided into the CMD group and 40 (51%) into the control group. Age, prevalence of hypertension, diabetes, dyslipidemia, and smokers were significantly higher in the CMD group than in the control group (all P<0.05). Tei index was higher, IVCT and TTP were longer, PSD was higher, ET was shorter, and absolute GLS was lower in the CMD group than in the control group (all P<0.05). The results of logistic regression analysis showed that longer IVCT, higher Tei index, higher time to PSD and lower absolute GLS were the independent risk factors of CMD. The ROC curve revealed that the predicting efficacy on CMD was satisfactiory with the combined predictors: AUC=0.884, sensitivity of 82% and specificity of 80%. Conclusions: TDI combined with 2D-STI is associated with a good diagnostic value on the diagnosis of CMD and left ventricular dysfunction in patients with ANOCA, which provides a feasible non-invasive tool for the diagnosis of CMD and risk stratification of patients with ANOCA.

Emerging salt marshes as a source of Trichoderma arenarium sp. nov. and other fungal bioeffectors for biosaline agriculture.

AIMS: Sustainable agriculture requires effective and safe biofertilizers and biofungicides with low environmental impact. Natural ecosystems that closely resemble the conditions of biosaline agriculture may present a reservoir for fungal strains that can be used as novel bioeffectors. METHODS AND RESULTS: We isolated a library of fungi from the rhizosphere of three natural halotolerant plants grown in the emerging tidal salt marshes on the south-east coast of China. DNA barcoding of 116 isolates based on the rRNA ITS1 and 2 and other markers (tef1 or rpb2) revealed 38 fungal species, including plant pathogenic (41%), saprotrophic (24%) and mycoparasitic (28%) taxa. The mycoparasitic fungi were mainly species from the hypocrealean genus Trichoderma, including at least four novel phylotypes. Two of them, representing the taxa Trichoderma arenarium sp. nov. (described here) and T. asperelloides, showed antagonistic activity against five phytopathogenic fungi, and significant growth promotion on tomato seedlings under the conditions of saline agriculture. CONCLUSIONS: Trichoderma spp. of salt marshes play the role of natural biological control in young soil ecosystems with a putatively premature microbiome. SIGNIFICANCE AND IMPACT OF THE STUDY: The saline soil microbiome is a rich source of halotolerant bioeffectors that can be used in biosaline agriculture.

Nd3+/Yb3+ cascade-sensitized single-band red upconversion emission in active-core/active-shell nanocrystals.

Lanthanide-doped upconversion nanomaterials (UCNMs) have promoted extensive interest for its biological research and biomedical applications, benefiting from low autofluorescence background, deep light penetration depth, and minimal photo-damage to biological tissues. However, owing to the 980 nm laser-induced overheating issue and the attenuation effect associated with conventional multi-peak emissions, the usage of UCNMs as fluorescent bioprobes is still limited. To address these issues, an effective strategy has been proposed to tune both the excitation and emission peaks of UCNMs into the first biological window (650 âˆ¼ 900 nm), where the light absorption by water and hemoglobin in biological tissues is minimal. Based on the Nd3+/Yb3+ cascade-sensitized upconversion process and efficient exchange-energy transfer between Mn2+ and Er3+ in conjunction with the active-core@active-shell nanostructured design, we have developed a new class of upconversion nanoparticles (UCNPs) that exhibit strong single-band red emission upon excitation of an 808 nm near-infrared laser. Hopefully, the well-designed KMnF3:Yb/Er/Nd@ KMnF3:Yb/Nd core-shell nanocrystals will be considered a promising alternative to conventionally used UCNPs for biolabeling applications without the concern of the overheating issue and the attenuation constraints.

Separation and determination of ephedrine alkaloids and tetramethylpyrazine in Ephedra sinica Stapf by gas chromatography-mass spectrometry.

A simple, sensitive, and reliable method using gas chromatography (GC)-mass spectrometry (MS) is developed for the simultaneous determination of ephedrine alkaloids and 2,3,5,6-tetramethylpyrazine (TMP) in Ephedra sinica Stapf. The sample is extracted with ethyl ether and submitted to GC-MS for identification and quantitation without derivatization. The column used for GC is an HP-5 (30.0 m x 250 microm x 0.25 microm, 5% phenyl methyl siloxane), and the carrier gas is helium. The detection limits for ephedrine, pseudoephedrine, and TMP are 0.4 ng 0.7 ng, and 0.02 ng (signal-to-noise ratio of 3), respectively. The reproducibility of the total procedure is proved to be acceptable (RSD < 2%), and the recoveries are above 93%.

Studies on the reaction of p-hydroxybenzyl alcohol and hydroxyl radicals.

The reaction of p-hydroxybenzyl alcohol and hydroxyl radicals generated by the Fenton reaction is studied. The products of the reaction are separated and identified by high-performance liquid chromatography (HPLC)-diode-array detection and HPLC-mass spectrometry. According to the structures of the products, a mechanism of the reaction is proposed.

Simultaneous determination of p-hydroxybenzaldehyde, p-hydroxybenzyl alcohol, 4-(beta-D-glucopyranosyloxy)-benzyl alcohol, and sugars in Gastrodia elata blume measured as their acetylated derivatives by GC-MS.

A method for the simultaneous separation and determination of the active constituents and three sugars in the roots of Gastrodia elata Blume (GE), which is used as a famous Chinese traditional herbal medicine, by gas chromatography-mass spectrometry is established. The samples are acetylated with pyridine-acetic anhydride. The contents of 4-hydroxybenzaldehyde, 4-hydroxybenzyl alcohol (HA), fructose, glucose, 4-(beta-D-glucopyranosyloxy)-benzyl alcohol (GA), and sucrose in GE are 0.004%, 0.03%, 1.36%, 1.12%, 1.97%, and 4.25%, respectively, and the detection limits are 1.5, 3.0, 11.0, 5.0, 33.0, and 35.0 pg, respectively. The contents of HA and GA in the urine and brain of a mouse are also determined. This method is simple, reliable, and quick for the simultaneous determination of the active constituents and sugars in GE.

Simultaneous ion-exclusion chromatography and cation-exchange chromatography of anions and cations in environmental water samples on a weakly acidic cation-exchange resin by elution with pyridine-2,6-dicarboxylic acid.

A non-suppressed conductivity detection ion chromatographic method using a weakly acidic cation-exchange column (Tosoh TSKgel OApak-A) was developed for the simultaneous separation and determination of common inorganic anions (Cl-, NO3- and SO4(2-)) and cations (Na+, NH4+, K+, Mg2+ and Ca2+). A satisfactory separation of these anions and cations on the weakly acidic cation-exchange column was achieved in 25 min by elution with a mixture of 1.6 mmol L-1 pyridine-2,6-dicarboxylic acid and 8.0 mmol L-1 18-crown-6 at flow rate of 1.0 mL min-1. On this weakly acidic cation-exchange resin, anions were retained by an ion-exclusion mechanism and cations by a cation-exchange mechanism. The linear range of the peak area calibration curves for all analytes were up to two orders of magnitude. The detection limits calculated at S/N = 3 ranged from 0.25 to 1.9 mumol L-1 for anions and cations. The ion-exclusion chromatography-cation-exchange chromatography method developed in this work was successfully applied to the simultaneous determination of major inorganic anions and cations in rainwater, tap water and snow water samples.

Direct determination of nitrite traces in high ionic-strength samples by electrostatic ion chromatography using diluted acid solutions as eluent.

An ion-chromatographic (IC) system with high selectivity for separation of nitrite is described. It is analogous to the EIC (electrostatic IC) previously reported and was established using 3-(N,N-dimethylstearylammonio)propanesulfonate (C23H49NO3S, a sulfobetaine type of zwitterionic surfactants) as the stationary phase and dilute aqueous HCl solutions as the mobile phase. Five inorganic anions, sulfate, chloride, bromide, nitrate, and nitrite were chosen as the model analytes and were analyzed using this EIC system. Sulfate was always eluted first, followed by chloride, bromide and nitrate. Nitrite, however, could be eluted either before or after nitrate, depending on the concentration of HCl in the eluent. An elution order nitrate< nitrite was always obtained simply by using >3 mmol L(-1) HCl as the eluent. For nitrite the detection limit was better than 2.1 x 10(-7) mol L(-1) (100 microL sample injection volume, S/N=3, UV at 210 nm). Bromide and nitrate could also be separated under these HPLC conditions. The detection limit for bromide was 7.2 x 10(-8) mol L(-1) and for nitrate 6.5 x 10(-8) mol L(-1). Both nitrite and nitrate in real seawater samples were successfully determined with direct sample injection using this EIC system.

[Separation and determination of ephedrine alkaloids and 2,3,5,6-tetramethyl pyrazine in Ephedra herba by HPLC].

A sensitive and reliable high performance liquid chromatographic method(HPLC) has been developed for the first time for the simultaneous determination of the active ingredients of ephedrine alkaloids and 2,3,5,6-tetramethyl pyrazine (TMP) in Ephedra herba crude drug and two Chinese traditional medicines (Xiao-er qingfeiwan and Lu-si kewan). The HPLC assay was performed on a reversed phase C18 column (Nova-Pak C18, 3.9 mm i.d. x 150 mm) by using methanol-0.02 mol/L KH2PO4-acetic acid-triethyl amine (4:96:0.2:0.01, V/V) as mobile phase for the ephedrine alkaloids analysis and methanol-H2O-acetic acid (35:65:0.5, V/V) as mobile phase for TMP analysis. Regression equations revealed the linear relationships (correlation coefficients: 0.991-0.998) between the peak area of each constituent (E, PE, NE, NPE, TMP) and its concentration. The detection limits for E, PE, NE, NPE and TMP were 0.4 mg/L, 0.1 mg/L, 0.03 mg/L, 0.02 mg/L and 0.03 mg/L, respectively, and the recoveries ranged between 92%-103%. The contents of E, PE, NE, NPE, TMP in Ephedra herba, traditional medicine Xiao-er qingfeiwan and Lu-si kewan were determined respectively. The relative standard deviations (RSD) of the contents ranged between 1.1%-3%.

[Analysis of trehalose in transgenic tobacco extracts by high performance liquid chromatography with evaporative light scattering detection].

A high performance liquid chromatographic method with ethylenediamine dynamically modified silica column and evaporative light-scattering detection (ELSD) was developed for the direct determination of trehalose in transgenic tobacco extracts. The separation column (Zorbax Rx-SIL, 4.6 mm i.d. x 250 mm, 5 microns, Hewlett-Packard, USA) modified by ethylenediamine and a guard column (Zorbax Rx-SIL, 4.6 mm i.d. x 12.5 mm, 5 microns) were used. The mobile phase was a mixture of acetonitrile-water(2.6:1, V/V) containing 0.03% ethylenediamine. Regression equations revealed the linear relationships (r = 0.996-0.999) between the concentrations and peak areas of carbohydrates detected by ELSD. The detection limits of ELSD (S/N = 3:1) were 10 mg/L, 20 mg/L, 10 mg/L and 10 mg/L for fructose, glucose, sucrose and trehalose, respectively.

[Diol column as stationary phase for high performance liquid chromatographic analysis of carbohydrates in drinks with evaporative light scattering detection].

A high performance liquid chromatographic method with a diol column and evaporative light scattering detector (ELSD) was established for the direct analysis of fructose, glucose, sucrose, maltose and raffinose in mixture. A separation column (Lichrospher 100 Diol, 250 mm x 4.0 mm i.d., 5 microns, Hewlett-Packard, USA) and a guard column (Zorbax Rx-SIL, 12.5 mm x 4.6 mm i.d., 5 microns) were used. The mobile phase was a mixture of dichloromethane-methanol (3.2:1, volume ratio). Regression equations revealed linear relationship (correlation coefficients: 0.995-0.999) between the mass of carbohydrates injected and the peak area of carbohydrates detected by ELSD. The detection limits of ELSD (S/N = 3) were about 0.20 microgram for all carbohydrates. This system could be used for the routine analysis of simple carbohydrates in some common drinks on market.

[Studies on the active constituents of sichuan liang shan rhododendron L. I. Determination of two flavonoids in leaves, extracts and jinjuan liquors].

A reversed-phase HPLC method for the separation and determination of the two flavonoids: quercetin and kaempferol is described. The column was 25 cm x 4.6 mm i.d., packed with Zorbax SB-C18(5 microns). The mobile phase was a mixture of MeOH-H2O (60:40, V/V). The flow rate was 0.7 mL/min. UV detection was performed at 360 nm. External standard was used and the calibration curves showed good linearity over the range of 6.0-100 mg/L, r = 0.9995-0.9998, and detection limits were 3.3-6.2 mg/L. The recoveries were 96.0% and 97.3% for quercetin and kaempferol respectively. The relative standard deviations of the method were 2.1%-4.5%. The method is simple, fast, sensitive and accurate and can be applied to the analysis of quercetin and kaempferol. It provides a scientific basis for industrial production and quality control of Jinjuan liquor preparations for clinical uses.

[The evaporative light-scattering detection technology].

The theory, principles of operation and theoretical investigation of evaporative light-scattering detector (ELSD) are reviewed with 45 references. The applications of ELSD in HPLC on lipids, surfactants, pharmaceutical compounds and others are introduced.

[Determination of ferulic acid in chuanxiong and in animal serum and cerebrospinal fluid by reversed-phase high performance liquid chromatography].

An easy, rapid and sensitive method for the determination of ferulic acid(FA) in Chuanxiong extracts, animal (mouse) serum and cerebrospinal fluid by RP-HPLC has been developed. The FA was separated on an ODS column, Nova-Pak C18(3.9 mm i.d. x 150 mm) and detected at the wavelength of 320 nm. The mobile phase was methanol-water-acetic acid (35:65:0.5, V/V), with a flow rate of 0.8 mL/min. The detection limit of FA was 1.7 micrograms/L(S/N = 3) and the calibration curve was linear within the range of 0.85 mg/L-4.00 mg/L(r = 0.99904, n = 6). The mean recovery from animal serum and cerebrospinal was 95%-102%.

Analysis of carbohydrates in drinks by high-performance liquid chromatography with a dynamically modified amino column and evaporative light scattering detection.

A high-performance liquid chromatographic method with a dynamically modified amino column and evaporative light-scattering detector (ELSD) was established for the direct analysis of the carbohydrates in some drinks. A separation column (Zorbax Rx-SIL, 250 mm x 4.6 mm I.D., 5 microm, Hewlett-Packard, USA) which was modified by ethylenediamine and a guard column (Zorbax Rx-SIL, 12.5 mm x 4.6 mm I.D., 5 microm) were used. The mobile phase was a mixture of water-acetonitrile (1:2.6, v/v) containing 0.03% (v/v) ethylenediamine. Regression equations revealed linear relationship (correlation coefficients=0.996-0.999) between the mass of carbohydrates injected and the carbohydrates peak areas detected by ELSD. The detection limits of ELSD (S/N=3) were between 0.2 and 1.2 microg for different carbohydrates. This method is simple and sensitive.

[Chromatographic analysis of tea polyphenols].

A review is presented about the chromatographic analysis of the polyphenols. Some of the chromatographic methods such as plate chromatography, gas chromatography, reversed-phase high performance liquid chromatography and some new chromatographic methods are introduced.

[Determination of tetramethylpyrazine in animal serum and cerebrospinal fluid by high performance liquid chromatography].

A reversed-phase high performance liquid chromatographic (RP-HPLC) method for the determination of the tetramethylpyrazine(TMP) in Chuanxiong extract, the animal(mouse) serum and cerebrospinal fluid has been developed. The TMP was separated on an ODS column Zorbax SB-C18(4.6 mm i.d. x 250 mm, 5 microns) at room temperature and detected by using UV detector at 270 nm. The mobile phase was methanol-water (50:50, V/V) containing 0.2 mmol/L of NH4H2PO4 flowing at a rate of 0.8 mL/min and 20 microL samples were injected. The detection limit of TMP was 1 mg/L and the calibration curve is linear between 5 and 500 mg/L with a correlation coefficient (r) of 0.999. The recovery of TMP ranged 98%-103%. The extract of Chuanxiong and pretreated serum and cerebrospinal fluid sample are stable for a week at room temperature.