Water bridges as the trigger in an amino functionalized Zn-MOF for highly selective and sensitive fluorescent sensing of water

Water is a fundamental element for life. The highly selective and sensitive sensing of water is always attractive for mankind in activities such as physiological processes study and extraterrestrial life exploration. Fluorescent MOFs with precise channels and functional groups might specifically recognize water molecules with hydrogen-bond interaction or coordination effects and work as water sensors. As a proof of concept, herein, an amino functionalized Zn-MOF (named as complex 1) with pores that just right for water molecules to form hydrogen bond bridges is revealed for highly selective and sensitive fluorescent sensing of water. The single-crystal X-ray diffraction analysis indicates that the 3D framework of complex 1 is functionalized with free amino groups in the channels. Hydrogen bonds formed in the channel along b-axis as water bridges to connect two adjacent NH2bdc ligands and result in the restriction of intramolecular motions (RIM) which could responsible for the selective turn-on fluorescence response to water. Complex 1 exhibits high sensitive to trace amount of water in organic solvents and could be used for water detection in a wide range water contents. Take advantages of complex 1, portable sensors (complex 1@PMMA) were prepared and used in the highly sensitive water sensing.

Enhanced stability and tunable photoluminescence in Mn2+-doped one-dimensional hybrid lead halide perovskites for high-performance white light emitting diodes

Organic-inorganic hybrid low-dimensional lead halides have garnered significant interest in the realm of solid-state optical materials due to their unique properties and potential applications. In this study, we report the synthesis, characterization and application of Mn²⁺-doped one-dimensional (1D) [AEP]PbCl₅·H₂O hybrid lead halide perovskites with tunable photoluminescence properties. The Mn²⁺ doping leads to a redshift of the dominant emission wavelength from 463 nm to 630 nm, with the optimal doping concentration resulting in an enhanced photoluminescence quantum yield (PLQY) from less than 1% to 8.96%. The structural and optical stability of these doped perovskites have been thoroughly investigated revealing excellent performance under humid and high-temperature conditions. Perovskite-PVP composite films exhibit high crystallization and bright orange-red emission under UV excitation. Furthermore, we demonstrate the successful fabrication of a white LED device using the Mn²⁺-doped perovskite in combination with commercial green and blue phosphors. The fabricated LED exhibits a high color rendering index (CRI) of 87.2 and stable electroluminescence performance under various operating currents and extended operation times. Our findings highlight the potential of Mn²⁺-doped 1D hybrid lead halide perovskites as efficient and stable phosphors for high-performance white light emitting diodes and other optoelectronic applications.

A Cu2+ triggered reversible photochromic system: the structure photochromic response relationship study and potential applications

Fifteen rhodamine B hydrazide hydrazone (RhBHH) derivatives (compounds a-o) with various substituent groups at different position and their photochromic property triggered by Cu²⁺ were studied to illustrate the structure photochromic response relationship (SPRR). Three of them (compounds f-h) with a para-position hydroxyl group and two meta-position halogen substituents display Cu²⁺-triggered photochromic which is significantly different from the previous reports. It was found that halogen atoms, which were generally considered to have no remarkable regulation effect, exhibited great influences on the photochromic behaviour of RhBHH derivatives. Detail photochromic properties of the developed photochromic system were revealed by using compound g as the model substrate, and only Cu²⁺ displayed high selective trigger effect. Good reversible photochromic phenomenon was observed after stimulated with visible light irradiation and dark (or heat) bleaching consecutively. Furthermore, this photochromic system could be used in the preparation of photochromic glass, special security ink, molecular logic gate and two-dimensional code for security information storage.

LPCAT1 functions as a novel prognostic molecular marker in hepatocellular carcinoma

This study aimed to investigate the relationships between LPCAT1 expression and clinicopathologic parameters of hepatocellular carcinoma (HCC), further, to explore the effect of LPCAT1 on overall survival (OS) in patients with HCC, and its possible mechanism. Bioinformatics analysis using high throughput RNA-sequencing data from TCGA was utilized to explore the differential expression of LPCAT1 between normal and tumor tissues, and the associations between LPCAT1 expression and clinicopathological parameters. Survival analyses and subgroup survival analyses were utilized to elucidate the effect of LPCAT1 on OS in patients with HCC. Univariate analysis and multivariate analysis were used to investigate the prognostic factors. Potential LPCAT1 related tumor genes were identified by the methodology of differentially expressed genes (DEGs) screening. GO term enrichment analysis, KEGG pathway analysis and the PPI network were used to explore the potential mechanism. LPCAT1 was significantly overexpressed in HCC tumor tissues compared with normal tissues. The LPCAT1 expression was related to tumor grade, ECOG score, AFP and TNM stage, with P values of 0.000, 0.000, 0.007 and 0.000, respectively. Multivariate analysis demonstrated that LPCAT1 expression was independently associated with OS, with an HR of 1.04 (CI: 1.01-1.06, P = 0.003). The KEGG pathway enrichment analyses showed that overlapped DEGs mainly participate in the cell cycle. Finally, we identified a hub gene, CDK1, which has been reported to act on the cell cycle, consistent with the result of KEGG enrichment analysis. Collectively, these data confirmed LPCAT1 was upregulated in HCC, and was an independent predictor of the prognosis.

The Effects of Orthographic Neighborhood Size and the Influence of Individual Differences in Linguistic Skills During the Recognition of Chinese Words

There are still inconsistencies as to whether frequency and orthographic neighborhood size affect the reading and recognition of Chinese words. In addition, research on Chinese reading still adheres to the view that "all skilled readers read in the same way" and pays little attention to the influence of individual differences in linguistic skills on word recognition. In this research, we studied the recognition of Chinese two-character words in a lexical decision task (LDT) by manipulating neighborhood size and word frequency and controlling the frequency of the initial constituent character. Individual differences in linguistic skills were assessed through tests of spelling and reading comprehension. The results showed that: (1) A larger orthographic neighborhood size of the initial character had a facilitative effect on Chinese word recognition. The orthographic neighborhood size effect is modulated by word frequency, but this modulation effect was not stable. (2) Spelling and reading comprehension skills are good indicators to assess individual differences in Chinese linguistic skills, and they are significantly correlated. (3) Individual differences in linguistic skills influence the neighborhood size effect, which is moderated by word frequency.

Comparison of clinical characteristics and outcomes of infective endocarditis between haemodialysis and non-haemodialysis patients in China

Objective

To clarify differences in clinical characteristics and outcomes between patients with infective endocarditis (IE) receiving long-term haemodialysis (HD group) and those not receiving haemodialysis (non-HD group).

Methods

Medical records of patients with IE, admitted to hospital between January 2010 and December 2017, were retrospectively studied. Clinical characteristics and outcomes were compared between HD and non-HD groups. Risk factors for IE were assessed by COX regression.

Results

Twenty-one HD and 143 non-HD patients were included. Predisposing heart conditions were more frequently observed in the non-HD versus HD group (90.9% versus 19.0%). Inappropriate antibiotic therapy rate before admission and proportion of methicillin-resistant Staphylococcus aureus and Enterococcus-associated IE was higher in the HD versus non-HD group. In the HD group, fewer patients underwent heart surgery (9.5% versus 51.7%), all-cause in-hospital mortality was higher (52.4% versus 21%), and survival rate was lower versus the non-HD group. COX regression analysis revealed that haemodialysis, use of central venous catheter (CVC) and inappropriate antibiotic therapy before admission increased IE mortality, while surgery improved long-term prognosis.

Conclusions

Haemodialysis patients with IE may have higher mortality and lower survival rates than patients with IE not receiving haemodialysis. Haemodialysis, use of CVC and inappropriate antibiotic therapy before admission may increase IE mortality. Surgery may improve long-term prognosis.

Expression and significance of miR-223 in rats with pulmonary fibrosis

OBJECTIVE

To explore the expression and significance of miR-223 in mice with pulmonary fibrosis.

MATERIALS AND METHODS

The rats were separated into a control group (n=15), a sham operation group (n=15), and a model group (n=45) (which was then divided into a 3-day group, a 7-day group, and a 14-day group, with 15 rats in each group). The rat model of pulmonary fibrosis was established. The rats in the model group were injected with bleomycin solution, while those in the control group and sham operation group were given the same operation and injected with the same amount of normal saline. After observing the pulmonary function indexes of the rats on the 3rd, 7th and 14th days after modeling, the rats were sacrificed by cervical dislocation, the pulmonary inflammation and fibrosis of the rats were observed, and the HYP (hydroxyproline) content and miR-223 expression level were determined. Pearson correlation analysis was employed to analyze the correlation between miR-223 and HYP.

RESULTS

The pulmonary inflammation score of the model group was significantly higher than that of the sham group and the control group, and the pulmonary inflammation of the model group significantly increased with the increase of time (p<0.05). The pulmonary fibrosis score in the model group was markedly higher than that in the rest two groups, and the pulmonary fibrosis in the model group elevated significantly with the passage of time (p<0.05). The relevant pulmonary function indexes of the model group rats were significantly lower than those of the other two groups, and the pulmonary function of the model group rats gradually decreased with time (p<0.05). As to the HYP, it presented notably higher content in the model group than in the remaining two groups, and its content in the model group rats increased significantly with time (p<0.05). The expression of miR-223 decreased with the increase of fibrosis (p<0.05), and the expression level of miR-223 was negatively correlated with the HYP content (p<0.05).

CONCLUSIONS

MiR-572 targeted CDH1 to promote cell metastasis in WT by suppressing EMT.

A novel high sensitive Cd-MOF fluorescent probe for acetone vapor in air and picric acid in water: Synthesis, structure and sensing properties

A novel three-dimensional luminescence Cd-MOF sensor with the molecular formula {[(CH₃)₂NH₂]₂ Cd₃(ptptc)₂} (complex 1) has been synthesized by using terphenyl-3,3',5,5'-tetracarboxylic acid (H₄ptptc) and Cd(NO₃)₂·4H₂O under solvothermal conditions. Single crystal X-ray diffraction analysis shows that complex 1 crystallizes in the monoclinic system C2/c space group and consists of one-dimensional channels. Complex 1 exhibits characteristic fluorescence emission (λ_em = 380 nm) both in solid state and solvents upon excitation at 300 nm. Real-time fluorescence quenching of complex 1 was observed in the fluorescence sensing of acetone vapor and picric acid. Intriguingly, ppm scale detection limit for acetone vapor in air and nano-mole scale detection limit for picric acid in water were observed. Moreover, good reusability and liner/nonlinear relationships were observed in the fluorescent titration.

A novel Cd-MOF with enhanced thermo-sensitivity: the rational design, synthesis and multipurpose applications

A novel thermo-sensitive fluorescent Cd-MOF probe (complex 1) and its multipurpose sensing properties have been revealed.

A novel multi-purpose Zn-MOF fluorescent sensor for 2,4-dinitrophenylhydrazine, picric acid, La3+ and Ca2+: Synthesis, structure, selectivity, sensitivity and recyclability

A new three-dimensional luminescence Zn-MOF sensor with the molecular formula [Zn₄(μ₃-OH)₂(ptptc)_1.5(DMA)(H₂O)₂]·2DMA (complex 1) for the selective sensing of 2,4-dinitrophenylhydrazine (2,4-DNPH), picric acid (PA), La³⁺ and Ca²⁺ has been synthesized from terphenyl-3,3',5,5'-tetracarboxylic acid (H₄ptptc) and zinc nitrate under solvothermal conditions. XRD analysis reveals that complex 1 crystallizes in monoclinic system P2₁/n space group and consists of a three-dimensional network with one-dimensional channels, which are expected to facilitate the diffusion, concentration and detection processes. Real-time fluorescence quenching responses and good reversibility were observed in the fluorescence titration experiments with nano-molar scale detection limits for 2,4-dinitrophenylhydrazine (2,4-DNPH, 100 nM) and picric acid (PA, 500 nM). Noticeable emission band shift from 365 nm to 420 nm was observed when treated complex 1 with La³⁺ and a new emission band centered at 475 nm appeared when treated complex 1 with Ca²⁺ in the metal ions sensing experiments. In virtue of its high selectively, good sensitively and recyclability complex 1 could be a promising fluorescent sensor for explosives and metal ions.

A novel 3D Cd(ii) coordination polymer generated via in situ ligand synthesis involving C-O ester bond formation

A novel 3D Cd(ii) coordination polymer {[Cd(ddpa)(2,2′-bpy)]·H₂O}_n (1) (H₂ddpa = 5,10-dioxo-5,10-dihydro-4,9-dioxapyrene-2,7-dicarboxylic acid, 2,2′-bpy = 2,2′-bipyridine) is hydrothermally synthesized in situ, and the influencing factors and mechanism for the in situ reaction are briefly discussed. The synthesis of 1 requires the formation of a new C–O ester bond. This current study confirms that metal ions and N-donor ligands play important roles in the domination of the in situ ligand from 6,6′-dinitro-2,2′,4,4′-biphenyltetracarboxylic acid (H₄dbta). Furthermore, the structure, thermal stability and photoluminescent property of 1 are also investigated.

A 3D Cd(ii) coordination polymer comprising ligand molecules not included in the original reaction mixtures but instead formed via in situ ligand synthesis involving a C–O ester bond.

The 3D supramolecular architecture of copper(II) 6-methyl-2-pyridone-4-carboxylate: synthesis, structure, magnetic behavior and DFT studies

The reaction of Cu(NO3)2·3H2O and 6-methyl-2-pyridone-4-carboxylic acid (Hhmpca) under hydrothermal condition produced a new copper(II) coordination polymer [Cu(hmpca)2(H2O)2]·4H2O (1), which has been characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction. The Cu(II) ions are linked by coordinating water molecule bridges to generate a polymeric chain, and adjacent chains are connected to form a layer structure through interchain N–H···O hydrogen bonding. Because of the strong hydrogen bonds of free water molecules, ladder-shaped water chains are produced. Further, the layers and the water chains are linked into a three-dimensional supramolecular structure through strong O–H···O hydrogen bonds. Magnetic susceptibility measurements have indicated that compound1shows antiferromagnetic interactions between the adjacent Cu(II) ions. Based on the crystal structure data, compound1was analyzed using hybrid density functional theory (DFT) methods at the B3LYP/6-31G(d) level, and a DFT-broken symmetry approach was applied to study the magnetic coupling behavior. The calculated exchange coupling constantJis in good agreement with the experimental data.

Scaling analysis of core pressure drop in reduced height integral test facility

Integral test plays essential role to assess the design of the emergency cooling system of nuclear reactors. Different from full height integral test facilities, reduced height integral test facilities have new problems on the pressure drop scaling. This paper mainly focuses on scaling of pressure drop across the core as it is the major pressure drop in primary loop. The analysis of pressure drop across the core has been divided into three terms and each term has been discussed separately based on two conditions: the normal operation condition and natural circulation condition. After that, the total pressure drop ratios under these two conditions have been discussed.

A FRET-based fluorescent and colorimetric probe for the specific detection of picric acid

Picric acid (PA) as an environmental pollutant and high explosive, has recently received considerable attention. In this paper, a novel fluorescent and colorimetric chemo-probe (L) for the highly selective and sensitive detection of picric acid has been revealed. The probe was facilely constructed using rhodamine B, ethylenediamine and 4-(9H-carbazol-9-yl)benzoyl chloride. Significant fluorescence changes based on an intramolecular fluorescence resonance energy transfer (FRET) effect followed by a distinct color change from colorless to pink were observed after addition of picric acid to the probe solution. Selectivity measurements revealed that the as-synthesized probe exhibited high selectivity toward PA in the presence or absence of other analytes. The experimental titration results suggested that the as-synthesized probe is an effective tool for detection of PA with a nanomolar scale detection limit (820 nM) and could also serve as a “naked-eye” indicator for PA detection.

A FRET-based fluorescent and colorimetric chemo-sensor has been designed and synthesized for the selective and sensitive detection of picric acid.

Fine-tuning the effects of auxiliary ligands on two trigonal-bipyramid cobalt(ii) complexes exhibiting field-induced slow magnetic relaxation

Two trigonal-bipyramid cobalt(ii) complexes exhibit field-induced slow magnetic relaxation effects due to their auxiliary ligands.

A novel microporous Tb-MOF fluorescent sensor for highly selective and sensitive detection of picric acid

A new three-dimensional metal–organic framework (MOF) sensor with molecular formula (C₂H₆NH₂)₂[Tb₂(ptptc)₂(DMF)(H₂O)]·DMF·6H₂O (complex 1) has been constructed from terphenyl-3,3′,5,5′-tetracarboxylic acid (H₄ptptc) and terbium nitrate under solvothermal conditions. The structure of complex 1 was characterized by single-crystal X-ray diffraction analysis (XRD), elemental analysis, IR spectroscopy and thermogravimetric (TG) analysis, and the purity was further confirmed by powder X-ray diffraction (PXRD) analysis. XRD analysis reveals that complex 1 crystallizes in a triclinic system P1̄ space group and consists of a three-dimensional anionic network which has one-dimensional channels. Fluorescence titration experiments showed that complex 1 displayed real-time, highly selective and sensitive fluorescence quenching behavior towards picric acid with a nanomolar scale experimental detection limit (100 nM). Recycling titration experiments suggested that the as-synthesized probe has good reversibility and can be used for at least five cycles in fluorescence titration experiments without obvious fluorescence intensity reduction or framework structure destruction. Furthermore, the high selectivity and sensitivity as well as good recyclability of complex 1 make it a potential fluorescent sensor for picric acid.

A new three-dimensional reusable Tb-MOF fluorescent sensor for the highly selective and sensitive detection of picric acid was reported.

Determination of 6258-70, a new semi-synthetic taxane, in rat plasma and tissues: Application to the pharmacokinetics and tissue distribution study

Cancer is the leading cause of death all over the world. Among the chemotherapy drugs, taxanes play an important role in cancer treatment. 6258-70 is a new semi-synthetic taxane which has a broad spectrum of antitumor activity. A fast and reliable high performance liquid chromatography-tandem mass spectrometry (HPLC–MS/MS) method was developed for quantification of 6258-70 in rat plasma and tissues in this paper. After extraction by liquid-liquid extraction method with methyl tert-butyl ether, the samples were separated on a Kinetex C₁₈ column (50 mm×2.1 mm, 2.6 µm, Phenomenex, USA) within 3 min. The method was fully validated with the matrix effect between 87.7% and 99.5% and the recovery ranging from 80.3% to 90.1%. The intra- and inter-day precisions were less than 9.5% and the accuracy ranged from −3.8% to 6.5%. The reliable method was successfully applied to the pharmacokinetics and tissue distribution studies of 6258-70 after intravenous administration in rats. The pharmacokinetic results indicated that the pharmacokinetic behavior of 6258-70 in rats was in accordance with linear features within tested dosage of 1 to 4 mg/kg, and there was no significant difference between the two genders. The tissue distribution study showed that 6258-70 had an effective penetration, spread widely and rapidly and could cross blood-brain barrier. The results of pharmacokinetics and tissue distribution may provide a guide for future study.

The absolute bioavailability investigation of LS177 in rats using ultra-performance liquid chromatography-tandem mass spectrometry

LS177 is a novel inhibitor of mesenchymal epithelial transition (MET) that was used as an anticancer agent. The present study was to evaluate the absolute bioavailability of LS177 in rats. A rapid and sensitive ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS/MS) method has been developed and validated for the determination of LS177 in rat plasma. LS177 and internal standard (IS, LS410) were extracted from rat plasma samples by protein precipitation (PPT) for intravenous group and liquid-liquid extraction (LLE) procedure for oral group, then separated on a Phenomenex Kinetex XB-C18 (2.1 mm I.D. × 50 mm, 2.6 µm) using a mobile phase consisting of 0.1% formic acid in acetonitrile-0.1% formic acid water with a gradient elution program. The standard curves were linear over the ranges of 5.0-2000.0 ng · mL(-1) for PPT and 1.0-200.0 ng · mL(-1) for LLE. The mean recovery of LS177 was greater than 83.4% for PPT and not less than 88.5% for LLE, respectively. The intra- and inter-day accuracy and precision were within the acceptable limits of less than 15.0% at all concentrations. The validated method was successfully applied to the bioavailability study in rat plasma of LS177 and its absolute bioavailability was 25.37%.

Evaluation of the indicative roles of seven potential biomarkers on hepato-nephrotoxicity induced by Genkwa Flos

ETHNOPHARMACOLOGICAL RELEVANCE

Genkwa Flos, a classical traditional Chinese medicine, is used for the definite antitumor activity and tends to be taken overdose or long term in these years. While the excessive application can result in damage to liver and kidney. In this study, the indicative roles of seven potential biomarkers were evaluated to investigate hepato-nephrotoxicity in the early stages after oral administration of Genkwa Flos for 14 days.

MATERIALS AND METHODS

Histopathology, serum biochemistry and seven potential biomarkers in serum or urine from male Sprague-Dawley rats were monitored. Hepatic and renal tissues were histopathologically examined to identify specific changes occurring. Routine serum biochemical parameters were tested by using standard clinical laboratory methods. Seven biomarkers including cholic acid, taurine, 5-oxoproline, hippuric acid, uric acid, 3-indoxyl sulfate and kynurenic acid were detected by a developed LC-MS method.

RESULTS

The histopathological alterations and the increased levels of serum biochemistry were detected on the 8th day after Genkwa Flos treated. The seven analytes were also found significantly changed in Genkwa Flos treated group, especially cholic acid, taurine, 5-oxoproline and hippuric acid which were changed on the 2nd or 4th day.

CONCLUSIONS

Although serum biochemistry and histopathology suggested that Genkwa Flos was responsible for the hepato-nephrotoxicity that occurred following the ingestion of this medicinal herb, evaluation of these biomarkers might be more beneficial for the early detection of liver and kidney injuries. This study could be further used in hepatic and renal failures caused by other reasons in the following research works.

Dynamics in the Sakaguchi-Kuramoto model with two subpopulations [corrected]

The dynamics in a variant of globally coupled Sakaguchi-Kuramoto [corrected]. phase oscillators is studied. The model consists of two subpopulations, each with a different phase lag and interaction strength. Using Ott-Antonson ansatz, we analyze the dynamics in the model and present the numerical results. There exist stationary synchronous states which are generalized π states and two types of traveling wave states. We find that the traveling wave states are the dominant dynamics in comparison with the stationary states. Particularly, we find that the stationary and traveling wave states can be smoothly connected through the properly chosen parameter paths.

A study of Semen Strychni-induced renal injury and herb-herb interaction of Radix Glycyrrhizae extract and/or Rhizoma Ligustici extract on the comparative toxicokinetics of strychnine and brucine in rats

Recently, the renal injury caused by Semen strychni and its major toxic constituents, strychnine and brucine, was reported in many clinical cases. Hence, this study was conducted to investigate the renal injury induced by Semen Strychni and the protective effects of Radix Glycyrrhizae and Rhizoma Ligustici. The protective mechanisms were related to the comparative toxicokinetics of strychnine and brucine. Serum and urine uric acid and creatinine were used as renal function markers to evaluate the condition of kidney, and renal injury was directly reflected by histopathological changes. Compared with rats in blank group and protective herb groups, rats in Semen Strychni high-dose group showed significant differences in the results of renal function markers, and various glomerular and tubular degenerations were found in the histopathological study. The decreased AUC (only strychnine) and Cmax, the increased Tmax by Radix Glycyrrhizae and the decreased T1/2 by Radix Glycyrrhizae and Rhizoma Ligustici were found in model groups. Results indicated that high dose of Semen Strychni might induce renal injury. Radix Glycyrrhizae and Rhizoma Ligustici might work together and have effects on the elimination of strychnine and brucine. The protective effects of Radix Glycyrrhizae might also be explained by the slow absorption of the alkaloids.

Validated LC-MS method for simultaneous quantitation of catalpol and harpagide in rat plasma: application to a comparative pharmacokinetic study in normal and diabetic rats after oral administration of Zeng-Ye-Decoction

A simple and efficient liquid chromatography-mass spectrometry (LC-MS) method was developed and validated for simultaneous quantitation of catalpol and harpagide in normal and diabetic rat plasma. Protein precipitation extraction with acetonitrile was carried out using salidroside as the internal standard (IS). The LC separation was performed on an Elite C18 column (150 × 4.6 mm, 5 µm) with the mobile phase consisting of acetonitrile and water within a runtime of 12.0 min. The analytes were detected without endogenous interference in the selected ion monitoring mode with positive electrospray ionization. Calibration curves offered satisfactory linearity (r > 0.99) at linear range of 0.05-50.0 µg/mL for catalpol and 0.025-5.0 µg/mL for harpagide with the lower limits of quantitation of 0.05 and 0.025 µg/mL, respectively. Intra- and inter-day precisions (RSD) were <9.4%, and accuracy (RE) was in the -6.6 to 4.9% range. The extraction efficiencies of catalpol, harpagide and IS were all >76.5% and the matrix effects of the analytes ranged from 86.5 to 106.0%. The method was successfully applied to the pharmacokinetic study of catalpol and harpagide after oral administration of Zeng-Ye-Decoction to normal and diabetic rats, respectively.

Simultaneous non-destructive determination of two components of combined paracetamol and amantadine hydrochloride in tablets and powder by NIR spectroscopy and artificial neural networks

The two components (paracetamol and amantadine hydrochloride) were simultaneously determined in combined paracetamol and amantadine hydrochloride tablets and powder by using near-infrared (NIR) spectroscopy and artificial neural networks (ANNs). The ANN models of three pretreated spectra (first-derivative, second-derivative and standard normal variate (SNV), respectively) were established. The mathematical corrected models of tablets were compared with those of the powder. In the models, the concentrations of paracetamol and amantadine hydrochloride as the active components were determined simultaneously and compared with the results of their separate determination. The parameters that affected the network were studied and the concentrations of the test set samples were predicted. The degree of approximation, a new evaluation criterion of the network was employed to prove the accuracy of the predicted results.