Marine toxins in environment: Recent updates on depuration techniques.

Marine toxins pose a significant safety risk, leading to human intoxications and causing substantial economic losses in seafood-producing regions. The development of rapid, cost-effective, efficient, and reliable approaches for the containment of these substances is therefore crucial in order to mitigate the adverse impact of marine toxins. This research conducted a comprehensive review on the toxicity and influencing factors of marine toxins production. Additionally, depuration technologies, including adsorption, advanced oxidation processes, biodegradation, heating treatment, temporary maintenance and purification, and drug inhibition, were systematically summarized. The study also provided a comparative analysis of the advantages and disadvantages of various depuration technologies and proposed strategies for future development.

Clinical Comparison of Preterm Birth and Spontaneous Preterm Birth in Severe Preeclampsia.

Severe preeclampsia is accompanied by many complications, which is extremely harmful to pregnant women and fetuses. However, in the classification of preterm birth, it is generally divided into spontaneous preterm birth and therapeutic preterm birth, and insufficient attention has been paid to preterm birth in severe preeclampsia. This article aims to explore the clinical difference between preterm birth in severe preeclampsia and spontaneous preterm birth. In the experiment, this paper selected pregnant women who delivered and were treated in a hospital from April 2010 to April 2020 as cases. In terms of grouping, not only are they divided into severe eclampsia group (observation group 1), spontaneous preterm birth group (observation group 2), and general delivery group (control group) according to the cause of premature birth, but also according to the gestational age of severe eclampsia onset, preterm weeks, and other groups. Not only the clinical difference between severe preeclampsia preterm birth and spontaneous preterm birth was compared horizontally, but also the factors affecting the complications of preterm pregnant women, perinatal asphyxia rate, and mortality were longitudinally analyzed. The experimental results in this paper showed that there were significant differences in maternal complications and neonatal mortality between the severe preeclampsia preterm group and the spontaneous preterm group (P < 0.05). In addition, the severe preeclampsia preterm birth group was more harmful than the spontaneous preterm birth group. The complication rate of the severe preeclampsia preterm birth group was 10% higher than that of the spontaneous preterm birth group, and the neonatal mortality rate was 2% higher.

A possible covalent xanthine oxidase inhibitor TS10: Inhibition mechanism, metabolites identification and PDPK assessment.

Xanthine oxidase (XO) inhibitors are widely used in the control of serum uric acid levels in the clinical management of gout. Our continuous efforts in searching novel amide-based XO inhibitors culminated in the identification of N-(4-((3-cyanobenzyl)oxy)-3-(1H-tetrazol-1-yl)phenyl)isonicotinamide (TS10), which exhibited comparable in vitro inhibition to that of topiroxostat (TS10, IC50 = 0.031 µM; topiroxostat, IC50 = 0.020 µM). According to the molecular modeling, we speculated that, as well as topiroxostat, TS10 would be biotransformed by XO to yield TS10-2-OH. In this work, TS10-2-OH was successfully identified in XO targeted metabolism study, demonstrated that TS10 underwent a covalent binding with XO via a TS10-O-Mo intermediate after anchoring in the XO molybdenum cofactor pocket. Furthermore, TS10-2-OH is a weak active metabolite, and its potency was explained by the molecular docking. In metabolites identification, TS10 could be oxidized by CYP2C9, CYP3A4 and CYP3A5 to generate two mono-hydroxylated metabolites (not TS10-2-OH); and could occur degradation in plasma to mainly generate a hydrolytic metabolite (TS10-hydrolysate). In pharmacokinetic assessment, the low oral system exposure was observed (Cmax = 14.73 ± 2.66 ng/mL and AUClast = 9.17 ± 1.42 h⋅ng/mL), which could be explained by the poor oral absorption property found in excretion studies. Nonetheless, in pharmacodynamic evaluation, TS10 exhibited significant uric acid-lowering effect after oral administration in a dose-dependent manner. Briefly, in addition to allopurinol and topiroxostat, TS10 is possibly another explicitly mechanism-based XO inhibitor with powerful covalent inhibition.

Two new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from the subtropical monsoon region in Southern China, with a discussion on reproductive modalities.

BACKGROUND: Freshwater planarians of the genus Dugesia (Platyhelminthes, Tricladida, Dugesiidae) are distributed in a major part of the Old World and Australia, although until recently only very few species were known from China. RESULTS: Two new species of Dugesia from Southern China are described on the basis of an integrative taxonomic approach. BI and ML phylogenetic trees based on the independent genes and on the concatenated dataset had similar topologies, only differing in some nodes that were weakly supported. Phylogenetic trees based on the concatenated dataset revealed that D. adunca Chen & Sluys, sp. nov. and D. tumida Chen & Sluys, sp. nov. are not closely related and belong to different clades. The two new species occupy separate long branches with high support values and, thus, are well-differentiated from their congeners. Separate species status of D. adunca and D. tumida is supported also by the genetic distances between the species included in our analysis, albeit that COI distances varied greatly among species. Dugesia adunca from Guangxi Province is characterized by the following features: living mature animals rather small; asymmetrical openings of the oviducts into the bursal canal; penis papilla with shape of an aquiline bill, albeit with a blunt tip; asymmetrical penis papilla, with a large antero-dorsal lip and a much smaller ventro-posterior lip; very large seminal vesicle, provided with trabeculae; small diaphragm; mixoploid karyotype with diploid complements of 2n = 2x = 16 and triploid complements of 2n = 3x = 24, with all chromosomes being metacentric. Dugesia tumida from Guangdong Province is characterized by a penis papilla provided with a large, symmetrical penial valve from the middle of which arises the small, distal section of the papilla; a duct intercalated between the seminal vesicle and the small diaphragm; ventrally displaced ejaculatory duct curving upwards before opening to the exterior; penis papilla highly asymmetrical, having a slim and long ventral portion and a short and stubby dorsal part; vasa deferentia separately opening into antero-dorsal portion of seminal vesicle; oviducts openings symmetrically into ventral portion of the bursal canal, near its opening into the atrium; mixoploid karyotype, with diploid chromosome portraits of 2n = 2x = 16, and triploid complements of 2n = 3x = 24, with all chromosomes being metacentric. In the context of the various kinds of mixoploidy and the sexualization of specimens, reproductive modalities within the genus Dugesia are shortly discussed. CONCLUSION: Molecular, morphological, and karyological markers show that the two populations examined represent members of the genus Dugesia and constitute two new, distinct species.

Analysis of risk factors, pathogenic bacteria of maternal sepsis in term pregnant women with positive blood culture during hospitalization.

ABSTRACT: The objective of this study was to evaluate the risk factors, pathogenic bacteria and drug sensitivity of maternal sepsis, and provide evidence for clinical prevention and treatment.A retrospective investigation of pregnant women with full-term maternal sepsis was performed to analyze the risk factors, pathogenic bacteria, and drug sensitivity of maternal sepsis.Univariate analysis showed that temperature, serum procalcitonin (PCT) and C-reactive protein (CRP) at admission, white blood cell count (WBC), PCT, CRP and neutrophilic granulocyte percentage (N%) during fever, premature rupture of membranes (PROM), antibiotic use within 1 week, mode of production, onset and duration of fever, between groups were statistically significant (P < .05). Logistic regression analysis showed that cesarean section was an independent risk factor for sepsis (OR = 11.839, 95%CI: 3.121-44.906). Apparent increase was found in body temperature (OR = 3.664, 95%CI: 1.722-7.795), duration of fever (OR = 1.953, 95%CI: 1.242-3.071), and PCT (OR = 1.080, 95%CI: 1.002-1.163). Also, increasing neutrophil ratio (OR = 1.180, 95%CI: 1.073-1.297) indicated a high possibility of maternal sepsis. The organism Escherichia coli (E. coli) was the most common pathogenic bacteria in the positive blood culture group (90%), and the sensitivity to carbapenems (meropenem and imipenem/cilastatin) was 100%, that to piperacillin-tazobactam and amoxicillin sulbactam was over 90%, and that to ceftazidime was 95%.Cesarean section was an independent risk factor for maternal sepsis in term pregnant women with positive blood culture. Besides, the E. coli was the most common pathogenic bacteria in the positive blood culture group. Antibiotics should be used in time and reasonably when the temperature was significantly increased with elevated PCT and N% after a cesarean section.

Comparative pharmacokinetics study of leonurine and stachydrine in normal rats and rats with cold-stagnation and blood-stasis primary dysmenorrhoea after the administration of Leonurus japonicus houtt electuary.

Leonurus japonicus houtt, a well-known herb of traditional Chinese medicine, is widely used to treat gynaecological diseases. In this study, a rapid and sensitive liquid chromatography with tandem mass spectrometry method for simultaneously quantifying leonurine and stachydrine, the two main bioactive components in Leonurus japonicus houtt, was developed and validated. Plasma samples were prepared by protein precipitation with acetonitrile and separation by a Hewlett Packard XDB-C8 column (150 × 4.6 mm, id, 5 µm) equipped with a gradient elution system containing methanol-water and 0.1% formic acid at a flow-rate of 0.4 mL/min. Components were then detected by a mass spectrometer in positive electrospray ionization mode. This method showed good linearity, precision, accuracy, recovery, stability, and negligible matrix effects, which were within acceptable ranges. The method was successfully applied to compare the pharmacokinetics in normal rats and rats with cold-stagnation and blood-stasis primary dysmenorrhoea treated with Leonurus japonicus houtt electuary. The result showed significant differences (p < 0.05) in the pharmacokinetic parameters between the primary dysmenorrhoea and normal groups. This result implied that Leonurus japonicus houtt electuary remained longer and was absorbed slower in rats with primary dysmenorrhoea and exhibited higher bioavailability and peak concentration.

Vapor-induced motion of two pure liquid droplets.

The movement of evaporating liquid droplets on a surface can be triggered by the Marangoni effect arising from heterogeneities in the surface tension or a gradient in the surface energy of the substrate. Here, we show that, on a high energy surface that remains uniform, the motion of two pure liquid droplets can be induced by a gradient in the liquid vapor resulting from evaporation. The droplets always attract each other, moving from the high evaporation side to the low evaporation side, to reduce energy dissipation. By varying the volume of the droplets or the distance between droplets, the motion of the droplets can be effectively controlled.

Ultra-Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS)-Based Pharmacokinetics and Tissue Distribution Study of Koumine and the Detoxification Mechanism of Glycyrrhiza uralensis Fisch on Gelsemium elegans Benth.

Gelsemium elegans Benth. (G. elegans), which is a famous Chinese folk medicine, has been commonly used to treat certain types of skin ulcers and alleviate inflammation, headaches, and cancer pain. However, the extensive clinical use of G. elegans has been greatly hampered by its toxicity. As one of the most widely used herbal medicines, Glycyrrhiza uralensis Fisch, has a unique effect on detoxification of G. elegans. In the present study, a rapid and sensitive method using ultra-liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was established and validated for determination of koumine, the most abundant molecule among the alkaloids of G. elegans, in rat plasma, tissue, and liver microsome. The developed method was successfully applied to the pharmacokinetics, tissue distribution, and in vitro metabolism study in rat with or without pre-treated Glycyrrhiza uralensis Fisch extract. Meanwhile, the expression level of CYP3A1 mRNA was analyzed to explain the detoxification mechanism of Glycyrrhiza uralensis Fisch on G. elegans. As a result, our work demonstrated that Glycyrrhiza uralensis Fisch could significantly affect the pharmacokinetics and tissue distribution of koumine in rats. The detoxification mechanism of Glycyrrhiza uralensis Fisch on G. elegans may be its cytochrome enzyme up-regulation effect.

Simultaneous determination of gelsemine and koumine in rat plasma by UPLC-MS/MS and application to pharmacokinetic study after oral administration of Gelsemium elegans Benth extract.

A simple, rapid and sensitive method using UPLC-MS/MS was established and validated for simultaneous determination of gelsemine and koumine in rat plasma after oral administration of Gelsemium elegans Benth extract. Plasma was performed with methanol precipitation and berberine was chosen as the internal standard. Plasma samples were separated on an Acquity UPLC® BEH C18 column (3.0 × 50 mm, 1.7 µm) with gradient elution using acetonitrile and 0.1% formic acid aqueous solution as the mobile phase at a flow rate of 0.4 mL/min. Multiple reaction monitoring mode in positive ion mode was utilized for detection. The calibration curves were linear over the range of 0.2-100 ng/mL for gelsemine and 0.1-50 ng/mL for koumine, with the lower limits of quantification 0.2 and 0.1 ng/mL, respectively. The intra- and inter-precision and accuracy were well within the acceptable ranges. The developed method was successfully applied to an in vivo pharmacokinetic study in rat after oral administration of 10 mg/kg Gelsemium elegans Benth extract.

Fractional-order gradient descent learning of BP neural networks with Caputo derivative.

Fractional calculus has been found to be a promising area of research for information processing and modeling of some physical systems. In this paper, we propose a fractional gradient descent method for the backpropagation (BP) training of neural networks. In particular, the Caputo derivative is employed to evaluate the fractional-order gradient of the error defined as the traditional quadratic energy function. The monotonicity and weak (strong) convergence of the proposed approach are proved in detail. Two simulations have been implemented to illustrate the performance of presented fractional-order BP algorithm on three small datasets and one large dataset. The numerical simulations effectively verify the theoretical observations of this paper as well.

A Novel Fluorescent Biosensor for Detection of Silver Ions Based on Upconversion Nanoparticles.

In this paper, we report a simple and sensitive fluorescent biosensor for the quantitative analysis of silver ions (Ag+) by using NaYF4:Yb3+, Tm3+ upconversion nanoparticles (UCNPs). Ag+ could oxidize o-phenylenediamine (OPD) to the oxidized OPD (oxOPD) directly. The fluorescence of UCNPs can be significantly quenched by oxOPD through inner filter effects (IFE). Under the optimized conditions, the Ag+ concentration is proportional to the changes of the fluorescence intensity of UCNPs. The proposed method shows high selectivity and Ag+ could be quantitatively detected in the range of 0 to 0.5 mM with a low detection limit of 33 nM for Ag+. The selectivity and sensitivity of the detection can also be satisfactory. More importantly, this method has potential in practical application to detect Ag+ in real samples without interference.

Rapid and highly-sensitive uric acid sensing based on enzymatic catalysis-induced upconversion inner filter effect.

In this work, a novel and simple fluorescence method for detection of uric acid (UA) based on NaYF4:Yb(3+), Tm(3+) upconversion nanoparticles (UCNPs) is developed. The proposed method is based on the fact that uricase can oxidize uric acid to allantoin and hydrogen peroxide, which, on its turn, can oxidize o-phenylenediamine (OPD) to the oxidized OPD (oxOPD). The fluorescence of UCNPs can be significantly quenched by oxOPD through inner filter effects (IFE). Under the optimized conditions, the UA concentration was proportional to the changes in fluorescence intensity of UCNPs. A linear response was obtained over the concentration range from 20 to 850µΜ with the low detection limit of 6.7µΜ for uric acid. More importantly, this method has the potential to detect uric acid in human serum samples, suggesting the nanosensor can be used in a complex biological sample matrix.

Simultaneous determination of lidamycin enediyne chromophore (LDC) and its aromatized derivative (LDCA) using puerarin as internal standard in rat plasma by LC-MS/MS.

Lidamycin (LDM), a promising enediyne antitumor antibiotic, was quantified by detecting lidamycin enediyne chromophore (LDC) using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the first time. A simple, rapid and reliable method was developed and validated to determine LDC and its aromatized derivative (LDCA) simultaneously in plasma. Puerarin was used as an internal standard (IS), and plasma samples were pretreated with one-step precipitation by acetonitrile. Separation was achieved on a reverse-phase C(18) column with a mobile phase composed of methanol and water containing 5 mm ammonium acetate at pH 3.5 in gradient elution mode. Detection was performed on a triple quadrupole tandem mass spectrometer using electrospray ionization (ESI) by multiple reaction monitoring (MRM) in the negative ion mode. Good linearity was obtained over the concentration range of 0.2-100 µg/mL for LDM. Precision and accuracy were validated by RSD% values in the range of 2.6-13.0% and RE% values between -4.6 and 3.8%, respectively. In addition, no specificity and matrix effects were observed. The recovery was found to be 99.2-111.0% and stability in various conditions was found to be acceptable. This method was applied in preclinical pharmacokinetic studies for routine monitoring of LDM in rat plasma.

[Lidamycin metabolism in vitro].

This paper is to report the study of the metabolism of lidamycin in vitro including in plasma and microsomes to guide clinical therapy. Lidamycin was quantified by detecting its active ingredient using HPLC-MS/MS. The metabolic stability of lidamycin in rat, Beagle dog, monkey and human plasma and liver microsomes, and its inhibition to cytochrome P450 isoforms in human liver microsomes were studied. Results showed that lidamycin was metabolized in the four species of plasma, and the sequence of metabolic rates in plasma were in rat > in dog > in human > in monkey. But among the four species of liver microsomes, lidamycin was metabolized only in monkey liver microsomes. There was almost no inhibition to cytochrome P450 isoforms at the concentrations of between 0.0005 and 10 ng x mL(-1). Therefore, the property of lidamycin metabolism in human is similar with that in dog, and metabolism of other drugs would not be decreased by cytochrome P450 as used along with lidamycin in clinic.

Ultrasensitive electrochemical aptasensor for thrombin based on the amplification of aptamer-AuNPs-HRP conjugates.

Successful development of an ultrasensitive and highly specific electrochemical aptasensor for thrombin based on amplification of aptamer-gold nanoparticles-horseradish peroxidase (aptamer-AuNPs-HRP) conjugates was reported. In this electrochemical protocol, aptamer1 (Apt1) was immobilized on core/shell Fe(3)O(4)/Au magnetic nanoparticles (AuMNPs) and served as capture probe. Aptamer2 (Apt2) was dual labeled with AuNPs and HRP and used as detection probe. In the presence of thrombin, the sandwich format of AuMNPs-Apt1/thrombin/Apt2-AuNPs-HRP was fabricated. Remarkable signal amplification was realized by taking the advantage of AuNPs and catalytic reactions of HRP. Other proteins, such as human serum albumin, lysozyme, fibrinogen, and IgG did not show significant interference with the assay for thrombin. Linear response to thrombin concentration in the range of 0.1-60 pM and lower detection limit down to 30 fM (S/N=3) was obtained with the proposed method. This electrochemical aptasensor is simple, rapid (the whole detection period for a thrombin sample is less than 35 min), sensitive and highly specific, it shows promising potential in protein detection and disease diagnosis.

Anti-thrombotic activity and chemical characterization of steroidal saponins from Dioscorea zingiberensis C.H. Wright.

Steroidal saponins have long attracted scientific attention, due to their structural diversity and significant biological activities. Total steroidal saponins (TSS) extracted from the rhizomes of Dioscorea zingiberensis C.H. Wright (DZW) constitute an effective treatment for cardiovascular disease. However, the active constituents contained in DZW rhizomes and their pharmacological properties are not fully understood. The aim of this work is to determine and quantify the active constituents in DZW rhizomes using fingerprint technique, and evaluate its anti-thrombotic activity using inferior vena cava ligation thrombosis rat model and pulmonary thrombosis mice model after being gavaged with TSS for 1 or 2weeks. In the study, a chemical fingerprint method was firstly established and validated to quantify and standardize TSS from DZW rhizomes including parvifloside, protodeltonin, protodioscin, protogracillin, zingiberensis saponin, deltonin, dioscin and trillin. TSS extracted from DZW rhizomes were showed to have the inhibitions on platelet aggregation (PAG) and thrombosis, and prolong activated partial thromboplastin time (APTT), thrombin time (TT), and prothrombin time (PT) in a dose-dependent manner in rats. TSS also prolonged the bleeding time and clotting time in a dose-dependent manner in mice. The results indicate that TSS could inhibit thrombosis by both improving the anticoagulation activity and inhibiting PAG action, suggesting that TSS from DZW rhizomes have the potential to reduce the risk of cardiovascular diseases by anti-thrombotic action.

Structures and magnetism of azide- and carboxylate-bridged metal(II) systems derived from 1,2-bis(N-carboxymethyl-4-pyridinio)ethane.

Four coordination polymers of different transition metal ions with azide and the zwitterionic dicarboxylate ligand 1,2-bis(N-carboxymethyl-4-pyridinio)ethane (bcpe) were synthesized, and structurally and magnetically characterized. They are formulated as [M(2)(bcpe)(N(3))(4)].H(2)O (M = Mn, 1; Co, 2; and Ni, 3) and [Cu(3)(bcpe)(N(3))(6)].(H(2)O)(2) (4). In the isomorphous compounds , octahedral metal ions are linked by the mixed (micro(2)-syn,syn-COO)(mu(2)-EO-N(3))(2) triple bridges (EO = end-on) to give anionic uniform chains, which are cross-linked by the cationic bis(pyridinium) spacers to produce two-dimensional coordination layers. Magnetic studies demonstrated that the magnetic coupling through the mixed triple bridge is antiferromagnetic in the Mn(ii) compound (1) but ferromagnetic in the Co(ii) and Ni(ii) species (2 and 3). Compound 4 also consists of two-dimensional coordination layers in which Cu(ii) chains are interlinked by the organic spacers, but the chain has mixed mu(2)-EO-azide, mu(3)-EO-azide and mu(2)-O(carboxylate) bridges and features tetranuclear dicubane-based units sharing Cu ions or alternatively linear trinuclear units connected by long axial Cu-N/O bonds. Magnetic studies suggested that the Cu(ii) ions linked by the double azide bridges in the equatorial-equatorial fashion are strongly coupled to give a ferromagnetic S = 3/2 ground state for the trinuclear units, with very weak antiferromagnetic interactions through the equatorial-axial bridges between the units.

Tetra-aqua-diazido-cobalt(II) 3,3'-dicarb-oxy-l-ato-1,1'-ethyl-enedipyridinium.

The asymmetric unit of the title compound, [Co(N(3))(2)(H(2)O)(4)]·C(14)H(12)N(2)O(4), comprises half of the cobalt(II) complex mol-ecule and a half of the 3,3'-dicarboxyl-ato-1,1'-ethyl-enedipyridinium mol-ecule. The Co(II) atom is located on an inversion centre and hence the complex mol-ecule adopts a centrosymmetric trans-octa-hedral geometry. The zwitterionic organic mol-ecule is also centrosymmetric with the centre of the C-C bond of the ethyl-ene moiety coinciding with an inversion centre. The adduct of metal complex and organic mol-ecule is associated into a three-dimenional network through O-H⋯O hydrogen bonds.

Spectroscopic studies on the interaction between nicotinamide and bovine serum albumin.

The interaction of nicotinamide (NA) and bovine serum albumin (BSA) was studied by fluorescence and absorption spectroscopy at different temperatures. The results revealed that NA caused the fluorescence quenching of BSA through a static quenching procedure. The binding constants K(A), and the number of binding sites n, corresponding thermodynamic parameters DeltaG, DeltaH, DeltaS between NA and BSA at different temperatures were calculated. The primary binding pattern between NA and BSA was interpreted as hydrophobic interaction. In addition, the effect of NA on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy. The binding average distance, r between the donor (BSA) and acceptor (NA) was determined based on the Förster's theory and it was found to be 3.1 nm.