[Investigate of the etiology and prevention status of liver cirrhosis].

Objective: To investigate the etiology, prevention and treatment status, and their corresponding regional differences of the patients with liver cirrhosis in China, in order to provide scientific basis for the development of diagnosis and control strategies in China. Methods: Clinical data of patients diagnosed with liver cirrhosis for the first time through January 1, 2018 to December 31, 2020 from 50 hospitals in seven different regions of China were collected and analyzed retrospectively, and the difference of etiology, treatment, and their differences in various regions were analyzed. Results: A total of 11 861 cases with liver cirrhosis were included in the study. Thereinto, 5 093 cases (42.94%) were diagnosed as compensated cirrhosis, and 6 768 cases (57.06%) had decompensated cirrhosis. Notably, 8 439 cases (71.15%) were determined as chronic hepatitis B-caused cirrhosis, 1 337 cases (11.27%) were alcoholic liver disease, 963 cases (8.12%) were chronic hepatitis C, 698 cases (5.88%) were autoimmune liver disease, 367 cases (3.09%) were schistosomiasis, 177 cases (1.49%) were nonalcoholic fatty liver, and 743 cases (6.26%) of other types of liver disease. There were significant differences in the incidence of chronic hepatitis B, chronic hepatitis C, alcoholic liver disease, fatty liver, schistosomiasis liver disease, and autoimmune liver disease among the seven regions (P<0.001). Only 1 139 cases (9.60%) underwent endoscopic therapy, thereinto, 718 cases (6.05%) underwent surgical therapy, and 456 cases (3.84%) underwent interventional therapy treatment. In patients with compensated liver cirrhosis, 60 cases (0.51%) underwent non-selective ß receptor blockers(NSBB), including 59 cases (0.50%) underwent propranolol and 1 case (0.01%) underwent carvedilol treatment. In patients with decompensated liver cirrhosis, 310 cases (2.61%) underwent NSBB treatment, including 303 cases (2.55%) underwent propranolol treatment and 7 cases (0.06%) underwent carvedilol treatment. Interestingly, there were significant differences in receiving endoscopic therapy, interventional therapy, NSBB therapy, splenectomy and other surgical treatments among the seven regions (P<0.001). Conclusion: Currently, chronic hepatitis B is the main cause (71.15%) of liver cirrhosis in several regions of China, and alcoholic liver disease has become the second cause (11.27%) of liver cirrhosis in China. The three-level prevention and control of cirrhosis in China should be further strengthened.

Magnetic resonance imaging in determination of myocardial ischemia and viability: comparison with positron emission tomography and single-photon emission computed tomography in a porcine model.

BACKGROUND: In patients with chronic left ventricular dysfunction, the size of the viable cardiac muscle is correlated with the prognosis and the outcome of myocardial revascularization. PURPOSE: To evaluate the diagnostic value of various imaging techniques in determination of myocardial ischemia and viability. MATERIAL AND METHODS: A chronic myocardial ischemia animal model was established, in which 10 pigs underwent magnetic resonance imaging (MRI), positron emission tomography (PET), and single-photon emission computed tomography (201Tl SPECT) before and 1-2 months after modeling. The size of myocardial ischemia and necrosis was judged, and the imaging manifestations were compared with pathologic findings. RESULTS: Seven of the 10 animals completed all examinations uneventfully. On dobutamine-stressed cine MRI, 10 (8.93%) segments were found to be akinetic. Perfusion was abnormal in 34 (30.35%) segments. Delayed hyperenhancement was observed in 12 (10.71%) segments. PET detected myocardial necrosis in 17 (15.18%) segments, and SPECT detected myocardial necrosis in nine (8.04%) segments. Histological examination with triphenyltetrazolium chloride (TTC) showed pale necrosis in 14 (12.50%) segments. The number of necrotic segments detected by PET was significantly greater than that by contrast-enhanced MRI (chi2 = 5, P = 0.0253, kappa = 0.8028) and cine MRI (chi2 = 7, P = 0.0082, kappa = 0.7079). It was also greater than that by TTC (chi2 = 3, P = 0.0833, kappa = 0.8879), although the difference was statistically insignificant. The number of necrotic segments detected by SPECT was significantly smaller than that by TTC (chi2 = 5, P = 0.0253, kappa = 0.7590), as was the number of necrotic segments detected by cine MRI (chi2 = 4, P = 0.0455, kappa = 0.8100). There was no statistically significant difference in the detection of necrotic segments between contrast-enhanced MRI and TTC (chi2 = 2, P = 0.1573, kappa = 0.9130). CONCLUSION: Cardiac MRI can determine viable myocardium and clearly delineate the location and degree of myocardial necrosis. PET slightly overestimates the extent of the necrotic myocardium and is unable to distinguish transmural necrosis from subendocardial necrosis.

Self-assembly with postmodification: kinetically stabilized metalla-supramolecular rectangles.

Interaction of a predesigned molecular "clip" (4) with rigid dipyridyl bridging ligands, in acetone/water mixtures, leads to the formation of molecular rectangles (5-8) in 92-97% isolated yields via spontaneous self-assembly. Characterization was accomplished with multinuclear NMR and UV-vis spectroscopy, FAB mass spectrometry, and X-ray crystallography. The length of these metallamacrocycles ranges from 2 to 3 nm. Postmodification via non-nucleophilic counterion exchange results in enhanced structural integrity for the assemblies.

Direct and simultaneous determination of copper, chromium, aluminum, and manganese in urine with a multielement graphite furnace atomic absorption spectrometer.

A simple method was developed for the direct and simultaneous determination of copper, chromium, aluminum, and manganese in urine using a multielement GFAAS (Perkin-Elmer SIMAA6000). Pd was used as the chemical modifier along with a special purge gas (5% H2 in Ar). A simple calibration curve method can be used (with 1:1 dilution). A standard reference material (Seronorm Trace Elements Urine) was used to find the optimal temperature program and to confirm the accuracy of the technique. The analyzed values were within 90-110% of the certified values. The relative standard deviations were 1.7, 1.5, 1.6, and 1.5% for these four elements and the detection limits were 0.08 microg L(-1) for Cu, 0.05 microg L(-1) for Cr, 0.06 microg L(-1) for Al, and 0.06 microg L(-1) for Mn. The recoveries of Cu, Cr, Al, and Mn from real urine samples were 100 +/- 5%, except for Cu (80%). The found values of Cu, Cr, Al, and Mn in a real urine sample were 14.3, 0.78, 18.9, and 0.06 microg L(-1), respectively. Scanning electron micrographs were used to investigate the physical form of Pd on the surface of the platform in the graphite furnace. Use of 5% H2 in Ar as the purge gas resulted in smaller and more uniformly distributed Pd particles (Pd particle diameters 0.4-0.6 microm using 5% H2 in Ar compared to 0.4-1.2 microm using pure Ar), increasing the effect of the Pd chemical modifier and promoting the efficiency of atomization.

Direct determination of cadmium and copper in seawater using a transversely heated graphite furnace atomic absorption spectrometer with Zeeman-effect background corrector.

Methods for the direct determination of copper and cadmium in seawater were described using a graphite furnace atomic absorption spectrometer (GFAAS) equipped with a transversely heated graphite atomizer (THGA) and a longitudinal Zeeman effect background corrector. Ammonium nitrate was used as the chemical modifier to determine copper. The mixture of di-ammonium hydrogen phosphate and ammonium nitrate was used as the chemical modifier to determine cadmium. The matrix interference was removed completely so that a simple calibration curve method could be applied. This work is the first one with the capability of determining cadmium in unpolluted seawater directly with GFAAS using calibration curve based on simple aqueous standards. The accuracy of the methods was confirmed by analysis of three kinds of certified reference saline waters. The detection limits (LODs), with injection of a 20-mul aliquot of seawater sample, were 0.06 mug l(-1) for copper and 0.005 mug l(-1) for cadmium.

Highly oxygenated pseudopterane and cembranolide diterpenes from the Caribbean sea feather Pseudopterogorgia bipinnata.

A chemical study of the sea feather Pseudopterogorgia bipinnata from Colombia has produced four known metabolites, namely, kallolide A (1), bipinnatin A (2), bipinnatin C (3), and bipinnatin J (4), in addition to nine previously undescribed diterpenes possessing an uncommonly high level of oxygenation. One of them, bipinnapterolide A (5), is a new representative of the pseudopterane family of diterpenes possessing the rare 2,3-epoxy-1,4-dione moiety. The other metabolites, bipinnatins G-I (6-8) and bipinnatolides F-J (9-13), are highly oxygenated cembranolide diterpenes. Their chemical structures including relative stereochemistry were established by detailed analysis of the spectral data in addition to X-ray diffraction analysis and NMR spectral comparisons with known pseudopterane and cembranolide models.

Dichlorobis(1-methyl-1H-benzimidazole-N3)-cobalt(II).

The metal atom in the title complex, [CoCl2(C8H8N2)2], has a slightly distorted tetrahedral coordination involving two Cl- ions and two N atoms from the aromatic groups. The dihedral angle between the planes of the two 1-methylbenzimidazole ligands is 117.7 (7) degrees.

A potassium sodium double salt of metavanadate, KNa(VO3)2.

Potassium sodium metavanadate, KNa(VO3)2, crystallizes with the pyroxene structure and is made up of VO4 tetrahedral chains, NaO6 octahedra and KO8 dodecahedra. The chains of corner-sharing VO4 tetrahedra are crosslinked through the NaO6 octahedra and KO8 dodecahedra to form a three-dimensional structure with the K+ and Na+ cations, which lie on twofold axes, situated in the void space. The coordination around the Na+ ion is close to normal octahedral, while the O atoms coordinated to the K+ ion are arranged approximately in a dodecahedral fashion.

(C2H10N2)[Co(H2O)6](HPO4)2: a supramolecular three-dimensional hydrogen-bonding network.

The title compound, ethylenediammonium hexaaquacobalt bis(hydrogenphosphate), consists of [Co(H2O)6]2+ and [enH2]2+ cations (en is ethylenediamine), and [HPO4]2- anions interconnected by an extensive intermolecular three-dimensional hydrogen-bonding network. The [enH2]2+ cations play an important role in the templating effect. Both [Co(H2O)6]2+ cations are situated on inversion centers. The average Co-O and P-O bond distances are 2.075 (6) and 1.54 (2) A, respectively.

Determination of hydroxyaromatic compounds in water by solid-phase microextraction coupled to high-performance liquid chromatography.

Solid-phase microextraction (SPME) coupled with high-performance liquid chromatography (HPLC) for the analysis of hydroxyaromatic compounds is described. Three kinds of fibers [50 microns carbowax-templated resin (CW-TPR), 60 microns polydimethylsiloxane-divinylbenzene (PDMS-DVB) and 85 microns polyacrylate (PA) fibers] were evaluated. CW-TPR and PDMS-DVB were selected for further study. The parameters of the desorption procedure (such as desorption mode, the composition of the solvent for desorption and the duration of fiber soaking) were studied and optimized. The effect of the structure and physical properties of analytes, carryover, duration of absorption, temperature of absorption, pH and ionic strength of samples were also investigated. The method was applied to environmental samples (lake water) using a simple calibration curve.

Determination of organophosphorus pesticides in water by solid-phase microextraction.

A solid-phase microextraction method coupled with a flame photometric detector was developed for the analysis of organophosphorus pesticides in water. Two kinds of fiber (100 mum polydimethyl siloxane (PDMS) and 85 mum polyacrylate (PA) fibers) were used and compared. Parameters that may affect the extraction, such as the duration of absorption and desorption, temperature of absorption, ionic strength, elutropic strength, and concentration of humic acid were investigated. Higher sensitivity and lower detection limits were achieved using a PA fiber than using a PDMS fiber. The detection limit is less than 0.3 mug l(-1) for most of the analytes, except for mevinphos (420 mug l(-1)). The precision is better than 9%.

N-borane-N-(trimethylsilyl)morpholine.

The title compound, C7H20BNOSi, features an N,N-disubstituted six-membered morpholine ring in a chair conformation, with the trimethylsilyl group in the equatorial position and the borane group in the axial position. The least-squares plane formed by the four C atoms of the morpholine ring has a mean deviation of 0.013 (2) A. The O and N atoms are 0.672 (2) and 0.650 (2) A above and below the plane, respectively.

Methoxyamericanolide B.

The title compound, C16H20O5, was isolated from the gorgonian coral P. americana found in the Caribbean zone of the West Indies. The compound belongs to a well known family of sesquiterpenoid lactones. Its structure features a guaiane skeleton incorporating three types of oxygen functionalities. Thus, the five O atoms that are incorporated in the skeleton form two epoxy groups, a lactone moiety and an ether link. This study assigns the relative stereochemistry at the six chiral centers as 1R, 2R, 4S, 5S, 8R, 10S.

Erythro-1-(benzothiazol-2-yl)-1,2-dibromo-2-(2-chloro-5-nitrophenyl)ethane.

The title compound, C15H9Br2CIN2O2S, was synthesized by electrophilic addition of bromine to 2-(2-chloro-5-nitrostyryl)benzothiazole. The molecule consists of benzothiazole and 2-chloro-5-nitrophenyl rings linked by a 1,2-dibromoethane moiety. The dihedral angle between the benzothiazole and phenyl rings is 8.2(9) degrees. The benzothiazole ring is planar with a mean deviation of 0.168(7)A. The Br1--C8 and Br2--C9 bond distances are 1.972(5) and 2.007(6)A, respectively.

N-(o-tolyl)-2-bromo-4,5-dimethoxybenzamide.

The molecular structure of the title compound, C16H16BrNO3, consists of 2-bromo-4,5-dimethoxy-benzene and o-methylphenyl rings linked by an amide group. The two methoxy groups are almost coplanar with the phenyl ring.

(NH4)8[Ce2(SO4)8].4H2O.

Crystals of the title compound, octaammonium dicerium octasulfate tetrahydrate, suitable for X-ray work, were prepared by a hydrothermal reaction. The structure is made up of [Ce2(SO4)8]8- anions, interacting with the crystallization waters and the NH4+ cations through hydrogen bonds. The CeIV atom in the [Ce2(SO4)8]8- anion is ninefold coordinated by O atoms belonging to sulfate groups. The coordination polyhedron is a somewhat distorted tricapped trigonal prism. The Ce-O distances range from 2.325(2) to 2.478(2) A.

(E,Z)-2-(2-chloro-5-nitrostyryl)-1-(1-propenyl)benzimidazole.

The title compound, C18H14ClN3O2, was synthesized by the condensation of 2-chloro-5-nitrobenzaldehyde with 2-methyl-1-propenylbenzimidazole, and the molecule comprises a 2-chloro-5-nitrobenzene and a 1-(Z)-propenylbenzimidazole. The two aromatic moieties are conjugated through the vinyl group. The dihedral angle between the two rings is 1.4(6) degrees. The propenyl group lies out of the benzimidazole plane with a dihedral angle of 112.9(9) degrees.

1-(1,3-Benzothiazol-2-yl)-2-(2-bromo-5-nitrophenyl)ethanone.

The title compound, C15H9BrN2O3S, was isolated as an unexpected product from the reaction of the anion of sodium 2-(1,3-benzothiazolyl)ethanonitrile with alpha,2-dibromo-5-nitrotoluene. Its structure features a benzothiazole fragment and a bromo- and nitro-substituted phenyl ring linked by a methyl ketone group. The dihedral angle between the benzothiazole and phenyl rings is 103.7 (2) degrees. The benzothiazole fragment is planar, with a maximum deviation of 0.021 (2) A. The nitro group is slightly rotated out of the phenyl-ring plane, with a O(2)-N(2)-C(14)-C(15) torsion angle of 16.4(7) degrees.

Bis[(E)-2-(2,4-dichloro-5-nitrostyryl)-1,3-benzothiazole] hydrate.

The title compound, bis[(E)-2-(2,4-dichloro-5-nitrostyryl)-1,3-benzothiazole] hydrate, 2C15H8Cl2N2O2S.-H2O, was obtained from the condensation of 2-methyl-benzothiazole with 2,4-dichloro-5-nitrobenzaldehyde. Single-crystal X-ray analysis showed that the asymmetric unit contains two crystallographically unique but structurally similar molecules. The dihedral angle between the benzothiazole fragment and the phenyl ring is 6.1 (4) degrees in molecule A and 19.5 (4) degrees in molecule B.

Euniciniatin.

Euniciniatin [4(S),7(R)-epoxy-3(R)-hydroxy-1(R),11(S) -dolabella-8(Z),12(18)-dien-13-one; (1R,3R,4S,7R,11S) -3-hydroxy-12-isopropylidene-15-oxa-1,4,8-trimethyltricyclo [9.3.0.1(4,7)]pentadec-8(Z)-3n-13-one], C20H30O3, was synthesized from a known dolabellane constituent of E. laciniata, namely, dolabellatrienone. The structure of this compound has a trans-bicyclo[9.3.0]tetradecane nucleus containing an additional 4,7-oxa bridge. The three O atoms in the molecule all belong to different functional groups, i.e. one is part of an ether bridge [O(3)-C(4) 1.452 (5) and O(3)-C(7) 1.429 (5) A], one an alcohol [O(2)-C(3) 1.429 (6) A] and one a ketone [O(1)-C(13) 1.233 (5) A].