Perovskite solar cell has gained widespread attention as a promising technology for renewable energy.However, their commercial viability has been hampered by their long-term stability and potential Pb leakage. Herein,...Perovskite solar cell has gained widespread attention as a promising technology for renewable energy.However, their commercial viability has been hampered by their long-term stability and potential Pb leakage. Herein, we demonstrate a bifunctional passivator of the potassium tartrate(PT) to address both challenges. PT minimizes the Pb leakage in perovskites and also heals cationic vacancy defects, resulting in improved device performance and stability. Benefiting from PT modification, the power conversion efficiency(PCE) is improved to 23.26% and the Pb leakage in unencapsulated films is significantly reduced to 9.79 ppm. Furthermore, the corresponding device exhibits no significant decay in PCE after tracking at the maximum power point(MPP) for 2000 h under illumination(LED source, 100 mW cm^(-2)).展开更多
Effect of various counterions of tartrate on the crystallization of calcium oxalate in gel system was investigated using scanning electron microscopy and X-ray diffraction. Various tartrates with hydrogen (H2tart), ...Effect of various counterions of tartrate on the crystallization of calcium oxalate in gel system was investigated using scanning electron microscopy and X-ray diffraction. Various tartrates with hydrogen (H2tart), sodium (Na2tart), potassium (K2tart), ammonium ((NH4)2tart), and a mixture of sodium and potassium cations (NaKtart) were considered. For H2tart, Na2tart, and (NH4)2tart, calcium oxalate dihydrate (COD) was induced. However, for K2tart and NaKtart, calcium oxalate trihydrate (COT) was obtained.展开更多
To compare the effects and adverse reactions of dihydrocodeine tartrate andcodeine phosphate in treating moderate cancer pain. Methods: Sixty-nine cases of cancer patientswith moderate pain were treated with dihydroco...To compare the effects and adverse reactions of dihydrocodeine tartrate andcodeine phosphate in treating moderate cancer pain. Methods: Sixty-nine cases of cancer patientswith moderate pain were treated with dihydrocodeine tartrate or codeine phosphate respectively bydouble-blind, controlled randomized methods and the effects and adverse reactions were observed.Results: After administration of dihydrocodeine tartrate or codeine phosphate, in treatment group orcontrol group, the total effective rate was 86.6% and 93.6%, and common adverse symptoms includedconstipation (31.3%/12.9%), nausea (18.8%/19.7%), gastric trouble (18.8%/19.7%), skin pruritus(12.5%/10%), vomit (9.3% and 6.5%) with the difference being not significant. Conclusion: Theeffects of dihydrocodeine tartrate in treating moderate cancer pain are similar to codeinephosphate. Both them can be used to treat moderate cancer pain.展开更多
The current United States Pharmacopeia–National Formulary(USP–NF) includes more than 250 monographs of fixed dose combinations(FDCs), and some of them need to be updated due to incompleteness of impurity profiles an...The current United States Pharmacopeia–National Formulary(USP–NF) includes more than 250 monographs of fixed dose combinations(FDCs), and some of them need to be updated due to incompleteness of impurity profiles and obsolescence of analytical methodologies. A case study of metoprolol tartrate and hydrochlorothiazide tablets is presented to summarize challenges encountered during the USP monograph modernization initiative of FDCs and to highlight an "adoption and adaptation" approach employed for method development. To this end, a single stability-indicating HPLC method was developed to separate the two drug substances and eight related compounds with resolution 2.0 or higher between all critical pairs. Chromatographic separations were achieved on a Symmetry column(C18,100 mm*4.6 mm, 3.5 mm) using sodium phosphate buffer(pH 3.0; 34 mM) and acetonitrile as mobile phase in a gradient elution mode. The stability-indicating capability of this method has been demonstrated by analyzing stressed samples of the two drug substances. The developed HPLC method was validated for simultaneous determination of metoprolol tartrate and hydrochlorothiazide and relevant impurities in the tablets. Moreover, the developed method was successfully applied to the analysis of commercial tablet dosage forms and proved to be suitable for routine quality control use. The case study could be used to streamline USP's monograph modernization process of FDCs and strengthen compendial procedures.展开更多
An ionic conductivity prediction equation at low concentration for two acid salts is proposed taking into account the dissociation and association equilibria among ions. The salts considered are sodium and potassium h...An ionic conductivity prediction equation at low concentration for two acid salts is proposed taking into account the dissociation and association equilibria among ions. The salts considered are sodium and potassium hydrogen tartrates. There is no additional parameter of high order terms except for the Onsager's coefficient of limited term in the new equation. Results show a complex conductance of acidic tartrates in aqueous solution. The molar conductivities of metal ions are nearly constant such that the contributions from hydrogen and tartrate ions decrease with concentration, while the molar conductivity of bitartrate ion increases with concentration.展开更多
The coordination structure of cupric tartrate(Cu−TA)complex was investigated by ultraviolet−visible(UV-Vis)and liquid chromatography/mass spectrometer(LC-MS)firstly;furthermore,effective coordination configurations an...The coordination structure of cupric tartrate(Cu−TA)complex was investigated by ultraviolet−visible(UV-Vis)and liquid chromatography/mass spectrometer(LC-MS)firstly;furthermore,effective coordination configurations and electronic properties of Cu−TA in aqueous solution were systematically revealed by density functional theory(DFT)calculations.Consistently,Job plots show the possible existence of[Cu(TA)]and[Cu(TA)_(2)]^(2-)at 230 and 255 nm based on UV-Vis results.LC-MS results confirm the existence of the single and high coordination complexes[Cu_(2)(TA)_(2)]^(+),[Cu(TA)_(2)]^(+)and[Cu_(2)(TA)_(3)(H_(2)O)_(2)(OH)_(2)]^(2+).DFT calculation results show that carboxylic oxygen and hydroxyl oxygen of tartaric acid(TA)are preferred sites for Cu(Ⅱ)coordination.[Cu(TA)](1H,3H sites O of TA coordinated with Cu(Ⅱ)),[Cu(TA)_(2)]^(2-)(two 1^(C),2^(H) sites O of TA coordinated with Cu(Ⅱ)),and[Cu(TA)_(3)]^(4-)(three 2H,3H sites O of TA coordinated with Cu(Ⅱ))should be dominant coordination configurations of Cu−TA.The corresponding Gibbs reaction energies are-170.1,-136.2,and-90.2 kJ/mol,respectively.展开更多
Two new tartrate derivative glucosides, coelovirin C (1) and D (2), were isolated from rhizomes of Coeloglossum viride ( L.) Hartm. var. bracteatum ( Willd.) Richter (Orchidaceae). Their structures were elucidated as ...Two new tartrate derivative glucosides, coelovirin C (1) and D (2), were isolated from rhizomes of Coeloglossum viride ( L.) Hartm. var. bracteatum ( Willd.) Richter (Orchidaceae). Their structures were elucidated as (2R, 3S)-2-b-D-glucopyranosyl-2-isobutyltartrate1-(4-b-D- glucopyranosyloxybenzyl) ester 1 and (2R, 3S)-2-b-D-glucopyranosyl-2-isobutyltartrate-4-(4-b-D- glucopyranosyloxybenzyl) ester 2 by means of chemical and spectroscopic methods.展开更多
To develop suitable nicotine derivatives for potential use in next generation tobacco products,mixtures of nicotine with tartaric acid were prepared.The prepared freeze-dried product was a white powder with good water...To develop suitable nicotine derivatives for potential use in next generation tobacco products,mixtures of nicotine with tartaric acid were prepared.The prepared freeze-dried product was a white powder with good water solubility.The structure of nicotine tartrate was evaluated with X-ray powder diffraction,near infrared diffuse reflectance spectroscopy and solid-state Nuclear Magnetic Resonance(ss-NMR).The crystal structure of nicotine tartrate was analyzed by single-crystal X-ray diffraction.According to the obtained atomic coordinates,equivalent temperature factor,bond length and torsion angles,the chemical formula of nicotine tartrate was proposed as 2(C4H5O6)· C10H16N2·H2O.The relative molecular mass was 480.42,and the crystal density was 1.501 mg/m^3 The crystal structure of nicotine tartrate belongs to the orthorhombic system and the monoclinic space group is P212121.Nicotine tartrate was used in gum-based chewing tobacco to substitute pure nicotine,which showed a sustained nicotine release when compared to traditional ultrafine tobacco powder as assessed by an in situ dissolution method.展开更多
This work intends to investigate the inhibition behaviour of 2-butine 1, 4diol and potassium sodium tartrate and their synergistic effects on 3003 aluminium alloy corrosion in 0.5% NaCl solution. Experiments were carr...This work intends to investigate the inhibition behaviour of 2-butine 1, 4diol and potassium sodium tartrate and their synergistic effects on 3003 aluminium alloy corrosion in 0.5% NaCl solution. Experiments were carried out by electrochemical impedance spectroscopy (EIS) and Tafel polarization method in a three-electrode cell. It was concluded that the inhibition efficiencies increased with an increase in the concentrations of inhibitors. For 2-butinel, 4diol and tartrate salt, the optimum in the inhibition efficiency, at room temperature and neutral pH, was observed for concentrations close to 10-3 mol/L and 1.5×10^-3mol/L, respectively. The electrochemical results illustrated that 2-butinel, 4diol and tartrate salt, have significant synergistic inhibition effects on corrosion of 3003 aluminium alloy in 0.5% NaCl solution. The optimum ratio of concentrations for tartrate to alcohol was 2:1.展开更多
The single crystals of the title compound NH4+C4H5O6- (C4H9NO6, Mr = 167.1) were obtained from a hot aqueous solution containing L-glutamine and D,L-tartaric acid in mole ratio1:1.5. The crystal belongs to monoclinic ...The single crystals of the title compound NH4+C4H5O6- (C4H9NO6, Mr = 167.1) were obtained from a hot aqueous solution containing L-glutamine and D,L-tartaric acid in mole ratio1:1.5. The crystal belongs to monoclinic space group P21/c with a = 7.646(2), b = 7.804(2), c = 11.502(3)? ?= 102.26(2)o, V = 670.7(3)?, Z = 4, F(000) = 352, Dc = 1.655 g.cm-3, m(MoKa) = 0.16 mm-1, R = 0.035, wR = 0.094 for 1028 observed reflections (I>2s(I)). The enatiomeric anions of the tartrate with both (2S,3S)- and (2R,3R)-configuration co-exist in the unit cell. The carbon skeleton assumes a coplanar arrangement with a torsion angle of 181.5o. The three- dimensional H-bonding network exists in the crystal. While tartrate groups link each other by H-bonds between carboxyl and hydroxyl groups, the ammonium cations insert between the tartrate groups to form a sandwich-like crystal structure.展开更多
Experiments performed on the grwth of mixed crystals of rare earth tartrates (Y1-xSmx)2 (C4H4O6)3.zH2O (0≤x≤1) from silica gels at 35~40℃ and 25~30℃ employing single-diffusion technique. are discussed. The crysta...Experiments performed on the grwth of mixed crystals of rare earth tartrates (Y1-xSmx)2 (C4H4O6)3.zH2O (0≤x≤1) from silica gels at 35~40℃ and 25~30℃ employing single-diffusion technique. are discussed. The crystals maintain spherulitic morphology, irrespective of the value of x, concentration of upper and lower reactants, gel pH, gel age and gel temperature. Formation Of Liesegang rings in this system is a temperature dependent phenomenon. It is shown that with the increase of the value of x the system passes from Liesegangring phenomenon to singlezone phenomenon. Operative mechanism of crystallization in the higher (35~40℃) and lower temperature ranges (25~30℃) is explained. Seeded growth experiments indicate the possibility of increasing the size of the spherulites in the gel medium展开更多
L0-(+)-diethyl tartrate was bound to hydroxymethyl polystyrene bead as a chiral stationaryphase in high-performance liquid chromatography(HPLC) for the resolution of pharmaceuticallyracemic compounds, such as D,L-amyg...L0-(+)-diethyl tartrate was bound to hydroxymethyl polystyrene bead as a chiral stationaryphase in high-performance liquid chromatography(HPLC) for the resolution of pharmaceuticallyracemic compounds, such as D,L-amygdalic acid, D,L-brufen, and D,L-phenylephrine in an isocraticelution mode.展开更多
Objective: To analyze the effect and advantages in analgesia and sedation of butorphanol tartrate combined with dexmedetomidine in severe cerebral hemorrhage for patients with mechanical ventilation. Methods: 120 pati...Objective: To analyze the effect and advantages in analgesia and sedation of butorphanol tartrate combined with dexmedetomidine in severe cerebral hemorrhage for patients with mechanical ventilation. Methods: 120 patients with severe cerebral hemorrhage requiring analgesia and sedation were randomly selected and divided into two groups: the control group (dexmedetomidine treatment group) and the test group (dexmedetomidine combined with butorphanol tartrate). Two groups of patients with different drugs were analyzed. Results: The average dose of dexmedetomidine (microgram) and the total adverse events (Times) in the test group were significantly lower than those in the control group within 48 hours (P < 0.05);The dose of Butorphanol in the test group was small, and the patients in the control group used other opioid analgesics to pump more significantly. Conclusion: Using butorphanol tartrate combined with dexmedetomidine can achieve the same sedative effect and enhance the analgesic effect as using dexmedetomidine alone with less dose of dexmedetomidine, and the clinical effect is significant. It also solves the problem that adverse reactions such as blood pressure change and bradycardia are easy to occur when using large dose of dexmedetomidine and the infusion speed is fast in clinical application, and significantly reduces the incidence of adverse reactions. It is worthy of clinical application.展开更多
Cerium tartrate(CeTar),produced in this study by precipitating cerium nitrate with potassium sodium tartrate(KNaTar),was examined as a corrosion inhibitor.Weight loss tests show inhibition efficiency of 71.7% with Ce(...Cerium tartrate(CeTar),produced in this study by precipitating cerium nitrate with potassium sodium tartrate(KNaTar),was examined as a corrosion inhibitor.Weight loss tests show inhibition efficiency of 71.7% with Ce(NO_(3))_(3) and 88.7% with CeTar inhibitor for one-month exposure to mild steel in 7 g/L NaCl solution.The inhibition efficiency drops to 28.6% with the fo rmer and remains around 8 7% with the latter inhibitor after six months of exposure.Similar results from electrochemical testing indicate that the inhibition efficiency decreases by adding cerium nitrate.Still,the cerium tartrate inhibitor demonstrates a nearly constant inhibition efficiency for up to 30 d,i.e.,≈90%.Electrochemical impedance spectroscopy(EIS) performed in these cases shows the following results:(ⅰ) with cerium nitrate,a film of iron and cerium oxide,which on prolonged exposure diminishes,and(ⅱ) with cerium tartrate,the formation of a bimetallic film(Fe-tartrate-Ce) and a mixture of cerium hydroxide and iro n oxide that protects steel for a longer duration.These inferences are based on the analyses of scanning electron microscopy/energydispersive X-ray analysis(SEM/EDAX),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron(XPS),and Raman spectroscopy results.展开更多
Aryloxypropanolamine is an essential structural scaffold for a variety of b-adrenergic receptor antagonists such as metoprolol.Molecules with such a structural motif tend to degrade into α,β ehydroxypropanolamine im...Aryloxypropanolamine is an essential structural scaffold for a variety of b-adrenergic receptor antagonists such as metoprolol.Molecules with such a structural motif tend to degrade into α,β ehydroxypropanolamine impurities via a radicaleinitiated oxidation pathway.These impurities are typically polar and nonchromophoric,and are thus often overlooked using traditional reversed phase chromatography and UV detection.In this work,stress testing of metoprolol confirmed the generation of 3-isopropylamino-1,2-propanediol as a degradation product,which is a specified impurity of metoprolol in the European Pharmacopoeia(impurity N).To ensure the safety and quality of metoprolol drug products,hydrophilic interaction chromatography(HILIC)methods using Halo Penta HILIC column(150mm×4.6 mm,5 μm)coupled with charged aerosol detection(CAD)were developed and optimized for the separation and quantitation of metoprolol impurity N in metoprolol drug products including metoprolol tartrate injection,metoprolol tartrate tablets,and metoprolol succinate extended-release tablets.These HILIC-CAD methods were validated per USP validation guidelines with respect to specificity,linearity,accuracy,and precision,and have been successfully applied to determine impurity N in metoprolol drug products.展开更多
基金funding support from the National Natural Science Foundation of China (52172182, 21975028, 22011540377, 22005035, U21A20172)。
文摘Perovskite solar cell has gained widespread attention as a promising technology for renewable energy.However, their commercial viability has been hampered by their long-term stability and potential Pb leakage. Herein, we demonstrate a bifunctional passivator of the potassium tartrate(PT) to address both challenges. PT minimizes the Pb leakage in perovskites and also heals cationic vacancy defects, resulting in improved device performance and stability. Benefiting from PT modification, the power conversion efficiency(PCE) is improved to 23.26% and the Pb leakage in unencapsulated films is significantly reduced to 9.79 ppm. Furthermore, the corresponding device exhibits no significant decay in PCE after tracking at the maximum power point(MPP) for 2000 h under illumination(LED source, 100 mW cm^(-2)).
基金granted by the Key Project of Guangdong Province(013202,C31401)the Key Project of Natural Science Foundation of China(20031010)
文摘Effect of various counterions of tartrate on the crystallization of calcium oxalate in gel system was investigated using scanning electron microscopy and X-ray diffraction. Various tartrates with hydrogen (H2tart), sodium (Na2tart), potassium (K2tart), ammonium ((NH4)2tart), and a mixture of sodium and potassium cations (NaKtart) were considered. For H2tart, Na2tart, and (NH4)2tart, calcium oxalate dihydrate (COD) was induced. However, for K2tart and NaKtart, calcium oxalate trihydrate (COT) was obtained.
文摘To compare the effects and adverse reactions of dihydrocodeine tartrate andcodeine phosphate in treating moderate cancer pain. Methods: Sixty-nine cases of cancer patientswith moderate pain were treated with dihydrocodeine tartrate or codeine phosphate respectively bydouble-blind, controlled randomized methods and the effects and adverse reactions were observed.Results: After administration of dihydrocodeine tartrate or codeine phosphate, in treatment group orcontrol group, the total effective rate was 86.6% and 93.6%, and common adverse symptoms includedconstipation (31.3%/12.9%), nausea (18.8%/19.7%), gastric trouble (18.8%/19.7%), skin pruritus(12.5%/10%), vomit (9.3% and 6.5%) with the difference being not significant. Conclusion: Theeffects of dihydrocodeine tartrate in treating moderate cancer pain are similar to codeinephosphate. Both them can be used to treat moderate cancer pain.
文摘The current United States Pharmacopeia–National Formulary(USP–NF) includes more than 250 monographs of fixed dose combinations(FDCs), and some of them need to be updated due to incompleteness of impurity profiles and obsolescence of analytical methodologies. A case study of metoprolol tartrate and hydrochlorothiazide tablets is presented to summarize challenges encountered during the USP monograph modernization initiative of FDCs and to highlight an "adoption and adaptation" approach employed for method development. To this end, a single stability-indicating HPLC method was developed to separate the two drug substances and eight related compounds with resolution 2.0 or higher between all critical pairs. Chromatographic separations were achieved on a Symmetry column(C18,100 mm*4.6 mm, 3.5 mm) using sodium phosphate buffer(pH 3.0; 34 mM) and acetonitrile as mobile phase in a gradient elution mode. The stability-indicating capability of this method has been demonstrated by analyzing stressed samples of the two drug substances. The developed HPLC method was validated for simultaneous determination of metoprolol tartrate and hydrochlorothiazide and relevant impurities in the tablets. Moreover, the developed method was successfully applied to the analysis of commercial tablet dosage forms and proved to be suitable for routine quality control use. The case study could be used to streamline USP's monograph modernization process of FDCs and strengthen compendial procedures.
基金Supported by the National Natural Science Foundation of China(No.29736170)
文摘An ionic conductivity prediction equation at low concentration for two acid salts is proposed taking into account the dissociation and association equilibria among ions. The salts considered are sodium and potassium hydrogen tartrates. There is no additional parameter of high order terms except for the Onsager's coefficient of limited term in the new equation. Results show a complex conductance of acidic tartrates in aqueous solution. The molar conductivities of metal ions are nearly constant such that the contributions from hydrogen and tartrate ions decrease with concentration, while the molar conductivity of bitartrate ion increases with concentration.
基金the National Key Research and Development Program of China(No.2019YFC0408303)the Natural Science Foundation of Hunan Province,China(No.2021JJ20069)+2 种基金the Changsha Science and Technology Project,China(Nos.kq2106016,kq2009005)Higher Education Discipline Innovation Project(111 Project),China(No.B14034)the Fundamental Research Funds for the Central Universities of Central South University,China(No.2021zzts0887).
文摘The coordination structure of cupric tartrate(Cu−TA)complex was investigated by ultraviolet−visible(UV-Vis)and liquid chromatography/mass spectrometer(LC-MS)firstly;furthermore,effective coordination configurations and electronic properties of Cu−TA in aqueous solution were systematically revealed by density functional theory(DFT)calculations.Consistently,Job plots show the possible existence of[Cu(TA)]and[Cu(TA)_(2)]^(2-)at 230 and 255 nm based on UV-Vis results.LC-MS results confirm the existence of the single and high coordination complexes[Cu_(2)(TA)_(2)]^(+),[Cu(TA)_(2)]^(+)and[Cu_(2)(TA)_(3)(H_(2)O)_(2)(OH)_(2)]^(2+).DFT calculation results show that carboxylic oxygen and hydroxyl oxygen of tartaric acid(TA)are preferred sites for Cu(Ⅱ)coordination.[Cu(TA)](1H,3H sites O of TA coordinated with Cu(Ⅱ)),[Cu(TA)_(2)]^(2-)(two 1^(C),2^(H) sites O of TA coordinated with Cu(Ⅱ)),and[Cu(TA)_(3)]^(4-)(three 2H,3H sites O of TA coordinated with Cu(Ⅱ))should be dominant coordination configurations of Cu−TA.The corresponding Gibbs reaction energies are-170.1,-136.2,and-90.2 kJ/mol,respectively.
文摘Two new tartrate derivative glucosides, coelovirin C (1) and D (2), were isolated from rhizomes of Coeloglossum viride ( L.) Hartm. var. bracteatum ( Willd.) Richter (Orchidaceae). Their structures were elucidated as (2R, 3S)-2-b-D-glucopyranosyl-2-isobutyltartrate1-(4-b-D- glucopyranosyloxybenzyl) ester 1 and (2R, 3S)-2-b-D-glucopyranosyl-2-isobutyltartrate-4-(4-b-D- glucopyranosyloxybenzyl) ester 2 by means of chemical and spectroscopic methods.
文摘To develop suitable nicotine derivatives for potential use in next generation tobacco products,mixtures of nicotine with tartaric acid were prepared.The prepared freeze-dried product was a white powder with good water solubility.The structure of nicotine tartrate was evaluated with X-ray powder diffraction,near infrared diffuse reflectance spectroscopy and solid-state Nuclear Magnetic Resonance(ss-NMR).The crystal structure of nicotine tartrate was analyzed by single-crystal X-ray diffraction.According to the obtained atomic coordinates,equivalent temperature factor,bond length and torsion angles,the chemical formula of nicotine tartrate was proposed as 2(C4H5O6)· C10H16N2·H2O.The relative molecular mass was 480.42,and the crystal density was 1.501 mg/m^3 The crystal structure of nicotine tartrate belongs to the orthorhombic system and the monoclinic space group is P212121.Nicotine tartrate was used in gum-based chewing tobacco to substitute pure nicotine,which showed a sustained nicotine release when compared to traditional ultrafine tobacco powder as assessed by an in situ dissolution method.
文摘This work intends to investigate the inhibition behaviour of 2-butine 1, 4diol and potassium sodium tartrate and their synergistic effects on 3003 aluminium alloy corrosion in 0.5% NaCl solution. Experiments were carried out by electrochemical impedance spectroscopy (EIS) and Tafel polarization method in a three-electrode cell. It was concluded that the inhibition efficiencies increased with an increase in the concentrations of inhibitors. For 2-butinel, 4diol and tartrate salt, the optimum in the inhibition efficiency, at room temperature and neutral pH, was observed for concentrations close to 10-3 mol/L and 1.5×10^-3mol/L, respectively. The electrochemical results illustrated that 2-butinel, 4diol and tartrate salt, have significant synergistic inhibition effects on corrosion of 3003 aluminium alloy in 0.5% NaCl solution. The optimum ratio of concentrations for tartrate to alcohol was 2:1.
文摘The single crystals of the title compound NH4+C4H5O6- (C4H9NO6, Mr = 167.1) were obtained from a hot aqueous solution containing L-glutamine and D,L-tartaric acid in mole ratio1:1.5. The crystal belongs to monoclinic space group P21/c with a = 7.646(2), b = 7.804(2), c = 11.502(3)? ?= 102.26(2)o, V = 670.7(3)?, Z = 4, F(000) = 352, Dc = 1.655 g.cm-3, m(MoKa) = 0.16 mm-1, R = 0.035, wR = 0.094 for 1028 observed reflections (I>2s(I)). The enatiomeric anions of the tartrate with both (2S,3S)- and (2R,3R)-configuration co-exist in the unit cell. The carbon skeleton assumes a coplanar arrangement with a torsion angle of 181.5o. The three- dimensional H-bonding network exists in the crystal. While tartrate groups link each other by H-bonds between carboxyl and hydroxyl groups, the ammonium cations insert between the tartrate groups to form a sandwich-like crystal structure.
文摘Experiments performed on the grwth of mixed crystals of rare earth tartrates (Y1-xSmx)2 (C4H4O6)3.zH2O (0≤x≤1) from silica gels at 35~40℃ and 25~30℃ employing single-diffusion technique. are discussed. The crystals maintain spherulitic morphology, irrespective of the value of x, concentration of upper and lower reactants, gel pH, gel age and gel temperature. Formation Of Liesegang rings in this system is a temperature dependent phenomenon. It is shown that with the increase of the value of x the system passes from Liesegangring phenomenon to singlezone phenomenon. Operative mechanism of crystallization in the higher (35~40℃) and lower temperature ranges (25~30℃) is explained. Seeded growth experiments indicate the possibility of increasing the size of the spherulites in the gel medium
文摘L0-(+)-diethyl tartrate was bound to hydroxymethyl polystyrene bead as a chiral stationaryphase in high-performance liquid chromatography(HPLC) for the resolution of pharmaceuticallyracemic compounds, such as D,L-amygdalic acid, D,L-brufen, and D,L-phenylephrine in an isocraticelution mode.
文摘Objective: To analyze the effect and advantages in analgesia and sedation of butorphanol tartrate combined with dexmedetomidine in severe cerebral hemorrhage for patients with mechanical ventilation. Methods: 120 patients with severe cerebral hemorrhage requiring analgesia and sedation were randomly selected and divided into two groups: the control group (dexmedetomidine treatment group) and the test group (dexmedetomidine combined with butorphanol tartrate). Two groups of patients with different drugs were analyzed. Results: The average dose of dexmedetomidine (microgram) and the total adverse events (Times) in the test group were significantly lower than those in the control group within 48 hours (P < 0.05);The dose of Butorphanol in the test group was small, and the patients in the control group used other opioid analgesics to pump more significantly. Conclusion: Using butorphanol tartrate combined with dexmedetomidine can achieve the same sedative effect and enhance the analgesic effect as using dexmedetomidine alone with less dose of dexmedetomidine, and the clinical effect is significant. It also solves the problem that adverse reactions such as blood pressure change and bradycardia are easy to occur when using large dose of dexmedetomidine and the infusion speed is fast in clinical application, and significantly reduces the incidence of adverse reactions. It is worthy of clinical application.
基金funding agency University Grants Commission (UGC),Government of India,for giving a fellowship and other financial assistance for her Ph.D.thesis study。
文摘Cerium tartrate(CeTar),produced in this study by precipitating cerium nitrate with potassium sodium tartrate(KNaTar),was examined as a corrosion inhibitor.Weight loss tests show inhibition efficiency of 71.7% with Ce(NO_(3))_(3) and 88.7% with CeTar inhibitor for one-month exposure to mild steel in 7 g/L NaCl solution.The inhibition efficiency drops to 28.6% with the fo rmer and remains around 8 7% with the latter inhibitor after six months of exposure.Similar results from electrochemical testing indicate that the inhibition efficiency decreases by adding cerium nitrate.Still,the cerium tartrate inhibitor demonstrates a nearly constant inhibition efficiency for up to 30 d,i.e.,≈90%.Electrochemical impedance spectroscopy(EIS) performed in these cases shows the following results:(ⅰ) with cerium nitrate,a film of iron and cerium oxide,which on prolonged exposure diminishes,and(ⅱ) with cerium tartrate,the formation of a bimetallic film(Fe-tartrate-Ce) and a mixture of cerium hydroxide and iro n oxide that protects steel for a longer duration.These inferences are based on the analyses of scanning electron microscopy/energydispersive X-ray analysis(SEM/EDAX),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron(XPS),and Raman spectroscopy results.
文摘Aryloxypropanolamine is an essential structural scaffold for a variety of b-adrenergic receptor antagonists such as metoprolol.Molecules with such a structural motif tend to degrade into α,β ehydroxypropanolamine impurities via a radicaleinitiated oxidation pathway.These impurities are typically polar and nonchromophoric,and are thus often overlooked using traditional reversed phase chromatography and UV detection.In this work,stress testing of metoprolol confirmed the generation of 3-isopropylamino-1,2-propanediol as a degradation product,which is a specified impurity of metoprolol in the European Pharmacopoeia(impurity N).To ensure the safety and quality of metoprolol drug products,hydrophilic interaction chromatography(HILIC)methods using Halo Penta HILIC column(150mm×4.6 mm,5 μm)coupled with charged aerosol detection(CAD)were developed and optimized for the separation and quantitation of metoprolol impurity N in metoprolol drug products including metoprolol tartrate injection,metoprolol tartrate tablets,and metoprolol succinate extended-release tablets.These HILIC-CAD methods were validated per USP validation guidelines with respect to specificity,linearity,accuracy,and precision,and have been successfully applied to determine impurity N in metoprolol drug products.