Unraveling Anionic Redox for Sodium Layered Oxide Cathodes: Breakthroughs and Perspectives.

Sodium-ion batteries (SIBs) as the next generation of sustainable energy technologies have received widespread investigations for large-scale energy storage systems (EESs) and smart grids due to the huge natural abundance and low cost of sodium. Although the great efforts are made in exploring layered transition metal oxide cathode for SIBs, their performances have reached the bottleneck for further practical application. Nowadays, anionic redox in layered transition metal oxides has emerged as a new paradigm to increase the energy density of rechargeable batteries. Based on this point, in this review, the development history of anionic redox reaction is attempted to systematically summarize and provide an in-depth discussion on the anionic redox mechanism. Particularly, the major challenges of anionic redox and the corresponding available strategies toward triggering and stabilizing anionic redox are proposed. Subsequently, several types of sodium layered oxide cathodes are classified and comparatively discussed according to Na-rich or Na-deficient materials. A large amount of progressive characterization techniques of anionic oxygen redox is also summarized. Finally, an overview of the existing prospective and the future development directions of sodium layered transition oxide with anionic redox reaction are analyzed and suggested.

Hyperaccumulation Route to Ca-Rich Hard Carbon Materials with Cation Self-Incorporation and Interlayer Spacing Optimization for High-Performance Sodium-Ion Batteries.

The hard carbon (HC) has been emerging as one of the most promising anode materials for sodium-ion batteries (SIBs). Incorporation of cations into the HC lattice proved to be effective to regulate their d-interlayer spacing with a modified SIB performance. However, the complexity and high cost of current synthetic processes limited its large-scale application in SIBs. Through the natural hyperaccumulation process, a cost-effective and scale-up-driven procedure to produce Ca-ion self-incorporated HC materials was proposed by applying tamarind fruits as the precursor with the enrichment of Ca ions. In virtue of one-step pyrolysis, the self-incorporated and well-distributed Ca ions in tamarind fruits had successfully served as the buffer layer to expand the d-interlayer spacing of HC materials. Furthermore, the natural porosity hierarchy could be largely preserved by the optimization of calcination temperature. As a result, the Ca-rich HC material had exhibited the optimized cycling performance (326.7 mA h g-1 at 50 mA g-1 and capacity retention rate of 89.40% after 250 cycles) with a high initial Coulombic efficiency of 70.39%. This work provided insight into applying the hyperaccumulation effect of biomass precursors to produce doped HC materials with ion self-incorporation and the optimized d-interlayer spacing, navigating its large-scale application for high-performance SIBs.

Suicidal ideation and attempted suicide amongst Chinese transgender persons: National population study.

BACKGROUND: This study aims to understand suicidal ideation and suicide attempts among transgender individuals through an in-depth analysis of a nation-wide population general survey in China. METHODS: Transgender Men (TM) and Women (TW) were investigated through a cross-sectional survey. A structured questionnaire was used to investigate participants' demographic information, perceived sexuality conflicts, childhood adversity and mental health conditions. Logistic regression models were utilized to investigate risk factors associated with suicidal ideation and suicide attempts in these groups. We also conducted a quasi-meta-analysis in order to compare the prevalence of suicidal ideation and attempted suicide between general and transgender populations in China. RESULTS: A total of 1309 participants across 32 provinces and municipalities in China took part in this survey, out of 2060 valid questionnaires. In this transgender population, the lifetime prevalence of suicidal ideation and an attempt at suicide were 56.4% and 16.1%, respectively. This estimated prevalence rate is far greater than in Chinese community samples. For all transgender people, disliking birth-assigned sex, seeking sex reassignment surgery, having intense conflicts with parents, lifetime history of suffering from major depressive disorder, a recent episode of depression, self-harm, and seeking mental health services were significantly associated with increased risk of suicidal ideation. An education level of high school or equivalent, being married and/or separated/divorced, having intense conflicts with parents, or self-harm and seeking mental health services were all significantly associated with increased risk of suicide attempt. Although most risk factors for TM and TW were equivalent across groups, differences were observed in both suicidal ideation and suicide attempt models. LIMITATIONS: The cross-sectional study design and lack of follow-up data are limitations of this study. CONCLUSIONS: This is the first study to examine suicide within a Chinese transgender population. The clinical implications of these findings for Chinese mental health professionals are discussed. Also, the evidence from this study can be used to inform the practices of suicide prevention workers, and policy makers working with the transgender population.

Chinese college freshmen's mental health problems and their subsequent help-seeking behaviors: A cohort design (2005-2011).

Based on cohort data obtained from 13,085 college freshmen's (2005 to 2011) SCL-90 (the Symptom Check-List-90) reports and their subsequent 4-year psychological counseling help-seeking records, this study examined the association between college students' mental health problems and help-seeking behaviors across four college years. Female students' mental health problems and help-seeking behaviors increased from the 2005 to the 2011 cohorts and no changes emerged for male students across cohorts. Overall, male students reported higher levels of mental health problems than did female students in the first college year, whereas female students reported more help-seeking behaviors than did male students in the following four college years. College students' mental health problems was associated positively with help-seeking behaviors. College students were more likely to seek help from the college psychological counselling center when they experienced relatively few or quite a lot of mental health issues (i.e., an inversed U shape). Implications for future studies and practices are discussed.

Capillary electrophoresis-chemiluminescence determination of norfloxacin and prulifloxacin.

A capillary electrophoresis (CE)-chemiluminescence (CL) method for determining norfloxacin (NFLX) and prulifloxacin (PFLX) was developed based on the enhanced CL intensity of the cerium(IV)-sulfite-fluoroquinolone (FQ) reaction sensitized by terbium(III). The separation was conducted in buffer composed of 20 mM sodium citrate, 4 mM citric acid and 10 mM sodium sulfite at pH 6.1. The CL reagent solution consisted of 2 mM cerium(IV), 4 mM terbium(III) and 1.1 mM hydrochloric acid. NFLX and PFLX were baseline separated within 11 min with detection limits (S/N=3) of 0.057 and 0.084 microg mL(-1), respectively. The maximum intra- and inter-day relative standard deviations (R.S.D.s) of migration time of the analytes were less than 4.0% and 4.2%, respectively. The proposed method was applied to detect NFLX and PFLX in fortified urine sample and the results were comparable to high-performance liquid chromatography (HPLC)-UV method. Moreover, the high selectivity of the CL detection and the high-separation efficiency of CE render the method the potential of quick analyzing fluoroquinolones in real complex matrix.

Flow-injection chemiluminescence determination of ofloxacin using the Ru(bpy)2(CIP)2+-Ce(IV) system and its application.

This paper reports a flow-injection chemiluminescence method for the determination of ofloxacin (OFLX) using the Ru(bpy)2(CIP)2+-Ce(IV) system. Under the optimum conditions, the relative CL intensity was proportional to the concentration of OFLX in the range 3.0 x 10(-8)-1.0 x 10(-5) mol/L and the detection limit was 4.2 x 10(-9) mol/L. The proposed method has been successfully applied to the determination of ofloxacin in pharmaceuticals and human urine. The chemiluminescence mechanism of the system is also discussed.

Determination of ulifloxacin by terbium-sensitized fluorescence with second-order scattering and its applications.

This paper reports the determination of ulifloxacin (UFX) by terbium-sensitized fluorescence using a second-order scattering method. UFX and Tb(III) ion form a fluorescence complex in aqueous solution, and its maximum excitation and emission wavelengths are located at 273 and 545 nm, respectively. In optimum conditions, the relative intensity at 545 nm has a linear relationship to the concentration of UFX in the range of 2.0 x 10(-8) - 1.0 x 10(-5) mol L(-1) and the detection limit is 3.9 x 10(-9) mol L(-1). The proposed method was applied to the determination of UFX in spiked human serum and urine satisfactorily. The luminescence property of UFX is also discussed by comparing with norfloxacin (NFLX) and ofloxacin (OFLX).

Protein analysis with terbium (III) and sodium dodecyl sulphonate by a second-order scattering technique.

This is the first report of terbium(III) as a probe of second-order scattering (SOS) for the determination of proteins in human serum at nanogram levels. A sensitive method has been developed using light scattering, based on the fact that the weak SOS of proteins can be enhanced in the presence of terbium(III) and sodium dodecyl sulphonate (SDS). With this method, 7.0 x 10(-9)-1.0 x 10(-5) g/mL human serum albumin (HSA) and 5.0 x 10(-9)-5.0 x 10(-6) g/mL gamma-globulin can be determined; the detection limits were 4.4 ng/mL for HSA and 3.1 ng/mL for gamma-globulin. The method has been applied to the detection of total proteins in human serum samples, and the results are consistent with those obtained by the Coomassie brilliant blue (CBB) G-250 assay.

[Nanosilver sensitized fluorescence and second-order scattering of Tb (III)-norfloxacin and its application].

Norfloxacin (NFLX) can form complex with Tb(III) ion, and the intramolecular energy transfer from NFLX to Tb (III) takes place when excited. And thus the characteristic fluorescence of Tb (III) ion is enhanced and the maximum fluorescence peak locates at 545 nm. The second-order scattering (SOS) peak at 545 nm also appears for the Tb (III)-NFLX complex with the excitation wavelength of 272 rnm. When the silver nanoparticles were added to the Tb (III)-NFLX binary system, the luminescence intensity at 545 nm greatly increased. And the relative intensity is proportional to the amount of NFLX. Based on this phenomenon, a novel method for the determination of NFLX has been developed by using a common spectrofluorometer to measure the intensity of fluorescence and SOS. The calibration graphs for NFLX are linear in the range of 6.0 x 10(-9)-1.0 x 10(-5) mol x L(-1), and the detection limit is 4.4 x 10(-9) x mol x L(-1). This method was applied satisfactorily to the determination o f NFLX in capsule and eye drop samples. The experimental results showed that it is the certain size and certain concentration of silver nanoparticles that can greatly enhance the fluorescence-SOS intensity.

Chiral separation of four fluoroquinolone compounds using capillary electrophoresis with hydroxypropyl-beta-cyclodextrin as chiral selector.

A capillary zone electrophoresis (CZE) investigation on the enantiomeric separation of lomefloxacin, gatifloxacin, pazufloxacin and ofloxacin was undertaken. Resolution of the enantiomers was achieved using hydroxypropyl-beta-cyclodextrin (HP-beta-CD) as the chiral selector. Parameters influencing separation include cyclodextrin concentration, separational potential, pH and organic additive are discussed. A buffer consisting of 70 mM phosphate and 40 mM HP-beta-CD at pH 3.96 was found to be highly efficient for the separation of lomefloxacin, at pH 3.90 for gatifloxacin, at pH 5.04 for pazufloxacin and at pH 2.16 for ofloxacin. To the best of our knowledge, this is the first report on the enantiomeric resolution of lomefloxacin and gatifloxacin applying CE.

Nucleic acids analysis with nano-Ag-Tb(III) by a resonance light scattering technique.

The nano-Ag-terbium(III)-mucleic acids system was observed by a resonance light scattering (RLS) technique for the first time, and the quantitative analysis of nucleic acids at nanogram levels was established. Studies showed that the RLS intensity of the nano-Ag-terbium(III) system can be obviously enhanced by nucleic acid, which was characterized by the RLS spectrum and the UV-Vis spectrum. In this system, the nanoparticles were only of a definite size and in a limited particle concentration region. Further research indicated that under the optimum conditions, the enhanced intensity of RLS is in proportion to the concentration of nucleic acids in the ranges of 7.0 x 10(-9) g ml(-1) to 8.0 x 10(-6) g ml(-1) for calf thymus DNA (ctDNA), 2.0 x 10(-8) g ml(-1) to 1.0 x 10(-6) g ml(-1) for fish sperm DNA (fsDNA) and 1.0 x 10(-9) g ml(-1) to 1.0 x 10(-7) g ml(-1) for yeast RNA (yRNA). The detection limits were 1.4 ng ml(-1) for ctDNA, 1.2 ng ml(-1) for fsDNA and 0.85 ng ml(-1) for yRNA, respectively. Synthetic and real samples were determined satisfactorily.

Determination of norfloxacin using a terbium-sensitized electrogenerated chemiluminescence method.

A simple electrogenerated chemiluminescence (ECL) analysis method for the determination of norfloxacin (NFLX) is reported. It is based on ECL produced by Na(2)SO(3), which is sensitized by the Tb-NFLX complex. The relative ECL intensity of the Tb(3+)-NFLX-Na(2)SO(3) system is proportional to the amount of NFLX. The optimized experimental conditions were investigated. The linear range and detection limit for NFLX were 1.0 x 10(-10)-8.0 x 10(-7) mol/L and 2.8 x 10(-11) mol/L, respectively. This method was successfully applied to the determination of NFLX in a capsule. NFLX in urine can be directly detected without pretreatment or separation.

Electrochemiluminescence of terbium (III)-two fluoroquinolones-sodium sulfite system in aqueous solution.

The electrochemiluminescence (ECL) of Tb3+-enoxacin-Na2SO3 system (ENX system) and Tb3+-ofloxacin-Na2SO3 system (OFLX system) in aqueous solution is reported. ECL is generated by the oxidation of Na2SO3, which is enhanced by Tb3+-fluoroquinolone (FQ) complex. The ECL intensity peak versus potential corresponds to oxidation of Na2SO3, and the ECL emission spectra (the peaks are at 490, 545, 585 and 620 nm) match the characteristic emission spectrum of Tb3+, indicating that the emission is from the excited state of Tb3+. The mechanism of ECL is proposed and the difference of ECL intensity between ENX system and OFLX system is explained. Conditions for ECL emission were optimized. The linear range of ECL intensity versus concentrations of pharmaceuticals is 2.0 x 10(-10) -8.0 x 10(-7)mol l(-1) for ENX and 6.0 x 10(-10) -6.0 x 10(-7)mol l(-1) for OFLX, respectively. A theoretical limit of detection is 5.4 x 10(-11)mol l(-1) for ENX and 1.6 x 10(-10)mol l(-1) for OFLX, respectively. The ECL was satisfactorily applied to the determination of the two FQs in dosage form and urine sample.

Flow-injection with enhanced chemiluminescence detection of ofloxacin in human plasma.

A simple, rapid and sensitive method for the determination of ofloxacin in plasma has been developed based on flow-injection analysis with enhanced chemiluminescence (CL) detection. This method employs the CL reaction of cerium(IV) and sulphite sensitized by a Tb(III)-ofloxacin complex. Plasma samples were deproteinized with acetonitrile before analysis. Under optimal conditions, the method allowed the quantitative analysis of ofloxacin in plasma over the range of 22.5-900 ng/mL with a detection limit of 7.5 ng/mL (3sigma). The intra-day and inter-day precision was < 3.0% (n = 11) and < 7.0% (n = 3), respectively. The method was a convenient tool, rapid (20 s/analysis) and well suited for pharmacokinetics studies in which thousands of samples must be analysed daily. It was applied to pharmacokinetics studies of ofloxacin.

The second-order scattering study of the Tb(III)-RNA and determination of RNA.

The second-order scattering technique (SOS), using a common spectrofluorometer, was first developed as a sensitive instrumental analysis method for determination of the ribonucleic acid (RNA). The results indicate that RNA had a weak SOS peak and the Tb(III) ion can greatly enhance the SOS intensity of RNA with the maximum peak located at 612.0 nm. Mechanism study shows that the peak results from the long-range assembly of Tb(III) ion on the molecular surface of RNA. At the pH 7.50 and with cetyltrimethylammonium bromide (CTMAB) (6.0 x 10(-5)M), the enhanced SOS intensity was in proportion to the concentration of RNA in the range of 2.0 x 10(-8) to 2.0 x 10(-5)g/ml. The detection limit was 1.96 ng/ml. The relative standard deviation (five replicates) was within +/-5% in the linear range. This method has been used satisfactorily for the determination of both synthetic and real samples. In comparison with most other methods for the determination of ribonucleic acids, this method is more sensitive.

Terbium sensitized determination of tosufloxacin using electrochemiluminescence method.

A novel method for determination of trace amounts of tosufloxacin (TFLX) based on electrochemiluminescence (ECL) has been developed. The calibration graphs for TFLX were linear in the range of 5.0 x 10(-11)-3.5 x 10(-7) mol/L, with the detection limit of 1.3 x 10(-11) mol/L. Key factors affecting the determination of TFLX were investigated. TFLX amounts in capsule and serum samples were successfully detected by this method. A possible mechanism of energy transfer, and thus the explanation of ECL in the Tb3+-TFLX-Na2S2O4 system are discussed.

Terbium-sensitized fluorescence method for the determination of pazufloxacin mesilate and its application.

A simple, rapid and highly sensitive fluorometric method for the determination of pazufloxacin mesilate (PZFX) is described. It is based on the formation of the complex [Tb(PZFX)2](3+), which shows the intensive characteristic bands of Tb3+. Optimum conditions for the determination were investigated. Under the optimum experimental condition, the fluorescence intensity responds linearly to the PZFX concentration in the range of 2.0 x 10(-8) - 5.0 x 10(-6) mol/l with a detection limit of 6.2 x 10(-9) mol/l. The method has been successfully applied to the determination of PZFX in urine and serum samples.

[A study on europium sensitized chemiluminescence of pipemidic acid].

A flow injection chemiluminescence method for the determination of Pipemidic acid (PPA) was developed. It is based on luminescence produced with KMnO4-Na2S2O4 CL system sensitized by Eu3+-PPA. The familar excipients such as starch and dextrine do not cause interference. The several kinds of affect on chemiluminescence were studied. The linear range and detection limit for PPA are 7.00 x 10(-9)-9.00 x 10(-7) mol x L(-1) and 4.09 x 10(-9) mol x L(-1), respectively. This method have successfully been applied to the determination of PPA in tablet and urine. And the mechanism of chemiluminescence is proposed.

Flow-injection chemiluminescence study of Ce(IV)-Na2SO3-Tb(III)-fluoquinolone antibiotic system with DNA.

A novel flow injection chemiluminescence (CL) system is developed to determine DNA. According to the fact that DNA linearly quenches the CL intensity of Ce(IV)-Na(2)SO(3)-Tb(III)-fluoquinolone antibiotic (FLUQ) system, DNA concentration is determined. The calibration graphs are linear in the range of 0.04-10 microg/ml (for both natural and denatured DNA), and the 3sigma limits of detection are 7.8 ng/ml (natural DNA) and 9.5 ng/ml (denatured DNA). According to fluorescence spectrum and CL spectrum, and through studying the reaction of Ce(IV)-Na(2)SO(3)-Tb(III)-FLUQ with nucleotides and bases, we conclude that DNA counteracts the energy transfer from FLUQ to Tb(III), and this function is related to both bases and phosphate groups in DNA.

Flow-injection analysis of two fluoquinolones by the sensitizing effect of terbium(III) on chemiluminescence of the potassium permanganate-sodium sulfite system.

A simple, rapid and sensitive method for the determination of two fluoquinolones (FQs), enoxacin (ENX) and ofloxacin (OFLX) is described by using flow injection analysis with potassium permanganate-sodium sulfite chemiluminescence detection. The calibration graphs for ENX and OFLX are linear in the range of 8.0x10(-10)-1.0x10(-5) and 1.0x10(-9)-1.0x10(-6) mol l(-1), respectively. The 3sigma limits of detection are 2.4x10(-10) mol l(-1) for ENX and 5.6x10(-10) mol l(-1) for OFLX. The method is applied satisfactorily to the determination of the two FQs in dosage form and urine sample. The possible mechanism is also proposed.