catena-Poly[zinc(II)-bis-[µ-2-(2,4-dichloro-phen-oxy)acetato]].

The title polymeric compound, [Zn(C(8)H(5)Cl(2)O(3))(2)](n), was prepared by reaction of zinc(II) chloride with 2,4-dichloro-phenoxy-acetic acid and sodium hydroxide under hydro-thermal conditions. The Zn(II) atom is coordinated in a distorted tetra-hedral environment by four O atoms from four 2,4-dichloro-phenoxy-acetate ligands. Each ligand bridges two Zn(II) atoms, forming a polymeric chain along the a axis. Adjacent chains are connected via C-H⋯Cl hydrogen bonds.

Poly[[bis-(µ(2)-4,4'-bipyridine)[µ(2)-(2,4-dichloro-phen-oxy)acetato]copper(I)] nitrate].

The title compound, {[Cu(2)(C(8)H(5)Cl(2)O(3))(C(10)H(8)N(2))(2)]NO(3)}(n) was prepared by reacting copper(II) nitrate with 4,4'-bipyridine (4,4'-bipy) and (2,4-dichloro-phen-oxy)acetic acid under solvothermal conditions. Each of two copper(I) atoms in the asymmetric unit is three-coordinated by two N atoms from two 4,4'-bipy ligands and one O atom from the (2,4-dichloro-phen-oxy)acetate ligand. As both ligands act as bridging ligands, a double-stranded chain structure is observed.

[Synthesis of a novel calix[4]arene derivative with 2-methylquinoline and study of it's spectrum character with Zn(II) and Cu(II)].

A novel calix[4]arene derivative(25,27-two2-methylquinoline t-butylcalix[4]arene, MQBC) with the lower rim modified fluorescence groups was synthesized. IR spectra, elemental analysis, HNMR spectra and MS were used to determine its structure. Meanwhile, the spectra characters of MQBC and the fluorescent behaviors of the complex with zinc(II) and copper (II) were investigated, and the results showed that the lower rim oxygen atoms in calix[4]arenes may act as electrons donor to metal ions. Calix[4] arene was chosen as a basic skeleton of a photoresponsive ion carrier because its quinolin derivatives are known to emit fluorescence and absorb UV in the solution, and the information of the complex with metal ions will be known by spectra experiment. The UV absorbance became weak at the band of 226 nm but was enhanced at the band of 315 nm when it bound zinc ions, The complex constant(K) and binding ratio(x) were determined to be 2 064 L x mol(-1) and 1, respectively, by UV spectra experiment. It is expected that MQBC will be applied to the detection of trace zinc ions. The fluorecence spectra experiment found that MQBC is has feeble fluorecence attributed to the intramolecular photoinduced electron transfer(PET) between oxygen atoms and methylquinoline groups. When MQBC was combined with zinc(II) and copper(II), it caused the inhibiting photoinduced electron transfer process between oxygen atoms and methylquinoline groups leading to the enhancement of fluorescence. In addition, the photoinduced electron mechanism was discussed and the influence of the concentration of zinc(II) and copper(II) on the fluorescence intensities was studied.

Community-based survey of HCV and HIV coinfection in injection drug abusers in Sichuan Province of China.

AIM: To investigate the prevalence and risk factors of HCV/HIV coinfection in injection drug abusers (IDAs) in Lianshan Yi Autonomous Prefecture of Sichuan province, China. METHODS: From November 8, 2002 to November 29, 2002, a community-based survey was conducted to investigate the demographic characteristics, patterns of shared injectors devices and sexual behaviors in IDAs. Blood samples were also collected to test HCV and HIV infection. A total of 379 subjects were recruited in the study through community outreach and peer recruiting methods. RESULTS: Of the 379 IDAs, the HCV prevalence and HIV prevalence were 71.0% and 11.3%, respectively, and HCV/HIV coinfection was 11.3%. HCV infection was found in 100% and 67.3% of HIV-positive and HIV-negative IDAs, respectively. HIV prevalence was 16.0% in HCV positive IDAs while none of the HCV negative IDAs was positive for HIV. Ethnicity, shared needles or syringes and cotton in the past 3 mo and syphilis infection were associated with HCV/HIV coinfection shown by univariate analysis using chi-square test. Multivariate logistic regression analysis showed that shared needles or syringes in the past 3 mo (Odds ratio=3.121, 95% CI: 1.278-7.617, P<0.05) and syphilis infection (Odds ratio=2.914, 95% CI: 1.327-6.398, P<0.01) were significantly associated with HCV infection. No statistically significant association was found in univariate analysis between sexual behaviors and HCV/HIV coinfection. CONCLUSION: Shared needles and syringes in the past 3 mo and syphilis infection were significantly associated with HCV infection. Further sero-epidemiological prospective cohort studies should be conducted to clarify the impact of syphilis and high risk sexual behaviors on HCV transmission through unprotected sexual intercourse.

[Community-based survey on human immunodeficiency virus infection among injection drug users in Sichuan, China].

OBJECTIVE: To investigate prevalence of human immunodeficiency virus (HIV) infection and risk factors for its transmission among injection drug users (IDUs) in Liangshan Yizu Autonomous Prefecture of Sichuan Province, China. METHODS: A community-based survey was conducted to investigate demographic characteristics, pattern and frequency of sharing injection equipment, and sexual behaviors in IDUs. Blood samples were also collected from them to detect for antibodies against HIV and syphilis. RESULTS: A total of 379 subjects were recruited with informed consent for study through community outreach and peer recruiting methods. Their prevalence of HIV infection was 11.3% (43/379). Ethnicity, frequency of sharing syringes and cotton swab during the past three months and syphilis infection associated with HIV infection by univariate analysis using chi-square test. Multivariate logistic regression analysis showed odds ratio of frequency of sharing syringes for HIV infection during the past three months was 2.28 (95% CI 1.18 - 4.43), and that for syphilis infection 3.10 (95% CI 1.48 - 6.48). CONCLUSION: Frequency of sharing syringes during the past three months associated with syphilis and HIV infection.

[A prospective cohort study on human immunodeficiency virus and syphilis seroconversion among injecting drug users].

OBJECTIVE: To study the rate of human immunodeficiency virus (HIV) seroconversion, HIV transmission and related risk factors among injecting drug users (IDUs) in an area of Sichuan province. METHODS: In November 2002, a community-based baseline survey was conducted to recruit 333 HIV-seronegative IDUs for a prospective cohort study in Xichang county of Sichuan province, China. Follow-up visits were carried out every 6 months to study the situation of drug use, sexual behaviors of the IDUs and blood specimens were collected to test for antibodies against HIV and syphilis. RESULTS: During a 24-month follow-up period, cohort retention rate and HIV incidence were 75.7% and 2.53 per 100 person-years [95% confidence interval (CI): 1.10-3.97)], respectively. Multivariate Poisson regression model showed that risk factors which were significantly associated with HIV seroconversion would include: ethnicity (RR = 12.42; 95% CI: 2.72-56.74, P = 0.0012) and needle or syringe sharing in the past 3 months (RR = 4.06; 95% CI: 1.29-12.81, P = 0.0168). Syphilis seroconversion in this cohort was 4.71 per 100 person-years (95% CI: 2.59-6.82). In multivariate Poisson regression being female (RR = 4.42; 95% CI: 1.78-10.99, P = 0.0014) appeared to be the only factor which was significantly associated with syphilis seroconversion. CONCLUSION: Our study results showed that there was a rapid transmission of HIV and syphilis among IDUs in Sichuan province, suggesting that effective intervention should be urgently taken.

[An 1-year prospective cohort study on mortality of injecting drug users].

OBJECTIVE: To study the mortality among injecting drug users (IDUs) from an IDUs cohort in Liangshan of Sichuan province. METHODS: In November 2002, 376 injecting drug users were recruited and followed up for 1 year as part of a prospective cohort study. Socio-demographics and risk behaviors on drug use were recorded. After one year, the mortality rate was estimated and risk factors for mortality were analyzed using Cox regression. RESULTS: Out of the original cohort of 376 participants, there were 28 reported and confirmed deaths during the one year follow-up period. The mortality rate of the cohort was 77.32 per 1000 person-years (95% CI: 48.68 - 105.95) with the standardized mortality ratio (SMR) as 47.62 (95% CI: 31.63 - 68.71). Out of the 28 deaths, 64.3% (18/28) caused by overdoses of drug. No variables were found to be associated with death of all causes, but being un-married and >or= 9 year history of injecting drugs were found to be associated with overdose-related mortality in the final model of Cox regression. The hazard ratios were 4.51 (95% CI: 1.03 - 19.67) and 2.77 (95% CI: 1.10 - 7.00) respectively. CONCLUSION: Overdose served the most frequent cause of deaths in Liangshan of Sichuan province. Future studies should be conducted to focus on mortality and risk factors associated with mortality among IDUs to provide targeted interventions in reducing unnatural mortality.

[Study on the relationship between hepatitis C virus infection and sharing injection equipment, sexual behavior among injecting drug users].

OBJECTIVE: To study hepatitis C virus (HCV) transmission through different modes of sharing injection equipment and sexual behavior among injecting drug users (IDUs) in Liangshan of Sichuan province. METHODS: A community-based survey was conducted to investigate past and current demographic data, injection equipment sharing patterns and sexual behavior of IDUs. Blood samples were also taken to test for HCV. The survey was conducted between Nov 8 and Nov 29, 2002. 379 subjects were screened through outreach recruitment and peer informing. SPSS (11.5) was used for data analysis. RESULTS: HCV prevalence was 71.0% (269/379). Needles or syringes sharing in the past three months and past syphilis infection were strongly associated with HCV transmission after univariate analysis using chi-square test. Trend analysis indicated that HCV infection rate increased along with the increase of needles or syringes sharing, sharing of rinse water and the number of peers sharing the equipments. Data from multivariate logistic regression showed that sharing of needles or syringes and history of syphilis infection were significantly associated with HCV transmission. No significant difference was found between HCV infection and sexual behavior after univariate analysis using chi-square test. CONCLUSION: Further sero-epidemiological prospective cohort studies should be conducted to clarify the relationship between different modes of sharing injection equipment, sexual behavior and HCV infection.