Terahertz spectra of electrolyte solutions under applied electric and magnetic fields

Most biomolecules require an aqueous environment to fully exert their biological activity. However, the rotation mode, vibration mode, and energy associated with the hydrogen bonding network of water are in the terahertz band, resulting in strong absorption. Therefore, it is difficult to detect liquid biological samples using the terahertz technology. Here, a high-transmittance double-layer microfluidic chip was prepared using a cycloolefin copolymer material with high transmittance of terahertz waves. Combined with terahertz time-domain spectroscopy, the terahertz spectral characteristics of deionized water, NaCl, NaCO3, and CH3COONa solutions were studied. The changes in the terahertz transmission intensity of these electrolyte solutions under constant electric and magnetic fields were measured. The results show that the terahertz spectra of different sodium salt solutions with the same concentration of 0.9 mol/L are different. Furthermore, the terahertz absorption coefficients of the different electrolyte solutions gradually decrease with the increase of their residence time under the electric field, which is contrary to the results obtained under the external magnetic field. This study provides a new idea for the detection of sodium salt solution and lays a foundation for the development of THz technology

The effect of HIV infection on overdose mortality

Objectives: To quantify the association of HIV infection with overdose mortality and explore the potential mechanisms. Design: A prospective cohort study. Methods: A total of 1927 actively injecting drug users who were HIV seronegative at baseline, of whom 308 later HIV seroconverted, were followed semi-annually for death from 1988 to 2001. Survival analyses using marginal structural and standard Cox models were used to evaluate the effect of HIV infection on the risk of overdose mortality. Results: Overdose death rates were higher in HIV-seropositive than HIV-seronegative drug users: 13.9 and 5.6 per 1000 person-years, respectively (P < 0.01). The hazard ratio (HR) was 2.54 [95% confidence interval (CI) 1.47, 4.38] for the marginal structural model and 2.06 (95% CI 1.25, 3.38) for the standard Cox model, both adjusted for demographics, drug injection characteristics, alcohol abuse, substance abuse treatment, and sexual orientation. Adjusting for possible time-varying mediators (i.e. drug use, medical conditions and healthcare access) in extended marginal structural models reduced the effect of HIV on overdose mortality by 30% (HR 1.82, 95% CI 1.01, 3.30). Abnormal liver function was associated with a higher risk of overdose mortality (HR 2.00, 95% CI 1.05, 3.84); adjustment for this further reduced the effect of HIV on overdose mortality. Conclusion: HIV infection was associated with a higher risk of overdose mortality. Drug use behavior, systematic disease and liver damage associated with HIV infection appeared to account for a substantial portion of this association. The data suggest a group to target with interventions to reduce overdose mortality rates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/40279/2/Wang_The Effect of HIV Infection on Overdose_2005.pd

Dynamic Relationship between China and the World: From a Political Economic Perspective

The grudges between China and the world have never stopped since British cracked gate of China. The development context between China and the world can be divided into several stages. From "closed door state" to "open to the outside world" under the premise of maintaining China’s independence in all fields of politics and economy. It is different from the passive and invading opening to the outside world. Under the general trend of globalization, opportunities and challenges are coexisting. Facing the frequent trade friction, formulating its global strategic view, safeguarding its national interests and homeland security, China adheres to the principle of "one world, one dream" and adheres to the path of peaceful development. The relationship between China and the world is no longer "grudge" but "harmonious coexistence and common development"

Synthesis of chlorodiphenylgermanium dithiocarbamates

1510-1512Thirteen chlorodiphenylgermanium dithiocarbamates of the general formula, Ph2Ge(Cl)S2CNRR', [where NRR'=NMe2, NEt2, N(n-Pr)2, N(n-Bu)2, N(CH2)4, N(CH2)5, N(CH2CH2)2O, N(CH2CH2OH)2, N(CH3)Ph, NPh2, N(CH3)COPh, N(COCH2)2, N(CH=CH)2] have been prepared by the reaction of dithiocarbamates with the appropriate diphenylgermanium dichloride in 1:1 stoichiometry. Their structures have been characterized by elemental analyses, IR, 1H NMR and mass spectra. These results reveal that the dithiocarbamate ligands are coordinated to Ge in an anisobidentate fashion

The mitochondrial genome of Himalayan marmot, Marmota himalayana (Rodentia: Sciuridae) using next-generation sequencing

The complete mitochondrial genome of Marmota himalayana was determined based on next-generation sequencing. Genome length consisted of 16,442 bp, with a base composition of 32.1% A, 31.4% T, 23.7% C, and 12.8% G. It consists of 13 protein-coding genes, 22 tRNAs, 2 ribosomal RNAs, and a control region. The gene order and organization were similar to most of the other vertebrates. The molecular data here we presented could play a useful role to study the evolutionary relationships and population genetics of H. marmot

Health Risk Assessment Based on Source Identification of Heavy Metal(loid)s: A Case Study of Surface Water in the Lijiang River, China

In this study, 24 surface water samples were collected from the main trunk/tributary of the Lijiang River during the wet season (April) and the dry season (December) in 2021. The total concentration of 11 heavy metal(loid)s (Al, Cu, Pb, Zn, Cr, Ni, Co, Cd, Mn, As, and Hg) was determined to investigate their physicochemical properties and spatial-temporal distribution characteristics. The heavy metal evaluation index (HEI) and the positive matrix factorization (PMF) model were employed to evaluate water quality and to reveal quantitatively identified pollution sources for further investigation to obtain a health risk assessment using the hazard index (HI) and carcinogenic risk (CR) of various pollution sources. The mean concentrations of heavy metal(loid)s in surface water in the wet and dry seasons were ranked as: Al > Mn > Zn > Ni > Cd > Cr > Cu > As >Hg = Pb > Co, with the mean concentration of Hg being higher than the national Class II surface water environmental quality standard (GB3838-2002). In terms of time scale, the concentration of most heavy metal(loid)s was higher in the wet season; most heavy metal(loid)s were distributed mainly in the midstream area. HEI index indicated that the main water quality status was “slightly affected” in the study area. Five potential sources of pollution were obtained from the PMF model, including industrial activities, traffic sources, agricultural activities, domestic waste emissions, and natural resources. The source-oriented risk assessment indicated that the largest contributions of HI and CR were agricultural sources in the Lijiang River. This study provides a “target” for the precise control of pollution sources, which has a broad impact on improving the fine management of the water environment in the basin

Terahertz Characteristics of Magnetic Fluid Based on Microfluidic Technology

Magnetic fluid is a new functional material with both liquid fluidity and solid magnetism, which has important application value in medicine, biology, and so on. In this study, terahertz technology and microfluidic technology were combined to investigate the terahertz transmission characteristics of a magnetic fluid in different magnetic fields and different electric fields. In the external magnetic field, the intensity of the terahertz spectrum increased with an increase in the magnetic field intensity, and the response to the magnetic field in different directions was different. Under the applied electric field, the intensity of the terahertz spectrum decreased with an increase in the electric field intensity. This method is convenient for studying the terahertz characteristics of magnetic fluid and provides technical support for in-depth studies of magnetic fluid

Terahertz spectra of electrolyte solutions under applied electric and magnetic fields

Most biomolecules require an aqueous environment to fully exert their biological activity. However, the rotation mode, vibration mode, and energy associated with the hydrogen bonding network of water are in the terahertz band, resulting in strong absorption. Therefore, it is difficult to detect liquid biological samples using the terahertz technology. Here, a high-transmittance double-layer microfluidic chip was prepared using a cycloolefin copolymer material with high transmittance of terahertz waves. Combined with terahertz time-domain spectroscopy, the terahertz spectral characteristics of deionized water, NaCl, NaCO3, and CH3COONa solutions were studied. The changes in the terahertz transmission intensity of these electrolyte solutions under constant electric and magnetic fields were measured. The results show that the terahertz spectra of different sodium salt solutions with the same concentration of 0.9 mol/L are different. Furthermore, the terahertz absorption coefficients of the different electrolyte solutions gradually decrease with the increase of their residence time under the electric field, which is contrary to the results obtained under the external magnetic field. This study provides a new idea for the detection of sodium salt solution and lays a foundation for the development of THz technology