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Soil erosion is an important global environmental issue that severely affects regional ecological environment and socio-economic development. The Yellow River (YR) is China’s second largest river and the fifth largest one worldwide. Its watershed is key to China’s economic growth and environmental security. In this study, six impact factors, including rainfall erosivity (R), soil erosivity (K), slope length (L), slope steepness (S), cover management (C), and protective measures (P), were used. Based on the revised universal soil loss equation (RUSLE) model, and combined with a geographic information system (GIS), the temporal and spatial distribution of soil erosion (SE) in the YR from 2000 to 2020 was estimated. The patch-generating land use simulation (PLUS) model was used to simulate the land-use and land-cover change (LUCC) under two scenarios (natural development and ecological protection) in 2040; the RUSLE factor P was found to be associated with LUCC in 2040, and soil erosion in the Yellow River Basin (YRB) in 2040 under the two scenarios were predicted and evaluated. This method has great advantages in land-use simulation, but soil erosion is greatly affected by rainfall and slope, and it only focuses on the link between land-usage alteration and SE. Therefore, this method has certain limitations in assessing soil erosion by simulating and predicting land-use change. We found that there is generally slight soil erosivity in the YRB, with the most serious soil erosion occurring in 2000. Areas with serious SE are predominantly situated in the upper reaches (URs), followed by the middle reaches (MRs), and soil erosion is less severe in the lower reaches. Soil erosion in the YRB decreased 11.92% from 2000 to 2020; thus, soil erosion has gradually reduced in this area over time. Based on the GIS statistics, land-use change strongly influences SE, while an increase in woodland area has an important positive effect in reducing soil erosion. By predicting land-use changes in 2040, compared to the natural development scenario, woodland and grassland under the ecological protection scenario can be increased by 1978 km2 and 2407 km2, respectively. Soil erosion can be decreased by 6.24%, indicating the implementation of woodland and grassland protection will help reduce soil erosion. Policies such as forest protection and grassland restoration should be further developed and implemented on the MRs and URs of the YR. Our research results possess important trend-setting significance for soil erosion control protocols and ecological environmental protection in other large river basins worldwide.

Background The age-distribution of men who have sex with men (MSM) continues to change in the ‘Treat-All’ era as effective test-and-treat programs target key-populations. However, the nature of these changes and potential racial heterogeneities remain uncertain. Methods The PEARL model is an agent-based simulation of MSM in HIV care in the US, calibrated to data from the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD). Results PEARL projects a gradual decrease in median age of MSM at ART initiation from 36 to 31 years during 2010–2030, accompanied by changes in mortality among Black, White, and Hispanic MSM on ART by -8.4%, 42.4% and -19.6%. The median age of all MSM on ART is projected to increase from 45 to 47 years from 2010–2030, with the proportion of ART-users age ≥60y increasing from 6.7% to 28.0%. Almost half (49.7%) of White MSM ART-users are projected to age ≥60y by 2030, compared to 19.5% of Black and 17.2% of Hispanic MSM. Conclusions The overall age of US MSM in HIV care is expected to increase over the next decade, and differentially by race/ethnicity. As this population age, HIV programs should expand care for age-related causes of morbidity and mortality.

Here, we report a new state-diagram for aqueous solutions based on concentration-dependent glass-transition temperatures of concentrated and ice freeze-concentrated solutions. Different from the equilibrium phase diagram, this new state-diagram can provide comprehensive information about the hydration numbers of solutes, nonequilibrium vitrification/cold-crystallization, and vitrification/devitrification processes of aqueous solutions in three distinct concentration zones separated by two critical water-content points of only functions of the hydration number. Based on this new state-diagram, we observe the comparable hydration ability of LiTFSI to LiCl and an atypical concentration-dependent cold-crystallization behavior of the LiTFSI-H2O system. These results unveil the negligible hydration ability of TFSI- in a water-rich solution, characterize the antiplasticizing effect of water induced by the strengthened Li+-TFSI--H2O interaction when only hydration water and confined water are present, and confirm the increasing fraction of water-rich domains with the decrease in water content when the cation and anion become incompletely hydrated on average. These results highlight the novel water-content-mediated interactions among the anion, cation, and H2O for LiTFSI-H2O.

OBJECTIVE To project the future age distribution of people with HIV using antiretroviral therapy (ART) in the US, under expected trends in HIV diagnosis and survival (baseline scenario) and achieving the Ending the HIV Epidemic (EHE) goals of a 75% reduction in HIV diagnoses from 2020-25 and sustaining levels to 2030 (EHE75% scenario). DESIGN An agent-based simulation model with mathematical functions estimated from North American AIDS Cohort Collaboration on Research and Design data and parameters from the US Centers for Disease Control and Prevention's annual HIV surveillance reports. METHODS The PEARL (ProjEcting Age, multimoRbidity, and poLypharmacy in adults with HIV) model simulated individuals in 15 subgroups of sex-and-HIV acquisition risk and race/ethnicity. Simulation outcomes from the baseline scenario are compared with outcomes from the EHE75% scenario. RESULTS Under the baseline scenario, PEARL projects a substantial increase in number of ART-users over time, reaching a population of 909,638 [95%uncertaintyrange(UR):878,449-946,513] by 2030. The overall median age increased from 50 years (y) in 2020 to 52y in 2030, with 23% of ART-users age ≥65y in 2030. Under the EHE75% scenario, the projected number of ART-users was 718,348 [703,044-737,817] (median age=56y) in 2030, with a 70% relative reduction in ART-users

We characterized trends in statin eligibility and subsequent statin initiation among people with HIV (PWH) from 2001 to 2017 and identified predictors of statin initiation between 2014 and 2017.PWH participating in the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) enrolled in 12 US cohorts collecting data on statin eligibility criteria/prescriptions from 2001 to 2017.We determined the annual proportion eligible for statins, initiating statins, and median waiting time (from statin eligibility to initiation). Eligibility was defined using ATP III guidelines (2001-2013) and ACC/AHA guidelines (2014-2017). We assessed initiation predictors in 2014-2017 among statin-eligible PWH using Poisson regression, estimating adjusted prevalence ratios (aPRs) with 95% confidence intervals (95% CIs).Among 16,409 PWH, 7386 (45%) met statin eligibility criteria per guidelines (2001-2017). From 2001 to 2013, statin eligibility ranged from 22% to 25%. Initiation increased from 13% to 45%. In 2014, 51% were statin-eligible, among whom 25% initiated statins, which increased to 32% by 2017. Median waiting time to initiation among those we observed declined over time. Per 10-year increase in age, initiation increased 46% (aPR 1.46, 95% CI: 1.29 to 1.67). Per 1-year increase in calendar year from 2014 to 2017, there was a 41% increase in the likelihood of statin initiation (aPR 1.41, 95% CI: 1.25 to 1.58).There is a substantial statin treatment gap, amplified by the 2013 ACC/AHA guidelines. Measures are warranted to clarify reasons we observe this gap, and if necessary, increase statin use consistent with guidelines including efforts to help providers identify appropriate candidates.

Climate is a dominant factor affecting the potential geographical distribution of species. Understanding the impact of climate change on the potential geographic distribution of species, which is of great significance to the exploitation, utilization, and protection of resources, as well as ecologically sustainable development. Betula platyphylla Suk. is one of the most widely distributed temperate deciduous tree species in East Asia and has important economic and ecological value. Based on 231 species distribution data points of Betula platyphylla Suk. in China and 37 bioclimatic, soil, and topography variables (with correlation coefficients < 0.75), the potential geographical distribution pattern of Betula platyphylla Suk. under Representative Concentration Pathway (RCP) climate change scenarios at present and in the 2050s and 2070s was predicted using the MaxEnt model. We analyzed the main environmental variables affecting the distribution and change of suitable areas and compared the scope and change of suitable areas under different climate scenarios. This study found: (1) At present, the main suitable area for Betula platyphylla Suk. extends from northeastern to southwestern China, with the periphery area showing fragmented distribution. (2) Annual precipitation, precipitation of the warmest quarter, mean temperature of the warmest quarter, annual mean temperature, and precipitation of the driest month are the dominant environmental variables that affect the potential geographical distribution of Betula platyphylla Suk. (3) The suitable area for Betula platyphylla Suk. is expected to expand under global warming scenarios. In recent years, due to the impact of diseases and insect infestation, and environmental damage, the natural Betula platyphylla Suk. forest in China has gradually narrowed. This study accurately predicted the potential geographical distribution of Betula platyphylla Suk. under current and future climate change scenarios, which can provide the scientific basis for the cultivation, management, and sustainable utilization of Betula platyphylla Suk. resources.

BACKGROUND: Use of electronic health records (EHRs) in health research may lead to the false assumption of complete event ascertainment. We present a systematic approach to estimate “observation windows” (OWs), defined as time periods within which the assumption of complete ascertainment of events is more likely to hold, as a quality control approach to reducing the likelihood of this false assumption. We demonstrate the impact of observation windows on estimating the rates of type 2 diabetes mellitus (diabetes) using EHR diagnosis, medication, and laboratory data from HIV clinical cohorts. METHODS: Data contributed by 16 HIV clinical cohorts to the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) were used to identify and evaluate OWs for an operationalized definition of diabetes occurrence as a case study. Procedures included: 1) gathering cohort-level data; 2) visualizing and summarizing gaps in observations; 3) systematically establishing start and stop dates during which complete ascertainment of diabetes events was reasonable; and 4) visualizing the diabetes OWs relative to the cohort open and close dates to identify periods of time during which immortal person time was accumulated and events were not fully ascertained. We estimated diabetes occurrence event rates and 95% confidence intervals ([,]) in the most recent decade that data were available (Jan 1, 2007 to Dec 31, 2016). RESULTS: The number of diabetes events decreased by 17% with the use of the diabetes OWs; immortal person-time was removed decreasing total person-years by 23%. Consequently, the diabetes rate increased from 1.23 (95% confidence interval [1.20, 1.25]) per 100 person-years to 1.32 ([1.29, 1.35] per 100 person-years with the use of diabetes OWs. CONCLUSIONS: As the use of EHR-curated data for event-driven health research continues to expand, OWs have utility as a quality control approach to complete event ascertainment, helping to improve accuracy of estimates by removing immortal person-time when ascertainment is incomplete.

As a new and emerging technology, photocatalytic oxidation is widely used in the fields of sewage treatment and organic pollution control. In this study, CdS nanoparticles were prepared at room temperature by an innovative preparation method, then TiO2 nanorod&ndash, CdS nanoparticle heterojunction photocatalysts were prepared using the solvothermal method, with TiCl3 used as the precursor for TiO2 nanorods. This study mainly took advantage of the small size of the CdS nanoparticles in combination with TiO2 nanorods, and the resultant heterojunctions had large specific surface areas, thereby increasing the contact area between the catalysts and the contaminants. In addition, due to the lower band gap energy (2.4 eV) of CdS, the photo response range of the heterojunction photocatalysts was also increased. In an experimental study, through photocatalytic performance tests of the catalysts with different weight ratios, it was found that the TiO2(40%)@CdS composite had the best photocatalytic performance and the highest catalytic rate. BET, SEM, and other tests showed that the specific surface area of the TiO2(40%)@CdS composite was the largest. TiO2 nanorods and CdS particles were uniformly distributed in the composite, and the optical response range was extended to the visible light region.

Background People living with human immunodeficiency virus (HIV; PLWH) have a markedly elevated anal cancer risk, largely due to loss of immunoregulatory control of oncogenic human papillomavirus infection. To better understand anal cancer development and prevention, we determined whether recent, past, cumulative, or nadir/peak CD4+ T-cell count (CD4) and/or HIV-1 RNA level (HIV RNA) best predict anal cancer risk. Methods We studied 102 777 PLWH during 1996–2014 from 21 cohorts participating in the North American AIDS Cohort Collaboration on Research and Design. Using demographics-adjusted, cohort-stratified Cox models, we assessed associations between anal cancer risk and various time-updated CD4 and HIV RNA measures, including cumulative and nadir/peak measures during prespecified moving time windows. We compared models using the Akaike information criterion. Results Cumulative and nadir/peak CD4 or HIV RNA measures from approximately 8.5 to 4.5 years in the past were generally better predictors for anal cancer risk than their corresponding more recent measures. However, the best model included CD4 nadir (ie, the lowest CD4) from approximately 8.5 years to 6 months in the past (hazard ratio [HR] for Conclusions Our results are consistent with anal cancer promotion by severe, prolonged HIV-induced immunosuppression. Nadir and cumulative CD4 may represent useful markers for identifying PLWH at higher anal cancer risk.

BackgroundResearch is needed to better understand relations between immunosuppression and HIV viraemia and risk for non-Hodgkin lymphoma, a common cancer in people living with HIV. We aimed to identify key CD4 count and HIV RNA (viral load) predictors of risk for non-Hodgkin lymphoma, overall and by subtype.MethodsWe studied people living with HIV during 1996-2014 from 21 Canadian and US cohorts participating in the North American AIDS Cohort Collaboration on Research and Design. To determine key independent predictors of risk for non-Hodgkin lymphoma, we assessed associations with time-updated recent, past, cumulative, and nadir or peak measures of CD4 count and viral load, using demographics-adjusted, cohort-stratified Cox models, and we compared models using Akaike's information criterion.FindingsOf 102 131 people living with HIV during the study period, 712 people developed non-Hodgkin lymphoma. The key independent predictors of risk for overall non-Hodgkin lymphoma were recent CD4 count (ie, lagged by 6 months

In this study, we investigated the dynamic characteristics of bubbles in a vibrated airflow force field and the mechanism under which the vibration energy restrains the bubble motion in the bubble fluidization state using digital image processing and signal analysis. Through a comparative analysis of the pressure drop signal and the bubble characteristic images, the results show that the bubble coalescence causes a sudden peak value of the pressure drop signal, and fracturing causes a decrease of the pressure drop signal. When the bed is fully fluidized, the high-amplitude pressure drop signal is mainly distributed in the range of 0–12 Hz, and the amplitude range is 480–1354 Pa. During the violent bubbling of bed, the amplitude of pressure drop signal in the frequency range of 0–12 Hz decreases, and the frequency band of the high-amplitude pressure drop signal shifts to a high-frequency band. The introduction of vibration energy significantly influences on the dynamic behavior of bubbles, and when the vibration frequency is f = 20 Hz, v = 0.32 m/s, and A = 2 mm, the shape of bubbles at the bottom of the bed is mostly a flat strip and the number of bubbles is less evenly distributed, the size of the bubbles are small, the bed voidage and its standard deviation are low, and the fluidization quality of the bed is uniform and stable.

Background: There is persistent confusion as to whether abacavir (ABC) increases the risk of myocardial infarction (MI), and whether such risk differs by type 1 (T1MI) or 2 (T2MI) MI in adults with HIV. Methods: Incident MIs in North American Cohort Collaboration on Research and Design participants were identified from 2001 to 2013. Discrete time marginal structural models addressed channeling biases and time-dependent confounding to estimate crude hazard ratio (HR) and adjusted hazard ratio (aHR) and 95% confidence intervals; analyses were performed for T1MI and T2MI separately. A sensitivity analysis evaluated whether Framingham risk score (FRS) modified the effect of ABC on MI occurrence. Results: Eight thousand two hundred sixty-five adults who initiated antiretroviral therapy contributed 29,077 person-years and 123 MI events (65 T1MI and 58 T2MI). Median follow-up time was 2.9 (interquartile range 1.4-5.1) years. ABC initiators were more likely to have a history of injection drug use, hepatitis C virus infection, hypertension, diabetes, impaired kidney function, hyperlipidemia, low (,200 cells/mm3) CD4 counts, and a history of AIDS. The risk of the combined MI outcome was greater for persons who used ABC in the previous 6 months [aHR = 1.84 (1.17-2.91)]; and persisted for T1MI (aHR = 1.62 [1.01]) and T2MI [aHR = 2.11 (1.08-4.29)]. FRS did not modify the effect of ABC on MI (P = 0.14) and inclusion of FRS in the MSM did not diminish the effect of recent ABC use on the combined outcome. Conclusions: Recent ABC use was associated with MI after adjustment for known risk factors and for FRS. However, screening for T1MI risks may not identify all or even most persons at risk of ABC use-associated MIs.

A subset of HIV-infected individuals termed elite controllers (ECs) maintain CD4 + T cell counts and control viral replication in the absence of antiretroviral therapy (ART). Systemic cytokine responses may differentiate ECs from subjects with uncontrolled viral replication or from those who require ART to suppress viral replication. We measured 87 cytokines in four groups of women: 73 ECs, 42 with pharmacologically suppressed viremia (ART), 42 with uncontrolled viral replication (noncontrollers [NCs]), and 48 HIV-uninfected (NEG) subjects. Four cytokines were elevated in ECs but not NCs or ART subjects: CCL14, CCL21, CCL27, and XCL1. In addition, median stromal cell-derived factor-1 (SDF-1) levels were 43% higher in ECs than in NCs. The combination of the five cytokines suppressed R5 and X4 virus replication in resting CD4 + T cells, and individually SDF-1β, CCL14, and CCL27 suppressed R5 virus replication, while SDF-1β, CCL21, and CCL14 suppressed X4 virus replication. Functional studies revealed that the combination of the five cytokines upregulated CD69 and CCR5 and downregulated CXCR4 and CCR7 on CD4 + T cells. The CD69 and CXCR4 effects were driven by SDF-1, while CCL21 downregulated CCR7. The combination of the EC-associated cytokines induced expression of the anti-HIV host restriction factors IFITM1 and IFITM2 and suppressed expression of RNase L and SAMHD1. These results identify a set of cytokines that are elevated in ECs and define their effects on cellular activation, HIV coreceptor expression, and innate restriction factor expression. This cytokine pattern may be a signature characteristic of HIV-1 elite control, potentially important for HIV therapeutic and curative strategies. IMPORTANCE Approximately 1% of people infected with HIV control virus replication without taking antiviral medications. These subjects, termed elite controllers (ECs), are known to have stronger immune responses targeting HIV than the typical HIV-infected subject, but the exact mechanisms of how their immune responses control infection are not known. In this study, we identified five soluble immune signaling molecules (cytokines) in the blood that were higher in ECs than in subjects with typical chronic HIV infection. We demonstrated that these cytokines can activate CD4 + T cells, the target cells for HIV infection. Furthermore, these five EC-associated cytokines could change expression levels of intrinsic resistance factors, or molecules inside the target cell that fight HIV infection. This study is significant in that it identified cytokines elevated in subjects with a good immune response against HIV and defined potential mechanisms as to how these cytokines could induce resistance to the virus in target cells.

Author(s): Drozd, Daniel R; Kitahata, Mari M; Althoff, Keri N; Zhang, Jinbing; Gange, Stephen J; Napravnik, Sonia; Burkholder, Greer A; Mathews, William C; Silverberg, Michael J; Sterling, Timothy R; Heckbert, Susan R; Budoff, Matthew J; Van Rompaey, Stephen; Delaney, Joseph AC; Wong, Cherise; Tong, Weiqun; Palella, Frank J; Elion, Richard A; Martin, Jeffrey N; Brooks, John T; Jacobson, Lisa P; Eron, Joseph J; Justice, Amy C; Freiberg, Matthew S; Klein, Daniel B; Post, Wendy S; Saag, Michael S; Moore, Richard D; Crane, Heidi M | Abstract: BackgroundPrevious studies of cardiovascular disease (CVD) among HIV-infected individuals have been limited by the inability to validate and differentiate atherosclerotic type 1 myocardial infarctions (T1MIs) from other events. We sought to define the incidence of T1MIs and risk attributable to traditional and HIV-specific factors among participants in the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) and compare adjusted incidence rates (IRs) to the general population Atherosclerosis Risk in Communities (ARIC) cohort.MethodsWe ascertained and adjudicated incident MIs among individuals enrolled in 7 NA-ACCORD cohorts between 1995 and 2014. We calculated IRs, adjusted incidence rate ratios (aIRRs), and 95% confidence intervals of risk factors for T1MI using Poisson regression. We compared aIRRs of T1MIs in NA-ACCORD with those from ARIC.ResultsAmong 29,169 HIV-infected individuals, the IR for T1MIs was 2.57 (2.30 to 2.86) per 1000 person-years, and the aIRR was significantly higher compared with participants in ARIC [1.30 (1.09 to 1.56)]. In multivariable analysis restricted to HIV-infected individuals and including traditional CVD risk factors, the rate of T1MI increased with decreasing CD4 count [≥500 cells/μL: ref; 350-499 cells/μL: aIRR = 1.32 (0.98 to 1.77); 200-349 cells/μL: aIRR = 1.37 (1.01 to 1.86); 100-199 cells/μL: aIRR = 1.60 (1.09 to 2.34); l100 cells/μL: aIRR = 2.19 (1.44 to 3.33)]. Risk associated with detectable HIV RNA [l400 copies/mL: ref; ≥400 copies/mL: aIRR = 1.36 (1.06 to 1.75)] was significantly increased only when CD4 was excluded.ConclusionsThe higher incidence of T1MI in HIV-infected individuals and increased risk associated with lower CD4 count and detectable HIV RNA suggest that early suppressive antiretroviral treatment and aggressive management of traditional CVD risk factors are necessary to maximally reduce MI risk.

A subset of HIV-infected individuals termed elite controllers (ECs) maintain CD4+ T cell counts and control viral replication in the absence of antiretroviral therapy (ART). Systemic cytokine responses may differentiate ECs from subjects with uncontrolled viral replication or from those who require ART to suppress viral replication. We measured 87 cytokines in four groups of women: 73 ECs, 42 with pharmacologically suppressed viremia (ART), 42 with uncontrolled viral replication (noncontrollers [NCs]), and 48 HIV-uninfected (NEG) subjects. Four cytokines were elevated in ECs but not NCs or ART subjects: CCL14, CCL21, CCL27, and XCL1. In addition, median stromal cell-derived factor-1 (SDF-1) levels were 43% higher in ECs than in NCs. The combination of the five cytokines suppressed R5 and X4 virus replication in resting CD4+ T cells, and individually SDF-1β, CCL14, and CCL27 suppressed R5 virus replication, while SDF-1β, CCL21, and CCL14 suppressed X4 virus replication. Functional studies revealed that the combination of the five cytokines upregulated CD69 and CCR5 and downregulated CXCR4 and CCR7 on CD4+ T cells. The CD69 and CXCR4 effects were driven by SDF-1, while CCL21 downregulated CCR7. The combination of the EC-associated cytokines induced expression of the anti-HIV host restriction factors IFITM1 and IFITM2 and suppressed expression of RNase L and SAMHD1. These results identify a set of cytokines that are elevated in ECs and define their effects on cellular activation, HIV coreceptor expression, and innate restriction factor expression. This cytokine pattern may be a signature characteristic of HIV-1 elite control, potentially important for HIV therapeutic and curative strategies.

HIV causes inflammation that can be at least partially corrected by HAART. To determine the qualitative and quantitative nature of cytokine perturbation, we compared cytokine patterns in three HIV clinical groups, including HAART responders (HAART), untreated HIV noncontrollers, and HIV-uninfected (NEG).Multiplex assays were used to measure 32 cytokines in a cross-sectional study of participants in the Women's Interagency HIV Study. Participants from three groups were included: HAART (n = 17), noncontrollers (n = 14), and HIV NEG (n = 17).Several cytokines and chemokines showed significant differences between noncontrollers and NEG participants, including elevated interferon gamma-induced 10 (IP-10) and tumor necrosis factor-α (TNF-α) and decreased interleukin-12(p40) [IL-12(p40)], IL-15, and fibroblast growth factor-2 (FGF-2) in noncontroller participants. Biomarker levels among HAART women more closely resembled the NEG, with the exception of TNF-α and FGF-2. Secondary analyses of the combined HAART and noncontroller groups revealed that IP-10 showed a strong, positive correlation with viral load and negative correlation with CD4(+) T-cell counts. The growth factors vascular endothelial growth factor, epidermal growth factor, and FGF-2 all showed a positive correlation with increased CD4(+) T-cell counts.Untreated, progressive HIV infection was associated with decreased serum levels of cytokines important in T-cell homeostasis (IL-15) and T-cell phenotype determination (IL-12), and increased levels of innate inflammatory mediators such as IP-10 and TNF-α. HAART was associated with cytokine profiles that more closely resembled those of HIV-uninfected women. The distinctive pattern of cytokine levels in the three study groups may provide insights into HIV pathogenesis, and responses to therapy.

In this paper, the electrochemical impedance spectroscopy (EIS) mathematical model of TiO2 photoelectrocatalytic (PEC) reactions involving charge transfer and recombination through surface states was developed. The model was used to study the kinetics of photoelectrocatalytic decomposition of salicylic acid. The model simulation results show that the appearance of two distinguishable semicircles in the EIS response depends on the charging of surface state and light intensity. The experimental results demonstrated that similar phenomena to the theoretical simulation results. The model provides a way to obtain the rate constants for the photoelectrochemical reactions of surface states mediating charge transfer and recombination. The applied potential changes not only the recombination rate constant but also the charge-transfer rate constant. Moreover, the experimental EIS results here and those previous published on PEC degradation reactions can be explained by the present model satisfactorily. The relevance of surface states was discussed briefly. The results demonstrated that EIS is a powerful tool for studying the kinetics of PEC decomposition of organic pollutants on TiO2 electrodes.

Background Hepatitis C virus (HCV) is quickly spread through injection drug use. The prevalence and incidence of HCV in Chinese heroin users has been rarely reported. Methods A longitudinal cohort of young injection drug users (IDU) from southern China was established to study the risk factors for blood-borne infections (597 subjects). Individuals underwent analysis for the presence of hepatitis B surface antigen and antibodies to human immunodeficiency virus type 1 (HIV-1), HCV and hepatitis B surface antigen. Using self-reported risk behaviours, multivariate regression analysis was performed for factors associated with HCV prevalence and seroconversion. Results At baseline, HIV-1 and HCV prevalence was 17% and 72%, respectively. Significant factors associated with HCV seroprevalence included age >25 years (odds ratio [OR] = 1.71) and injection drug use for >2 years (OR = 2.60). HCV prevalence within one year of starting heroin use was 57% for any route of administration, and 80% if restricted to injectors. After two 6-month follow-up visits, 56 out of 159 baseline HCV seronegative individuals (148.9 total person years [py]), underwent seroconversion at an incidence rate of 37.6 per 100 py. Individuals who reported injection drug use were more likely to undergo HCV seroconversion (rate ratio [RR] = 6.59). Conclusions HCV infection is rapidly acquired in heroin users who adopt injection in southern China. This study emphasizes the urgent need to implement and expand injection prevention and primary substance abuse prevention programmes in China.

Hepatitis C virus (HCV) coinfection is present in 25% to 30% of HIV-infected persons in the United States [1]. Epidemiologic studies suggest that HCV seropositivity is linked to increased risk for chronic kidney disease (CKD) and end-stage renal disease (ESRD), in both the general population [2, 3] and human immunodeficiency virus (HIV)-infected individuals [4–6]. The association between HCV and CKD may be mediated by several potential mechanisms. First, HCV is associated with immune activation and immune complex glomerulonephritis [7–9]. Second, progressive liver disease, associated with longstanding HCV, may lead to hepatorenal syndrome. Third, HCV has been associated with an increased risk for diabetes [10], a leading cause of CKD and ESRD [11]. Additionally, the observed relationship between HCV and CKD may be confounded by heroin or cocaine use [12, 13], lower socioeconomic status [14, 15], and other factors that are associated with increased risk of CKD and ESRD. Approximately 20% of individuals who are infected with HCV clear the viremia, although the rate of HCV clearance is lower in HIV-infected persons [16]. To explore the contribution of persistent HCV viremia on CKD risk, we compared CKD incidence in a large cohort of HIV-infected subjects in North America according to HCV exposure status: (1) HCV seronegative, (2) HCV viremic (detectable HCV RNA) and (3) HCV aviremic (HCV seropositive with undetectable HCV RNA).

The risk of developing tuberculosis among persons infected with human immunodeficiency virus (HIV) has been reported to be extremely high in the first 3 months after initiation of highly active antiretroviral therapy (HAART), with rates ranging from 1300 to 1700 per 100000 person-years in developed countries [1, 2] and from 10700 to 23000 per 100000 person-years in developing countries [2, 3]. Tuberculosis diagnosed after HAART initiation may represent previously undiagnosed prevalent disease, newly acquired tuberculosis (ie, acquired since HAART initiation), or progression of subclinical tuberculosis that was not recognized prior to initiation of antiretroviral therapy (so-called tuberculosis unmasking) [4]. A subset of persons in the latter group may have immune reconstitution inflammatory syndrome, with a severe and/or pronounced clinical presentation [5–7]. With continued use of HAART, tuberculosis risk decreases over time, although the risk remains higher than in HIV-seronegative persons [1–3]. Tuberculosis rates shortly after HAART initiation could potentially be decreased if screening for active tuberculosis prior to HAART initiation were optimized. In the United States, it is recommended that persons infected with HIV undergo screening for latent Mycobacterium tuberculosis infection at the time of HIV diagnosis, and annually thereafter if they are at high risk for exposure to tuberculosis [8]. However, the guidelines do not address screening prior to HAART initiation—for either latent M. tuberculosis infection or active disease. Screening for tuberculosis prior to HAART initiation is not routinely performed in the United States and Canada [9, 10]. Risk factors for developing tuberculosis shortly after HAART initiation are incompletely understood. Predisposing factors in developed countries include low CD4+ lymphocyte count prior to HAART initiation and HIV transmission risk factors of heterosexual sex and injection drug use [1, 2]. In developing countries, risk factors include low CD4+ lymphocyte count, younger age, and male sex [2]. However, in a study from South Africa, only low CD4+ lymphocyte count in the 4 months prior to tuberculosis diagnosis was significantly associated with increased tuberculosis risk during antiretroviral therapy [3]. Low CD4+ lymphocyte count prior to antiretroviral therapy initiation also appears to be associated with “tuberculosis unmasking” [5, 7, 11]. Unmasked tuberculosis can become acid-fast bacillus smear-positive and therefore perhaps more readily transmitted to others than subclinical disease [7]. In one study, tuberculosis diagnosed in AIDS patients during the first 3 months of antiretroviral therapy was also associated with a 3-fold higher mortality rate than when diagnosed before or more than 3 months after antiretroviral therapy initiation [12]. The authors suggested that patients with tuberculosis unmasking have a higher mortality rate due to delays in tuberculosis diagnosis and initiation of antituberculosis therapy. A better understanding of the risk factors for developing tuberculosis in the first few months after antiretroviral therapy initiation—the objective of the present analysis—can help inform screening strategies to target patients at highest risk, both before and shortly after antiretroviral therapy initiation.

Determination of the prevalence of accumulated antiretroviral drug resistance among persons infected with human immunodeficiency virus (HIV) is complicated by the lack of routine measurement in clinical care. By using data from 8 clinic-based cohorts from the North American AIDS Cohort Collaboration on Research and Design, drug-resistance mutations from those with genotype tests were determined and scored using the Genotypic Resistance Interpretation Algorithm developed at Stanford University. For each year from 2000 through 2005, the prevalence was calculated using data from the tested subset, assumptions that incorporated clinical knowledge, and multiple imputation methods to yield a complete data set. A total of 9,289 patients contributed data to the analysis; 3,959 had at least 1 viral load above 1,000 copies/mL, of whom 2,962 (75%) had undergone at least 1 genotype test. Using these methods, the authors estimated that the prevalence of accumulated resistance to 2 or more antiretroviral drug classes had increased from 14% in 2000 to 17% in 2005 (P < 0.001). In contrast, the prevalence of resistance in the tested subset declined from 57% to 36% for 2 or more classes. The authors' use of clinical knowledge and multiple imputation methods revealed trends in HIV drug resistance among patients in care that were markedly different from those observed using only data from patients who had undergone genotype tests.

Background. We sought to examine coinfection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) among injection drug users (IDUs) in Guangxi, China. Methods. A longitudinal cohort of IDUs (547 subjects) was established to study risk factors for bloodborne infections. At each visit, participants completed questionnaires defining demographic characteristics, patterns of drug use, and sexual behaviors. Blood samples were collected and analyzed for the presence and genotype of HIV and HCV. Results. Coinfection with HIV and HCV was found in 17.6% of the IDUs. HCV was present in 95.1% of HIV-positive and 70.4% of HIV-negative heroin users. The prevalence of HIV in HCV-positive and HCV-negative heroin users was 23.4% and 3.6%, respectively. Multivariate logistic regression analysis revealed that sexual activity during the past 6 months and duration of injection drug use were significantly associated with coinfection with HIV and HCV. The main circulating HCV genotypes included 6a (38%), 3b (37%), and 1a (19%), whereas genotypes 6e (4%), 3a (2%), and 1b (1%) were present in only a few IDUs. Multiple HCV genotypes were present at each study site and did not segregate by HIV status or subtype. Conclusions. HCV is highly prevalent in IDUs throughout southern China. In Guangxi, HIV infections are the result of parenteral and sexual transmission, and, therefore, all IDUs are at high risk of coinfection with HIV and HCV. Molecular tracking of HCV may be a more sensitive predictor of the future spread of the HIV-1 epidemic than is HIV subtyping. This study emphasizes that, without implementation of injection prevention and primary substance abuse programs in China, the extent and effect of coinfection with HIV and HCV will only increase.

There is a vigorous change in cytokine response in individuals with HIV infection. Although this is mitigated by highly active antiretroviral therapy (HAART) and natural control of virus, cytokine levels remain perturbed. To identify and investigate serum cytokines that may play a role in control of viremia or immune-related pathogenesis, we compared four groups from the Women’s Interagency HIV Study defined by HIV clinical status: ELITE controllers (viral load

Perturbation bounds of subspaces, such as eigen-spaces, singular subspaces, and canonical subspaces, have been extensively studied in the literature. In this paper, we study perturbations of some constrained subspaces of 1×2, 2×1, and 2×2 block matrices, in which only one of the sub-matrices can be changed. Such problems rise from the least squares–total least squares problem, the constrained least squares problem, and the constrained total least squares problem.

In the 30 years since the HIV epidemic was recognized in the United States, remarkable advances in treatment have turned a rapidly fatal disease into a chronic illness for persons who are aware of their infection and can access effective care (1, 2). The Centers for Disease Control and Prevention (CDC) estimates that 1.2 million persons live with HIV in the United States (3). The estimated annual rate of new HIV infections between 2006 and 2009 ranged from 19.0 to 22.5 per 100 000 population (approximately 47 800 to 56 000 new infections per year), with most occurring among men who have sex with men (MSM) and African Americans (4). A central component of the National HIV/AIDS Strategy (5) is to monitor the health of the growing number of Americans living with HIV infection who receive HIV treatment. Although seemingly simple, such monitoring is actually a substantial epidemiologic challenge because of the complexity of the U.S. health care system. Many of the studies that have reported trends in the clinical outcomes of persons receiving HIV care (6–12) have been limited to discrete populations, and their findings have not been generalizable to all HIV-infected Americans. Two projects have been specifically designed to be nationally representative. The HCSUS (HIV Cost and Services Utilization Study) (13, 14) enrolled a national probability sample of HIV-infected adults receiving care from 1996 to 1998. Although useful a decade ago, data from this population no longer reflect the substantial improvements in HIV care in the past 14 years. The Medicapl Monitoring Project is an ongoing CDC-sponsored, multisite, supplemental national surveillance project designed to capture contemporary data about behaviors, medical care, and health status of HIV-infected adults in the United States through annual cross-sectional surveys (15). Data are compiled from the medical records of persons in care, who are selected through a 3-stage probability sampling scheme designed to produce a representative sample. Participants in the Medical Monitoring Project are not followed longitudinally, which limits its capacity to evaluate such associations as those between treatment and clinical outcomes, including survival. Conversely, even very large longitudinal cohort studies are not perfectly representative. Neither longitudinal cohort studies nor cross-sectional probability surveys alone can provide the most complete and accurate picture of HIV-infected persons in care; however, by addressing limitations of the other, together they provide highly useful, complementary information. The NA-ACCORD (North American AIDS Cohort Collaboration on Research and Design) is the continent’s largest collaboration of longitudinal HIV cohort studies and has compiled clinical data from more than 100 clinical sites in the United States and Canada since 2005 (16). In this analysis, we assessed the extent to which attributes of persons receiving HIV care in an NA-ACCORD–participating U.S. clinical cohort are similar to those of persons living with HIV in the United States (PLWH-US) who are reported to the CDC’s HARS (Center’s for Disease Control’s HIV/AIDS Reporting System). We then examined the following illustrative and linked health outcomes among HIV-infected persons in care: trends in prescribed antiretroviral therapy (ART), HIV RNA plasma viral load (HIV VL), and CD4 T-lymphocyte (CD4) cell count at death. Our objective was to investigate the utility of NA-ACCORD for monitoring the U.S. HIV epidemic and for informing the progress made toward achieving the targets of the National HIV/AIDS Strategy.