Hydraulic characteristics of orifice plate

957-962In some hydropower projects, the height of the dams exceed the level of 300 m. Orifice plate energy dissipater, as a kind of effective energy dissipater with characteristics of economic value, has been welcomed more and more by hydraulics researchers. The energy loss coefficient relating directly to the energy dissipation ratio is an important index for this energy dissipater design. In the present paper, this coefficient and relative parameters, such as contraction ratio of the orifice plate diameter and the flood discharge tunnel diameter, ratio of the orifice plate thickness to the tunnel diameter, and Reynolds number of the flow through orifice, were analyzed by theoretical considerations and their relationship expressions obtained by experiment. It could be concluded that the energy loss coefficient was mainly dominated by the contraction ratio of the orifice plate. The less the contraction ratio of the orifice plate is the larger is this coefficient. The research results demonstrate that the effects of Reynolds number could be neglected on this coefficient when Reynolds number is larger than 105 and that the orifice plate’s thickness has slight impact on the energy loss coefficient

Enlarging the Stokes Shift by Weakening the π-Conjugation of Cyanines for High Signal-To-Noise Ratiometric Imaging

The signal-to-noise ratio (SNR) is one of the key features of a fluorescent probe and one that often defines its potential utility for in vivo labeling and analyte detection applications. Here, it is reported that introducing a pyridine group into traditional cyanine-7 dyes in an asymmetric manner provides a series of tunable NIR fluorescent dyes (Cy-Mu-7) characterized by enhanced Stokes shifts (≈230 nm) compared to the parent cyanine 7 dye (nm). The observed Stokes shift increase is ascribed to symmetry breaking of the Cy-Mu-7 core and a reduction in the extent of conjugation. The fluorescence signals of the Cy-Mu-7 dyes are enhanced upon confinement within the hydrophobic cavity of albumin or via spontaneous encapsulation within micelles in aqueous media. Utilizing the Cy-Mu-7, ultra-fast in vivo kidney labeling in mice is realized, and it is found that the liver injury will aggravate the burden of kidney by monitoring the fluorescence intensity ratio of kidney to liver. In addition, Cy-Mu-7 could be used as efficient chemiluminescence resonance energy transfer acceptor for the reaction between H O and bisoxalate. The potential utility of Cy-Mu-7 is illustrated via direct monitoring fluctuations in endogenous H O levels in a mouse model to mimic emergency room trauma

Gender Difference in 2-Year Mortality and Immunological Response to ART in an HIV-Infected Chinese Population, 2006–2008

Since it was initiated in 2002, the China Free Antiretroviral Treatment (ART) Program has been progressing from an emergency response to a standardized treatment and care system. As of December 31, 2009, a total of 81,880 patients in 31 provinces, autonomous regions, and special municipalities received free ART. Gender differences, however, in mortality and immunological response to ART in this cohort have never been described.To understand whether women and men who enrolled in the China National Free ART Program responded equally well to the treatment.A retrospective analysis of the national free ART databases from June 2006-December 2008 was performed. HIV-infected subjects who were 18 years or older, ART naïve at baseline, and on a 3TC regimen enrolled in the program from June 1 to December 31, 2006, were included in this study, then followed up to 2 years.Among 3457 enrolled subjects who met the inclusion criteria, 59.2% were male and 40.8% female. The majority of the subjects were 19-44 years old (77%) and married (72%). Over the full 24 months of follow-up, the mortality rate was 19.0% in males and 11.4% in females (p = 0.0014). Males on therapy for 3-24 months were more likely to die than females (HR = 1.46, 95% CI: 1.04-2.06, p = 0.0307) after adjusting for baseline characteristics. Compared to men, women had higher CD4+ counts over time after initiating ART (p<0.0001).Our study showed that women had an overall lower mortality and higher CD4+ counts than men in response to ART treatment, which may be attributed to adherence, biological factors, social, cultural and economic reasons. Further study is needed to explore these factors that might contribute to the gender differences in mortality and immunological response to ART

Effects and interaction of air pollution and meteorological factors on pertussis incidence in P.R.China

Background: Previous studies on the risk of pertussis exposure to atmospheric pollutants are still inconclusive. Methods: Air pollutant, meteorological data and epidemiological distribution of pertussis cases in China during 2004–2018 were concluded in this study. A distributed lag nonlinear model (DLNM) for a maximum lag of 15 months was developed to evaluate the lag effects of monthly air pollutants and meteorological factors on pertussis incidence. Then a generalized additive model (GAM) was constructed to explore the interaction effect among air pollutants, meteorological factors and pertussis incidence and the stratified effect of selected variables. Results: A total of 74,249 cases of pertussis were included during 2004–2018 in China. Long-term exposure to NO2 was positively associated with the risk of pertussis at 32–94 µg/m3. Interaction and stratified analyses showed that there were certain correlations between 4 air pollutants (PM2.5, SO2, NO2, and O3) and 3 meteorological factors (temperature, sunlight and wind speed). In the high PM2.5 environment, a unit increment in NO2 contributed to a 2.52% (95% CI: 2.13%-2.92%) increase in pertussis incidence risk, while in a low PM2.5 environment, a unit increment of NO2 contributed to a 2.16% (95% CI: 1.64%-2.69%) increase in pertussis incidence risk. Conclusions: Our study indicated that air pollutants and meteorological factors have delayed effects on the occurrence of pertussis in China, and the effect of NO2 can be modified by PM2.5, SO2, and O3. In the prevention and control of pertussis, the additive effect of different factors on pertussis and the variability of weather should be considered

Distribution and genetic diversity of adeno-associated viruses in bats from coastal areas of Southeast China

Bats are associated with several important zoonotic viruses from different families. One example includes adeno-associated viruses (AAVs), that are extensively detected in several animals, especially primates. To understand AAVs distribution and genetic diversity in the coastal areas of Southeast China, a total of 415 intestine samples were mostly collected from two provinces of southeast China, i.e., Zhejiang and Fujian province. Intestine samples from five bat species were collected for AAVs detection. The average prevalence rate for AAV detection among these samples was 18.6% (77 positives out of 415 samples) and ranged from 11.8 to 28.9% between the five bat species. This suggests that AAVs are widely distributed in diverse bat populations in southeast coastal areas of China. Based on the genome sequence of bat adeno-associated virus-CXC1(BtAAV-CXC1) from one AAV-positive sample, the genetic diversity of the detected AAVs were assessed and analyzed. Phylogenetic analysis revealed that BtAAV-CXC1 was comparatively distant to other major AAVs from mammals and non-mammals, with only a 52.9~64.7% nucleotide identity. However, they were phylogenetically closer to Rhinolophus sinicus bat adeno-associated virus (Rs-BtAAV1), with a 74.5% nt similarity. Partial analysis of the rep and cap overlapping open reading frame (ORF) sequences from bat AAV samples revealed 48 partial rep sequences and 23 partial cap sequences from positive samples shared 86.9 to 100% and 72.3 to 98.8% nucleotide identities among themselves, respectively. This suggests that the detected AAVs had a distinctly high genetic diversity. These findings led us to conclude that diverse AAVs may be widely distributed in bat populations from the southeast regions of China