Search

Cre-lox technology has revolutionized research in renal physiology by allowing site-specific genetic recombination in individual nephron segments. The distal convoluted tubule (DCT), consisting of distinct early (DCT1) and late (DCT2) segments, plays a central role in Na+ and K+ homeostasis. The only established Cre line targeting the DCT is Pvalb-Cre, which is limited by noninducibility, activity along DCT1 only, and activity in neurons. Here, we report the characterization of the first Cre line specific to the entire DCT. CRISPR/Cas9 targeting was used to introduce a tamoxifen-inducible IRES-Cre-ERT2 cassette downstream of the coding region of the Slc12a3 gene encoding the NaCl cotransporter (NCC). The resulting Slc12a3-Cre-ERT2 mice were crossed with R26R-YFP reporter mice, which revealed minimal leakiness with 6.3% of NCC-positive cells expressing yellow fluorescent protein (YFP) in the absence of tamoxifen. After tamoxifen injection, YFP expression was observed in 91.2% of NCC-positive cells and only in NCC-positive cells, revealing high recombination efficiency and DCT specificity. Crossing to R26R-TdTomato mice revealed higher leakiness (64.5%), suggesting differential sensitivity of the floxed site. Western blot analysis revealed no differences in abundances of total NCC or the active phosphorylated form of NCC in Slc12a3-Cre-ERT2 mice of either sex compared with controls. Plasma K+ and Mg2+ concentrations and thiazide-sensitive Na+ and K+ excretion did not differ in Slc12a3-Cre-ERT2 mice compared with controls when sex matched. These data suggest genetic modification had no obvious effect on NCC function. Slc12a3-Cre-ERT2 mice are the first line generated demonstrating inducible Cre recombinase activity along the entire DCT and will be a useful tool to study DCT function.

In this study, the scenario analysis method was used to establish motor vehicle exhaust emission inventories based on road-traffic-flow information of the Beijing subsidiary administrative center under different scenarios, with a base year of 2015. The pollutant emissions in 2020 and 2025 were forecast by calculating the motor vehicle pollutant emission inventories of future road-traffic-flow information and various scenarios. The results showed that the kilometers travelled via motor vehicles and the road network density of the Beijing subsidiary administrative center both will increase continuously over the next 10 years. Compared with the baseline scenario, each control scenario had a certain degree of reduction in pollutant emissions, and the reduction rates increased with the strengthening of the measures. The emission reductions of pollutants were significant in the new energy vehicle promotion scenario, especially for NO

This study proposes a method for high-resolution vehicle emission inventories at county scale based on field investigations and Google Earth satellite images, using the Tongzhou district of Beijing as an example for data analysis. VKT and the corresponding emissions of each pollutant were calculated using the number of registered vehicles and the real-time traffic volumes, respectively. The results showed that the mileage calculated based on the method using registered vehicles is about 37% less than that based on real-time traffic volumes, with the latter method providing data closer to the actual situation. The mileage for small passenger cars, large passenger vehicles, and medium-duty trucks were underestimated, and that for light trucks, heavy trucks, low-speed trucks were overestimated based on the registered vehicle method. Emissions from small passenger cars were also underestimated by about 51%, using the registered vehicle method. For emissions of large passenger vehicles, light trucks, and medium-duty trucks, there was less difference between the two methods. Based on the registered vehicle method, emissions of heavy trucks, low-speed trucks, and motorcycles were overestimated by about 41%, 30%, and 30%, respectively.

Despite advances in conventional therapies, treatment of prostate cancer is still a challenge. The study aims to assess the possible anti-cancer effects of tangeretin, a dietary flavonoid on human prostate cancer cells (DU145, PC3, LNCaP). Tangeretin (25, 50 and 100 µM) significantly inhibited cancer cell viability and induced DNA fragmentation and apoptosis by increasing caspase-3 and pro-apoptotic proteins (Bad and Bax) with reduced anti-apoptotic proteins (Bcl-2 and Bcl-xL) expressions. Significant inhibition of androgen receptor (AR) and prostate specific antigen (PSA) were seen. Dose-dependent inhibition in Notch signal was observed in expression of Notch 1 and Jagged 1 along with PI3/Akt/mTOR signalling pathway. The results suggest that tangeretin inhibited prostate cancer cell proliferation and induced apoptosis via inhibiting critical pathways in cancer development - AR signalling and PI3/Akt/mTOR - Notch signalling pathways.

In the designing of the straight line conjugate internal meshing gear pump, it is very important for us to analyze its flow field performance. In this paper, FLUEN is utilized to analyze its flow field which bases on moving grid computing ,the paper can get factors that structure impacts on performance. The work provides reference and a certain theory foundation for optimization of the gear pump and straight line conjugate internal meshing gear pump will be widely used in engineering machinery.

The system models for analysis and optimization of an electro-hydraulic proportional synchronous system is presented based on AMESim. This paper studies the control strategy for the improvements of the response time, steady-state accuracy, stability and synchronization of the system. The speed of a hydraulic motor can be controlled through regulation of the PID controller by the genetic algorithm. Simulation results show that performances of the system have been improved and expected results can also have been obtained.

Focusing on the performance of proportional valve controlled cylinder, by using AMESim simulation software, dynamic performance of the system has been simulated. Starting by the control strategy, using Genetic Algorithm,the PID parameters which can affect the hydraulic cylinder position accuracy will be optimized. The simulation results show that the optimized parameters can improve system performance, and achieved excellent results.

Vehicle emission is one of the primary factors affecting the quality of atmospheric environment in Beijing. In order to improve the air quality during APEC conference, strict control measures including vehicle emission control were taken in Beijing during APEC meeting. Based on the activity level data of traffic volume, vehicle speed and vehicle types, the inventory of motor vehicle emissions in Beijing was developed following bottom-up methodology to assess the effectiveness of the control measures. The results showed that the traffic volume of Beijing road network during the APEC meeting decreased significantly, the vehicle speed increased obviously, and the largest decline of traffic volume was car. CO, NOx, HC and PM emissions of vehicle exhaust were reduced by 15.1%, 22.4%, 18.4% and 21.8% for freeways, 29.9%, 36.4%, 32.7% and 35.8% for major arterial, 35.7%, 41.7%, 38.4% and 41.2% for minor arterial, 40.8%, 46.5%, 43.1% and 46.0% for collectors, respectively. The vehicles exhaust emissions inventory before and during APEC conference was developed based on bottom-up emissions inventory method. The results indicated that CO, NOx, HC and PM emissions of vehicle exhaust were reduced by 37.5%, 43.4%, 39.9% and 42.9% in the study area, respectively.

High-quality β-Ga2O3 films andβ-Ga2O3 /ZnO/β-Ga2O3 nano composite thin films were fabricated on the sapphire substrates in the high vacuum atmosphere by laser molecular beam epitaxy (LMBE). The lattice structure and optical properties of these films were characterized.With the increase of the sputtering time of ZnO target ,Photoluminescence spectrums and Raman spectrums of the β-Ga2O3 /ZnO/β-Ga2O3 nano composite films were shifted regularly . When the ZnO target was sputtered 30min , the stronggest peak of Raman spectrum was appeared at 267nm . Besides,the composition ofβ-Ga2O3 /ZnO/β-Ga2O3 nano composite film was described .

Background Clinical isolates of human cytomegalovirus (HCMV) display polymorphisms in multiple genes. Some authors have suggested that polymorphisms are implicated in HCMV-induced immunopathogenesis, as well as in strain-specific behaviors, such as tissue-tropism and the ability to establish persistent or latent infections. Objective To describe the features of HCMV UL148A, UL148B, UL148C and UL148D open reading frames (ORFs) and the variable sites within the frames in clinical strains. Study design PCR was performed to amplify these ORFs in 22 clinical strains. PCR amplification products were sequenced directly and analyzed. Results The nucleotide diversity of UL148A, UL148B, UL148C and UL148D ORFs in studied strains is 0.5–8.3%, 0.5–4.6%, 0.5–3% and 1.7–8.1%, respectively; the amino acid diversity of their putative proteins is 1.3–6.3%, 1.3–5.0%, 1.3–3.9% and 1.7–8.1%, respectively, related to the Merlin strain. The modification sites of UL148A, UL148B, UL148C and UL148D predicted proteins from strains in unpassaged urine samples were conserved, except for strain U96, compared with that of the Merlin strain. By phylogenetic and statistical analysis, the UL148A and UL148D sequences of clinical strains were classified into three groups. Conclusion Compared to the UL148A, UL148B and UL148D ORFs, the UL148C ORF was relatively conserved, as was the amino acid sequence of the UL148C putative protein. Isolates that have been passaged several times in human embryonic lung fibroblasts (HELF) showed some changes of modification sites, however. A discrete linkage was found between the groups of UL148A gene and those of UL148D gene.

SummaryA balance between Six2-dependent self-renewal and canonical Wnt signaling-directed commitment regulates mammalian nephrogenesis. Intersectional studies using chromatin immunoprecipitation and transcriptional profiling identified direct target genes shared by each pathway within nephron progenitors. Wnt4 and Fgf8 are essential for progenitor commitment; cis-regulatory modules flanking each gene are cobound by Six2 and β-catenin and are dependent on conserved Lef/Tcf binding sites for activity. In vitro and in vivo analyses suggest that Six2 and Lef/Tcf factors form a regulatory complex that promotes progenitor maintenance while entry of β-catenin into this complex promotes nephrogenesis. Alternative transcriptional responses associated with Six2 and β-catenin cobinding events occur through non-Lef/Tcf DNA binding mechanisms, highlighting the regulatory complexity downstream of Wnt signaling in the developing mammalian kidney.

Human cytomegalovirus (HCMV) is often a dangerous opportunistic pathogen that causes significant morbidity and mortality in newborn children and immunocompromised patients. The different symptoms and tissue tropisms of HCMV infection may result from genetic polymorphism. This study investigated the sequence variability of the HCMV US28 ORF, which shows sequence homology to the G protein-coupled receptor. HCMV isolated from suspected pediatric cases and isolates from AIDS patients were compared in order to examine the possible associations between polymorphisms and pathogenesis. Seventy children with suspected congenital HCMV infection, who suffered from jaundice (47), megacolon (10), and microcephaly (13), and 17 AIDS patients, were studied. Mutation was prevalent among the sequences of US28, with a focus on the two ends of US28. The important functional groups of US28 are highly conserved. An unrooted tree showed that all sequences from suspected congenitally infected infants and AIDS patients were divided into three groups. Comparison showed that most of the sequences (12/17) from pediatric patients were included in the first group (G1), whereas most of the sequences (11/17) from AIDS patients were included in the third group (G3). The specific high mutation sites in US28 from children were located at the C terminus of the protein, whereas those from AIDS patients were located at the N terminus. We demonstrated the existence of polymorphisms among the US28 genes of clinical isolates of HCMV from infants with suspected congenital infection. Comparison of US28 sequences from AIDS patients with those from children showed that both sequences have their own specific high mutation points.

There are some problems of hydraulic performance in the low specific speed centrifugal pump, such as small capacity, low efficiency. In this paper, the long-short blade method and enlarging flow method is applied to optimize the impeller. In design of impeller optimizing, author uses CFD technology to predict model performance, analyzes the test results, finally gets the best parameters combination of the impeller. Testing result for the prototype of product proves that the optimized impeller model has a good hydraulic performance, indicating that CFD will help designer optimize centrifugal pumps.

To study the polymorphism of human cytomegalovirus US28 gene in children and investigate the relationship between the polymorphism and pathogenesis.The FQ-PCR was carried out to determine the DNA quantity of clinical isolate and then the segmental PCR and HMA-SSCP were performed to test the mutation of US28 gene. The typical isolates from different diseases were selected to clone and sequence, then the results were analyzed.The nucleic acid mutation is frequent among the sequence of US28, those mutations focus on the two ends of US28, but most of them are sense mutation. The important functional groups of US28 are highly conserved. The amino acid mutation of some isolates resulted in the change of secondary structure, but the phylogenetic tree analysis did not show any clear association between the pathogenesis and the distribution of clinical isolates. The comparison of US28 sequences from AIDS patients with the sequences from children in our study showed that both sequences have their own specific high mutation points.There is polymorphism among the HCMV-US28 gene of clinical isolates from children. There observed no clear relationship was between the pathogenesis and the distribution of clinical isolates.