The effects of transboundary air pollution following major events in China on air quality in the U.S.: Evidence from Chinese New Year and sandstorms

Transboundary air pollution is a global environmental and public health problem including in the U.S., where pollution emissions from China, the largest emitter of anthropogenic air pollution in the world, can travel across the Pacific Ocean and reach places like California and Oregon. We examine the effects of transboundary air pollution following major events in China, specifically sandstorms, a natural-occurring source of air pollution, and Chinese New Year, a major 7-day holiday, on background air quality in the U.S. We focus on high elevation sites on the west coast between 2000 and 2013. We use regression analysis and a natural experiment to exploit the variation in the timing of these events in China, which are plausibly uncorrelated to other factors that affect air quality in China and the U.S. We find that sandstorms are associated with statistically significant increases in background coarse and fine particulate matter (PM) in the U.S., representing between 16 and 39% of average weekly PM levels. We also find Chinese New Year is associated with modest reductions in background air quality in the U.S., representing between 0.4 and 2.5% of PM levels. Findings are robust to different models and falsification tests. These results suggest that regression analysis could be a powerful tool to complement other, more widely used techniques in the environmental sciences that study this problem. This also has important implications for policymakers, who could track major sandstorms in China and prepare for possible increased foreign pollution emissions in the U.S.

Palladium-Catalyzed Enantioselective Desymmetrizing Aza-Wacker Reaction: Development and Application to the Total Synthesis of (-)-Mesembrane and (+)-Crinane

Reported is an unprecedented catalytic enantioselective desymmetrizing aza-Wacker reaction. In the presence of a catalytic amount of a newly developed Pd(CPA)₂ (MeCN)₂ catalyst (CPA=chiral phosphoric acid), a pyrox ligand, and molecular oxygen, cyclization of properly functionalized prochiral 3,3-disubstituted cyclohexa-1,4-dienes afforded enantioenriched cis-3a-substituted tetrahydroindoles in good yields with excellent enantioselectivities. A cooperative effect between the phosphoric acid and the pyrox ligand ensured efficient transformation. This reaction was tailor-made for Amaryllidaceae and Sceletium alkaloids as illustrated by its application in the development of the concise and divergent total synthesis of (-)-mesembrane and (+)-crinane.

A remote computing based point-of-care colorimetric detection system with a smartphone under complex ambient light conditions

Colorimetric detection under complex ambient light conditions without a light-tight box.

miR-122 promotes metastasis of clear-cell renal cell carcinoma by downregulating Dicer

Although overall downregulation of microRNAs (miRNAs) is a general feature of clear-cell renal cell carcinoma (ccRCC), several miRNAs are consistently upregulated, among which miR-122 was markedly increased in ccRCC tissues. Our study aims to determine the functional importance and underlying mechanism of miR-122 in ccRCC metastasis. Here, we demonstrate that the expression of miR-122 increased in ccRCC tissues, and higher miR-122 expression was found in ccRCC tissues with metastatic disease than in those without metastasis. The increased miR-122 levels were associated with poor metastasis-free survival in ccRCC patients with localized disease. Dicer was validated as a direct functional target of miR-122. Overexpression of miR-122 promoted migration and invasion of ccRCC cells in vitro and metastatic behavior of ccRCC cells in vivo. Inhibition of miR-122 attenuated this metastatic phenotype in vitro. Importantly, miR-122 exerted its pro-metastatic properties in ccRCC cells by downregulating Dicer and its downstream effector, the miR-200 family, thereby inducing epithelial-mesenchymal transition (EMT). Our results suggest an important role of the miR-122/Dicer/miR-200s/EMT pathway in ccRCC metastasis. Furthermore, miR-122 may serve as a biomarker for discriminating ccRCC with metastatic potential.

A highly sensitive turn-on fluorescent chemosensor for recognition of Zn2+ and Hg2+ and applications

A fluorescence probe has been designed and synthesized, and applied with a combined theoretical and experimental study. Research suggests that the probe can be used to sense Zn²⁺ and Hg²⁺ through selective turn-on fluorescence responses in the aqueous HEPES buffer (0.05M, pH=7.4). The limit of detection (LOD) were determined as 1.46×10^-7M (Zn²⁺) and 2.50×10^-7M (Hg²⁺). Moreover, based on DFT, the geometry optimizations of probe 1, [1-Hg²⁺] complex and [1-Zn²⁺] complex were carried out using the Gaussian 09 program, in which the B3LYP function was used. The electronic properties of free probe 1 and the metal complexes were studied based on the Natural Bond Orbital (NBO) analyses. The probe 1 has also been successfully applied to detection of Zn²⁺ and Hg²⁺ in living cells.

The gut microbiota, bile acids and their correlation in primary sclerosing cholangitis associated with inflammatory bowel disease

Background

Patients with primary sclerosing cholangitis associated with inflammatory bowel disease (PSC-IBD) have a very high risk of developing colorectal neoplasia. Alterations in the gut microbiota and/or gut bile acids could account for the increase in this risk. However, no studies have yet investigated the net result of cholestasis and a potentially altered bile acid pool interacting with a dysbiotic gut flora in the inflamed colon of PSC-IBD.

Aim

The aim of this study was to compare the gut microbiota and stool bile acid profiles, as well as and their correlation in patients with PSC-IBD and inflammatory bowel disease alone.

Methods

Thirty patients with extensive colitis (15 with concomitant primary sclerosing cholangitis) were prospectively recruited and fresh stool samples were collected. The microbiota composition in stool was profiled using bacterial 16S rRNA sequencing. Stool bile acids were assessed by high-performance liquid chromatography tandem mass spectrometry.

Results

The total stool bile acid pool was significantly reduced in PSC-IBD. Although no major differences were observed in the individual bile acid species in stool, their overall combination allowed a good separation between PSC-IBD and inflammatory bowel disease. Compared with inflammatory bowel disease alone, PSC-IBD patients demonstrated a different gut microbiota composition with enrichment in Ruminococcus and Fusobacterium genus compared with inflammatory bowel disease. At the operational taxonomic unit level major shifts were observed within the Firmicutes (73%) and Bacteroidetes phyla (17%). Specific microbiota-bile acid correlations were observed in PSC-IBD, where 12% of the operational taxonomic units strongly correlated with stool bile acids, compared with only 0.4% in non-PSC-IBD.

Conclusions

Patients with PSC-IBD had distinct microbiota and microbiota-stool bile acid correlations as compared with inflammatory bowel disease. Whether these changes are associated with, or may predispose to, an increased risk of colorectal neoplasia needs to be further clarified.

Expression of Dominant Negative K6W-Ubiquitin in the Lens Epithelium via an Adenoviral Vector Delays Posterior Capsule Opacification in a Rabbit Model

PURPOSE

Ubiquitin is involved in cell proliferation and differentiation, and the objective of this study is to investigate the potential of dominant negative Ubiquitin (Ub) with a lysine to tryptophan mutation at the 6 position (K6W) through an adenoviral expression vector in the prevention of posterior capsule opacification (PCO) in a rabbit PCO model.

METHODS

Recombinant dominant negative K6W-Ub adenovirus (RAd-K6W-Ub) with green fluorescent protein (RAd-K6W-Ub/GFP) and RAd-GFP viruses (control) were generated with QBI-HEK 293A cells. New Zealand rabbits receiving lens phacoemulsification were given an intraoperative anterior chamber injection of the viruses. The images of anterior segment photography taken by a slit lamp biomicroscopy were analyzed by posterior capsule opacification manual software (POCOman) for PCO grading. The intraocular pressure (IOP) was detected with a non-contact tonometer (NCT). The expression of α-smooth muscle actin (α-SMA) was assessed by Western blotting. Cell migration ability in cultured rabbit's lens epithelial cells (LECs) was evaluated by scratch healing assay.

RESULTS

The expression of GFP and Ub in the lens epithelium was markedly upregulated after 48 hours vector injection. Eyes injected with RAd-K6W-Ub showed a significantly lower PCO degree compared with controls. Meanwhile, higher IOP and corneal edema was observed in groups with a higher RAd-K6W-Ub virus dosage. The expression of α-SMA was down-regulated in the RAd-K6W-Ub eyes as compared to controls at the 15th day after injection. Cell migration was inhibited by RAd-K6W-Ub infection.

CONCLUSIONS

RAd-K6W-Ub at an appropriate dosage could inhibit the proliferation of LECs and the formation of PCO in rabbit models. However, a higher dosage of Rad- K6W-Ub viral vector caused toxic effects to the surrounding tissues, such as corneal edema and high IOP.

Chymotrypsin with sialendoscopy-assisted surgery for the treatment of chronic obstructive parotitis

Chronic obstructive parotitis (COP) is a common disease of the parotid gland. A total of 104 patients with COP were identified and randomized into a treatment group (52 cases) and a control group (52 cases). All patients underwent sialography and salivary gland scintigraphy (SGS) examinations before surgery. The patients in the treatment group received chymotrypsin combined with gentamicin via interventional sialendoscopy to irrigate the duct, and the control group received gentamicin alone. All patients were asked to record their pain on a visual analogue scale (VAS) before treatment and at 1 week, 2 weeks, 1 month, 3 months, and 6 months after surgery. The VAS score for pain intensity was decreased at 1 week post-treatment in both groups (P<0.05). Compared to the control group, the VAS score was lower in the treatment group at 1 week, 2 weeks, and 1 month post-treatment (P<0.05). The 6-month postoperative SGS results showed improved uptake and excretion in both groups (P<0.05). The treatment group exhibited higher scores for postoperative SGS excretion than the control group (P<0.05). The administration of chymotrypsin combined with gentamicin by sialendoscopy is effective for the treatment of non-stone-related COP and specifically improves the excretion function of the parotid gland.

A multifunctional Schiff base as a fluorescence sensor for Fe3+ and Zn2+ ions, and a colorimetric sensor for Cu2+ and applications

Chemosensors play important parts in the selective recognition of ions, which is widely applied in various fields of environment, industry and biological sciences. In this work, a chemosensor for multi-metal ions based on rhodamine B derivative was synthesized, which could selectively recognize various metal ions in different solvent system. The addition of Cu²⁺ caused the color change from colorless to pink in EtOH/H₂O (v/v=1:1) solvent system, which could be quickly identified by the naked eyes with a detection limit of 8.27×10^-8M. In ethanol solution system, the addition of Fe³⁺ and Zn²⁺ caused different fluorescence changes with the detection limit of 2.12×10^-7M and 6.64×10^-7M respectively. The binding ratios are 1:1 (1-Cu²⁺), 2:1 (1-Fe³⁺) and 1:1 (1-Zn²⁺), respectively. Meanwhile, the probe 1 was used to detect the trace metal ions in real water samples. Besides, the probe 1 showed sensitive fluorescence signals for Fe³⁺ in biological cells. The experimental results further verify the application value of the sensor.

Upregulation of Far Upstream Element-Binding Protein 1 (FUBP1) Promotes Tumor Proliferation and Tumorigenesis of Clear Cell Renal Cell Carcinoma

OBJECTIVE

The far upstream element (FUSE)-binding protein 1 (FUBP1) is a transactivator of human c-myc proto-oncogene transcription, with important roles in carcinogenesis. However, the expression pattern and potential biological function of FUBP1 in clear cell renal cell carcinoma (ccRCC) is yet to be established.

METHODS

FUBP1 expression was detected in ccRCC tissues and cell lines by real-time RT-PCR, Western blot analysis, and immunohistochemistry. The correlations of FUBP1 mRNA expression levels with clinicopathological factors were evaluated. The biological function of FUBP1 during tumor cell proliferation was studied by MTS, colony formation, and soft-agar colony formation. The effects of FUBP1 on cell cycle distribution and apoptosis were analyzed by flow cytometry. Western blot analysis was used to identify the potential mechanism of FUBP1 regulating cell cycle and apoptosis.

RESULTS

The levels of FUBP1 mRNA and protein expression were upregulated in human ccRCC tissues compared with adjacent noncancerous tissues. High levels of FUBP1 mRNA expression were associated with higher tumor stage and tumor size. FUBP1 knockdown inhibited cell proliferation and induced cell cycle arrest and apoptosis. Meanwhile, the expression levels of c-myc and p21 mRNA were correlated with that of FUBP1 mRNA.

CONCLUSIONS

FUBP1 acts as a potential oncogene in ccRCC and may be considered as a novel biomarker or an attractive treatment target of ccRCC.

Traffic Vehicle Counting in Jam Flow Conditions Using Low-Cost and Energy-Efficient Wireless Magnetic Sensors

The jam flow condition is one of the main traffic states in traffic flow theory and the most difficult state for sectional traffic information acquisition. Since traffic information acquisition is the basis for the application of an intelligent transportation system, research on traffic vehicle counting methods for the jam flow conditions has been worthwhile. A low-cost and energy-efficient type of multi-function wireless traffic magnetic sensor was designed and developed. Several advantages of the traffic magnetic sensor are that it is suitable for large-scale deployment and time-sustainable detection for traffic information acquisition. Based on the traffic magnetic sensor, a basic vehicle detection algorithm (DWVDA) with less computational complexity was introduced for vehicle counting in low traffic volume conditions. To improve the detection performance in jam flow conditions with a “tailgating effect” between front vehicles and rear vehicles, an improved vehicle detection algorithm (SA-DWVDA) was proposed and applied in field traffic environments. By deploying traffic magnetic sensor nodes in field traffic scenarios, two field experiments were conducted to test and verify the DWVDA and the SA-DWVDA algorithms. The experimental results have shown that both DWVDA and the SA-DWVDA algorithms yield a satisfactory performance in low traffic volume conditions (scenario I) and both of their mean absolute percent errors are less than 1% in this scenario. However, for jam flow conditions with heavy traffic volumes (scenario II), the SA-DWVDA was proven to achieve better results, and the mean absolute percent error of the SA-DWVDA is 2.54% with corresponding results of the DWVDA 7.07%. The results conclude that the proposed SA-DWVDA can implement efficient and accurate vehicle detection in jam flow conditions and can be employed in field traffic environments.

Sensor Location Problem Optimization for Traffic Network with Different Spatial Distributions of Traffic Information

To obtain adequate traffic information, the density of traffic sensors should be sufficiently high to cover the entire transportation network. However, deploying sensors densely over the entire network may not be realistic for practical applications due to the budgetary constraints of traffic management agencies. This paper describes several possible spatial distributions of traffic information credibility and proposes corresponding different sensor information credibility functions to describe these spatial distribution properties. A maximum benefit model and its simplified model are proposed to solve the traffic sensor location problem. The relationships between the benefit and the number of sensors are formulated with different sensor information credibility functions. Next, expanding models and algorithms in analytic results are performed. For each case, the maximum benefit, the optimal number and spacing of sensors are obtained and the analytic formulations of the optimal sensor locations are derived as well. Finally, a numerical example is proposed to verify the validity and availability of the proposed models for solving a network sensor location problem. The results show that the optimal number of sensors of segments with different model parameters in an entire freeway network can be calculated. Besides, it can also be concluded that the optimal sensor spacing is independent of end restrictions but dependent on the values of model parameters that represent the physical conditions of sensors and roads.

A smartphone-based colorimetric reader coupled with a remote server for rapid on-site catechols analysis

The search of a practical method to analyze cis-diol-containing compounds outside laboratory settings remains a substantial scientific challenge. Herein, a smartphone-based colorimetric reader was coupled with a remote server for rapid on-site analysis of catechols. A smallest-scale 2×2 colorimetric sensor array composed of pH indicators and phenylboronic acid was configured. The array was able to distinguish 13 catechols at 6 serial concentrations, through simultaneous treatment via principal component analysis, hierarchical cluster analysis, and linear discriminant analysis. After both the discriminatory power of the array and the prediction ability of the partial least squares quantitative models were proved to be predominant, the smartphone was coupled to the remote server. All the ΔRGB data were uploaded to the remote server wherein linear discriminant analysis and partial least squares processing modules were established to provide qualitative discrimination and quantitative calculation, respectively, of the analytes in real time. The applicability of this novel method to a real-life scenario was confirmed by the on-site analysis of various catechols from a water sample of the Yangtze River; the feedback result in the smartphone showed the method was able to identify the catechols with 100% accuracy and predict the concentrations to within 0.706-2.240 standard deviation.

CHIP Knockdown Reduced Heat Shock Response and Protein Quality Control Capacity in Lens Epithelial Cells

Protein quality control (PQC) systems, including molecular chaperones and ubiquitin-proteasome pathway (UPP), plays an important role in maintaining intracellular protein homeostasis. Carboxyl terminus of Hsc70- interacting protein (CHIP) links the chaperone and UPPs, thus contributing to the repair or removal of damaged proteins. Over-expression of CHIP had previously been used to protect cells from environmental stress. In order to gain a more physiologic mechanism of the advantage conferred by CHIP, we induced a CHIP knockdown and monitored the ability of cells to cope with environmental stress. To knockdown CHIP, the human lens epithelial cell line HLE B3 was transfected with lentiviral particles that encode a CHIP short hairpin RNA (shRNA) or negative control lentiviral particles. Stable CHIP-knock down cells (KD) and negative control cells (NC) were selected with puromycin. After exposure to heat shock stress, there was no change observed in the expression of Hsp90. In contrast, Hsp70 levels increased significantly in NC cells but less so in KD cells. Hsp27 levels also increased after heat shock, but only in NC cells. Protein ubiquitination was reduced when CHIP was knocked down. CHIP knockdown reduced the ability to clear aggregation proteins. When same levels of aggregation-prone RFP-mutant crystallin fusion protein, RFP/V76D-γD, was expressed, there was ~9- fold more aggregates in KD cells as compared to that observed in NC cells. Furthermore, KD cells were more sensitive to toxicity of amino acid analog canavanine as compared to NC cells. Together, these data indicate that CHIP is required for PQC and that CHIP knockdown diminished cellular PQC capacity in lens cells.