2,613 research outputs found

    Real-time detection of an airborne microorganism using inertial impaction and mini-fluorescent microscopy

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    To achieve successful real-time detection of airborne pathogenic microorganisms, the problem must be considered in terms of their physical size and biological characteristics. We developed an airborne microorganism detection chip to realize the detection of microorganisms, ensuring compactness, sensitivity, cost-efficiency, and portability, using three key components: an inertial impaction system, a cartridge-type impaction plate, and a mini-fluorescent microscope. The inertial impaction system was used to separate microorganisms in terms of their aerodynamic particle size, and was fabricated with three impaction stages. Numerical analysis was performed to design the system; the calculated cutoff diameter at each impaction stage was 2.02 (first stage), 0.88 (second stage), and 0.54 μm (third stage). The measured cutoff diameters were 2.24, 0.91, and 0.49 μm, respectively. A cartridge-type impaction plate was used, composed of molded polydimethylsiloxane (PDMS) and an actual impaction region made of a SYBR green I dye-stained agar plate. A mini-fluorescent microscope was used to distinguish microbes from non-biological particles. Images of the microorganisms deposited at the impaction zone were obtained via mini-fluorescent microscopy, and fluorescent intensities of the images were calculated using in-house image-processing software. The results showed that the developed system successfully identified aerosolized biological particles from non-biological particles in real time

    Initial Experiences with Proton MR Spectroscopy in Treatment Monitoring of Mitochondrial Encephalopathy

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    PURPOSE: Mitochondrial encephalopathy (ME) is a rare disorder of energy metabolism. The disease course can roughly be evaluated by clinical findings. The purpose of this study was to evaluate metabolic spectral changes using proton MR spectroscopy (MRS), and to establish a way to monitor ME by neuroimaging. MATERIALS AND METHODS: Proton MRS data were retrospectively reviewed in 12 patients with muscle biopsy-confirmed ME (M : F = 7 : 5, Mean age = 4.8 years). All received 1H-MRS initially and also after a ketogenic diet and mitochondrial disease treatment cocktail (follow up average was 10.2 months). Changes of N-acetylaspartate/ creatine (NAA/Cr) ratio, choline/creatine (Cho/Cr) ratio, and lactate peak in basal ganglia at 1.2 ppm were evaluated before and after treatment. Findings on conventional T2 weighted MR images were also evaluated. RESULTS: On conventional MRI, increased basal ganglia T2 signal intensity was the most common finding with ME (n = 9, 75%), followed by diffuse cerebral atrophy (n = 8, 67%), T2 hyperintense lesions at pons and midbrain (n = 4, 33%), and brain atrophy (n = 2, 17%). Lactate peak was found in 4 patients; 2 had disappearance of the peak on follow up MRS. Quantitative analysis showed relative decrease of Cho/Cr ratio on follow up MRS (p = 0.0058, paired t-test, two-tailed). There was no significant change in NAA/Cr ratio. CONCLUSION: MRS is a useful tool for monitoring disease progression or improvement in ME, and decrease or disappearance of lactate peak and reduction of Cho/Cr fraction were correlated well with improvement of clinical symptoms.ope

    Effects of Genetic and Pharmacologic Inhibition of COX-2 on Colitis-associated Carcinogenesis in Mice

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    COX-2 has been inappropriately overexpressed in various human malignancies, and is considered as one of the representative targets for the chemoprevention of inflammation-associated cancer. In order to assess the role of COX-2 in colitis-induced carcinogenesis, the selective COX-2 inhibitor celecoxib and COX-2 null mice were exploited in an azoxymethane (AOM)-initiated and dextran sulfate sodium (DSS)-promoted murine colon carcinogenesis model. The administration of 2% DSS in drinking water for 1 week after a single intraperitoneal injection of AOM produced colorectal adenomas in 83% of mice, whereas only 27% of mice given AOM alone developed tumors. Oral administration of celecoxib significantly lowered the incidence as well as the multiplicity of colon tumors. The expression of COX-2 and inducible nitric oxide synthase (iNOS) was upregulated in the colon tissues of mice treated with AOM and DSS, and this was inhibited by celecoxib administration. Likewise, celecoxib treatment abrogated the DNA binding of NF-kappa B, a key transcription factor responsible for regulating expression of aforementioned pro-inflammatory enzymes, which was associated with suppression of I kappa B alpha degradation. In the COX-2 null (COX-2(-/-)) mice, there was about 30% reduction in the incidence of colon tumors, and the tumor multiplicity was also markedly reduced (7.7 +/- 2.5 vs. 2.43 +/- 1.4, P < 0.01). As both pharmacologic inhibition and genetic ablation of COX- 2 gene could not completely suppress colon tumor formation following treatment with AOM and DSS, it is speculated that other pro-inflammatory mediators, including COX-1 and iNOS, should be additionally targeted to prevent inflammation-associated colon carcinogenesis.

    Extraction and separation of hexavalent molybdenum from acidic sulfate solutions using Alamine 336 as an extractant

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    Extraction and separation of hexavalent molybdenum from acidic sulfate solutions using Alamine 336 as an extractant and kerosene as diluent is described. Variation of acid concentration influences the percentage of extraction of hexavalent molybdenum indicating the ion exchange type mechanism. Effect of concentration of Alamine 336 on the extraction of hexavalent molybdenum in the presence of divalent copper and trivalent iron is also presented. The upper limit of concentration of extractant for extraction of hexavalent molybdenum free from divalent copper and trivalent iron is observed with 0.1 mol/L of Alamine 336. However, when the concentration of Alamine 336 is increased to 1.0 mol/L, about 48% of copper is extracted along with molybdenum but without any iron. The method is suitable for the separation of molybdenum from copper and iron contained leach liquor. The optimized experimental parameters such as phase contact time, effect of extractant, metal, loading capacity of extractant and followed by strip ping studies with ammonia, hydrogen peroxide, sodium hydroxide, sodium thiosulfate and thiourea is presented. From the above experimental data we proposed the aqueous mechanism for hexavalent molybdenum extraction processes

    Glutaminase 1 inhibition reduces thymidine synthesis in NSCLC

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    AbstractWe found that non-small cell lung cancer (NSCLC) is remarkably sensitive to the regulation of glutamine supply by testing the metabolic dependency of 11 cancer cell lines against regulation of glycolysis, autophagy, fatty acid synthesis, and glutamine supply. Glutamine is known as a key supplement of cancer cell growth that is converted to α-ketoglutarate for anabolic biogenesis via glutamate by glutaminase 1 (GLS1). GLS1 inhibition using 10 μM of bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl)ethyl sulfide (BPTES) showed about 50% cell growth arrest by SRB assay. By testing the synergistic effects of conventional therapeutics, BPTES combined with 5-fluorouracil (5-FU), an irreversible inhibitor of thymidylate synthase, significant effects were observed on cell growth arrest in NSCLC. We found that GLS1 inhibition using BPTES reduced metabolic intermediates including thymidine and carbamoyl phosphate. Reduction of thymidine and carbamoyl-phosphate synthesis by BPTES treatment exacerbated pyrimidine supply by combination with 5-FU, which induced cell death synergistically in NSCLC

    High-resolution near-IR Spectral mapping with H2_{2} and [Fe II] lines of Multiple Outflows around LkHα\alpha 234

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    We present a high-resolution, near-IR spectroscopic study of multiple outflows in the LkHα\alpha 234 star formation region using the Immersion GRating INfrared Spectrometer (IGRINS). Spectral mapping over the blueshifted emission of HH 167 allowed us to distinguish at least three separate, spatially overlapped, outflows in H2{_2} and [Fe II] emission. We show that the H2{_2} emission represents not a single jet, but complex multiple outflows driven by three known embedded sources: MM1, VLA 2, and VLA 3. There is a redshifted H2{_2} outflow at a low velocity, \VLSR << ++50 {\kms}, with respect to the systemic velocity of \VLSR == -11.5 {\kms}, that coincides with the H2{_2}O masers seen in earlier radio observations two arcseconds southwest of VLA 2. We found that the previously detected [Fe II] jet with |\VLSR| >> 100 {\kms} driven by VLA 3B is also detected in H2{_2} emission, and confirm that this jet has a position angle about 240°\degree. Spectra of the redshifted knots at 14\arcsec-65\arcsec northeast of LkHα\alpha 234 are presented for the first time. These spectra also provide clues to the existence of multiple outflows. We detected high-velocity (50-120 {\kms}) H2{_2} gas in the multiple outflows around LkHα\alpha 234. Since these gases move at speeds well over the dissociation velocity (>> 40 {\kms}), the emission must originate from the jet itself rather than H2{_2} gas in the ambient medium. Also, position-velocity diagrams and excitation diagram indicate that emission from knot C in HH 167 come from two different phenomena, shocks and photodissociation.Comment: 32 pages, 12 figures, 2 tables, Accepted for publication in the Astrophysical Journa
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