Design of a Microchannel‐Nanochannel‐Microchannel Array Based Nanoelectroporation System for Precise Gene Transfection

A micro/nano‐fabrication process of a nanochannel electroporation (NEP) array and its application for precise delivery of plasmid for non‐viral gene transfection is described. A dip‐combing device is optimized to produce DNA nanowires across a microridge array patterned on the polydimethylsiloxane (PDMS) surface with a yield up to 95%. Molecular imprinting based on a low viscosity resin, 1,4‐butanediol diacrylate (1,4‐BDDA), adopted to convert the microridge‐nanowire‐microridge array into a microchannel‐nanochannel‐microchannel (MNM) array. Secondary machining by femtosecond laser ablation is applied to shorten one side of microchannels from 3000 to 50 μm to facilitate cell loading and unloading. The biochip is then sealed in a packaging case with reservoirs and microfluidic channels to enable cell and plasmid loading, and to protect the biochip from leakage and contamination. The package case can be opened for cell unloading after NEP to allow for the follow‐up cell culture and analysis. These NEP cases can be placed in a spinning disc and up to ten discs can be piled together for spinning. The resulting centrifugal force can simultaneously manipulate hundreds or thousands of cells into microchannels of NEP arrays within 3 minutes. To demonstrate its application, a 13 kbp OSKM plasmid of induced pluripotent stem cell (iPSC) is injected into mouse embryonic fibroblasts cells (MEFCs). Fluorescence detection of transfected cells within the NEP biochips shows that the delivered dosage is high and much more uniform compared with similar gene transfection carried out by the conventional bulk electroporation (BEP) method.     

Very Large Photoconduction Enhancement Upon Self‐Assembly of a New Triindole Derivative in Solution‐Processed Films

A new carbazole‐related small molecule exhibiting self‐assembly into ordered nanostructures in solution‐processed cast films has been synthesized and its charge‐photogeneration and ‐transport properties have been investigated. Large photoconductivity was measured in the amorphous state while an enormous improvement in the photoconduction properties was observed when the molecules spontaneously organized. Photocurrents increased upon self‐assembly by up to four orders of magnitude, mostly due to the drastic enhancement of the charge photogeneration. A greatly favorable arrangement of the aromatic cores in the resulting nanostructures, which were characterized by X‐ray analysis, may explain these improvements. Photocurrents of mA cm^?2, on/off ratios of 10⁴ and quantum efficiencies of unity at low field and light intensity, which are among the best values reported to date, along with the simplicity of fabrication, give this readily‐available organic system great potential for use in plastic optoelectronic devices.     

Subsectional-polynomial E-pulse synthesis and application to radartarget discrimination

A new family of extinction-pulses (E-pulses), called subsectional-polynomial E-pulses, is presented. This new type of E-pulse is constructed by choosing polynomials of degree Q as subsectional basis-functions in the E-pulse expansion. The main feature of this family of E-pulses is that the waveforms are continuous and smooth. Several topics concerning the E-pulse technique are investigated, such as: insensitivity to the exact number of natural modes present in the target response; aspect-angle independence; and effects of additive white Gaussian noise. Numerical results, using the response of a thin cylinder and a sphere, show that the subsectional-polynomial E-pulses improve the results obtained using subsectional-rectangular E-pulses     

Renal carcinoma and von Hippel-Lindau disease

We report a case of life-threatening esophageal hemorrhage after metal stent implantation successfully treated by arterial embolization. An 85-year-old woman was admitted in shock secondary to massive hematemesis and melena. Recent medical history revealed esophageal cancer treated 8 weeks previously by endoesophageal radiotherapy (40 Gy) and endoscopic placement of a covered Wall-stent prosthesis. Selective arteriography of the fifth posterior right intercostal artery showed massive contrast extravasation in the esophagus. Embolization was performed with 150-250-micron polyvinyl alcohol particles. Follow-up at 5 months was uneventful. Arteriography and embolization are advised when severe hemorrhage occurs after esophageal implantation of metal stents.     

Vascular enumeration as a significant prognosticator for invasive breast carcinoma

PURPOSE: Vascular enumeration has been claimed to be an independent prognosticator for invasive breast cancer. Most of the studies have performed a manual count of the vessels. Few investigators have used image analyzers to reduce subjectivity in the measures. The aim of this retrospective study was to compare the manual vessel count to the counts obtained with an image analyzer and to estimate their possible prognostic influence. MATERIALS AND METHODS: We selected 112 patients with invasive ductal carcinoma, treated with radical mastectomy followed by chemotherapy and with a minimal follow-up time of 60 months (5 years). After immunostaining with factor VIII, we performed a double count of the vessels. First, we performed a manual count following Gasparini's criteria, and second, we used an image analyzer (Microm, Barcelona, Spain) to count the vessels in eight adjacent microscopic fields with a 20x objective, to reach a total area of 0.98 mm2. The image analyzer calculated the total number of vessels, their size and also the percentage of the field occupied by the vessels. RESULTS: In our series, vascular enumeration showed no significant association with histologic grade (Bloom-Scarff-Richardson grading), tumor size, or staging. CONCLUSION: Vascular enumeration with both methods was an independent prognosticator for relapse-free-survival (RFS) in both node-negative and -positive patients in the univariate analysis, but only vascular enumeration with the image analyzer was an independent prognostic factor in the multivariate analysis, together with lymph node metastases.     

Speciation of organometallic compounds in environmental samples by gas chromatography after flow preconcentration on fullerenes and nanotubes

The development of a simple speciation method for the determination of lead (trimethyllead(I), dimethyllead(II), triethyllead(I), and diethyllead(II)), mercury (methylmercury(I), ethylmercury(I), mercury(II)), and tin (n-butyltin(III), di-n-butyltin(II), tri-n-butyltin(I), tin(IV)) compounds in environmental samples was described. The potential of C70 fullerenes and multiwalled carbon nanotubes (MWNTs) as sorbents was investigated for the first time; this study revealed that there are no significant differences between them in terms of sensitivity, selectivity, precision, and reusability. Comparative studies showed that MWNTs and C60 and C70 fullerenes were superior to graphitized carbon black and RP-C18 for the extraction of the 11 compounds studied. The accuracy of the MWNT method was evaluated from recovery values with two standard reference coastal sediments, and good concordance in the results were obtained. Detection limits of 0.5-2 pg/mL were obtained when using a sorbent column containing 160 mg of MWNTs (sample breakthrough, 50 mL of water). The method was successfully applied to the determination of lead, mercury, and tin compounds in water and coastal sediment samples with satisfactory results.     

Anti-S-100 antibody recognizes ellipsoid-associated cells and other dendritic cells in the chicken spleen

We examined the activation of genes induced by erythropoietin (Epo) in erythroid progenitor cells that were isolated from the spleens of mice infected with anemia-inducing strain of the Friend virus. These erythroid progenitor cells, termed FVA cells, undergo in vitro differentiation to erythrocytes under the influence of Epo within 2 to 3 days. We used a differential hybridization procedure to screen a cDNA library constructed from FVA cells that were treated with Epo 2U/mL in the absence of serum for 2 hours. Of 20,000 recombinant phages, 47 plaques hybridized preferentially to cDNA probe prepared from Epo-stimulated cells. We found at least three different Epo-responsive genes (ERGs) and one of them corresponds to the mouse virus-like (VL30) element, similar to already reported BVL-1. The induction of VL30, which was evident within 30 minutes after Epo exposure, reached a maximum by 1 hour and remained stable for up to 4 hours. The treatment of FVA cells with cycloheximide (CHX) 10 micrograms/mL, which in itself activates the expression of VL30 caused a superinduction of the Epo signal. Changes in intracellular Ca2+ concentrations, either raised by ionomycin or depleted by EGTA, had no effect on the Epo-induced VL30 expression. In addition, protein kinase C (PKC) inhibitors such as staurosporine (3 mumol/L) or H7 (20 mumol/L) and a tyrosine kinase inhibitor, genistein (200 mumol/L), did not inhibit the Epo-induced expression of VL30. TPA (100 ng/mL), a PKC agonist, did not induce VL30 expression. Although the physiologic role of VL30 in the differentiation of erythroid progenitor cells is not known, our findings demonstrate that VL30 is an early ERG, and may be a useful indicator of the initial molecular actions of Epo.     

Evaluation of soil biological activity after a diesel fuel spill

Diesel fuel contamination in soils may be toxic to soil microorganisms and plants and acts as a source of groundwater contamination. The objective of this study was to evaluate the soil biological activity and phytotoxicity to garden cress (Lepidium sativum L.) in a soil polluted with diesel fuel. For this, a diesel fuel spill was simulated on agricultural soil at dose 1 l m^− 2. During the experiment (400 days) the soil was not covered in vegetation and no agricultural tasks were carried out. A stress period of 18 days following the spill led to a decrease in soil biological activity, reflected by the soil microbial biomass and soil enzymatic activities, after which it increased again. The n-C₁₇/Pristine and n-C₁₈/Phytane ratios were correlated negatively and significantly with the dehydrogenase, arylsulphatase, protease, phosphatase and urease activities and with the soil microbial biomass during the course of the experiment. The β-glucosidase activity indicated no significant connection with the parameters related with the evolution of hydrocarbons in the soil. Finally, the germination activity of the soil was seen to recover 200 days after the spill.