Tip-enhanced raman spectroscopy (TERS) for biomolecular analyses at nanometer / sub-nanometer scale

Es wurden TERS Experimente an verschiedenen DNS/RNS Einzelsträngen durchgeführt,um die Eignung von TERS als Marker-freie Sequenzierungsmethode zu überprüfen. In ersten TERS Messungen an Uracil Homopolymersträngen konnte die Reproduzierbarkeit dieser Methode anhand von einheitlichen Spektren deutlich herausgestellt werden. In TERS Spektren einer Kalbsthymus DNS Probe wurden alle vier verschiedenen Nukleobasen detektiert werden, wobei es Anzeichen einer Sequenzänderung unter der Spitze gab. Die Untersuchungen wurden auf speziell für diese Arbeit synthetisierte DNS Proben ausgedehnt. So konnten in den TERS Spektren von (A10C15)8 DNS Einzelsträngen die Nukleobasen Adenin und Cytosin mit einer lateralen Auflösung im Subnanometerbereich unterschieden werden. Aus diesen Ergebnissen lässt sich schließen, dass TERS das Potential zur direkten DNS/RNS Sequenzierung hat, wobei diese Methode für andere kettenförmige Biomakromoleküle (z. B. Proteine) zum Einsatz kommen könnte. In zukünftigen Projekten soll TERS auf synthetische DNA Stränge bekannter Sequenz mit allen vier Nukleobasen angewandt werden. Das ultimative Ziel ist die Untersuchung von Strängen mit einer unbekannten Abfolge der Nukleobasen

The Research of Biology Coupling Characteristics on the Shells of Haliotis discus hannai Ino

The surface morphologies, structures and materials of Haliotis discus hannai Ino shells were qualitatively studied by means of a stereoscopic microscope，a field emission scanning electronic microscopy, energy dispersive spectrometer and X-ray diffractometer, and abrasive particle wear was qualitatively and quantitatively studied by means of a pin-on-disc apparatus. The results showed that the outer layer surface of Haliotis discus hannai Ino shells was non-smooth and had some strumae or similar parallel convex wave. The shells of Haliotis discus hannai Ino are polycrystalline composites of calcium carbonate and proteins and glycoproteins and consist of the periostracum, prismatic and nacreous layers with calcite in the outer prismatic layer and aragonite in the inner nacreous layer. Nacreous layer is a natural composite comprised of calcium carbonate in the aragonite polymorph with organic macromolecules sandwiched in between, and the coupling of platelet interlocks and organic materials makes nacreous layer to be strong and tough.The abrasive particle wear tests showed that the abrasion resistance was different on the different parts of the shells, and the left of the shells possessed the highest abrasion resistance and the abrasion resistance of the shells was the lowest on the edge of the right. The nacreous layer possessed higher abrasion resistance than prismatic layer because of the coupling of structure and materials of nacreous layer. Key words: Haliotis discus hannai Ino shells; morphology; structure; materials; anti-wear; biological character; couplin

Correlation between infection with demodex folliculorum of eyelash and Meibomian gland dysfunction in elderly patients

AIM:To investigate the prevalence of demodex folliculorum in eyelashes of elderly patients with Meibomian gland dysfunction(MGD)and to find the correlation between the presence of demodex folliculorum and MGD. METHODS: The study involved elderly patients(age≥40)who visited Department of Ophthalmology in Fujian Provincial Hospital for the Elderly between September 2017 and March 2018. Patients were divided into MGD group(137 patients 137 eyes)and non-MGD group(96 patients 96 eyes). The patients underwent eyelid examinations by slit lamp, lipid secretion of the Meibomian gland, fluorescein corneal staining(FL), tear film breakup time(BUT). At the same time underwent epilation of eyelashes, and the number of Demodex was counted. The positive rate of demodex was compared between the two groups, the relation of number of demodex with eyelid margin score, lipid secretion of the meibomian gland, FL score and BUT were evaluated. RESULTS: The positive rate of demodex in MGD group was 89.1%, significantly higher than that of group non-MGD 74.0%(Pr=0.89, Pr=0.67, Pr=0.35, Pr=-0.37, PPCONCLUSION: There is a strong correlation between ocular moderate or severe demodex mites infection and MGD, suggesting that demodex folliculorum may play a pathogenic role in elderly patients with MGD

Integrated application of uniform design and least-squares support vector machines to transfection optimization

<p>Abstract</p> <p>Background</p> <p>Transfection in mammalian cells based on liposome presents great challenge for biological professionals. To protect themselves from exogenous insults, mammalian cells tend to manifest poor transfection efficiency. In order to gain high efficiency, we have to optimize several conditions of transfection, such as amount of liposome, amount of plasmid, and cell density at transfection. However, this process may be time-consuming and energy-consuming. Fortunately, several mathematical methods, developed in the past decades, may facilitate the resolution of this issue. This study investigates the possibility of optimizing transfection efficiency by using a method referred to as least-squares support vector machine, which requires only a few experiments and maintains fairly high accuracy.</p> <p>Results</p> <p>A protocol consists of 15 experiments was performed according to the principle of uniform design. In this protocol, amount of liposome, amount of plasmid, and the number of seeded cells 24 h before transfection were set as independent variables and transfection efficiency was set as dependent variable. A model was deduced from independent variables and their respective dependent variable. Another protocol made up by 10 experiments was performed to test the accuracy of the model. The model manifested a high accuracy. Compared to traditional method, the integrated application of uniform design and least-squares support vector machine greatly reduced the number of required experiments. What's more, higher transfection efficiency was achieved.</p> <p>Conclusion</p> <p>The integrated application of uniform design and least-squares support vector machine is a simple technique for obtaining high transfection efficiency. Using this novel method, the number of required experiments would be greatly cut down while higher efficiency would be gained. Least-squares support vector machine may be applicable to many other problems that need to be optimized.</p

Baicalein inhibits acinar-to-ductal metaplasia of pancreatic acinal cell AR42J via improving the inflammatory microenvironment

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers. Recent research has demonstrated that chronic pancreatitis (CP) is associated with an increased risk of PDAC, partly due to acinar-to-ductal metaplasia (ADM). Baicalein has been shown to exert anti-inflammatory and anti-tumor effects for CP or PDAC, respectively. The aim of our study was to investigate the effect of baicalein, and the putative underlying mechanism, on inflammatory cytokines-induced ADM of rat pancreatic acinar cell line AR42J. To investigate ADM and baicalein effects in vitro, AR42J were treated with recombinant rat Tumor Necrosis Factor alpha (rTNFα) with or without baicalein for 5 days. Results showed that rTNFα-induced AR42J cells switched their phenotype from dominantly amylase-positive acinar cells to dominantly cytokeratin 19-positive ductal cells. Moreover, expression of the transcripts for TNFα or Hes-1, a Notch target, was up-regulated in these cells. Interestingly, baicalein reduced the population of ADM as well as cytokines gene expression but not Hes-1. Baicalein inhibited NF-κB activation induced by rTNFα in AR42J, but no effect on Notch 1activation. Moreover, baicalein suppressed the secretion of TNFα and Nitric Oxide (NO) in macrophages stimulated with LPS and further inhibited ADM of conditional medium-treated AR42J cells. Baicalein also suppressed the inflammatory response of LPS-activated macrophages, thereby inhibited ADM of AR42J by altering their microenvironment. Taken together, our study indicates that baicalein reduces rTNFα-induced ADM of AR42J cells by inhibiting NF-κB activation. It also sheds new light on Chinese material medica therapy of pancreatitis and thereby prevention of PDAC

Enhanced Raman Scattering by Polystyrene Microspheres and Application for Detecting Molecules Adsorbed on Au Single Crystal Surface

By assembling polystyrene microsphores on a sample Surface, the surface Raman signal Could be enhanced. The dependence of the enhancement effect on the size of microparticles was systematically investigated and it was found that microparticles with a diameter of 3.00 mu m showed the highest enhancement of ca 5 folds. By utilizing the enhancement effect of the microspheres. the surface Raman intensity of malachite green isothiocyanate (MGITC) adsorbed on Au(111) surface could be enhanced by 20 folds, indicating that this method could effectively improve the detection sensitivity of surface Raman spectroscopy for the adsorbed species on single crystal surface. The later signal increment corresponds to the Raman enhancement effect of nearly 3 orders of magnitude. The enhancement effect is mainly owing to the formation of nanojets when a laser is focused on the microspheres of appropriate diameter. The formation of nanojets will lead to the highly localized electromagnetic field, which will then significantly enhance the Raman process in the nanojets. The main reason for obtaining different enhancements on two types of samples was analyzed

Analisa Kepuasan Konsumen Di Restaurant “X” Di Surabaya

Penelitian ini ditunjukan untuk menganalisa tingkat kesenjangan antara harapan dari konsumen terhadap Kenyataan yang diterima oleh konsumen dan mengukur tingkat kepuasan konsumen di Restoran “X” dengan menggunakan atribut DINESERV. Penelitian ini menggunakan Importance Performance Analysis(IPA). Hasil dari penelitian ini adalah kesenjangan antara harapan dan Kenyataan yang diukur menggunakan atribut DINESERV adalah Kenyataan yang diterima oleh konsumen sangat tidak sesuai dengan harapan konsumen dan konsumen sangat tidak puas terutama dengan atribut Convenience Restoran yaitu Jarak dari Restoran “X” di Surabay

Gastropod chemoreception behaviors—Mechanisms underlying the perception and location of targets and implications for shellfish fishery development in aquatic environments

Chemoreception is one of the most important senses and it plays a key role in the survival and adaptation of animals to their environments. Many gastropods, such as Rapana venosa and Neptunea cumingii, have emerged as economically important shellfish. Meanwhile, invasive gastropods have destroyed commercial shellfisheries in many countries. Given the importance of chemoreception in the behavior of aquatic gastropods, the mechanism of their chemical perception has recently garnered attention. To provide a foundation for understanding the chemoreception of aquatic gastropods, we reviewed recent studies and summarized the chemoreception behaviors and mechanisms that gastropods use to perceive and locate targets in aquatic environments, along with relevant molecular and genetic insights. We highlight several of the implications of these studies for chemoreception-related research and shellfish fishery development. This review should aid in the rational development and utilization of gastropod resources as well as in controlling the populations of invasive species

Fabrication of Chitosan/Silk Fibroin Composite Nanofibers for Wound-dressing Applications

Chitosan, a naturally occurring polysaccharide with abundant resources, has been extensively exploited for various biomedical applications, typically as wound dressings owing to its unique biocompatibility, good biodegradability and excellent antibacterial properties. In this work, composite nanofibrous membranes of chitosan (CS) and silk fibroin (SF) were successfully fabricated by electrospinning. The morphology of electrospun blend nanofibers was observed by scanning electron microscopy (SEM) and the fiber diameters decreased with the increasing percentage of chitosan. Further, the mechanical test illustrated that the addition of silk fibroin enhanced the mechanical properties of CS/SF nanofibers. The antibacterial activities against Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) were evaluated by the turbidity measurement method; and results suggest that the antibacterial effect of composite nanofibers varied on the type of bacteria. Furthermore, the biocompatibility of murine fibroblast on as-prepared nanofibrous membranes was investigated by hematoxylin and eosin (H&E) staining and MTT assays in vitro, and the membranes were found to promote the cell attachment and proliferation. These results suggest that as-prepared chitosan/silk fibroin (CS/SF) composite nanofibrous membranes could be a promising candidate for wound healing applications