Search

Background Introduction of gut flora into the biliary system is common owing to biliary stenting in patients with obstructing pancreatic head cancer. We hypothesize that alteration of biliary microbiome modifies bile content that modulates pancreatic cancer cell survival. Methods Human bile samples were collected during pancreaticoduodenectomy. Bacterial strains were isolated from contaminated (stented) bile and identified using 16S ribosomal RNA sequencing. Human pancreatic cancer cells (AsPC1, CFPAC, Panc1) were treated for 24 hours with sterile (nonstented) bile, contaminated (stented) bile, and sterile bile preincubated with 106 colony forming unit of live bacteria isolated from contaminated bile or a panel of bile acids for 24 hours at 37°C, and evaluated using CellTiter-Blue Cell Viability Assay (Promega Corp. Madison, WI). Human bile (30–50 μl/mouse) was coinjected intraperitoneally with 105 Panc02 mouse pancreatic cancer cells in C57BL6/N mice to evaluate the impact of bile on peritoneal metastasis 3 to 4 weeks after tumor challenge. Results While all bile samples significantly reduced peritoneal metastasis of Panc02 cells in mice, some contaminated bile samples had diminished antitumor effect. All sterile bile (n = 4) reduced pancreatic cancer cell survival in vitro. Only 40% (2/5) of contaminated bile samples had significant effect. Preincubation of sterile bile with live Enterococcus faecalis or Streptococcus oralis modified the antitumor effect of sterile bile. These changes were not observed with culture media preincubated with live bacteria, suggesting live gut bacteria can modify the antitumor components present in bile. Conjugated bile acids were more potent than unconjugated cholic acid in reducing pancreatic cancer cell survival. Conclusion Alteration of bile microbiome from biliary stenting has a direct impact on pancreatic cancer cell survival. Further study is warranted to determine if this microbiome shift alters tumor microenvironment.

Many real-world tasks involve exploratory movements for the manipulation of objects with a wide range of physical properties. Historically, neurophysiological research has emphasized how force sensations and perceptions arise due to descending motor commands and ascending afferent feedback from proprioceptors. However, how force sensation and perception contribute to stable percepts of handheld objects’ properties, such as moments of mass (moment, moment of inertia, etc.), to facilitate smooth interaction and manipulation is unclear. Studies have shown that wielding movements, and the associated Ia re-afferent activity, may be necessary to perceive a handheld object’s moments of mass. Recent theoretical frameworks provide a novel basis to rethink how somatosensory information from different mechanoreceptors could be integrated with other sensory modalities, such as vision, to create stable percepts of object affordances associated with different moments of mass.

In the past few years, aluminum alloys have been widely used in the field of automation, aeronautical, and heavy industries due to their light weight, high specific strength, high corrosion resistance, and excellent formability. However, the properties related to microstructure and dispersed medium are constant throughout the past research. The present research work is focused on the tensile tests of LM25 (reinforced with 10% SiC) metal matrix composites (MMCs) for its applications in aerospace industry through ultrasonic treatment (UST) of the liquid melt by varying the ultrasonic sonotrode (US) power and ultrasonic frequency. The high intensity UST is carried out on the LM25 MMCs reinforced with 10% SiC (proportion by weight) in a temperature range between 850 and 750 °C. The preheated mold at 250 °C temperature is used to cast the liquid melt after the UST. The castings are produced by varying time intervals and temperature ranges at distinct US power levels such as (a) 65% and (b) 75%. The casting process samples are prepared as per ASTM standard for tensile tests to reveal the effects of the UST. In the present investigation, the effects of UST on melt temperature, processing time, US power, and ultrasonic frequency (kHz) are studied in detail.

Increased fall risk in older adults and clinical populations is linked with increased amount and altered temporal structure of step width variability. One approach to rehabilitation seeks to reduce fall risk in older adults by reducing the amount of step width variability and restoring the temporal structure characteristic of healthy young adults. The success of such a program depends on our ability to modulate step width variability effectively. To this end, we investigated how manipulation of the visual walking space in a virtual environment could modulate the amount and temporal structure of step width variability. Nine healthy adults performed self-paced treadmill walking in a virtual alley in a fixed-width Control condition (1.91 m) and two conditions in which the alley's width oscillated sinusoidally at 0.03 Hz: between 0.38 and 1.14 m and 0.38-2.67 m in Narrow and Wide conditions, respectively. The step width time series from each condition was evaluated using: (i) the standard deviation to identify changes in the amount of variability and (ii) the fractal scaling exponent estimated using detrended fluctuation analysis (DFA) to identify changes in the temporal structure of variability in terms of persistence in fluctuations. The Wide condition neither affected the standard deviation nor the fractal scaling exponent of step width time series. The Narrow condition did not affect the standard deviation of step width time series compared to the Control condition but significantly increased its fractal scaling exponent compared to the Control and Wide conditions, suggestive of more persistent fluctuations characteristic of a healthy gait. These results show that virtual reality based rehabilitative intervention can modulate step width variability to potentially reduce fall risk in older adults and clinical populations.

Turing inspired a computer metaphor of the mind and brain that has been handy and has spawned decades of empirical investigation, but he did much more and offered behavioral and cognitive sciences another metaphor-that of the cascade. The time has come to confront Turing's cascading instability, which suggests a geometrical framework driven by power laws and can be studied using multifractal formalism and multiscale probability density function analysis. Here, we review a rapidly growing body of scientific investigations revealing signatures of cascade instability and their consequences for a perceiving, acting, and thinking organism. We review work related to executive functioning (planning to act), postural control (bodily poise for turning plans into action), and effortful perception (action to gather information in a single modality and action to blend multimodal information). We also review findings on neuronal avalanches in the brain, specifically about neural participation in body-wide cascades. Turing's cascade instability blends the mind, brain, and behavior across space and time scales and provides an alternative to the dominant computer metaphor.

The present study entails a simple chemical method for the preparation of high-quality silver / reduced graphene oxide (Ag/rGO) nanocomposite. Ag/rGO nanocomposite was characterized using UV–Visible spectroscopy, High Resolution Transmission Spectroscopy (HR-TEM), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Brunauer–Emmett–Teller (BET) analysis and X-ray Diffraction spectroscopy (XRD). SEM results showed the Silver (Ag) nanoparticles were deposited on graphene oxide (GO) nanosheets. XRD results confirmed the crystalline structure of Ag/rGO nanocomposite. The photocatalytic activity and stability of Ag/rGO nanocomposite for the degradation of methyl orange (MeO) dye was significantly increased in comparison to GO nanosheets under visible light. The adsorption capacity of Total Dissolved Solids (TDS) by Ag/rGO nanocomposite and GO nanosheets were further studied by utilizing wastewater as sample. The adsorption isothermal and kinetic studies suggest that 0.4 g/L Ag/rGO nanocomposite produce optimum separation capacity. Therefore, considering the excellent photocatalytic activity and adsorptivity nature of Ag/rGO nanocomposite, the present investigation can be effective in energy and environment related application.

Transition metal oxide nanoparticles, especially nickel oxide (NiO) have profound interests to the scientific commune on account of their dimension-reliant attributes and peculiar progression in optical, electrochemical, and magnetic characteristics. Herein, the undoped and tin (Sn) doped nickel oxide nanoparticles of varied concentrations were synthesized by highly favourable citrate assisted sol-gel technique. An array of extensive investigations were discussed on the structural, optical, and magnetic properties of synthesized nanoparticles. The crystallite size and strain of as-synthesized samples decreased with significant augmentation in dopant discrepancy which was confirmed by Scherrer and Williamson-Hall model. The optical energy band gap was evaluated from UltraViolet-visible (UV-vis) spectroscopy analysis and a notable blue shift was observed over the wide absorption spectrum. Refractive index, Urbach energy, and other optical parameters anchored in opto-electrical applications were evaluated from optical studies. Fourier Transform Infrared Spectroscopy (FTIR) analysis conducted at room temperature from spectral span 400–4000 cm−1 affirmed the cubic configuration and elucidated bond lengths of pure and tin-doped nanoparticles. Scanning electron microscopy studies portrayed surface morphological features and slight porous particles were observed. Transmission Electron Microscopy (TEM) analysis confirmed the spherical shape of nanoparticles and the grain size estimated is in accordance with the XRD results. The surface area and porosity of pure and doped samples were deeply investigated by Brunauer-Emmett-Teller (BET) analysis. Magnetic parameters such as saturation magnetization, coercivity, retentivity, magnetic moment were enumerated from Vibrating Sample Magnetometer (VSM) investigations and two critical magnetic parameters were extracted from the Law of Approach to Saturation model (LAS). The sample with 6% of Sn shows the highest coercivity of 147 Oe. Further, synthesized pure and doped traces of nickel oxide nanoparticles were deliberated for their competent application in the domain of antibiotics independent antimicrobial activity.