Iodide Functionalized Paper-Based SERS Sensors for Improved Detection of Narcotics.

An inkjet-printed paper-based Surface-enhanced Raman scattering (SERS) sensor is a robust and versatile device that provides trace sensing capabilities for the detection and analysis of narcotics and drugs. Such sensors generally work well for analytes with good binding affinity towards the Au or Ag plasmonic nanoparticles (NPs) resident in the sensors. In this report, we show that iodide functionalization of the printed sensors helps to remove adsorbed contaminants from AuNP surfaces enabling superior performance with improved detection of narcotics such as fentanyl, heroin and cocaine by SERS. SERS signals are easily doubled with the iodide-functionalized sensors which also showed orders of magnitude improvement in detection limit. In this report, we show that a short (90 s) iodide treatment of the sensors significantly improved the detection of heroin. We propose that iodide functionalization be integrated into field detection kits through the solvent that wets paper-based sensor prior to swabbing for narcotics. Alternatively, we have also demonstrated that iodide functionalized sensors can be stored in ambient for up to 1 week and retain the improved performance towards heroin detection. This report will help to significantly improve the performance of paper-based sensors for field detection of narcotic drugs.

A Predictive 3D Multi-Scale Model of Biliary Fluid Dynamics in the Liver Lobule.

Bile, the central metabolic product of the liver, is transported by the bile canaliculi network. The impairment of bile flow in cholestatic liver diseases has urged a demand for insights into its regulation. Here, we developed a predictive 3D multi-scale model that simulates fluid dynamic properties successively from the subcellular to the tissue level. The model integrates the structure of the bile canalicular network in the mouse liver lobule, as determined by high-resolution confocal and serial block-face scanning electron microscopy, with measurements of bile transport by intravital microscopy. The combined experiment-theory approach revealed spatial heterogeneities of biliary geometry and hepatocyte transport activity. Based on this, our model predicts gradients of bile velocity and pressure in the liver lobule. Validation of the model predictions by pharmacological inhibition of Rho kinase demonstrated a requirement of canaliculi contractility for bile flow in vivo. Our model can be applied to functionally characterize liver diseases and quantitatively estimate biliary transport upon drug-induced liver injury.

One-Component Dual Actuation: Poly(NIPAM) Can Actuate to Stable 3D Forms with Reversible Size Change.

A rare example of a one-component dual actuator is provided, which displays irreversible change in shape by rolling on contact with water and reversible size change on changing the temperature. The actuator has a bilayer structure with aligned and randomly oriented fibers of poly(N-isopropyl acrylamide). A combination of anisotropic E modulus and temperature dependent swelling/shrinkage provides the dual actuation.

Knowledge and attitude toward evidence-based medicine among medical students in Semnan, Iran.

OBJECTIVES: Evidence-based medicine (EBM) has gained widespread acceptance in medicine. Little is known about the attitudes, knowledge, and behavior of medical students toward EBM in developing countries. This study was designed to assess medical students' awareness and attitudes toward EBM and to obtain the basis required for developing appropriate teaching and learning opportunities. METHODS: This was a cross-sectional study in which medical students completed a questionnaire to determine their attitudes, knowledge, and perceptions regarding EBM. RESULTS: Completed questionnaires were received from 84% (143) of 170 medical students. Only 24.5% of respondents had good basic information and familiarity with the term of EBM. The majority (89.3%) of participants had positive attitude toward EBM and agreed that it was useful in the management of patients. Mostly were interested in learning the skills of EBM. Most of the respondents (80.2%) had no or little awareness of EBM resources especially the Cochrane, DARE, and Bandolier clinical evidence database. Forty-two (29%) reported having had formal training in search strategies. Most of the respondents did not understand but would like to learn about technical terms used in EBM, and about a third felt able to explain to others the meaning of some of these terms. CONCLUSIONS: This study demonstrates lack of adequate knowledge about basic concepts of EBM among medical student. On the other hands, there is an overall positive attitude toward EBM. There is need for educational interventions and incorporating formal teaching of EBM at medical education.

Small airways involvement in patients with rheumatoid arthritis.

OBJECTIVES: One of the common causes of morbidity in patients with RA is pulmonary involvement. Some studies have shown that the possible abnormal results of pulmonary function tests in rheumatoid disease are higher than usual. We aimed to evaluate the prevalence of spirometric abnormalities in patients with RA. MATERIALS & METHODS: This case-control study was conducted on 99 patients with RA who referred to a rheumatology clinic in Qazvin, northwest Iran. Sixty five age- and sex-matched healthy controls were recruited as well. History taking, physical examination, laboratory tests and spirometry were performed for the participants. RA severity was assessed according to Disease Activity Score 28 (DAS28). The data were processed using SPSS software version 16. Chi square and student's t test and multiple logistic regressions were used as appropriated. RESULTS: The mean (±SD) age of the patients was 46 (±10.5) years. The mean (±SD) duration of disease was 4.8 (±5.4) years, and the mean (±SD) DAS28 was 2.5 (±1.1). Dyspnea was the most common respiratory complaint (6.1%). Three (3%) patients had mild restrictive, 2 (2%) patients mild obstructive, and one (1%) patient moderate obstructive diseases. In the control group, only one participant had mild restrictive pulmonary disease (P<0.05). A significant decrease of FEF25 [OR=3.2; 95%CI (1.9-4.5)], FEF50 [OR=2.5; 95% CI (1.7-3.1)], FEF75 [OR=2.3; 95% CI (1.4-2.7)] and FEF25-75 [OR=2.7; 95% CI (1.7-3.5)] was observed in patients compared with the control group. We found no correlation between the patients' age, duration and severity of the disease, and laboratory tests with spirometric indices. CONCLUSION: It is recommended that patients with RA be visited on a regular basis and PFT be done for them for the early diagnosis of pulmonary involvement.