Quantitative Analysis of Fluorescence Detection Using a Smartphone Camera for a PCR Chip

Most existing commercial real-time polymerase chain reaction (RT-PCR) instruments are bulky because they contain expensive fluorescent detection sensors or complex optical structures. In this paper, we propose an RT-PCR system using a camera module for smartphones that is an ultra small, high-performance and low-cost sensor for fluorescence detection. The proposed system provides stable DNA amplification. A quantitative analysis of fluorescence intensity changes shows the camera’s performance compared with that of commercial instruments. Changes in the performance between the experiments and the sets were also observed based on the threshold cycle values in a commercial RT-PCR system. The overall difference in the measured threshold cycles between the commercial system and the proposed camera was only 0.76 cycles, verifying the performance of the proposed system. The set calibration even reduced the difference to 0.41 cycles, which was less than the experimental variation in the commercial system, and there was no difference in performance.

A low-cost, high-performance video-based binocular eye tracker for psychophysical research

We describe a high-performance, pupil-based binocular eye tracker that approaches the performance of a well-established commercial system, but at a fraction of the cost. The eye tracker is built from standard hardware components, and its software (written in Visual C++) can be easily implemented. Because of its fast and simple linear calibration scheme, the eye tracker performs best in the central 10 degrees of the visual field. The eye tracker possesses a number of useful features: (1) automated calibration simultaneously in both eyes while subjects fixate four fixation points sequentially on a computer screen, (2) automated real-time continuous analysis of measurement noise, (3) automated blink detection, (4) and real-time analysis of pupil centration artifacts. This last feature is critical because it is known that pupil diameter changes can be erroneously registered by pupil-based trackers as a change in eye position. We evaluated the performance of our system against that of a well-established commercial system using simultaneous measurements in 10 participants. We propose our low-cost eye tracker as a promising resource for studies of binocular eye movements.

Bacterial Cell Inactivation Using a Single-Frequency Batch-Type Ultrasound Device

Ultrasound technology employs cavitation to generate high-pressure soundwaves to disrupt bacterial cells. This study reveals the effectiveness of a single frequency ultrasound device for bacterial cell inactivation. A low-cost ultrasound device having a single frequency, i.e. 22 kHz for lab-scale application, was developed first, and the prototype was mechanically designed and analyzed using the finite-element method to assure the targeted natural frequency could be achieved. The prototype was then tested inactivating bacterial cells, Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis), in a simple medium and a food system, and the results were then compared to a commercial system. A treatment time of up to 15 minutes was able to reduce E. coli and B. subtilis cells by 3.3 log and 2.8 log, respectively, and these results were similar to those of the commercial system. The effectiveness of bacterial cell inactivation using the developed single-frequency ultrasound device is then discussed. The findings are useful for designing low-cost ultrasound devices for application in the food industry.

Commercial Linkages with Central Asia and Iran

While it may seem counterintuitive, the increase in Mughal India’s maritime trade contributed to a tightening of overland commercial connections with its Asian neighbors. The primary agents in this process were “Multanis,” members of any number of heavily capitalized, caste-based family firms centered in the northwest Indian region of Multan. The Multani firms had earlier developed an integrated commercial system that extended across the Punjab, Sind, and much of northern India. In the middle of the sixteenth century, Multanis first appear in historical sources as having established their own communities in Central Asia and Iran. By the middle of the seventeenth century, at any given point in time, a rotating population of some 35,000 Indian merchants orchestrated a network of communities that extended across dozens, if not hundreds, of cities and villages in Afghanistan, Central Asia, and Iran, stretching up the Caucasus and into Russia.

Efficacy of a Semi Automated Commercial Closed System for Autologous Leukocyte- and Platelet-Rich Plasma (l-prp) Production in Dogs: A Preliminary Study

Background: To characterize the cellular composition (platelets, erythrocytes, and leukocytes) and determine platelet-derived growth factor isoform BB (PDGF-BB) concentration in canine leukocyte- and platelet rich plasma (L-PRP) produced using a commercial semi-automated closed system. Methods: Twenty milliliters of citrated whole blood were obtained from 30 healthy un-sedated canine blood donors and processed using a semi-automated completely closed commercial system (CPUNT 20, Eltek group, Casale Monferrato, Alessandria, Italy) according to the manufacturer’s instructions. Erythrocyte, leukocyte, and platelet counts were determined in both whole blood (WB) and resultant L-PRP. The PDGF-BB concentration was evaluated after bovine thrombin activation of 10 L-PRP samples. Results: This commercial system produced on average 2.3 ± 0.7 mL of L-PRP containing a high concentration of platelets (767,633 ± 291,001 μL, p < 0.001), with a 4.4 fold increase in platelet count, lower concentration of erythrocytes (528,600 ± 222,773 μL, p < 0.001) and similar concentration of leukocytes (8422 ± 6346 μL, p = 0.9918) compared with WB. L-PRP had an average of 3442 ± 2061 pg/mL of PDGF-BB after thrombin activation. Neutrophils, lymphocytes and monocytes average percent content in L-PRP was 14.8 ± 13.2, 71.7 ± 18.5 and 10.7 ± 6.4, respectively. Conclusion: Sterile canine L-PRP prepared using this semi-automated closed system is easy to obtain, produces a significant increase in platelet count compared to WB and contains a detectable concentration of PDGF-BB after activation. Additional in vitro and in vivo studies are needed to assess inflammatory markers concentration and the therapeutic efficacy of this L-PRP in dogs.

Des meules neuves pour un pain meilleur? Un forgeron perpignanais et son commerce de meules, 1410-1422

Resumen: Joan Bastard était un forgeron établi à Perpignan au début du xve siècle. Toutefois, il semble avoir été avant tout un marchand de meules. Entre 1410 et 1422, il vendit en effet plus de 100 meules en Roussillon, Vallespir et Bas-Conflent. Les documents notariés relatifs à ce commerce sont d’une qualité exceptionnelle. Ils permettent non seulement d’étudier un système commercial particulier mais aussi de mieux connaître les meules en usage sur le versant septentrional des Pyrénées Orientales. Joan Bastard vendait ses meules à crédit. Il offrait principalement des meules importées, taillées dans de la « pierre de Montjuïc », un grès qui rendait possible l’obtention d’une farine plus fine que celles obtenues avec les meules de grès ou de granites locaux. Mots-clés: meules, grès (pierre), commerce, Roussillon médiéval, farine, xve siècle. Abstract: Joan Bastard was a blacksmith established in Perpignan in the early 15th century. Nevertheless, he seems to have developed his main professional activity as a millstone trader. Between 1410 and 1422, he sold more than 100 millstones in Roussillon, Vallespir and Bas-Conflent. Notarized documents related with this trade are of an exceptional quality. They allow not only to study a particular commercial system but also to know the millstone in use in the north side of Oriental Pyrenees. Joan Bastard sold his millstones at credit. He offered almost imported millstones of “Montjuïc stone”, a sandstone that made possible to obtain a flour finer than ones produced using millstones of local sandstone and granites. Key words: millstone, sandstone, trade, medieval Roussillon, flour, 15th century.