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Purpose: The purpose of this study was to access post-operative clinical as well as radioghraphic success of Diode Laser / Mineral Trioxide Aggregate (MTA) and Diode Laser /Biodentine (BD) pulpotomy procedures in comparison to conventional technique using Formocresol /Zinc Oxide Eugenol (FC/ZOE) pulpotomy for human primary molars. Materials and Methods: A total of 90 lower primary molars that had deep carious lesion and need pulpotomy treatment from 66 healthy and cooperative patients, aged 4-6 years old were chosen for this study. After removal of the coronal tissue and depending on the type of radicular pulp medicament, the teeth were divided randomly and equally into three groups; Group A (FC/ZOE), Group B (Diode Laser/MTA) and Group C (Diode laser/BD). Treatments in all groups were completed with Glass Ionommer restoration then stainless steel crowns. Results: The cumulative clinical and radiographic success rates after 12 months follow up were 90.3%, 96.3% and 100% for the FC/ZOE, Diode Laser/MTA and Diode Laser/BD pulpotomy groups respectively. Conclusion: Laser assessed pulpotomy in combination with MTA or Biodentine had a more advanced clinical and radiographic success rate correlated to FC/ZOE pulpotomy technique in primary molar. Statistically, no significance difference was found between the three study groups in the overall clinical and radiographic success rate.

Effect of Surface Treatments on the Color Change and Shear Bond Strength of Porcelain Laminate Veneer Aim of the study: the purpose of this Invitro study to evaluate the effect of surface treatments on the color change and shear bond strength of lithium disilicate glass ceramic veneers. Materials & Methods: Twenty square samples with dimensions (8x8x2) and another twenty samples with smaller dimensions (4x4x2) were cut from five IPS e-max CAD blocks of shade A3. The discs were divided into two groups: 1) Half of the small and large blocks were subjected to hydrofluoric acid (HF); 2) the other half was subjected to Co2 laser irradiation. The conditioned samples were subdivided according to the bonding agent: A) Silane application for 60 seconds; B) Single bond universal light cured for 10 seconds. Each small sample was cemented on the top of a large sample using Rely-x veneer cement with translucent shade. The color change was measured using spectrophotometer. The shear bond strength was tested using a universal testing machine. Results: HF resulted in higher bond shear bond strength and ΔE than Co2 laser. Single bond universal resulted in higher shear bond strength values than silane. Conclusion: HF followed by either single bond universal or silane could be the best surface treatment for e-max CAD ceramic. However, Co2 laser could be a promising alternative surface treatment.

The advancement of sample preparation techniques is essential for the field of cell-based therapeutics. To obtain cells suited for clinical applications, the entire process starting from acquiring donor tissue biopsy, all through cell transplantation into the recipient, should occur in an integrated, safe, and efficient system. The current laboratory approach for solid tissue-to-cell isolation is invasive and involves multiple incoherent manual procedures running in an open operator-dependent system. Such an approach provides a chain of events for systematic cell loss that would be unfavorable for rare cell populations such as adult and cancer stem cells. A few lab-on-chip platforms were proposed to process biological tissues, however, they were limited to partial tissue dissociation and required additional processing off-chip. Here, we report the first microfluidic platform that can dissociate native biological tissue into ready-to-use single cells. The platform can merge the successive steps of tissue dissociation, debris filtration, cell sieving, washing, and staining in one streamlined process. Performance of the platform was tested with diverse biological tissues and it could yield viable cells that were ready for on or off-chip cell culture without further processing. Microfluidic tissue dissociation using this platform produced a higher number of viable single cells (an average of 2262 cells/ml per milligram of tissue compared to 1233.25 cells/ml/mg with conventional dissociation). Refereed/Peer-reviewed

Objective: To assess the efficacy of agitation of chlorohexidine (CHX) and Silver nanoparticles “AgNps” with 810nm diode laser or sonic endoactivator compared to side –vented needle on infected root canals with Enterococcus “E” Faecalis biofilms. Material and Methods: Sixty-five extracted human premolars with single oval canals were instrumented by protaper system up to F3. Biofilms of E. faecalis were generated based on a previously established protocol. Two teeth were used to check the biofilm formation, then the remaining Teeth were randomly divided into three equal experimental groups according to agitation techniques used: group 1 (810 nm diode laser with 1 watt), group 2 (sonic endoactivator) and group 3 (Side vented needle). Each group was further divided into three equal subgroups according to the irrigant solution into; subgroup A: chlorohexidine, subgroup B: silver nanoparticles and subgroup C: distilled water: Confocal laser scanning microscopy “CLSM” was used to assess bacterial viability. Data were analyzed by appropriate statistical analyses with P = 0.05. Results: Regarding the activation method, all groups had a significantly high percentage of dead bacteria (P < 0.05). However, Laser was significantly the highest and Endoactivator the least (P < = 0.001). Diode laser agitation of AgNps irrigant showed the highest reduction percentage of bacteria (78.1%) with a significant difference with both CHX and water irrigation, Conclusion: Under the condition of the present study; results reinforced that laser activation is a useful adjunct, 810 nm diode laser agitation of AgNps or chlorhexidine was more effective in disinfection of oval root canals than endoactivator and side vented needle techniques.KeywordsDentinal infection; Silver-nanoparticles; chlorohexidine; agitation; Diode Laser; Sonic endoactivator.

Image processing is widely growing as a useful tool in biosensing applications. It can be used to convert any camera/microscope into an optical sensor with wide range of capabilities such as monitoring completion of colorimetric reactions, differentiating and counting cells, and tracking motile cells/organisms. However, implementation of image processing in Lab-on-Chip devices is still challenging for researchers with little expertise in this field. Here, we present a multi-purpose real-time machine vision platform for tracking and analyzing objects inside lab-on-chip devices and for automating many microfluidic applications. Our LabVIEW-based machine vision platform, which is freely available on our webpage ( http://www.assiutmicrofluidics.com/research ), enables non-experts in image processing and machine vision to easily assemble their image processing pipeline based on the intended application. The program was designed for plug and play interfacing with a wide range of imaging devices including USB microscopes, high-speed cameras, and smartphone cameras. Moreover, to achieve portability, the program can be loaded on myRIO, a portable pocket size fully functional LabVIEW platform, to perform all program capabilities outside the lab without the need for a PC. To prove functionality of our program, we used it in real-time closed loop control of hydrodynamic focusing and control of flow velocity of cells inside a microchannel. We also demonstrated the program abilities in different lab-on-chip applications such as tracking, differentiation, and counting of blood cells.

This paper introduces the design and implementation of a wide dynamic range CMOS image sensor (CIS) with high sensitivity. The sensor is designed and implemented in a 130 nm CMOS technology. The pixel occupies an area of 3 μm × 3 μm and consists of six NMOS transistors with one capacitor. The readout circuit features an extremely low output noise of 19 μV rms with a 4 MHz bandwidth. Power dissipation of 11.2 μW was achieved at low voltage operation of 1.6 V. The sensor has a combination of low noise and a 97 dB wide dynamic range due to the diode connected load configuration.

This paper presents an approach using gm/ID methodology for the design of the regulated cascode circuit (RGC) transimpedance amplifier (TIA) for optical receivers. The framework uses lookup tables produced using the gm/ID methodology to define the sizing of the transistors needed to reach the required specifications. The presented framework has the advantage of setting limits on the design space using intuitive equations derived from the circuit analyses. This gives insight into the effect of changing the value of different circuit parameters on the resulting design performance while decreasing the calculation time to reach the desired design. The proposed method can reach the required specifications with the flexibility to minimize the DC power consumption or the total input referred noise. The framework is implemented in a 130 ​nm CMOS process with a 1.5 ​V supply voltage producing two different designs. Both designs met the required specifications while optimizing power consumption or noise and were validated using simulations. The results obtained are discussed and compared against other similar designs from the state-of-the-art.

An innovative and simple microfabrication method for digital microfluidics is presented. In this method, devices are formed from copper substrates or gold compact disks using rapid marker masking to replace photolithography. The new method is capable of forming devices with inter-electrode gaps as small as 50 μm. Saran™ wrap (polyethylene film) and commercial water repellants were used as dielectric and hydrophobic coatings, respectively, to replace commonly used and more expensive materials such as parylene-C and Teflon-AF. Devices formed by the new method enabled single- and two-plate actuation of droplets with volumes of 1–12 μL. Fabricated devices were successfully tested for droplet manipulation, merging and splitting. We anticipate that this fabrication method will bring digital microfluidics within the reach of any laboratory with minimal facilities.

The viscous micropump consists of a cylinder placed eccentrically inside a microchannel, where the rotor axis is perpendicular to the channel axis. When the cylinder rotates, a net force is transferred to the fluid because of the unequal shear stresses on the upper and lower surfaces of the rotor. Consequently, this causes the surrounding fluid in the channel to displace toward the microchannel outlet. The simplicity of the viscous micropump renders it ideal for micropumping; however, previous studies have shown that its performance is still less than what is required for various applications. The performance of the viscous micropump, in terms of flow rate and pressure capabilities, may be enhanced by implementing more than one rotor into the configuration either horizontally or vertically oriented relative to each other. This is analogous to connecting multiple pumps in parallel or in series. The present study will numerically investigate the performance of various configurations of the viscous micropumps with multiple rotors, namely, the dual-horizontal rotor, triple-horizontal rotor, symmetrical dual-vertical rotor, and eight-shaped dual-vertical rotor. The development of drag-and-lift forces with time, as well as the viscous resisting torque on the cylinders were studied. In addition, the corresponding drag, lift, and moment coefficients were calculated. The flow pattern and pressure distribution on the cylinders’ surfaces are also included in the study. Results show that the symmetrical dual-vertical rotor configuration yields the best efficiency and generates the highest flow rate. The steady-state performance of the single-stage micropump was compared to the available experimental and numerical data and found to be in very good agreement. This work provides a foundation for future research on the subject of fluid phenomena in viscous micropumps.

Computers are rapidly becoming faster and more versatile, and as a result, high-powered integrated circuits have been produced in order to meet this need. However, these high-speed circuits are expected to generate heat fluxes that exceed the circuit's allowable operating temperature, and so an innovative cooling device is needed to solve this problem. Microchannel heat sinks were introduced in the early 1980s to be used as a means of cooling integrated circuits. Since then, many studies have been conducted in the field of these microchannel heat sinks. Earlier research used mainly single-phase coolants in their heat sinks, but two-phase coolants are now the focus of more recent research. The purpose of this article is to present a state-of-the art literature review of the progress of research in the field of microchannel heat sinks. This literature will focus mainly on the most recent research, starting with the latter half of the 1990s.

To estimate the effectiveness of gonadotropin-releasing hormone (GnRH) analogues cotreatment in preventing chemotherapy-induced amenorrhea in young breast cancer patients undergoing cyclophosphamide-based chemotherapy.One hundred hormone-insensitive breast cancer participants (aged 18-40 years) were recruited from two university-affiliated oncology centers in Egypt. Opting for type of cotreatment was based on available timeframe until start of chemotherapy. Fifty women ready for early chemotherapy were randomized to receive either chemotherapy alone (arm I) or chemotherapy after downregulation (estradiol less than 50 pg/mL) by GnRH antagonist and agonist (arm II). Then, GnRH antagonist was discontinued and agonist was continued until the end of chemotherapy. When chemotherapy was to start later than 10 days after study inclusion, 50 women were randomized to receive either chemotherapy alone (arm III) or chemotherapy after downregulation with GnRH agonist (arm IV). Resumption of menstruation at 12 months after end of chemotherapy was the primary outcome. Postchemotherapy hormonal and ultrasound changes were secondary outcomes.Twelve months after termination of chemotherapy, there were no differences in menstruation resumption rates between GnRH-treated patients and control group individuals in either early (80% in arms I and II, risk ratio 1, 95% confidence interval 0.7-.32; P=1.00) or delayed chemotherapy groups (80% and 84% in arms III and IV, risk ratio 0.95, 95% confidence interval 0.73-1.235; P=.71). There were no differences in hormonal and ultrasound markers between GnRH analogue users and control group individuals. The use of GnRH analogue cotreatment did not predict independently the odds of menstruating at 12 months.GnRH analogue cotreatment does not offer a significant protective effect on ovarian function in patients treated by cyclophosphamide-based chemotherapy.Australian New Zealand Clinical Trials Registry. www.anzctr.org.au, ACTRN12609001059257.I.

We introduce a method for 3D droplet actuation in digital microfluidics, which we have called all terrain droplet actuation (ATDA), in which droplets are manipulated on inclined, declined, vertical, twisted and upside down architectures. ATDA enables discrete processes on a single platform without thermal, chemical, or biological interference between them. To illustrate this capacity, we developed sensors capable of cycling droplets between distinct temperatures and oxygen milieu. We anticipate that ATDA will have significant impact in the field of microfluidics and the growing trend toward laboratory miniaturization.

Digital microfluidics is a popular tool for lab-on-a-chip applications and is typically implemented in one of two formats: single-plate (“open”) devices or two-plate (“closed”) devices. Single-plate devices have some advantages relative to the more common two-plate format such as faster mixing, the capacity to move larger volumes on a given footprint, and easier access to droplets for handling or optical detection. In contrast with the two-plate format, in which ground potential is generally supplied via a top electrode, in the single-plate format, many different geometries of ground wires/electrodes have been used. Until the present study, there has been no metric to determine which of these geometries is best suited for droplet actuation. Here, we present a combination of numerical simulations and experimental tests to compare six different single-plate designs. We applied finite element analysis, using the commercially available COMSOL software package to calculate the electrodynamic actuation forces in each of the different designs and used the results to optimize device design. Forces predicted by the electrodynamic model were in agreement with forces predicted using electromechanical models. More importantly, results were verified experimentally using a unique technique that permits indirect estimation of actuation forces on digital microfluidic devices. This work illustrates the promise of using numerical modeling to enhance the design and performance of digital microfluidic devices.

The viscous micropump consists of a cylinder placed eccentrically inside a microchannel, where the rotor axis is perpendicular to the channel axis. When the cylinder rotates, a net force is transferred to the fluid due to the unequal shear stresses on the upper and lower surfaces of the rotor. Consequently, this causes the surrounding fluid in the channel to displace towards the microchannel outlet. The simplicity of the viscous micropump renders it ideal for micro pumping, however, previous studies have shown that its performance is still less than what is required for various applications. The performance of the viscous micropump, in terms of flow rate, pressure head and efficiency, may be enhanced by implementing more than one rotor into the configuration. The present study will numerically investigate the performance of various configurations of the viscous micropumps with multiple rotors, namely the dual-horizontal rotor, the triple-horizontal rotor, the symmetrical-dual-vertical rotor, and the 8-shaped dual-vertical rotor. The development of drag force with time, as well as the viscous resisting torque on the cylinders were studied. In addition, the corresponding drag and moment coefficients were calculated. Results show that the symmetrical-dual-vertical rotor configuration yields the best efficiency, and generates the highest flow rate. The steady state performance of the single-stage micropump was compared with the available experimental and numerical data, and was found to be in very good agreement. This work provides a foundation for future research on the subject of fluid phenomena in viscous micropumps.Copyright © 2004 by ASME