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The use of microelectromechanical systems (MEMS) technology in medical and biological applications has increased dramatically in the past decade due to the potential for enhanced sensitivity, functionality, and performance associated with the miniaturization of devices, as well as the market potential for low-cost, personalized medicine. However, the utility of such devices in clinical medicine is ultimately limited due to factors associated with prevailing micromachined materials such as silicon, as it poses concerns of safety and reliability due to its intrinsically brittle properties, making it prone to catastrophic failure. Recent advances in titanium (Ti) micromachining provides an opportunity to create devices with enhanced safety and performance due to its proven biocompatibility and high fracture toughness, which causes it to fail by means of graceful, plasticity-based deformation. Motivated by this opportunity, we discuss our efforts to advance Ti MEMS technology in two ways: 1) Through the development of titanium-based microneedles (MNs) that seek to provide a safer, simpler, and more efficacious means of ocular drug delivery, and 2) Through the advancement of Ti anodic bonding for future realization of robust microfluidic devices for photocatalysis applications. As for the first of these thrusts, we show that MN devices with in-plane geometry and through-thickness fenestrations that serve as drug reservoirs for passive delivery via diffusive transport from fast-dissolving coatings can be fabricated utilizing Ti deep reactive ion etching (Ti DRIE). Our mechanical testing and finite element analysis (FEA) results suggest that these devices possess sufficient stiffness for reliable corneal insertion. Our MN coating studies show that, relative to solid MNs of identical shank dimension, fenestrated devices can increase drug carrying capacity by 5-fold. Furthermore, we demonstrate that through-etched fenestrations provide a protective cavity for delivering drugs subsurface, thereby enhancing delivery efficiencies in an ex vivo rabbit cornea model. Collectively, these results show the potential embodied in developing Ti MNs for effective, minimally invasive, and low-cost ocular drug delivery. Additionally, or the second of these thrusts, we report the development of an anodic bonding process that allows, for the first time, high-strength joining of bulk Ti and glass substrates at the wafer-scale, without need for interlayers or adhesives. We demonstrate that uniform, full-wafer bonding can be achieved at temperatures as low as 250°C, and that failure during burst pressure testing occurs via crack propagation through the glass, rather than the Ti/glass interface, thus demonstrating the robustness of the bonding. Moreover, using optimized bonding conditions, we demonstrate the fabrication of rudimentary Ti/glass-based microfluidic devices at the wafer-scale, and their leak-free operation under pressure-driven flow. Finally, we demonstrate the monolithic integration of nanoporous titanium dioxide within such devices, thus illustrating the promise embodied in Ti anodic bonding for future realization of robust microfluidic devices for photocatalysis applications. Together, these results demonstrate the potential embodied in utilizing Ti MEMS technology for the fabrication of novel drug delivery and microfluidic systems with enhanced robustness, safety, and performance.

We present avidity sequencing - a novel sequencing chemistry that separately optimizes the process of stepping along a DNA template and the process of identifying each nucleotide within the template. Nucleotide identification uses multivalent nucleotide ligands on dye-labeled cores to form polymerase-polymer nucleotide complexes bound to clonal copies of DNA targets. These polymer-nucleotide substrates, termed avidites, decrease the required concentration of reporting nucleotides from micromolar to nanomolar, and yield negligible dissociation rates. We demonstrate the use of avidites as a key component of a sequencing technology that surpasses Q40 accuracy and enables a diversity of applications that include single cell RNA-seq and whole human genome sequencing. We also show the advantages of this technology in sequencing through long homopolymers.

The rapid advancement of additive manufacturing (AM) technologies has provided new avenues for creating three-dimensional (3D) parts with intricate geometries. Fused Deposition Modeling (FDM) is a prominent technology in this domain, involving the layer-by-layer fabrication of objects by extruding a filament comprising a blend of polymer and metal powder. This study focuses on the FDM process using a filament of Copper–Polylactic Acid (Cu-PLA) composite, which capitalizes on the advantageous properties of copper (high electrical and thermal conductivity, corrosion resistance) combined with the easily processable thermoplastic PLA material. The research delves into the impact of FDM process parameters, specifically, infill percentage (IP), infill pattern (P), and layer thickness (LT) on the maximum failure load (N), percentage of elongation at break, and weight of Cu-PLA composite filament-based parts. The study employs the response surface method (RSM) with Design-Expert V11 software. The selected parameters include infill percentage at five levels (10, 20, 30, 40, and 50%), fill patterns at five levels (Grid, Triangle, Tri-Hexagonal, Cubic-Subdivision, and Lines), and layer thickness at five levels (0.1, 0.2, 0.3, 0.4, and 0.5 mm). Also, the optimal factor values were obtained. The findings highlight that layer thickness and infill percentage significantly influence the weight of the samples, with an observed increase as these parameters are raised. Additionally, an increase in layer thickness and infill percentage corresponds to a higher maximum failure load in the specimens. The peak maximum failure load (230 N) is achieved at a 0.5 mm layer thickness and Tri-Hexagonal pattern. As the infill percentage changes from 10% to 50%, the percentage of elongation at break decreases. The maximum percentage of elongation at break is attained with a 20% infill percentage, 0.2 mm layer thickness, and 0.5 Cubic-Subdivision pattern. Using a multi-objective response optimization, the layer thickness of 0.152 mm, an infill percentage of 32.909%, and a Grid infill pattern was found to be the best configuration.

BackgroundRosa damascena is an aromatic rose species, which is cultivated for its essential oil, and is widely used in perfume, cosmetic, pharmaceutical, and food industries in the world. This experiment was conducted to evaluate essential oil and morphological variations of 26 Damask rose genotypes. For this purpose, the effect of harvest time, i.e., early morning or evening, and sampling type, i.e., fresh or dried petals, on oil content was evaluated. In addition, the composition of essential oil of the genotypes was determined using gas chromatography–mass spectrometry (GC–MS).ResultsResults showed that early morning was the preferable time for flower collection based on oil content. Furthermore, the oil yield of fresh petals was higher than that of the dried petals. Twenty-five volatile compounds were found in the extracted oils. β-Damascenone, a key marker for the quality of rose oil, was found in 22 genotypes and was more than 1.5% concentration in G3, G6, and G11 genotypes. The highest components of the oil of Damask rose genotypes were nonadecane (42.51%), β-citronellol (40.82%), n-heneicosane (34.69%), geraniol (27.76%), and n-tricosane (14.2%). A wide variation in flower characteristics, such as petal color (from white to nearly red) and petal numbers from about 25 to 95, were also recorded. The G2, G5, and G15 genotypes, originated from Isfahan, Fars, and Kerman, respectively, were selected based on petal number, flower weight, and essential oil content in fresh and dried petals.ConclusionsResults suggest that morphological and biochemical diversity of Damask rose genotypes can be used effectively to characterize genetic diversity between different genotypes and to select special traits in breeding programs.

Introduction The extraction socket dimensional changes might arouse serious concerns, prompting clinicians to perform reconstructive treatments to increase bone volume before implant placement.1 Approximately 0.34-7.7 mm of resorption in the ridge width and 0.2-3.25 mm of reduction in height occurs 6-12 months after tooth extraction,2 which is the best time to preserve tooth socket dimensions.3 The ridge preservation methods prevent 40-60% of alveolar bone atrophy following tooth extraction, which usually occurs 2-3 months after tooth extraction, and resorption continues at a rate of 0.25-0.5% per year.4 The use of graft materials to repair bone lesions or increase the width or height of atrophic alveolar ridges has been evaluated by several experimental studies, the first of which was conducted by Boyne5 in 1970 and is still cited in recent years due to its high success. Research on suitable bone grafting materials has increased in recent years due to the limitations of autografts in some patients, the need for surgery at the donor site, and the limitations of available bone volume.9 Allografts, including FDBA (freeze-dried bone allograft) and DFDBA (demineralized freeze-dried bone allograft), have been successful in many studies, with effective results in alveolar ridge preservation, minimizing ridge resorption following tooth extraction.10,11 Since limited studies are available on the effect of ridge dimension preservation techniques after tooth extraction,12,13 with most being radiographic examinations and on animal models, this study aimed to histologically compare the FDBA graft material (absorbs with a slower rate compared to DFDBA) with natural socket healing in terms of bone quantity and quality for implant placement at different time intervals. [...]the cortical FDBA graft material with 500-1000-^m particles (Kish Tissue Regeneration Corporation, Iran) was used to graft the extraction socket. [...]the tissue was stained by conventional hematoxylin staining methods.14 The stained sections were examined by an oral pathologist to determine the percentage of viable bone, the amount of residual biomaterial, and inflammation at x100 magnification of a Nikon YS100 light microscope with a graduated lens (Figure 2).15 Statistical analysis The changes in histological indices, i.e., inflammation rate, bone formation percentage, and the amount of remaining biomaterial, at the two time intervals were evaluated with the Mann-Whitney U test.