Mathematical analysis of soft baking in photolithography

[[abstract]]The soft baking step of a photolithography process is analyzed theoretically, taking the effect of the temperature dependence of the diffusivity of solvent into account. A coordinates-transform technique is chosen to solve the moving boundary problem under consideration. The temporal variation of the thickness of a film is predicted, and the result obtained justified by fitting experimental data reported in the literature for both poly(methylmethacrylate) film and Shipley UVIII photoresist. We show that, depending upon the types of photoresist film and the operating conditions, the transport of solvent may be controlled by the diffusion of solvent in a film or the convective transport of solvent from the gas–film interface to the bulk gas phase.[[notice]]補正完畢[[journaltype]]國外[[booktype]]紙本[[booktype]]電子版[[countrycodes]]US

Electrokinetic Flow in a pH-regulated, Cylindrical Nanochannel Containing Multiple Ionic Species

[[abstract]]Considering the wide applications of the electrokinetic flow regulated by pH, we model the flow of an electrolyte solution containing multiple ionic species in a charge-regulated cylindrical nanochannel. This extends previous analyses, where only two kinds of ionic species are usually considered, and a charged surface assumed to maintain at either constant potential or constant charge density, to a case closer to reality. Adopting a fused silica channel containing an aqueous NaCl background salt solution with its pH adjusted by HCl and NaOH as an example, we show that if the density of the functional groups on the channel surface increases (decreases), it approaches a constant potential (charge density) surface; if that density is low, the channel behavior is similar to that of a constant charge density channel at high salt concentration and large channel radius. Several interesting results are observed, for example, the volumetric flow rate of a small channel has a local maximum as salt concentration varies, which is not seen in a constant potential or charge density channel.[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙本[[booktype]]電子

Nardosinane-Type Sesquiterpenoids from the Formosan Soft Coral Paralemnalia thyrsoides

Five new nardosinane-type sesquiterpenoids, paralemnolins Q–U (1–5), along with three known compounds (6–8), were isolated from the Formosan soft coral Paralemnalia thyrsoides. The structures of new metabolites were elucidated on the basis of extensive spectroscopic methods, and the absolute configuration of 1 was determined by the application of Mosher’s method on 1. Among these metabolites, 1 and 3 are rarely found nardosinane-type sesquiterpenoids, possessing novel polycyclic structures. Compounds 1, 3, 6 and 7 were found to possess neuroprotective activity

Women with endometriosis have higher comorbidities: Analysis of domestic data in Taiwan

AbstractEndometriosis, defined by the presence of viable extrauterine endometrial glands and stroma, can grow or bleed cyclically, and possesses characteristics including a destructive, invasive, and metastatic nature. Since endometriosis may result in pelvic inflammation, adhesion, chronic pain, and infertility, and can progress to biologically malignant tumors, it is a long-term major health issue in women of reproductive age. In this review, we analyze the Taiwan domestic research addressing associations between endometriosis and other diseases. Concerning malignant tumors, we identified four studies on the links between endometriosis and ovarian cancer, one on breast cancer, two on endometrial cancer, one on colorectal cancer, and one on other malignancies, as well as one on associations between endometriosis and irritable bowel syndrome, one on links with migraine headache, three on links with pelvic inflammatory diseases, four on links with infertility, four on links with obesity, four on links with chronic liver disease, four on links with rheumatoid arthritis, four on links with chronic renal disease, five on links with diabetes mellitus, and five on links with cardiovascular diseases (hypertension, hyperlipidemia, etc.). The data available to date support that women with endometriosis might be at risk of some chronic illnesses and certain malignancies, although we consider the evidence for some comorbidities to be of low quality, for example, the association between colon cancer and adenomyosis/endometriosis. We still believe that the risk of comorbidity might be higher in women with endometriosis than that we supposed before. More research is needed to determine whether women with endometriosis are really at risk of these comorbidities

3D simulations of hydrodynamic drag on a nonhomogeneously structured permeable sphere and advective flow thereof

[[abstract]]The influence of the structure of a permeable sphere on the flow field and the hydrodynamic drag acting on it are investigated theoretically under the conditions of low to medium large Reynolds number. The anisotropic nature of the permeability of the sphere is taken into account by considering a three-dimensional permeability model. We show that although the permeability in the main flow direction dominates, the permeability in the other directions cannot be neglected. If Reynolds number is small, the larger the permeability in the main flow direction the more significant the influence of the permeability in the other directions. If Reynolds number takes a medium large value, the influence of the permeability in the other directions may decrease if the permeability in the main flow direction is sufficiently large. Depending on the levels of Reynolds number and the permeability, the extent of that influence can be on the order of 10%.[[journaltype]]國外[[incitationindex]]SCI[[incitationindex]]EI[[ispeerreviewed]]Y[[booktype]]紙本[[countrycodes]]US

Electrical Potentials of Two Identical Particles with Fixed Surface Charge Density in a Salt-Free Medium

[[abstract]]The electrical potentials of two identical planar, cylindrical, and spherical particles immersed in a salt-free dispersion are solved analytically by a perturbation approach for the case of constant surface charge density. The system under consideration simulates, for example, micelles, where the ionic species in the liquid phase come mainly from the dissociation of the functional groups on the droplet surface. We show that for planar particles, the present zero-order perturbation solution is exact, and for cylindrical and spherical particles, the first-order perturbation solution provides sufficiently accurate results, with an averaged percentage deviation on the order of 1% under typical conditions. In general, the higher the surface charge density, the higher the valence of counterions, the smaller the separation distance between two particles, and the smaller the curvature of particle surface, the better the performance of the perturbation solution.[[journaltype]]國外[[incitationindex]]SCI[[booktype]]紙本[[countrycodes]]US

Electrophoresis of an arbitrarily oriented toroid in an unbounded electrolyte solution

[[abstract]]The electrophoresis of a non-conducting rigid toroid in an unbounded Newtonian electrolyte solution having an arbitrary orientation is modeled theoretically under the condition of low surface potential. In particular, the influence of the orientation angle, defined as the angle between the applied electric field and the center line of the toroid, on its electrophoretic behavior as the thickness of double layer varies is investigated. The results of numerical simulation reveal that both the thickness of double layer and the orientation angle can influence appreciably the mobility of the toroid. In general, for a fixed orientation, the mobility of the toroid increases with decreasing double layer thickness, and for a fixed double layer thickness, the scaled electrophoresis mobility increases with increasing orientation angle. If the double layer is infinitely thin, then the present result reduces to that predicted by Smoluchowski, that is, the scaled electrophoretic mobility of the toroid is unity, and is not influenced by its shape. On the other hand, if it is infinitely thick, then the present result follows the same trend as that predicted by Henry, that is, the electrophoretic mobility of the toroid depends highly on its form effect, and the thicker the double layer the smaller that mobility. If the thickness of double layer is comparable to the radius of a toroid, the variation in the orientation angle can lead to as much as 40% difference in the mobility.[[journaltype]]國外[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙本[[countrycodes]]NL

Diffusiophoresis of a Charge-Regulated Spherical Particle Normal to Two Parallel Disks

[[abstract]]The diffusiophoresis of a charge-regulated spherical particle normal to two parallel disks as a response to an applied uniform electrolyte concentration gradient is modeled theoretically. The fixed charge on the particle surface comes from the dissociation/association reactions of the functional groups, yielding a charge-regulated surface, which simulates biological cells. Numerical simulations are conducted to examine the behavior of a particle under various conditions: the parameters considered in the simulation include the thickness of the double layer, the charged conditions on the particle surface, the relative size of the particle, and the particle-disk distance. Because the diffusiophoretic mobility of a particle can be dominated by chemiphoresis, electrophoresis, or osmotic flow, the diffusiophoretic behavior of the particle is complicated. For instance, the diffusiophoretic mobility may have two local maximums and a local minimum as the thickness of the double layer varies. This behavior is of practical significance if diffusiophoresis is adopted as a separation operation or as a tool to characterize the surface properties of a particle.[[journaltype]]國外[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙本[[countrycodes]]US