Ratliffstein9474

Surface diffusion has been measured in the glass of an organic semiconductor, MTDATA, using the method of surface grating decay. The decay rate was measured as a function of temperature and grating wavelength, and the results indicate that the decay mechanism is viscous flow at high temperatures and surface diffusion at low temperatures. Surface diffusion in MTDATA is enhanced by 4 orders of magnitude relative to bulk diffusion when compared at the glass transition temperature Tg. The result on MTDATA has been analyzed along with the results on other molecular glasses without extensive hydrogen bonds. In total, these systems cover a wide range of molecular geometries from rod-like to quasi-spherical to discotic and their surface diffusion coefficients vary by 9 orders of magnitude. We find that the variation is well explained by the existence of a steep surface mobility gradient and the anchoring of surface molecules at different depths. Quantitative analysis of these results supports a recently proposed double-exponential form for the mobility gradient log D(T, z) = log Dv(T) + [log D0 - log Dv(T)]exp(-z/ξ), where D(T, z) is the depth-dependent diffusion coefficient, Dv(T) is the bulk diffusion coefficient, D0 ≈ 10-8 m2/s, and ξ ≈ 1.5 nm. Assuming representative bulk diffusion coefficients for these fragile glass formers, the model reproduces the presently known surface diffusion rates within 0.6 decade. Our result provides a general way to predict the surface diffusion rates in molecular glasses.Cell-free systems for gene expression have gained attention as platforms for the facile study of genetic circuits and as highly effective tools for teaching. Despite recent progress, the technology remains inaccessible for many in low- and middle-income countries due to the expensive reagents required for its manufacturing, as well as specialized equipment required for distribution and storage. To address these challenges, we deconstructed processes required for cell-free mixture preparation and developed a set of alternative low-cost strategies for easy production and sharing of extracts. First, we explored the stability of cell-free reactions dried through a low-cost device based on silica beads, as an alternative to commercial automated freeze dryers. Second, we report the positive effect of lactose as an additive for increasing protein synthesis in maltodextrin-based cell-free reactions using either circular or linear DNA templates. The modifications were used to produce active amounts of two high-value reagents the isothermal polymerase Bst and the restriction enzyme BsaI. Third, we demonstrated the endogenous regeneration of nucleoside triphosphates and synthesis of pyruvate in cell-free systems (CFSs) based on phosphoenol pyruvate (PEP) and maltodextrin (MDX). We exploited this novel finding to demonstrate the use of a cell-free mixture completely free of any exogenous nucleotide triphosphates (NTPs) to generate high yields of sfGFP expression. Together, these modifications can produce desiccated extracts that are 203-424-fold cheaper than commercial versions. These improvements will facilitate wider use of CFS for research and education purposes.We developed a new method for obtaining surface-enhanced Raman scattering (SERS) spectra with extremely high sensitivity and spectral resolution. In this method, thousands of SERS spectra are acquired, followed by a data selection procedure based on density-based spatial clustering of applications with noise (DBSCAN). Each spectrum is recorded by exposure to a single nanosecond laser pulse to avoid the effect of time averaging. The reconstructed spectrum consists of the data that belong to the clusters. The method was applied to a crystal violet aqueous solution with a concentration of 10-7 mol/L. The results suggest that several minor Raman peaks were successfully recovered, which cannot be detected in conventional SERS measurements. Moreover, the method is also effective for separately observing Raman peaks that overlap with other neighboring peaks. This method extends the possibilities of SERS and will contribute to future high-resolution spectroscopy in condensed phases.Herein, a multifunctional polyurethane (PU) composite foam with a hierarchical structure is fabricated by dip-coating a carbon nanotube/shear-thickening gel (CNT/STG) and spray-coating nano-SiO2/STG on PU foam. The prepared nano-SiO2/CNT/STG@PU (SCS@PU) composite foam is lightweight, highly compressive, electrically conductive, superhydrophobic, and impact-energy absorptive. As a result, it possesses an excellent sensing ability to compression with a stable response up to 80% strain, an outstanding linearity of R2 > 0.99, and a wide response frequency of 0.01 to 1 Hz; it can also be used for effectively detecting impact force and sensing various human motions. Moreover, the superhydrophobicity with a water contact angle up to 154° of SCS@PU composite foam endows it with an excellent resistance to hazardous liquids (strong acid and alkali) to ensure its service reliability under harsh circumstances. In particular, the SCS@PU exhibits an outstanding anti-impact capability with an impact force attenuation rate of SCS@PU as high as 81%. Finally, its applications as soft body armors are demonstrated in protecting a wearer wearing a helmet with the SCS@PU as liner and using the SCS@PU as a smart kneecap against impact. On consideration of its excellent strain-sensing ability, superhydrophobicity, and outstanding anti-impact capability, the multifunctional SCS@PU composite foam developed is promising for personal safety protection.Precise regulation of ion transport through nanoscale pores will profoundly impact diverse fields from separation to energy conversion but is still challenging to achieve in artificial ion channels. Herein, inspired by the exquisite ion selectivity of biological Na+ channels, we have successfully fabricated hierarchically grown metal-organic frameworks (MOFs) on an asymmetrical substrate assisted by atomically thin nanoporous graphene. Efficient separation of monovalent metal ions is realized by encapsulating 18-crown-6 into MOF crystals. The resulting 18-crown-6@ZIF-67/ZIF-8 device, with subnanochannels and specific K+ binding sites, shows an ultrahigh Li+ conductivity of 1.46 × 10-2 S cm-1 and selectivities of 9.56 and 6.43 for Li+/K+ and Na+/K+, respectively. The Li+ conductivity is around 1-2 orders of magnitude higher than reported values for the other MOF materials. It is the first time that MOFs with subnanochannels realize selective transport of Na+ (ionic diameter of 1.9 Å) over K+ (2.6 Å) based on subangstrom differences in their ionic diameter. Our work opens new avenues to develop crown ether@MOF platforms toward efficient ion transistors, fluidic logic devices, and biosensors.Soft actuators designed from stimuli-responsive polymers often possess a certain amount of bionic functionality because of their versatile deformation. Liquid-crystalline polymers (LCPs) and their composites are among the most fascinating materials for soft actuators due to their great advantages of flexible structure design and easy regulation. In this Spotlight on Applications, we mainly focus on our group's latest research progress in soft actuators based on LCPs and their composites. Some representative research findings from other groups are also included for a better understanding of this research field. Above all, the essential principles for the responsive behavior and reconfigurable performance of the soft actuators are discussed, from the perspective of material morphology and structure design. see more Further on, we analyze recent work on how to precisely regulate the responsive modes and quantify the operating parameters of soft actuators. Finally, some application examples are given to demonstrate well-designed soft actuators with different functions under varied working environments, which is expected to provide inspiration for future research in developing more intelligent and multifunctional integrated soft actuators.Testicular epidermoid cysts are relatively rare, accounting for about 1% of all testicular tumors, and are often treated by high orchiectomy. We describe here the case of a testicular epidermoid cyst treated by testicle-sparing surgery due to a preoperative diagnosis. A 23-year-old man complained of a painless mass in the right scrotum. Physical examination revealed a firm little fingertip-sized smooth-surfaced mass in the right testis. Ultrasonography showed a hypoechoic lesion with an echogenic rim in the right testis. A T2-weighted magnetic resonance image showed a well-demarcated mass with a low signal outline. On the basis of a preoperative diagnosis of epidermoid cyst, intraoperative testicular frozen section was performed, and the mass was resected surgically while preserving the testis.A 57-year-old man visited the urology department with a painful mass on the dorsal side of the penis. Magnetic resonance imaging sagittal image showed a small nodule. Leukemia recurrence was suspected due to his history of treatment for acute myeloid leukemia treated with allogeneic hematopoietic stem cell transplantation. No recurrence was identified by bone marrow biopsy ; however, two months later, the recurrence of leukemia was strongly suspected because the tumor grew over time and blasts were found in the peripheral blood. A biopsy of the penile tumor and bone marrow was performed, leading to the diagnosis of granulocytic sarcoma. Patients with a history of leukemia may be preceded by a single recurrence to extramedullary organs, even if blood and bone marrow findings suggest remission.In order to treat the iatrogenic ureteral stricture of more than 8 cm length after transurethral ureterolithotripsy, we planned to perform ureterocystoneostomy with psoas hitch and Boari flap. Because of the longer defect of the affected ureter than presurgically expected and the rigid and thickened ureteral stump resulting from chronic inflammation, anti-reflux technique by forming submucosal tunnel could not be achieved as in the standard Boari flap and we reluctantly anastomosed the ureteral stump to the end of the tubularized bladder wall flap in end-to-end fashion. In order to secure the anti-reflux mechanism we created a submucosal tunnel in the posterior bladder wall according to the technique reported by Casale and Rink where it originally worked as anti-incontinence mechanism of catheterizable vesicostomy. The follow-up examinations showed no recurrence of ureteral stricture nor occurrence of vesicoureteral reflux.An 81-year-old male was referred to our department with a tumor in the left wall of the urinary bladder, which was detected by contrast-enhanced abdominal computed tomographic scan (CT), incidentally. Cystoscopy revealed a smooth non-papillary tumor. The patient underwent transurethral resection (TUR) of tumor. An immunohistochemical study showed the tumor cells positively stained for chromogranin A, synaptophysin, CD56, and Ki67. The Ki67 index of the tumor was ＞0.5%, which confirmed the diagnosis of a pure carcinoid tumor. There was no recurrence of bladder tumor and no metastasis after the primary treatment.