Effect of protein fouling on filtrate flux and virus breakthrough behaviors during virus filtration process.

Virus filtration process is used to ensure viral safety in the biopharmaceutical downstream processes with high virus removal capacity (i.e., >4 log10 ). However, it is still constrained by protein fouling, which results in reduced filtration capacity and possible virus breakthrough. This study investigated the effects of protein fouling on filtrate flux and virus breakthrough using commercial membranes that had different symmetricity, nominal pore size, and pore size gradients. Flux decay tendency due to protein fouling was influenced by hydrodynamic drag force and protein concentration. As the results of prediction with the classical fouling model, standard blocking was suitable for most virus filters. Undesired virus breakthrough was observed in the membranes having relatively a large pore diameter of the retentive region. The study found that elevated levels of protein solution reduced virus removal performance. However, the impact of prefouled membranes was minimal. These findings shed light on the factors that influence protein fouling during the virus filtration process of biopharmaceutical production.

Ultrastrong and ductile steel welds achieved by fine interlocking microstructures with film-like retained austenite.

The degradation of mechanical properties caused by grain coarsening or the formation of brittle phases during welding reduces the longevity of products. Here, we report advances in the weld quality of ultra-high strength steels by utilizing Nb and Cr instead of Ni. Sole addition of Cr, as an alternative to Ni, has limitations in developing fine weld microstructure, while it is revealed that the coupling effects of Nb and Cr additions make a finer interlocking weld microstructures with a higher fraction of retained austenite due to the decrease in austenite to acicular ferrite and bainite transformation temperature and carbon activity. As a result, an alloying design with Nb and Cr creates ultrastrong and ductile steel welds with enhanced tensile properties, impact toughness, and fatigue strength, at 45% lower material costs and lower environmental impact by removing Ni.

Fe-Al-Mn-C lightweight structural alloys: a review on the microstructures and mechanical properties.

Adding a large amount of light elements such as aluminum to steels is not a new concept recalling that several Fe-Al-Mn-C alloys were patented in 1950s for replacement of nickel or chromium in corrosion resistance steels. However, the so-called lightweight steels or low-density steels were revisited recently, which is driven by demands from the industry where steel has served as a major structural material. Strengthening without loss of ductility has been a triumph in steel research, but lowering the density of steel by mixing with light elements will be another prospect that may support the competitiveness against emerging alternatives such as magnesium alloys. In this paper, we review recent studies on lightweight steels, emphasizing the concept of alloy design for microstructures and mechanical properties. The influence of alloying elements on the phase constituents, mechanical properties and the change of density is critically reviewed. Deformation mechanisms of various lightweight steels are discussed as well. This paper provides a reason why the success of lightweight steels is strongly dependent on scientific achievements even though alloy development is closely related to industrial applications. Finally, we summarize some of the main directions for future investigations necessary for vitalizing this field of interest.

Comparative Evaluation of the Performance of Sterile Filters for Bioburden Protection and Final Fill in Biopharmaceutical Processes.

Sterile filtration processes are widely used in the production of biotherapeutics for microorganism removal and product sterility. Sterile filtration processes can be applied to buffer preparation and cell culture media preparation in biotherapeutics processes, and to final sterilization or final filling in downstream processes. Owing to their broad range of applications in bioprocessing, various 0.2/0.22 µm sterile filters with different polymer materials (i.e., hydrophilic PVDF and PES) and nominal pore sizes are commercially available. The objective of this study was to evaluate two different commercial sterile filters in terms of filtration performance in various sterile filtration processes of biopharmaceutical production. The results demonstrate the importance of choosing the appropriate filter considering the process type and target removal/transport product to ensure efficient sterile filtration in the production of biotherapeutics.

A new class of lightweight, stainless steels with ultra-high strength and large ductility.

Steel is the global backbone material of industrialized societies, with more than 1.8 billion tons produced per year. However, steel-containing structures decay due to corrosion, destroying annually 3.4% (2.5 trillion US$) of the global gross domestic product. Besides this huge loss in value, a solution to the corrosion problem at minimum environmental impact would also leverage enhanced product longevity, providing an immense contribution to sustainability. Here, we report a leap forward toward this aim through the development of a new family of low-density stainless steels with ultra-high strength (> 1 GPa) and high ductility (> 35%). The alloys are based on the Fe-(20-30)Mn-(11.5-12.0)Al-1.5C-5Cr (wt%) system and are strengthened by dispersions of nano-sized Fe3AlC-type κ-carbide. The alloying with Cr enhances the ductility without sacrificing strength, by suppressing the precipitation of κ-carbide and thus stabilizing the austenite matrix. The formation of a protective Al-rich oxide film on the surface lends the alloys outstanding resistance to pitting corrosion similar to ferritic stainless steels. The new alloy class has thus the potential to replace commercial stainless steels as it has much higher strength at similar formability, 17% lower mass density and lower environmental impact, qualifying it for demanding lightweight, corrosion resistant, high-strength structural parts.

Simvastatin/Ezetimibe Therapy for Recalcitrant Alopecia Areata: An Open Prospective Study of 14 Patients.

BACKGROUND: Simvastatin belongs to the statin family, whose members have immunomodulatory activities. Ezetimibe have synergetic effects when co-administered with simvastatin. In several case reports, alopecia totalis and alopecia universalis were successfully treated with simvastatin/ezetimibe, suggesting that this combination could be a new efficient therapy for recalcitrant alopecia areata (AA). OBJECTIVE: To verify the efficacy of the simvastatin/ezetimibe combination therapy for recalcitrant AA and investigate the relationship between various treatment responses and prognostic factors. METHODS: This prospective open study was performed in patients with recalcitrant AA with the bald surface exceeding 75%. All patients took simvastatin (40 mg) and ezetimibe (10 mg) daily. The extent of hair regrowth expressed as percentage of the bald area was used to evaluate the effectiveness of the therapy. RESULTS: Of 14 enrolled patients, 4 patients (28.6%) were judged as responders showing regrowth of 30% to 80% after 3 months of treatment. The mean age of onset in non-responders was significantly lower than in responders. The total score of prognostic factors, calculated as a sum of factors related to poor prognosis, was much lower in responders than in non-responders. CONCLUSION: The remission rate in this study was unsatisfactory. However, since the recruited patients had not responded to any other treatments for AA, simvastatin/ezetimibe can still be considered as an alternative treatment for recalcitrant AA. The total scores of the prognostic factors were statistically different between responders and non-responders. These results can be used to predict the outcome of treatment with simvastatin/ezetimibe and anticipate prognosis.

Syringoid Eccrine Carcinoma of the Thigh.

Syringoid eccrine carcinoma (SEC) is a rare cutaneous malignant tumor thought to be derived from eccrine sweat apparatus. It is usually present in the head, neck and trunk region, and often occurs in the fourth to seventh decades of life. A 94-year-old male patient visited our department with an 80-year history of a lesion showing a 2×2 cm sized well-demarcated round shaped erythematous to pinkish colored nodule with ulcer on his left thigh. Histological findings revealed a tumor consisted mainly of numerous small cords and nests forming luminal or tubular structures and tumor cells showing variable atypia. Some ductal structures showed tadpole appearance. On immunohistochemical staining, epithelial membrane antigen, S-100, cytokeratin 7 and carcinoembryonic antigen were reactive and Ki-67 showed less than 10% positivity. Based on these findings, the final diagnosis was made as SEC. The patient was treated with local wide excision and didn't show any recurrence during the follow-up period of 12 months. Herein, we report a very rare case of SEC which occurred on the left thigh and discuss 10 cases of SEC presented on the extremities, including our case.

Investigations of the efficacy of diphenylcyclopropenone immunotherapy for the treatment of warts.

BACKGROUND: Diphenylcyclopropenone (DPCP) immunotherapy has been used to treat warts, particularly in patients, such as children, who cannot endure treatment-related pain and in patients with large numbers of warts. However, the efficacy of DPCP immunotherapy remains subject to much controversy. Specifically, cure rates and treatment durations have varied across reports, primarily because of the lack of large-scale studies. METHODS: We performed an uncontrolled, open-label study to investigate the efficacy of DPCP immunotherapy for the treatment of cutaneous warts. A total of 170 patients with warts were enrolled in this uncontrolled, open-label study from 2006 to 2012. Each patient was sensitized with 0.1% DPCP. Two weeks after sensitization, DPCP was applied to warts once per week. RESULTS: We achieved high clearance rates in 141 of 170 patients (82.9%) and 434 of 511 lesions (84.9%). Immunotherapy with DPCP was much more effective when the lesions were located on the hands and when the patient was aged < 20 years. The mean ± standard deviation number of applications was 9.02 ± 2.59. At the end of treatment, the most common final concentration was 0.1%, and most (77.0%) patients used a final concentration of > 0.005%. Side effects occurred in 36 patients, but no serious adverse effects occurred, and blistering at the sensitized site was the most common adverse effect. CONCLUSIONS: Immunotherapy with DPCP is an effective and well-tolerated option for the treatment of recalcitrant warts.

Analysis of transformation plasticity in steel using a finite element method coupled with a phase field model.

An implicit finite element model was developed to analyze the deformation behavior of low carbon steel during phase transformation. The finite element model was coupled hierarchically with a phase field model that could simulate the kinetics and micro-structural evolution during the austenite-to-ferrite transformation of low carbon steel. Thermo-elastic-plastic constitutive equations for each phase were adopted to confirm the transformation plasticity due to the weaker phase yielding that was proposed by Greenwood and Johnson. From the simulations under various possible plastic properties of each phase, a more quantitative understanding of the origin of transformation plasticity was attempted by a comparison with the experimental observation.

Holographic polarization-selective module based on a small dove prism coupler for magneto-optical pickup heads.

A new structure for polarization-selective elements, consisting of two holographic gratings and a Dove prism coupler, is proposed. The absence of a multistage waveguide and the benefits of compact size and lightweight volume are the outstanding features of the new structure. Based on the coupled-wave theory, the analysis and design of the structure are discussed in detail to calculate the required index modulation. Several parameters, such as the recording intensity, the exposure time, and the recording angles for the fabrication of the proposed element, are determined. Under these conditions, the element is fabricated in Dupont photopolymer HRF-150-38 material and with an operating wavelength of 532 nm. A simplified pickup head is constructed to evaluate the performance of the fabricated element.