Biochemical and transcriptomic characterization of glycoside hydrolases in \u3ci\u3eThermobia domestica\u3c/i\u3e and \u3ci\u3eCtenolepisma longicaudata\u3c/i\u3e

The digestive system of phytophagous insects is considered a relevant prospecting resource for identification of novel cellulolytic enzymes that may improve industrial processes of cellulose degradation. While much is known from insect models of cellulose digestion, such as termites and roaches (Blattodea), there is a dearth of information on insects belonging to basal hexapod groups. As part of a screening effort to identify insects with highly active cellulolytic systems, we detected species of Zygentoma as displaying the highest relative cellulolytic activity levels compared to all other tested insect orders, including Blattodea. The goals of the present study were to provide a morphohistological and biochemical characterization of the digestive system of Zygentoma, to annotate and screen for plant cell wall degrading enzyme (PCWDE) genes present in Thermobia domestica and Ctenolepisma longicaudata genomes, and to study their differential expression depending on diets with varying degree of cellulosic content.Morphohistological characterization supported no relevant differences in the digestive tube of T. domestica and C. longicaudata. Quantitative and qualitative cellulase assays identified the foregut as the region with the highest cellulolytic activity in both the tested insects, yet T. domestica was found to have higher endoglucanase, xylanase and pectinase activities compared to C. longicaudata. Annotation of predicted coding sequences from genomes of T. domestica and C. longicaudata reported numerous genes encoding for endoglucanases, glucosidases, β-1,3-glucanases, maltases, amylases, mannosidases, glucuronidases and lytic polysaccharide monoxygenases (LPMOs). Differential gene expression analysis of both species revealed that cellulase gene expression is primarily driven by type of tissue rather than diet. However, within each tissue of T. domestica and C. longicaudata, a higher number of PCWDEs and LPMOs were significantly up-regulated in paper, the most highly cellulosic diet, compared to all other tested diets. The annotation of coding sequences and differentially expressed PCWDE genes revealed highest identity to insect homologs, which suggests the potential conservation of PCWDEs through evolution and an ancient origin for cellulases in insects. These findings advance our understanding of cellulose digestion in a basal hexapod group and the identification of novel cellulolytic enzymes with potential application in the biofuel industry

Progress in antiretroviral drug delivery using nanotechnology

There are currently a number of antiretroviral drugs that have been approved by the Food and Drug Administration for use in the treatment of human immunodeficiency virus (HIV). More recently, antiretrovirals are being evaluated in the clinic for prevention of HIV infection. Due to the challenging nature of treatment and prevention of this disease, the use of nanocarriers to achieve more efficient delivery of antiretroviral drugs has been studied. Various forms of nanocarriers, such as nanoparticles (polymeric, inorganic, and solid lipid), liposomes, polymeric micelles, dendrimers, cyclodextrins, and cell-based nanoformulations have been studied for delivery of drugs intended for HIV prevention or therapy. The aim of this review is to provide a summary of the application of nanocarrier systems to the delivery of anti-HIV drugs, specifically antiretrovirals. For anti-HIV drugs to be effective, adequate distribution to specific sites in the body must be achieved, and effective drug concentrations must be maintained at those sites for the required period of time. Nanocarriers provide a means to overcome cellular and anatomical barriers to drug delivery. Their application in the area of HIV prevention and therapy may lead to the development of more effective drug products for combating this pandemic disease

Evaluation of subcooled MQL in cBN hard turning of powder-based Cr-Mo-V tool steel using simulations and experiments

Metal cutting fluids for improved cooling and lubrication are an environmental risk and a health risk for workers. Minimizing water consumption in industry is also a goal for a more sustainable production. Therefore, metal cutting emulsions that contain hazardous additives and consume considerable amounts of water are being replaced with more sustainable metal cutting fluids and delivery systems, like vegetable oils that are delivered in small aerosol droplets, i.e., via minimum quantity lubrication (MQL). Since the volume of the cutting fluid in MQL is small, the cooling capacity of MQL is not optimal. In order to improve the cooling capacity of the MQL, the spray can be subcooled using liquid nitrogen. This paper investigates subcooled MQL with machining simulations and experiments. The simulations provide complementary information to the experiments, which would be otherwise difficult to obtain, e.g., thermal behavior in the tool-chip contact and residual strains on the workpiece surface. The cBN hard turning simulations and experiments are done for powder-based Cr-Mo-V tool steel, Uddeholm Vanadis 8 using MQL subcooled to −10 \ub0C and regular MQL at room temperature. The cutting forces and tool wear are measured from the experiments that are used as the calibration factor for the simulations. After calibration, the simulations are used to evaluate the thermal effects of the subcooled MQL, and the surface residual strains on the workpiece. The simulations are in good agreement with the experiments in terms of chip morphology and cutting forces. The cutting experiments and simulations show that there is only a small difference between the subcooled MQL and regular MQL regarding the wear behavior, cutting forces, or process temperatures. The simulations predict substantial residual plastic strain on the workpiece surface after machining. The surface deformations are shown to have significant effect on the simulated cutting forces after the initial tool pass, an outcome that has major implications for inverse material modeling

Study of Mixed, Heterogenous Flow of Polymer Melts in a Converging Channel Die Using Elliptical Cylindrical Coordinates

School of Chemical Engineerin

Surface Integrity of Case-hardened Gears - with Particular Reference to Running-in and Micropitting

A gearbox with gears of different sizes is part of a vehicle transmission system and plays an important part in transmitting the engine power to the wheels. The efficient energy transmission highly relies on the performance of gears. Together, the mesh efficiency and durability determines the performance of gears.The hard finishing of gear surfaces by means of different methods; grinding, honing and superfinishing etc., produces unique characteristics in terms of surface roughness, microstructure and residual stresses. These characteristics of tooth affect the gear performance. Running-in process is known to alter them along with surface chemistry and presets the gear for service. This fact creates an interest to understand the initial running-in with the purpose to improve the performance of gears. Thus, this study addressed, the influence of running-in on the evolution of surface characteristics generated by the mentioned methods, and how they developed further during initial usage, represented by efficiency test. Gears tested in a FZG back-back test rig were characterized by combining different analytical techniques. These included scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Surface roughness was found to be the most influential factor and virtually all changes were confined to ~5 μm below the surface. The running-in process smoothened the surface asperities through plastic deformation and the severity of deformation increased with load. Micropitting was also associated with asperity deformation and hence only seen in ground and honed gears, while being absent for superfinished gears. Micropitting was promoted by higher running-in load and this trend continued for subsequent efficiency testing. The running-in load also promoted the deformation bands frequently found in connection with the cracks. Compressive residual stresses beneficial for fatigue life varied between finishing methods, highest stresses recorded for honed gears. The stresses differed between profile and axial direction after manufacturing and, reached similar levels after efficiency testing, but remained compressive throughout the test. The initial increase in compressive residual stresses was linked to retained austenite transformation and its later decrease to crack formation. The indicated tribofilm formation was connected to the surface roughness and promoted by running-in load.Micropitting is a surface contact fatigue failure that occurs in all types of gears. This failure mechanism was also investigated from material perspective. Gears were tested in a sequence from 200 to 2.2 x 107 cycles. The micropitting initiated due to the deformation of asperities and associated microstructural changes; plastically deformed regions (PDR) and deformation bands (thin martensite lath with epsilon carbides precipitated at boundaries). These structural changes started already within 200 cycles and cracks occurred after 2000 cycles, signifying that micropitting can initiate already after short period of operation. Thus, the running-in of gears from materials perspective can be as short as 2000 cycles. The findings presented are expected to contribute to the technical and industrial aims for optimized gear preparation

IcSDE+ -- An Indicator for Constrained Multi-Objective Optimization

The effectiveness of Constrained Multi-Objective Evolutionary Algorithms (CMOEAs) depends on their ability to reach the different feasible regions during evolution, by exploiting the information present in infeasible solutions, in addition to optimizing the several conflicting objectives. Over the years, researchers have proposed several CMOEAs to handle CMOPs. However, among the different CMOEAs proposed most of them are either decomposition-based or Pareto-based, with little focus on indicator-based CMOEAs. In literature, most indicator-based CMOEAs employ - a) traditional indicators used to solve unconstrained multi-objective problems to find the indicator values using objectives values and combine them with overall constraint violation to solve Constrained Multi-objective Optimization Problem (CMOP) as a single objective constraint problem, or b) consider each constraint or the overall constraint violation as objective(s) in addition to the actual objectives. In this paper, we propose an effective single-population indicator-based CMOEA referred to as IcSDE+ that can explore the different feasible regions in the search space. IcSDE+ is an (I)ndicator, that is an efficient fusion of constraint violation (c), shift-based density estimation (SDE) and sum of objectives (+). The performance of CMOEA with IcSDE+ is favorably compared against 9 state-of-the-art CMOEAs on 6 different benchmark suites with diverse characteristicsComment: 13 pages, 2 main figue

The influence of single-channel liquid CO2 and MQL delivery on surface integrity in machining of Inconel 718

Sustainable machining of difficult-to-cut materials requires effective cooling and lubrication techniques. To substitute conventional flood cooling and lubrication, different techniques such as cryogenic cooling and/or minimum quantity lubrication (MQL) can be used. Liquid carbon dioxide (LCO2) can be pre-mixed with different lubricants before its delivery to the cutting zone. This article investigates the influence of this recently developed cooling and lubrication method on surface integrity characteristics in milling of Inconel 718. Surface roughness, surface topography and microstructure were evaluated for flood lubrication, dry cutting and LCO2 machining using a single-channel LCO2 and MQL strategy. Moreover, two different lubricants were evaluated for MQL: (i) conventional MQL oil and (ii) solid lubricant molybdenum di-sulphide (MoS2). In addition to being environmentally friendly, MoS2 lubricated LCO2 showed comparable surface characteristics to flood lubrication. Also, the use of lubricated LCO2 resulted in higher part surface cleanliness compared to flood lubrication

Understanding the roles of partners in partnerships funded by the global fund

The field of international development has always been intertwined with the economic thought dominant in the West. Even before its conception with the Marshall Plan to rebuild Europe, it carried a strong Keynesian preference for the state. The neoliberal assault on the welfare state in the 80s, followed by the partnership era that brought both the public and the private sector together to work for a common cause have been the focus of attention by development scholars and others alike. The present study focuses on a multilateral development aid agency, the Global Fund, which funds public-private partnerships in the field of health care in developing countries. Drawing on the debates surrounding the welfare state and the civil society, as well as the debates surrounding the public-privates partnerships, the present study poses three questions in relation to the Global Fund: (1) how are the diseases framed in the partnership framework, (2) what are the roles of the private sector in partnership, and (3) what are the roles of the public sector in partnerships. Based on the textual analysis of fifteen proposals approved by the Global Fund in the sixth round of funding, this dissertation tries to situate the working of the Global Fund, and the proposals it funds, within the larger debates surrounding development and partnerships. The findings of the present study are: (1) the diseases are framed largely in socio-economic terms, (2) the private (for-profit) sector is marginalized in the discussion and implementation of proposals, (3) the civil society participation is seen as essential to the success of the proposals, and (3) the state is seen as important in the discussion of the diseases, although there is a great deal of ambiguity surrounding the roles of the public sector in partnerships. It is hypothesized in the concluding chapter that the reason Global Fund is able to attract a great deal of funds and support from actors across the political spectrum could be because the organization funds programs that foreground civil society, liked by people of different political inclinations, and backgrounds the discussion of the state, the epicenter of controversies surrounding development. By being “strategically ambiguous” about the role of the state in the development of the people, the proposals are made apolitical and appealing to people both on the left and the right