Specific Preparation Techniques Research Articles

Utilizing the Ex-Vivo Bovine Model in Retrograde Intrarenal Surgery Training

ObjectivesTo present an ex-vivo bovine model for retrograde intrarenal surgery (RIRS) training. Materials and MethodsThe model was specifically developed for a pre-congress course organized as part of the National Pediatric Urology Congress. The course involved a two-day online theoretical segment followed by hands-on training. Bovine kidneys were chosen for their anatomical resemblance to human kidneys. The kidneys were sourced from a local slaughterhouse, ensuring the intactness of the pelvis, ureters, and perirenal fat. A Modified Larssen solution was used for tissue preservation. The tissue was positioned within a cardboard box, with specific preparation techniques to ensure realism. During the hands-on training, participants utilized a flexible ureterorenoscope for practice. After the course, participants completed an 18-question survey assessing the model and training experience. Results24 participants completed the training and survey. Four out of eight procured kidneys were suitable. The model's cost was 18 euros. 87.5% of participants reported increased RIRS confidence. Those with prior course experience rated the model's anatomical resemblance higher (p=0.016). No significant difference was observed in feedback on the model's durability or tactile feedback based on prior experience (p>0.05). ConclusionThe ex-vivo bovine model provides a promising alternative for RIRS training. While further studies are needed to validate its widespread application, initial feedback suggests it offers a balance between cost-effectiveness and realistic training experience.

Structural design and performance optimization of Co/Bi0.5Sb1.5Te3 artificially tilted multilayer thermoelectric devices

Due to the complex principle of transverse thermoelectric conversion and the specific preparation technique, there are few studies on the three-dimensional structure of artificially tilted multilayer thermoelectric devices (ATMTDs), which also lags the development of ATMTDs for applications. It is necessary to optimize the three-dimensional structure of ATMTDs to satisfy the requirements of practical applications in thermal sensors, power generation, refrigeration, and so on. In this paper, Co/Bi0.5Sb1.5Te3 ATMTDs are selected as the research object. A COMSOL Multiphysics simulation analysis and experimental validation are used to establish the relationship between the structure and its thermal sensing, power generation, and cooling performance. Results indicate that increasing the length significantly improves the thermal response voltage. Increasing the length and width enhances output power while increasing the height of the ATMTD improves the thermoelectric conversion efficiency. The effective cooling temperature improves when the heat transfer area decreases or the height increases. Based on these findings, flexible thin-film thermal sensors, high-efficiency waste heat power generation tubular devices, and high-efficiency refrigeration pyramidal devices are designed. The results will lead to effective optimization and promote the multi-field application of ATMTDs.

Using formative research to design context-specific animal source food and multiple micronutrient powder interventions to improve the consumption of micronutrients by infants and young children in Tanzania, Kenya, Bangladesh and Pakistan.

Optimal complementary feeding practices including consumption of multiple micronutrient powders (MNP) are recommended to improve micronutrient intake by infants and young children (IYC) 6–23 months. Formative research was used to design the behaviour change strategy to improve IYC micronutrient intake for the multicountry ENRICH project in rural impoverished areas of Tanzania, Kenya, Bangladesh and Pakistan. Employing a qualitative approach with multiple methods and guided by a social ecological framework, the study was conducted in several phases: data collection in the community, household and health facilities, initial analysis and household trials (HHT). Results found limited use of animal source foods (ASF) for feeding IYC and MNP largely unavailable. Although cost constrained access to ASF, potential more affordable context‐specific ASF options were identified in each setting. Caregivers associated ASF with many positive attributes for IYC, but barriers to feeding them included lack of caregiver time and knowledge of specific preparation techniques, and limited advice from health workers. Feeding practices were identified that used time‐efficient, specific preparations for eggs and other ASF, and demonstrated good initial acceptability and feasibility during HHT. Testing MNP in HHT found good initial feasibility and acceptability and provided an understanding of the facilitators and constraints for preparing, feeding and promoting MNP. In conclusion, formative research led to the design of context‐specific ASF and MNP complementary feeding promotion strategies to improve IYC consumption of micronutrients by identifying the practices, benefits, motivations and alternative actions to overcome the barriers in each setting.

FeCrAl as a Catalyst Support.

The iron-chromium-aluminum alloy (FeCrAl) is an exceptional support for highly exothermic and endothermic reactions that operate above 700 °C in chemically aggressive environments, where low heat and mass transfer rates limit reaction yield. FeCrAl two- and three-dimensional structured networks-monoliths, foams, and fibers-maximize mass transfer rates, while their remarkable thermal conductivity minimizes hot spots and thermal gradients. Another advantage of the open FeCrAl structure is the low pressure drop due to the high void fraction and regularity of the internal path. The surface Al2O3 layer, formed after an initial thermal oxidation, supports a wide range of metal and metal oxide active phases. The aluminum oxide that adheres to the metal surface protects it from corrosive atmospheres and carbon (carburization), thus allowing FeCrAl to operate at a higher temperature. The top applications are industrial burners, in which compact knitted metal fibers distribute heat over large surface areas, and automotive tail gas converters. Future applications include producing H2 and syngas from remote natural gas in modular units. This Review summarizes the specific preparation techniques, details process operating conditions and catalyst performance of several classes of reactions, and highlights positive and challenging aspects of FeCrAl.

Are We Preparing Teachers for Literacy Leadership?

AbstractAll teachers must be literacy leaders in their classrooms and schools. Recent concerns surrounding teacher quality and literacy teacher preparation prompted the current inquiry, which examined the diverse ways in which literacy teacher educators cultivate literacy leadership among preservice teachers. The authors used a one‐shot qualitative research design and applied understandings related to distributed leadership and teacher leadership as theoretical lenses. Sixty‐five respondents participated in the current inquiry, and data were analyzed using a three‐level classification diversity analysis. Three themes emerged during data analysis: Two addressed specific preparation techniques for literacy leadership that occurred in university contexts and community and professional contexts, and the third drew attention to the inadequacy of preparation efforts with literacy leadership. A discussion of findings for each theme is provided, as well as implications and recommendations for literacy teacher educators and teacher preparation program administrators.

X-Ray Diffraction Application for the Study of the Fine Structure of Carbon Fibers

The fine structure of carbon fibers, obtained according to specific preparation techniques, has been studied. It has been shown that the fiber material is heterogeneous, its component composition is determined by thermomechanical treatment conditions and addition of boron; also it depends on the angle φ of coherent scattering domain orientation relative to the thread axis. The mean coherent scattering domain sizes increase in transition to the components corresponding to smaller d002 values. Increase in temperature and duration of heat treatment, as well as the presence of a boron-containing additive, ensures formation of the components corresponding to smaller interplanar spacing d002 values in the carbon material. The observed influence of temperature and duration of heat treatment, as well as the angle of coherent scattering domain orientation relative to the thread axis, upon the component composition makes it possible to assume that the process of carbon fiber material transformation into a state of greater stability presumably develops through a number of metastable stages.

Limitation of immunoaffinity column for the removal of abundant proteins from plasma in quantitative plasma proteomics

In plasma proteomics, before a proteome analysis, it is essential to prepare protein samples without high-abundance proteins, including albumin, via specific preparation techniques, such as immunoaffinity capture. However, our preliminary experiments suggested that functional changes with use alter the ability of the immunoaffinity column. Thus, in this study, to evaluate the changes of the removal ability of abundant proteins from plasma by the immunoaffinity column, plasma proteome analysis was performed for the long-term test for the reproducibility of the affinity column using the fluorogenic derivatization-liquid chromatography-tandem mass spectrometry method combined with an IgY column. The specific adsorption for albumin decreased with an increase in the number of the column usage before its expiration date. Moreover, it was demonstrated that hydrophobic high molecular weight compounds in plasma adsorbed onto the column materials surface contributed to the functional changes from specific immunoaffinity adsorption into hydrophobic interaction. These results suggested that, in quantitative plasma proteomics studies, it is important to keep in mind the risk of not only the nonselective loss but also the changes in the adsorption ability of the immunoafinity column.

Semen preparation techniques for intrauterine insemination

Semen preparation techniques for assisted reproduction, including intrauterine insemination (IUI), were developed to separate the motile morphological normal spermatozoa. Leucocytes, bacteria and dead spermatozoa produce oxygen radicals that negatively influence the ability to fertilize the egg. The yield of as many motile, morphologically normal spermatozoa as possible might influence treatment choices and therefore outcomes. To compare the effectiveness of gradient, swim-up, or wash and centrifugation semen preparation techniques on clinical outcome in subfertile couples undergoing intrauterine insemination (IUI). We searched the Menstrual Disorders and Subfertility Group Trials Register (13 January 2007), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 2), MEDLINE (1966 to January 2007 ), EMBASE (1980 to January 2007), Science Direct Database (1966 to January 2007), National Research Register (2000 to 2007), Biological Abstracts (2000 to January 2007), CINAHL (1982 to October 2006) and reference lists of relevant articles. We also contacted experts and authors in the field. Parallel randomized controlled trials (RCTs) comparing the efficacy of semen preparation techniques used for subfertile couples undergoing IUI in terms of clinical outcome were included. Two reviewer authors independently assessed trial quality and extracted data. Study authors were contacted for additional information. Five RCTs, including 262 couples in total, were included in the meta-analysis (Dodson 1998; Grigoriou 2005; Posada 2005; Soliman 2005; Xu 2000). Xu compared the three techniques; Soliman compared a gradient technique versus a wash technique; Dodson and Posada compared a gradient technique versus a swim-up technique; whereas Grigoriou compared swim-up versus a wash technique. No trials reported the primary outcome of live birth. There was no evidence of a difference between pregnancy rates (PR) for swim-up versus a gradient or wash and centrifugation technique (Peto OR 1.57, 95% CI 0.74 to 3.32; Peto OR 0.41, 95% CI 0.15 to 1.10, respectively); nor in the two studies comparing a gradient technique versus wash and centrifugation (Peto OR 1.76, 95% CI 0.57 to 5.44). There was no evidence of a difference in the miscarriage rate (MR) in two studies comparing swim-up versus a gradient technique (Peto OR 0.13, 95% CI 0.01 to 1.33). There is insufficient evidence to recommend any specific preparation technique. Large high quality randomised controlled trials, comparing the effectiveness of a gradient and/ or a swim-up and/ or wash and centrifugation technique on clinical outcome are lacking. Further randomised trials are warranted.

Semen preparation techniques for intrauterine insemination.

Semen preparation techniques for assisted reproduction, including intrauterine insemination (IUI), were developed to separate the motile morphological normal spermatozoa. Leucocytes, bacteria and dead spermatozoa produce oxygen radicals that negatively influence the ability to fertilize the egg. The yield of as many motile, morphologically normal spermatozoa might influence treatment choices and therefore outcomes. To compare the effectiveness of gradient, swim-up, or wash and centrifugation in subfertile couples undergoing intrauterine insemination (IUI) on clinical outcome as well as on semen parameters. We searched the Menstrual Disorders and Subfertility Group's trials register (30 June 2003), MEDLINE (1966 to July 2003), EMBASE (1980 to July 2003), Science Direct Database (1966 to July 2003), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 3, 2003), National Research Register (2000 to Issue 2, 2003), Biological Abstracts (2000 to June 2003), CINAHL (1982 to July 2003) and reference lists of relevant articles. We also contacted experts and authors in the field. Parallel randomised controlled trials (RCTs), comparing the efficacy of semen preparation techniques used for subfertile couples undergoing IUI, were included. RCTs or split sample studies examining semen parameters after different semen preparation techniques were also included. Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information. Two randomised controlled trials comparing clinical outcomes, including 81 participants in total, were included in the meta-analysis (Dodson 1998-I/ II; Xu 2000-I/ II). Both studies compared swim-up technique versus gradient technique in 65 subfertile couples undergoing IUI. One study compared the effectiveness of both techniques with wash technique. No trials reported the primary outcome of live birth. There was no statistically significant difference between pregnancy rates (PR) for swim-up versus gradient / wash centrifuge (Peto OR 0.55, 95% CI 0.17 to 1.76; Peto OR 1.74, 95% CI 0.2 to 14.9; PR/ couple swim-up 20%, gradient 40%, wash 12.5%) or gradient versus wash centrifuge (Peto OR 4.01, 95% CI 0.82 to 19.56; PR/ couple swim-up 15%, gradient 20%). There was no significant difference in the miscarriage rate (MR) per couple between either of the three treatment groups in the one trial reporting this outcome (MR/ couple swim-up 0%, gradient 10.3%, wash 0%. MR/ pregnancy gradient 30.3%). There was no statistically significant difference in the multiple pregnancy rate (MPR) per couple between either of the three treatment groups in Dodson 1998-I/ II (MPR/ couple swim -up 0%, gradient 0%, wash 6.3%). One triplet pregnancy was recorded. Fifteen studies comparing semen parameters after processing were included. Two studies were included in the meta-analysis, we were not able to pool results. There is insufficient evidence to recommend any specific preparation technique. Large high quality randomised controlled trials, comparing the effectiveness of a gradient and/ or a swim-up and/ or wash and centrifugation technique on clinical outcome are lacking. Further randomised trials are warranted. Results from studies comparing semen parameters may suggest a preference for gradient technique, but firm conclusions cannot be drawn and the limitations should be taken into consideration.

Systematics of disorder in quasiperiodic material.

We report new x-ray scattering data on AlMn alloys. None of our samples are perfect quasicrystals; all have finite-width x-ray peaks. Specific preparation techniques lead to samples with peak widths which correlate strongly with ${G}_{\ensuremath{\perp}}$ (phason momentum). We show that the data are consistent with either frozen-in phason strain or random icosahedral packing. These two models predict surprisingly similar but potentially distinguishable scattering widths, differing in their detailed dependence on ${G}_{\ensuremath{\perp}}$.

Long-term clinical study of porcelain-fused-to-gold restorations

S everal years ago porcelain-fused-to-gold (PFG) restorations were introduced to fixed partial denture prosthodontics. The new materials and related clinical techniques represent an important step toward an optimal solution to many problems in fixed prosthodontics, especially in the anterior region. The method combines the esthetic qualities of porcelain with the strength, accuracy, and marginal adaptation of the metal. Several studies have been published on the clinical and material aspects of PFG restorations.‘-6 The chemical characteristics of the porcelain-to-gold bonding and the possible defects caused by inadequate laboratory procedures also have been reported.‘-‘” Much attention has been paid to the strength of the bonding between gold and porcelain.“.?’ Hobo and Shillingburg2r described the specific preparation techniques and the coping design. In histologic studies others showed the positive clinical tolerance of the marginal periodontium to the porcelain.?“‘“’ As far as we know, only one long-term clinical study of PFG restorations has been published.3’ The purposes of this clinical long-term survey were to examine the frequency of mechanical failures of PFG restorations and to provide some suggestions for their possible prevention. -