Pretreatment Of Gel Research Articles

Eco-friendly one-step egg white gel preparation for sensitive detection of 13 trichothecenes in oats using UHPLC-MS/MS.

Oat products have gained widespread recognition as a health food due to their rich and balanced nutritional profile and convenience. However, the unique matrix composition of oats, which differs significantly from other cereals, presents specific challenges for mycotoxin analysis. This study presents an ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method enhanced with an innovative egg white gel pretreatment for the simultaneous analysis of 13 regulated and unregulated trichothecenes in oats. The method demonstrated excellent performance with high accuracy (> 87.5%), repeatability (< 5.7%), and reproducibility (< 8.1%). Analysis of 100 commercial oat products revealed a concerning detection rate (78%) for at least one of the 11 trichothecenes investigated. Notably, deoxynivalenol, exceeding the standard limit in 2% of samples, exhibited the highest detection rate (62%). Additionally, concerning co-occurrence patterns and positive correlations were observed, highlighting potential synergistic effects. The first-time detection of unregulated mycotoxins (T-2 triol, 4,15-diacetoxyscirpenol, 15-acetoxyscirpenol, and neosolaniol) underscores the need for comprehensive monitoring. This method, while developed for oats, shows potential for broader application to other cereals, though further investigation and confirmation are necessary. These findings suggest a potentially underestimated risk of trichothecenes in oats, necessitating continuous monitoring to ensure consumer safety.

The Effect of Transdermal Testosterone Gel Pretreatment on IVF Outcomes in Patients with Poor Ovarian Reserve

The Effect of Transdermal Testosterone Gel Pretreatment on IVF Outcomes in Patients with Poor Ovarian Reserve

Gel-assisted Welding of Epoxy Composite with Ethylene Glycol Mixed Catalyst

Effective and high-strength welding of thermosetting composites is badly in demand and always a challenge in industrial applications. Here, a gel-assisted welding method was proposed for traditional epoxy composites using a gel of 1,5,7-triazabicyclo [4.4.0] dec-5-ene mixed with ethylene glycol (TBD/EG gel) for pretreatment. Firstly, the influence of TBD/EG gel thickness, pretreatment time, pretreatment temperature, and pretreatment after soaking for the welding strength of the epoxy composite was studied. Then, the appropriate TBD/EG gel thickness (2 mm) and TBD/EG gel pretreatment conditions (140 °C for 60 min) were obtained. Compared to the different pretreatment methods for welding, the welding of TBD/EG gel pretreatment is feasible.

O-068 Transdermal testosterone gel (TTG) pre-treatment duration in improving ivf outcome in patients with poor prognosis (poseidon group 3 and 4): A randomised controlled trial.

Abstract Study question To compare the most effective duration of pre-treatment with transdermal testosterone gel in improving IVF outcomes using GnRH antagonist protocol in poor prognosis patients. Summary answer Pre-treatment with testosterone gel for 28 days had higher clinical pregnancy rate, more mature oocytes in lesser days and lower total dose of gonadotropins. What is known already Poor prognosis patients undergoing IVF exhibits subnormal ovarian response resulting in higher IVF cycle cancellation and lower clinical pregnancy. Amongst various adjuvants regimens use of androgen supplementation improves clinical pregnancy and probability of live birth in such patients. Androgen stimulates early stages of follicular growth, increase the number of primary, pre-antral and antral follicles. It increases FSH receptor expression in granulosa cells, in turn leading to better oocyte yield and pregnancy rate. We aim to compare the most effective duration of pre-treatment with transdermal testosterone gel in improving IVF outcomes using GnRH antagonist protocol in poor prognosis patients. Study design, size, duration A prospective, randomised controlled trial was carried out from 1st September 2021 to 31st August 2022 at a tertiary infertility centre in India. 100 poor prognosis patients POSEIDON group 3 and 4 (age 21-40 years, AFC &amp;lt;5 and AMH ≤1.2 ng/ml) were enrolled. They were randomized into 4 groups of 25 each by computer based program. Participants/materials, setting, methods Group 1, control received no pretreatment, Group 2, Group 3 and Group 4 received 1% TTG one actuation (12.5mg testosterone daily) for 2, 3 and 4 weeks respectively before start of ovarian stimulation. Patients received a starting dose of HP HMG dose 300 IU and dose was adjusted. Inj. Cetrorelix 0.25 mg started when lead follicle was 14 mm and Oocyte retrievals were performed 35 hours after 250 mcg r-HCG trigger. Main results and the role of chance All groups were comparable with regards to baseline FSH, AFC and AMH levels. Only one cycle was cancelled in control group because of lack of response to gonadotropins till day 5 of stimulation. Requirement of total days (9.68 Vz 8.95 days) and total dose of gonadotropins was significantly lower in group 4 as compared to control group 1. This showed that cases with pre-treatment of transdermal testosterone gel for longer duration, required less amount of gonadotropin (2826 IU Gp 1 Vz 2329 IU Gp 4) treatment (p &amp;lt; 0.01) and also the mean number of mature oocytes retrieved (0.80 Gp 1 Vz 3.38 Gp 4) were significantly higher (p &amp;lt; 0.01). Day 3 fresh embryo transfers were performed for all. Incidence of clinical pregnancy rate was 4.2%, 8%, 12% in group 1, 2, and 3 respectively which increased to 20% in group 4 (p-0.33). Miscarriage rate was 4.2% , 4%, 12% and 4% in group 1 ,2, 3 and 4 respectively (p-0.71). Ongoing pregnancy rate was 4% in group 1, while it was 7.7 %, 10.6 % and 19.2% in group 2,3 and 4 respectively (p-0.33). Limitations, reasons for caution The study was done at a single centre with small sample size, replication with more subjects and in different centers is needed. The long term effects of testosterone pretreatment requires further studies. Wider implications of the findings Pre-treatment with testosterone gel in poor prognosis patients improves response to gonadotrophin, reducing amount and days to complete stimulation and results in higher number of mature oocytes and improved clinical pregnancy rates. Transdermal testosterone treatment is advantageous as it is not first metabolized in the liver, convenient to the patient. Trial registration number CTRI/2022/03/040793

The Eff ect of Testosterone Gel for Patients with Poor Ovarian Response Prior to IVF Cycles: Is It really Eff ective?

Background: Classically, poor women respond with old maternal age and little ovarian standby. Though, some females unpredictably have little reply to measured ovarian stimulation. Aim of the Study: To evaluate the eff ectiveness of transdermal testosterone gel (TTG) before controlled ovarian stimulation (COS) in poor responders undergoing intracytoplasmic sperm injection (ICSI). Methods: An interventional prospective randomized control trial that included 60 females who were defi nite as unfortunate responders undergoing an intracytoplasmic sperm injection (ICSI) procedure. The population was divided into two groups. Approximately 30 patients received 10 mg TTG that was applied daily for 21 days in the cycle preceding COS for ICSI Transdermal testosterone gel (TTG) pretreatment group, while the other 30 patients are the control group. All patients were assessed for their AFC again and to begin in-vitro futilization (IVF) treatment with the beginning of the menstrual cycle. Serum testosterone was measured again in the study group. The primary outcome is the number of retrieved oocytes while the secondary outcome is the number and quality of embryos transferred, chemical gestation rate. Results: No important diff erences in sociodemographic features between both groups compared. Also there was an increase in total number of oocytes in the study group but again, this diff erence was statically non-signifi cant. Although the total dose of gonadotrophin (GT) and the duration of stimulation days were less in study group but this was statically non-signifi cant. No diff erences experiential regarding number and grading of embryos, chemical pregnancy rate nor clinical pregnancy rate. Conclusion: Pretreatment of transdermal testosterone at a dose of 10 mg/day for 21 days not upsurge the number of oocyte retrieved nor the number of embryos or pregnancy rate to a signifi cant level in poor responders undergoing ICSI

Development and evaluation studies of Corylin loaded nanostructured lipid carriers gel for topical treatment of UV-induced skin aging

We prepared nanostructured lipid carriers (NLC) to promote skin permeation of Corylin so that it can increase its effect on photoaging. Corylin-NLCs were prepared and characterized based on morphology, particle size, zeta potentials, FTIR and DSC. In vitro, we assess the cytotoxicity and lactate dehydrogenase (LDH) of HaCaT cells irradiated by UVB. Expression of antioxidant enzymes was evaluated by commercial kits. The effects of Corylin-NLC on apoptosis were confirmed by flow cytometry and western blotting. In vivo, we use UV irradiated mouse as the oxidative stress model to assess the therapeutic effect of Corylin loaded NLC gel. We identified the Corylin-NLCs can significantly suppress the LDH release, decrease MDA content, increase in CAT, SOD, GSH-Px activity, increase the expression of Bcl-2/Bax protein and reduce the expression of cleaved caspase-3/caspase-3 protein on UVB induced HaCaT cells. The histopathological lesions were significantly improved and observably decreased MDA level, increase in antioxidant enzymes activity in serum of mice by pretreatment of Corylin-NLCs gel. Overall, this study proposes a promising strategy for improving the therapeutic efficacy of photoaging.

P–612 Transdermal testosterone vs. Placebo (lubricant gel) pre-treatment in improving IVF outcomes in diminished ovarian reserve patients (POSEIDON group 3 and 4): a randomised controlled trial

Abstract Study question To compare the efficacy of transdermal testosterone with placebo (lubricant gel) in improving IVF outcomes using GnRH antagonist protocol in POSEIDON group 3 and 4 patients. Summary answer Patients receiving pre-treatment with testosterone gel had higher mean number of oocytes retrieved and grade A embryos as compared to the patients receiving lubricant gel. What is known already Diminished ovarian reserve (DOR) is associated with suboptimal ovarian response, higher cycle cancellation rate and lower clinical pregnancy rate following IVF cycles. Various treatment regimens have been devised for management of such patients and use of adjuvants in the form of oral or transdermal androgen is one of them. Androgens improves follicular response to gonadotropin stimulation as well as increase FSH receptor expression in granulosa cells, in turn leading to better oocyte yield and pregnancy rate. Aim was to compare the effect of transdermal testosterone gel with placebo gel on ART outcome in DOR patients (POSEIDON Group 3 and 4). Study design, size, duration A prospective, randomised controlled trial was carried out from 1st September 2019 to 31st October 2020 at a tertiary infertility centre in India. 50 patients fulfilling the criteria of Group 3 and Group 4 of POSEIDON classification were included in the study. Patients with endocrine disorders (thyroid, prolactin), endometrioma, history of surgery on the ovaries, sensitivity to testosterone gel, male factor infertility and deranged liver and renal function tests were excluded. Participants/materials, setting, methods Enrolled patients were randomised into two groups of 25 patients each, one group was pretreated (TTG group) with transdermal testosterone gel, 12.5 mg/day from day 6th of previous cycle to day 2nd of stimulation cycle while patients in other group took lubricant gel for the same duration before stimulation with GnRH antagonist fixed protocol followed by fresh Day 3 transfer. Main results and the role of chance The baseline characteristics of the two groups were comparable. The primary outcome measures were the number of oocytes retrieved and number of grade A embryos formed (according to Istanbul consensus). The secondary outcome measures were implantation rate, clinical pregnancy rate, miscarriage rate and ongoing pregnancy rate. The mean number of oocytes retrieved in TTG group was 5±1.02 which was significantly higher than placebo group–3.5±1.2, (p &amp;lt; 0.001). The mean number of Grade A embryos were also significantly higher (4.78±0.54 vs 3.00±0.23, p &amp;lt; 0.001) in TTG group. The TTG group had higher implantation rate (28% vs 20%, p = 0.49), clinical pregnancy rate (32% vs 18%, p = 0.41), ongoing pregnancy rate (32% vs 16%, p = 0.38) and lower miscarriage rate (0% vs 20%, p = 0.38), however, these differences were not statistically significant. Limitations, reasons for caution The study was done at a single centre with small sample size, replication with more subjects and in different centers is needed. Wider implications of the findings: Pre-treatment with testosterone gel in DOR patients improves ovarian response to stimulation and results in higher number of oocytes retrieved and good quality embryos resulting in improved clinical pregnancy rates. Transdermal testosterone is advantageous because of better bioavailability, easy application, patient friendly and less adverse effects. Trial registration number MCDH/2019/54

Ultrasonic Pretreatment as a Tool for the Preparation of Low-Defect Zeolite Mordenite.

The effects of the ultrasonic (US) pretreatment of synthesis gel for the preparation of mordenite zeolite were studied in comparison with the classical stirring method. Even though the US pretreatment was performed before the hydrothermal crystallization, it significantly affected the properties of the obtained mordenite crystals. The US-assisted procedure resulted in a material with improved textural characteristics, in particular, the micropore volume accessible for nitrogen molecules in the as-made form. On the other hand, mordenite prepared with the classical stirring method demonstrated comparable sorption properties only after a postsynthetic treatment. Moreover, in the case of US-pretreated mordenite, altered crystal shape and more homogeneous morphology were observed. 29Si magic-angle spinning nuclear magnetic resonance (MAS NMR) demonstrated that the US pretreatment introduced structural changes on the atomic level, resulting in fewer defects (reflected in the number of silanol groups) and less pore blockage (affected by Na+ cations) for the as-made sample.

Tailoring of berberine loaded transniosomes for the management of skin cancer in mice

Dermal products are essential categories of drug delivery systems, and their application is getting more common. The reason for preparing transniosomes (TN) was to enhance the permeability of berberine (BBR) and to deliver the encapsulated BBR specifically to a localized area of the skin. The TN exhibited higher efficacy than the niosomes in terms of skin penetration and incorporation of TN into gel could also upsurge the thickness of formulation and thereby promote the residence phase of optimized formulation at the application site. The goal of the present research was to optimize TN for accentuated dermal delivery of BBR. The optimization of BBR-loaded TN was done using the “Box–Behnken design”. The optimized formulation was characterized for vesicles size, entrapment efficiency (%) and in vitro BBR release. Additionally, transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM) and dermatokinetic study were performed for further evaluation of BBR-loaded optimized TN formulation. The optimized BBR-TN formulation presented sealed lamellar shaped vesicles, with vesicles size of 74.05 ± 1.55 nm, entrapment efficiency of 82.54 ± 0.54% and in vitro release of 61.44 ± 1.97%. The obtained CLSM images of mice's skin clearly exemplified that the rhodamine B-loaded TN gel disseminated to deeper layer than the control (rhodamine B-hydroethanolic solution). Further, the BBR-TN gel treated mice skin showed CSkin max and AUC0-t of 132.23 μg/cm2 (epidermis) and 683.07 μg/cm2h (epidermis) in comparison to CSkin max and AUC0-t of 59.86 μg/cm2 (epidermis) and 321.41 μg/cm2h (epidermis) presented by BBR conventional gel. The in-vivo study showed that the BBR-TN gel pre-treatment mitigates the tumor multiplicity and prevented the tumor size growth in mice. Further the BBR-TN gel formulation found to be safer for skin application as depicted by skin irritation study performed on mice. The present investigation validated that the prepared TN is a valuable drug carrier system for dermal delivery of BBR for the management of skin cancer in animal model.

In Situ Electrospinning Synthesis of N‐Doped C Nanofibers with Uniform Embedding of Mn Doped MFe1−xMnxPO4 (M = Li, Na) as a High Performance Cathode for Lithium/Sodium‐Ion Batteries

AbstractUsing polyvinyl alcohol and N‐rich polyacrylonitrile as carbon sources, uniform MFe1–xMnxPO4 (M = Li, Na)/N‐doped C nanofibers are synthesized by sol–gel pretreatment and an electrospinning method followed by calcination. The as‐prepared nanofibers exhibit a 3D homogenous network with uniform distribution of MFe1−xMnxPO4 nanoparticles. The lattice distorts after Mn‐doping without altering the original crystalline structure, increasing conductivity and enhancing the efficiency of Li+/Na+ diffusion. When applied for lithium ion batteries, the optimized LiFe0.8Mn0.2PO4/C nanofibers deliver a considerable initial capacity of 169.9 mAh g−1 with coulombic efficiency of 92.4%. It also displays the excellent cycling stability with reversible capacity of 160 mAh g−1 after 200 cycles at 0.1 C and high rate performances with the specific capacity of 93 mAh g−1 at 5 C. Furthermore, NaFexMn1−xPO4/N‐doped C nanofibers are also synthesized by the same method for sodium‐ion batteries, which exhibit an initial capacity of 134 mAh g−1 and specific capacity of 106 mAh g−1 at 0.1 C and 90 mAh g−1 at 1 C after 200 cycles. Owing to the facile fabrication process, these nanofibers are promising cathodes for lithium/sodium ion batteries with excellent electrochemical performances.

Effectiveness of pretreatment with phosphoric acid, sodium hypochlorite and sulfinic acid sodium salt on root canal dentin resin bonding

PurposeThe purpose of this study was to evaluate the effect of pretreatment using phosphoric acid, sodium hypochlorite and sulfinic acid sodium salt on the bonding of one-step self-etching adhesives to root canal dentin. MethodsThirty-six single-rooted sound human premolars were randomly assigned into three groups before applying the one-step self-etching adhesive. These comprised a control group with no pretreatment, an NC group that received phosphoric acid and subsequent sodium hypochlorite gel pretreatments, and an NC+AC group that received an additional treatment with sulfinic acid sodium salt following the same pretreatment applied to the NC group. Microtensile bond strength measurements, bonding interface observations by scanning electron microscopy (SEM), elemental analyses by X-ray photoelectron spectroscopy (XPS) and degree of polymerization (DOP) analyses by Raman spectroscopy were subsequently performed. ResultsThe bond strength was significantly higher in the NC+AC group than in the other two groups (Control: P=000.1 and NC: P=0.004). SEM observations showed that resin tags were present in the dentinal tubules in the NC and NC+AC groups. Compared to the control group, the adhesive resin layer had a lower DOP in the NC group, while the DOP for the NC+AC group was higher than that of the NC specimens. ConclusionsBonding to root canal dentin was improved by applying sulfinic acid sodium salt in addition to treatment with phosphoric acid followed by sodium hypochlorite. The DOP of the adhesive resin was reduced by sodium hypochlorite and subsequently restored by applying sulfinic acid sodium salt.

Surface Processing: An Elegant Way to Enhance the Femtosecond Laser Ablation Rate and Ablation Efficiency on Human Teeth.

The employability of the non-invasive femtosecond laser ablation technique for dental treatment has been severely limited by its low ablation rate despite the advantage of minimal tissue damage. The study explores a means ofimproving the femtosecond laser ablation rate and efficiency by physiochemical surface modification. Surface modification of dental hard tissues hasbeen carried out by food graded orthophosphoric acid and Carie care gel pretreatment. The laser ablation characteristics were studied by using a Ti:Sapphire laser (10 kHz, 10 mm/s, 100 fs, 800 nm) to ascertain the influence of pretreatment. Surface morphology and chemical composition were obtained by using an optical profiler, SEM and EDAX. The ablation threshold fluence decreased by almost one-third whereas the ablation rate and ablation efficiency nearly tripled upon pretreatment. The microstructural and compositional analysis clearly reveals that surface modification and demineralization reduce the threshold fluence and increase the ablation rate by effective utilization of the laser beam energy. The pretreatment effect is more pronounced in orthophosphoric acid as compared with Carie care gel. Physiochemical surface modification can be an efficient method to improve the laser ablation rate and ablation efficiency. Compositional analysis can be an elegant tool for pre-surgery determination of laser ablation characteristics. Pretreatment surface modification can be an effective way to overcome the limitation of the femtosecond laser for tooth preparation in the clinical setting by strongly enhancing the ablation rate. An enhanced ablation rate along with de nova prediction of ablation characteristics will enable the clinician to perform dental surgery in real time with minimal tissue damage. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Comparative evaluation of microhardness and morphology of permanent tooth enamel surface after laser irradiation and fluoride treatment - An in vitro study.

Background and aims: The aim of the study was to evaluate and compare the surface microhardness and surface morphology of permanent tooth enamel after Er,Cr:YSGG laser irradiation and Fluoride application. Materials and methods: One hundred and twenty premolars extracted for orthodontic purpose were used in the study and randomly divided into 6 groups. Group A was not subjected to any treatment. Group B was subjected to Er,Cr:YSGG laser irradiation. Group C was subjected to Er,Cr:YSGG laser irradiation followed by application of 2% NaF gel for 4 minutes. Group D was subjected to laser irradiation and 1.23% APF gel for 4 minutes. Group E was subjected to 2% NaF gel pretreatment technique followed by laser irradiation. Group F was subjected to 1.23% APF gel pretreatment technique followed by laser irradiation. All the test groups were subjected to microhardness testing and scanning electron microscope evaluation at 500 X and 1500 X. Results: All the treated groups showed an increase in microhardness value in comparison to the control group. The highest increase in microhardness was seen in Group F. Increase in microhardness values of Group B and Group D was not statistically significant as compared to Group A. Scanning Electron Micrographs showed few craters and fine porosities for Group A. These craters and porosities increased in size and often showed glass like appearance after laser irradiation. Conclusions: It can be suggested by means of present study that Er,Cr:YSGG laser irradiation alone or in combination with fluoride gel is an effective tool to provide resistance against the caries. Significantly higher resistance (p< 0.05) was seen when APF gel was used prior to Er,Cr:YSGG laser irradiation and this combination can act as an efficient tool for prevention against dental caries.

Enhanced Percutaneous Delivery of 1,1-bis(3'-indolyl)-1-(p-chlorophenyl) Methane for Skin Cancer Chemoprevention.

Skin cancer has high incidence in the United States and is mainly caused by ultraviolet B (UVB) radiation. In this study, we demonstrated the role of 1,1-bis(3'-indolyl)-1-(p-chlorophenyl) methane (DIM-D) in the prevention of skin photocarcinogenesis using an in vivo UVB-induced skin cancer model. We also evaluated the efficiency of oleic acid-modified nanostructured lipid carriers to deliver DIM-D across the skin barrier into the epidermis for chemopreventive activity. Nanocarriers were 203.00 ± 21.21 nm in diameter with polydispersity, zeta potential and entrapment efficiency of 0.33 ± 0.01, 37.17 ± 0.90 mV and 93.64 ± 0.65%, respectively. Oleic acid-modified nanocarriers were incorporated into Hydroxypropyl methylcellulose to form DIM-D-Nanogel (DIM-D-N). DIM-D-N pretreatment prior to UVB exposure delayed tumor initiation and reduced tumor multiplicity (p < 0.05) at the end of the study compared to Epigallocatechin gallate (EGCG) gel pretreatment. DIM-D-N pretreatment decreased UVB-induced damage to skin lipids and proteins (p < 0.05), respectively by 7.63 and 2.56-fold less than EGCG gel pretreatment and by 17.86 and 11.92-fold less than UVB-only treatment. Histology showed rete-ridge extension, epidermal thickening and hyperkeratosis for UVB-only treatment and EGCG gel pretreatment; DIM-D-N pretreatment showed similar features as the negative control. Western blot analysis showed increased Nurr1 expression (p < 0.05) for DIM-D-N pretreated group compared to EGCG gel (4.68-fold). DIM-D-N pretreatment reduced BCI-2 expression (p < 0.05) but increased Bax and cPARP. Knock down studies with Nurr1 siRNA reduced the expressions of Nurr1 and cPARP by 8.18 and 1.45-fold, respectively (p < 0.05). Our results suggest the role of DIM-D in skin cancer chemoprevention mediated by possible molecular therapeutic targets such as Nurr1.

Organic–inorganic hybrid sol–gel pretreatments for corrosion protection of mild steel in neutral and acidic solutions

This work aims to develop and study sol–gel-derived anticorrosion films for mild steel. Epoxy bis-silane precursor has been prepared by reaction of liquid epoxy resin and aminopropyl triethoxysilane. A pretreatment application bath (Sol) has been prepared by dissolving epoxy-silane precursor at constant solid content and fixed water/ethanol ratio, and the solution was adjusted to acidic pH. The organic–inorganic hybrid films were deposited on mild steel by dip-coating technique, by immersion of sample panels into the sol and their withdrawal at controlled rate to facilitate the desired and uniform film. Films were subsequently cured at room temperature. The anticorrosion properties of the coatings were studied using electrochemical impedance spectroscopy, DC polarisation techniques and neutral salt spray test. This study shows that very dense and protective hybrid coatings on mild steel can be obtained by controlling the resin/silane ratio during synthesis of the precursor.

Assessment of theca cell function: a prerequisite to androgen or luteinizing hormone supplementation in poor responders

Poor responders are a heterogeneous population, with some patients displaying a diminished ovarian reserve and others a poor ovarian reserve with preserved granulosa cell function. Androgen and LH/hCG supplementation has been advocated for poor responders, mainly those >40 years old. Although androgens synergistically act with FSH to support folliculogenesis, and ovarian androgen secretion declines with age, there is still no evidence that androgen therapy is actually effective to improve ovarian FSH sensitivity. The main reason seems to be that theca cell function has not been appropriately assessed in patients at risk of poor response. The definition of theca insufficiency is hampered by methodologic shortcomings in routine bioassays. Provocative tests for theca cells might help to identify those patients who could benefit from androgen supplementation. The lack of data regarding theca cells in these patients might contribute to explaining the absence of evidence for a positive effect of androgen therapy.

ZrO2 sol–gel pre-treatments doped with cerium nitrate for the corrosion protection of AA6060

Sol–gel coatings represent an alternative corrosion protection method to the chromate based systems which must be replaced. Recently, it was shown that ZrO2 based sol–gel coatings deposited on AA6060 can provide a good corrosion protection to AA6060. However, ZrO2 based sol–gel systems are not able to provide the self-healing effect which is instead the peculiar property of chromate conversion coatings. The structure of the ZrO2 based sol–gel systems does not contain species able to restore the barrier properties when defects or damages impair the coating protection.In this work, ZrO2 based sol–gel coatings containing cerium nitrate were deposited on AA6060 aluminum alloy in order to evaluate the corrosion inhibition provided by the incorporated cerium ions. The cerium nitrate was added to the starting sol based on zirconium alkoxide precursors. Three types of samples were produced: a non inhibited type consisting of 3 layers of ZrO2, an inhibited system consisting of two layers of ZrO2 with an intermediate layer doped with cerium nitrate and an inhibited system consisting of two layers containing cerium nitrate with a top layer of ZrO2.

Silane sol–gel film as pretreatment for improvement of barrier properties and filiform corrosion resistance of 6016 aluminium alloy covered by cataphoretic coating

The aim of this study is to develop a newly silane sol–gel pretreatment on the barrier properties and filiform corrosion resistance of 6016 aluminium alloy covered by cataphoretic coating. The sol–gel coatings are used as coupling agent between aluminium substrate and cataphoretic paint. The pretreatment is an aqueous solution of three different silane compounds (glycidyloxypropyltrimethoxysilane (GPS), tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES)) hydrolysed at two different pH (2 and 3.5). A system without pretreatment was studied as reference. The electrocoatings were cured between 155°C and 195°C in order to modify their mechanical properties.Polarisation curves, EIS and FT-IR measurements were used in order to characterize the silane layers. EIS measurements were used to follow the barrier properties and the water uptake evolution on intact coatings.The filiform corrosion protection of the coating was also evaluated by a normalized filiform corrosion test.

Flexible CO2 laser and submucosal gel injection for safe endoluminal resection in the intestines

The CO(2) laser's unique wavelength of 10.6μm has the advantage of being readily absorbed by water but historically limited it to line-of-sight procedures. Through recent technological advances, a flexible CO(2) laser fiber has been developed and holds promise for endoluminal surgery. We examined whether this laser, along with injection of a water-based gel in the submucosal space, will allow safe dissection of the intestines and enhance the potential of this tool for minimally invasive surgery. Using an ex vivo model with porcine intestines, spot ablation was performed with the flexible CO(2) laser at different power settings until transmural perforation. Additionally, excisions of mucosal patches were performed by submucosal dissection with and without submucosal injection of a water-based gel. With spot ablation at 5W, none of the specimens was perforated by 5min, which was the maximum recorded time. The time to perforation was significantly shorter with increased laser power, and gel pretreatment protected the intestines against spot ablation, increasing the time to perforation from 6 to 37s at 10W and from 1 to 7s at 15W. During excision of mucosal patches, 56 and 83% of untreated intestines perforated at 5 and 10W, respectively. Gel pretreatment prior to excision protected all intestines against perforation. These specimens were verified to be intact by inflation with air to over 100mmHg. Furthermore, excision of the mucosal patch was complete in gel-pretreated specimens, whereas 22% of untreated specimens had residual islands of mucosa after excision. The flexible CO(2) laser holds promise as a precise dissection and cutting tool for endoluminal surgery of the intestines. Pretreatment with a submucosal injection of a water-based gel protects the intestines from perforation during ablation and mucosal dissection.

The effect of transdermal testosterone gel pretreatment on controlled ovarian stimulation and IVF outcome in low responders

To investigate the effectiveness of treatment with transdermal testosterone gel (TTG) before controlled ovarian stimulation (COS) using GnRH antagonist multiple-dose protocol (MDP) in low responders undergoing IVF/intracytoplasmic sperm injection (ICSI). Prospective randomized controlled trial. University-affiliated infertility clinic. A total of 110 low responders, who were defined as patients who failed to produce ≤ 3 follicles with a mean diameter of ≥ 16 mm with the result that ≤ 3 oocytes were retrieved despite the use of a high gonadotropin dose (>2,500 IU) in a previous failed IVF/ICSI cycle. Patients were randomized into TTG pretreatment group or control group. For TTG pretreatment group, 12.5 mg TTG were applied daily for 21 days in the cycle preceding COS for IVF. COS results and IVF outcome. There were no differences in patients' characteristics between the two groups. Total dose and days of rhFSH used were significantly fewer in the TTG pretreatment group than in the control group. The numbers of oocytes retrieved, mature oocytes, fertilized oocytes, and good-quality embryos were significantly higher in the TTG pretreatment group. Embryo implantation rate and clinical pregnancy rate per cycle initiated also were significantly higher in the women pretreated with TTG. No patient reported adverse effects attributed to TTG use. TTG pretreatment might be beneficial in improving both response to COS and IVF outcome in low responders undergoing IVF/ICSI.