Alternative Method For Preparation Research Articles

Preparation of Sustainable Ni/SiO2 Catalysts from Rice Husk by Different Methods for CO2 Methanation.

Silicon dioxide (SiO2) from rice husk can be extracted and be used as support for Ni-based catalysts. The impregnation method (IM) is usually used for preparing Ni/SiO2 catalysts, but its catalytic activity in CO2 hydrogenation to CH4 remains unsatisfactory. In this work, we explored alternative preparation methods, using ammonia evaporation method (AEM) and hydrothermal method (HM) to prepare the catalysts. The results showed that the catalysts prepared by AEM and HM were significantly superior to that prepared by IM. Notably, the catalyst synthesized by AEM from sustainable silica exhibited the best performance, achieving 81.69% CO2 conversion and over 99% methane selectivity at low reaction temperature of 300 °C. The characterization techniques indicate that the Ni/SiO2-AEM catalyst can form nickel phyllosilicate with lamellar structure, leading to better Ni dispersion and higher specific surface area. Furthermore, the results of in-situ DRIFTS have revealed the potential catalytic mechanism over Ni/SiO2 catalysts, indicating that it involves pathways with both the CO* and HCOO* as the key intermediates.

Rotary barrel tumbling as a method of surface preparation for pin-on-disc wear testing samples

Surface preparation is essential to ensure sample homogeneity in terms of surface roughness and mechanical properties, as these factors can significantly affect wear behavior and test repeatability. Although conventional semi-automatic and automatic grinding and polishing processes are efficient and well established, limitations arise for the preparation of large numbers of samples of a hard material such as high-carbon steel, including issues with sample geometry, the need for on-demand sample holders, cost-related limitations, and even considerable human workload and expertise. This study aims to evaluate the use of rotary barrel tumbling—a polishing method that relies on the sliding of abrasive media over the samples’ surface inside a rotating barrel—as an alternative method to prepare the surface of wheel and rail steel samples for pin-on-disc wear testing. A 4-stage tumbling procedure was employed, using different compositions of tumbling media in each stage. Surface roughness and hardness were evaluated throughout the process via 2D and 3D profilometry, microhardness Vickers measurements, and optical microscopy. The proposed method resulted in significant reductions in the surface roughness and hardness of the samples, along with improved homogeneity between samples of different materials and within the same material. These findings suggest that rotary barrel tumbling is an effective alternative method for the surface preparation of pins and discs made of high-carbon steel, enhancing the samples’ suitability for subsequent wear tests.

Chitosan/Silica Hybrid Nanogels by Inverse Nanoemulsion for Encapsulating Hydrophilic Substances

AbstractA strategy for the preparation of a hybrid chitosan/silica nanohydrogel is reported, which combines the gelation of chitosan in a nanoemulsion system with a sol–gel process to produce silica. Chitosan is used as a biopolymer matrix, while silica acts as a structuring additive. Hydrogel nanocapsules are obtained through the ionic interaction of the cationic groups of chitosan with the anionic groups of sodium triphosphate (STP), which is used as a physical cross‐linker. Two alternative preparation methods are compared in this work: in the first one, STP is added to the continuous phase of an inverse emulsion of chitosan; in the second one, the fusion of droplets of two emulsions containing separate chitosan and STP takes place. The size of the obtained nanocapsules ranges from 50 to 200 nm. The efficiency of the formed hydrogel for entrapping a hydrophilic model substance (erioglaucine disodium salt) is investigated for the two systems by studying the release in a neutral aqueous medium. The results indicate that the hydrophilic cargo is efficiently encapsulated by both preparation methods, although the droplet‐fusion method yields more stable suspensions. As a general observation, the release behavior of erioglaucine is systematically retarded when silica is present in the systems.

Identification, Isolation, and Characterization of a Novel Degradation Impurity of Busulfan Using Preparative Chromatography, NMR, and LC-MS.

Busulfan is the most effective medication for treating chronic myelogenous or granulocytic leukemia because it has cytotoxic properties that harm or kill hematopoietic cells. It cannot absorb light in the Ultraviolet range due to its structure. Because of this, it is very challenging to quantify using traditional HPLC coupled with UV/Photodiode Array detectors. So, using sodium diethyldithiocarbamate, a derivatization method was developed to quantify related impurities. A significant unknown impurity was identified in derivatized samples of busulfan and a noticeably high percentage level was discovered during routine drug testing. We aimed to isolate, and characterize the unknown impurity observed in the samples and to identify its root cause. Preparative HPLC was used to isolate the unidentified, derivatized impurity, and 1H NMR, 13C NMR, and MS were used to decipher its structural components. The spectral characterization data analysis showed that the unknown impurity was related to busulfan. Additionally, it was noted that the impurity developed as a result of the residual buffer used to prepare the derivatizing reagent. The isolated impurity was found to be same as comparable to that found in busulfan drug substances, according to the results of the characterization tools. An alternative method of reagent preparation was optimized and deemed satisfactory because the buffer used in reagent preparation is the only factor contributing to the formation of impurities. Using cutting-edge analytical characterization tools, it was possible to explain the structural characteristics of an unknown impurity and discover that it was a novel impurity, which undoubtedly contributes to the comprehension of drug substance reaction properties.

(310) Severe Delayed Skin Reaction to Antiseptic Irrigation Solution Managed with Pinch Skin Grafting After Inflatable Penile Prosthesis Surgery: A Case Report

Abstract Introduction Inflatable penile prosthesis (IPP) surgery is a common procedure for treating erectile dysfunction, and skin preparation with antiseptic solutions is a standard practice to reduce infection risk. However, some antiseptic solutions, such as chlorhexidine-based Irrisept, have been associated with severe skin reactions. Several studies have reported cases of contact dermatitis, blistering, and chemical burns following the use of chlorhexidine-based antiseptic solutions before surgery. Objective This case report aims to highlight the potential risk of severe skin reactions when using Irrisept and other chlorhexidine antiseptic solutions during penile prosthesis surgery. It also explores the novel technique of pinch skin autografting used to salvage the implant and achieve successful wound healing after delayed skin necrosis. Methods 61-year-old male with a history of prostate cancer and erectile dysfunction who underwent insertion of an IPP. Results The patient's penile shaft developed blisters 3 weeks post-implantation, which progressed to full-thickness necrosis despite conservative treatment. The distribution and location of the reaction led to the hypothesis that it was caused by the chlorhexidine-based Irrisept antiseptic. The antiseptic solution used copiously throughout the case and 10CC was injected under pressure into the drain which also may explain the reaction observed. The patient underwent wound debridement and was treated with pinch skin autografts from the bilateral thighs. The autografts resulted in 95% epithelialization with excellent cosmetic outcomes with no other complications. To the best of our knowledge, this is the first reported case of Irrisept-induced delayed skin necrosis and the use of pinch skin grafting to salvage the implant after penile prosthesis surgery. Conclusions Skin reactions to Irrisept antiseptic solution during penile prosthesis surgery are rare but can be severe. Surgeons should be cautious and consider alternative skin preparation methods in patients with a history of skin allergies or sensitivities. This case also highlights the potential of pinch skin autografting as a salvage technique for post-IPP skin reactions. A multidisciplinary approach involving reconstructive burn surgeons and specialty wound care teams may be beneficial in optimizing outcomes in such cases. Disclosure No.

Thin-section- and matrix-free mass spectrometry imaging: Reproducible sample transfer using novel platinum-coated porous plate formed of glass beads.

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) typically requires sample preparation such as sectioning and spraying of the matrix. Sample transfer using a Pt-coated porous plate formed of glass beads simplifies preparation and enables reproducible MSI measurements. The surface of a sintered-glass-bead porous plate was coated with Pt on one side of the plate. Polymer additives and the cross-section of a strawberry were chosen as the sample and transferred to the Pt-coated surface of the plate. This process was completely thin-section- and matrix-free. The prepared plates were analyzed using a commercial MALDI time-of-flight instrument. Several constituents of the polymer additives (Irgafos 168 and Irganox 1010) and strawberry metabolites (hexose, citric acid, and sucrose) were detected without organic matrices. These ion images were obtained with a special distribution of the retained constituents. Duplicate prepared plates using the same strawberry cross-section reproduced the ion images. A sample transfer process using a Pt-coated porous plate formed of glass beads was demonstrated as an alternative preparation method for MSI. This process has the potential to simplify MSI preparation and achieve easily reproducible MSI measurements.

The development and validation of a new method for the fast determination of Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Sr and Zn in rice by inductively coupled plasma optical emission spectrometry.

An alternative method of rice sample preparation for measuring the total content of selected elements, i.e., Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Sr and Zn, by ICP OES was developed. The proposed approach is based on the ultrasound-assisted extraction (USAE) of rice samples in the presence of a small amount of concentrated HNO3. The optimal operating parameters were found using the design of experiments (DOE) approach, and the studied experimental factors were the temperature of the ultrasonic bath (A), the sonication time (B), and the volume of concentrated HNO3 added per 0.5 g of a rice sample (C). Under the optimal conditions of the USAE procedure, i.e., A = 60 °C, B = 16 min and C = 4.0 mL, the rice samples were readily solubilized, and the obtained sample solutions could be analyzed by ICP OES with the simple standard solution calibration (without matrix matching). The analysis of the certified reference material (rice flour, NIST SRM 1568b) confirmed the satisfactory trueness of the USAE-ICP OES method. Additionally, no statistically significant differences between the results obtained for the samples prepared by USAE and open-vessel wet digestion (WD, the reference method) were found. In comparison to the routinely used microwave-assisted digestion and open-vessel digestion, the USAE approach offers lower acid consumption, lower detection limits (LODs) of elements, ranging from 4.0 ng g-1 for Mn to 2.7 µg g-1 for K, and a much shorter time of sample preparation.

Synthetic and analytical considerations for the preparation of amorphous metal-organic frameworks.

Metal-organic frameworks (MOFs) are hybrid porous materials presenting several tuneable properties, allowing them to be utilised for a wide range of applications. To date, focus has been on the preparation of novel crystalline MOFs for specific applications. Recently, interest in amorphous MOFs (aMOFs), defined by their lack of correlated long-range order, is growing. This is due to their potential favourable properties compared to their crystalline equivalents, including increased defect concentration, improved processability and gas separation ability. Direct synthesis of these disordered materials presents an alternative method of preparation to post-synthetic amorphisation of a crystalline framework, potentially allowing for the preparation of aMOFs with varying compositions and structures, and very different properties to crystalline MOFs. This perspective summarises current literature on directly synthesised aMOFs, and proposes methods that could be utilised to modify existing syntheses for crystalline MOFs to form their amorphous counterparts. It outlines parameters that could discourage the ordering of crystalline MOFs, before examining the potential properties that could emerge. Methodologies of structural characterisation are discussed, in addition to the necessary analyses required to define a topologically amorphous structure.

A Recent Review of Electrospun Porous Carbon Nanofiber Mats for Energy Storage and Generation Applications.

Electrospun porous carbon nanofiber mats have excellent properties, such as a large surface area, tunable porosity, and excellent electrical conductivity, and have attracted great attention in energy storage and power generation applications. Moreover, due to their exceptional properties, they can be used in dye-sensitized solar cells (DSSCs), membrane electrodes for fuel cells, catalytic applications such as oxygen reduction reactions (ORRs), hydrogen evolution reactions (HERs), and oxygen evolution reactions (OERs), and sensing applications such as biosensors, electrochemical sensors, and chemical sensors, providing a comprehensive insight into energy storage development and applications. This study focuses on the role of electrospun porous carbon nanofiber mats in improving energy storage and generation and contributes to a better understanding of the fabrication process of electrospun porous carbon nanofiber mats. In addition, a comprehensive review of various alternative preparation methods covering a wide range from natural polymers to synthetic carbon-rich materials is provided, along with insights into the current literature.

Mechanisms of CaO particle gelation by laser ablation of CaO powder dispersed in alcohol

Our earlier study showed that CaO particle gel, with loosened agglomerations of CaO particles, was generated by laser ablation of CaO powder dispersed in ethanol. We also demonstrated that porous CaO, a candidate of a low-cost and non-toxic CO2 absorbent, was obtained by simply drying the gel. For the present study, we conducted further investigation of the gelation mechanism to utilize this phenomenon as a simple and alternative preparation method of porous CaO. First, we observed the relation between the agglomeration tendency, including gelation and non-gelation, and the electrostatic interaction of CaO particles in different alcohols (methanol, ethanol, 1-propanol), because we have assumed electrostatic interaction among CaO particles as the most important factor affecting the gelation. Results showed that the agglomeration tendency of CaO particles increased with the decreasing zeta potential of CaO particles in these alcohols, which is consistent with the assumption. However, no decreased electrostatic repulsion caused by laser ablation was observed, suggesting the presence of another important factor affecting the gelation. As a possible factor, the CaO particle size composition was inferred: the colloid should contain both large particles and small particles. Interestingly, this assumption was validated by the fact that the gel was formed by mixing a raw colloid and a colloid prepared using laser ablation.

Transitioning to work without school: experiences of the home educated

The school-to-work transition is widely acknowledged as difficult, requiring meaningful support for young people to navigate successfully. This paper examines the reported experiences of six families navigating 23 home educated young people’s transition from compulsory education to tertiary education and work. Data from semi-structured interviews with the parents were thematically analysed using Bourdieu's habitus, capital, and field. Findings indicate that the parents provided ample opportunity for self-exploration to encourage autonomy coupled with opportunity to explore and participate in the wider community, leading to a successful transition experience. The findings suggest that a contrasting, alternative career preparation method can be successful; one that values autonomy over the traditional approach which involves a scaffolded set of knowledge and skills. This study indicates that the transition can be successfully facilitated by providing young people with opportunity for autonomous self and career exploration in the community, without the standardised assistance provided through schools.

Review on Hydrophobic Thin Films Prepared Using Magnetron Sputtering Deposition.

Hydrophobic thin films have gained significant attention due to their broad applications in self-cleaning, anti-corrosion, anti-icing, medicine, oil-water separation, and other fields. The target hydrophobic materials can be deposited onto various surfaces thanks to the scalable and highly reproducible nature of magnetron sputtering, which is comprehensively overviewed in this review. While alternative preparation methods have been extensively analyzed, a systematic understanding of hydrophobic thin films fabricated using magnetron sputtering deposition is still absent. After outlining the fundamental mechanism of hydrophobicity, this review briefly summarizes three types of sputtering-deposited thin films that originate from oxides, polytetrafluoroethylene (PTFE), and diamond-like carbon (DLC), respectively, primarily focusing on the recent advances in their preparation, characteristics, and applications. Finally, the future applications, current challenges, and development of hydrophobic thin films are discussed, and a brief perspective on future research directions is provided.

Beyond raw: Investigating alternative preparation methods as a tool to increase acceptance of oysters in Sweden

The role of seafood in supporting transitions towards more sustainable and healthier diets is often overlooked. Oysters, for example, are a nutrient dense aquatic food whose production requires no feed, freshwater, or land use. However, oyster consumption in Sweden is limited, possibly in part due to being traditionally served raw. This study investigated consumer acceptance of oysters when cooked and prepared to resemble familiar foods and examined whether food neophobia (FN) was related to liking. Four oyster-based samples (raw oyster, oyster crepe, oyster burger, and oyster soup) were evaluated in an ecologically valid setting. Participants (N=102; convenience sampling) rated the samples in terms of hedonics (expected liking and liking after tasting), described which aspects of the samples were liked/disliked, and reported the contexts in which oyster consumption is perceived as appropriate. The findings suggest that FN was negatively associated with expected liking of raw oysters, but not with expected liking for cooked oyster-based products that were cooked to resemble familiar foods. On the other hand, familiarity with oysters was positively associated with expected liking of raw oysters. This suggests that expanding oyster preparations beyond its traditional raw format could be a valuable strategy to promote oyster consumption in Sweden.

Synthesis of benzoxazoles via a silver mediated oxidation

A silver carbonate-based method to synthesize benzoxazoles from imines has been developed. The reaction is extremely mild, tolerates several heterocycles and functional groups, and provides highly functionalized benzoxazoles in modest to good yields. The reaction proceeds in an array of solvents and atmospheric conditions, demonstrating the robustness of this oxidation method and its ability to provide an alternative method for the easy preparation and isolation of these bioactive compounds.

Alkaline hydrolysis of biomass as an alternative green method for bioplastics preparation: In situ cellulose nanofibrillation

Mild acid hydrolysis of various plant residues has been proposed in recent years as a novel way of transforming biomass into bioplastics. However, the alkaline hydrolysis of such residues has not yet been studied for this purpose. In this work, an in-depth comparative study is carried out for the first time on the physicochemical, thermal, mechanical, and morphological aspects of the bioplastics produced by acid and alkaline hydrolysis starting from two different plant residues: spinach stems (SS) and peanut shells (PS). The chemical treatments followed here, produced self-standing SS bioplastics and hydrolyzed PS powders that were incorporated as fillers in a thermoplastic starch (TPS) matrix to obtain composites. The alkaline hydrolysis led to bioplastics with superior mechanical and barrier properties than those obtained from acid hydrolyzed biomass. The Young's modulus (YM) of SS-bioplastics produced upon alkaline hydrolysis, tripled, their tensile strength (TS) almost doubled, and their water vapor permeability (WVP) was reduced by 15%, compared to SS-bioplastics produced upon acidic hydrolysis. TPS-alkali hydrolyzed PS composites showed increments of 22% in YM, 10% in TS, and a reduction of about 30% in their WVP compared to the respective acid hydrolyzed composites. The physicochemical, thermal, and morphological analysis confirmed that the main cause of these improvements was cellulose nanofibrillation, which was favored by the greater efficiency of the alkaline medium to hydrolyze the pectin, hemicellulose, and lignin polymers. This research represents a step ahead in understanding the processes of transforming non-edible vegetable wastes into sustainable bioplastics and comes in a critical moment when an urgent transition towards a circular economy is need, and industrial processes are expected to reduce their carbon footprint and generate zero waste.

Fabrication of Nylon 6-Montmorillonite Clay Nanocomposites with Enhanced Structural and Mechanical Properties by Solution Compounding.

Melt compounding has been favored by researchers for producing nylon 6/montmorillonite clay nanocomposites. It was reported that high compatibility between the clay and the nylon6 matrix is essential for producing exfoliated and well-dispersed clay particles within the nylon6 matrix. Though solution compounding represents an alternative preparation method, reported research for its use for the preparation of nylon 6/montmorillonite clay is limited. In the present work, solution compounding was used to prepare nylon6/montmorillonite clays and was found to produce exfoliated nylon 6/montmorillonite nanocomposites, for both organically modified clays with known compatibility with nylon 6 (Cloisite 30B) and clays with low/no compatibility with nylon 6 (Cloisite 15A and Na+-MMT), though to a lower extent. Additionally, solution compounding was found to produce the more stable α crystal structure for both blank nylon6 and nylon6/montmorillonite clays. The process was found to enhance the matrix crystallinity of blank nylon6 samples from 36 to 58%. The resulting composites were found to possess comparable mechanical properties to similar composites produced by melt blending.

EVALUATION OF THE EFFECTIVENESS OF THE USE OF NON-DRUG THERAPY FOR PRECONCEPTION PREPARATION OF WOMEN WITH BACTERIAL VAGINOSIS

Bacterial vaginosis (BV) is one of the most common conditions in women of reproductive age. BV is detected in 80–87% of women with abnormal vaginal discharge, the incidence of the disease in pregnant women reaches 37–40% and is a risk factor for complications. The purpose of the research is to study the clinical and microbiological efficacy of a two-stage scheme for the correction of vaginal dysbiosis using cavitated low-frequency ultrasound (LUS) as an alternative method for preconception preparation in women with bacterial vaginosis. Materials and methods. The study involved 67 patients with BV aged 19 to 35 years who consulted an obstetrician-gynecologist in connection with pregnancy planning. The results of bacterioscopic and bacteriological studies, the state of vaginal microbiocenosis were evaluated by PCR with real-time detection of results (RT-PCR). All patients according to the state of microbiocenosis were divided into two groups: I-moderate dysbiosis with the content of Lactobacillus spp.from 20% to 80% (n=39) and II-pronounced dysbiosis with the content of Lactobacillus spp.less than 20% (n=28). A two-stage scheme was applied to correct vaginal dysbiosis. At the first stage, all women underwent vaginal treatment with cavitated NUS aqueous 0.05% chlorhexidine solution.At the second stage, a lyophilized culture of lactobacilli was used to normalize and renew the vaginal microflora. The results of the study. In women of group I with moderate dysbiosis, a decrease in the content of lactoflora below the value of 107/g was revealed. The proportion of Gardnerella vaginalis was 35.9% (n=14), Atopobiumvaginae 25.6% (n=10), Eubacterium 23.1% (n=9), Megasphera 17.9% (n=7), Mobiluncus spp.20.5% (n=8), Peptostreptococcus 8% (n=3), Snethia spp.20.5% (n=8), Lachnobacterium spp.15.3 (n=6). In group II of examined women with severe dysbiosis, the content of lactoflora was less than 105/g; in most cases, lactobacilli were not detected. The majority of patients had microbial associations of Gardnerella vaginalis and Atopobiumvaginae 67.8% (n=19), Eubacterium 17.8% (n=5), Megasphera 14.2% (n=4), Mobiluncus spp.25% (n=7), Peptostreptococcus 28.5% (n=8), Snethia spp. 32.1% (n=9), Lachnobacterium spp.25% (n=7). After the course of treatment, the positive dynamics of the state of microbiocenosis according to real-time PCR was noted after the completion of the course of vaginal irrigation. The proportion of women with severe anaerobic dysbiosis decreased from 41.8% (n=28) to 13.4% (n=9), with moderate dysbiosis - from 58.2% (n=39) to 19.4% (n=13) among all examined women. At the same time, in 61.2% (n=41) of women, the microbiocenosis was restored to normocenosis. Conclusions. The proposed scheme for the correction of vaginal dysbiosis demonstrates the high efficiency of the method: restoration of normocenosis was achieved in every second patient. Positive dynamics was noted due to an increase in the proportion of lactoflora content in almost all observed women.

Bacterial Flora in Dental Cavities after Traditional and Alternative Methods for Cavity Preparation

The aim of the study was to establish the qualitative and quantitative composition of microbial flora of dental cavities (DCs) after traditional and alternative preparation, including different methods of isolating the working field. Material and Methods: Our study included 60 patients (mean age of 25.0±3.1 years) with DC Class 1 (Black's classification) without concomitant somatic pathology. To accomplish the study’s aim, 60 teeth were prepared. The main group (MG) consisted of 45 teeth prepared under absolute isolation with a rubber dam (RD). In the MG, 15 teeth were treated traditionally with a diamond bur with red and yellow markings (MG-1), 15 teeth were treated by ultrasound with a diamond tip (MG-2), and 15 teeth underwent hydrokinetic preparation (MG-3) with the Aquacut device (Velopex). In the comparison group (CG), which included 15 teeth, DCs were treated traditionally with a dental bur without the RD. The MG and CG were comparable in terms of the initial state of dental and microbiological status. The study of the qualitative and quantitative composition of the DC microflora showed that all DCs contained pathogenic β-hemolytic streptococcus in the CG. At the same time, the maximum number of cases (80%) was moderately contaminated.. MG-1 and MG-2, as in the CG, were characterized by the predominance of β-hemolytic streptococcus at the bottom of the treated cavity. At the same time, the incidence of moderate contamination decreased by 4 times and single contamination increased in the cultures to 80%, compared to the CG (P=0.001). In MG-3, β-hemolytic streptococcus also dominated in the bottom of DCs after RD setting. The number of colonies was single (66.7% of cases) and moderate (33.3% of cases), indicating a significant increase in single and a decrease in moderate infestation, compared to the CG (P<0.01). Analysis of the quantitative characteristics of the microbial composition of the cavity floor after preparation of fissure caries showed the highest bacterial contamination in CG: β-hemolytic streptococcus predominated, averaging 251.20±2.5CFU/tampon. Lactobacillus and Neisseria spp. were detected much less frequently (3.16±1.6 and 1.99±1.3 CFU/tampon, respectively). There was a 10-fold decrease in the number of β-hemolytic hemolytic streptococcus cultures in MG-1 (25.12±2.0 CFU/tampon), MG-2 (25.12±2.0 CFU/tampon) and MG-3 (19.95±2.0 CFU/tampon), compared to the CG (P=0.000). The opportunistic microorganisms in the treatment of hard tissues by different methods (burr, ultrasound, hydrokinetic) under absolute isolation conditions were identified in almost equal numbers, with the Lactobacillus contamination being significantly lower in MG-1, MG-2, and MG-3 than in the CG (P<0.01). Conclusion: After the preparation of DCs, a single presence of opportunistic microorganisms, moderate or single contamination with pathogenic bacteria, and absence of anaerobic bacteria were noted. Absolute isolation with RD provides a reduction of microbial infection regardless of the preparation method, and the maximum positive effect is DC preparation with dental burr and ultrasound.

Endometrial preparation and maternal and obstetrical outcomes after frozen blastocyst transfer

Two types of endometrial preparation protocols are used for frozen embryo transfers in current practice: hormone replacement and the natural cycle. Endometrial preparation in the natural cycle reportedly increases the chances of live birth and decreases early pregnancy loss compared with that in the hormone replacement cycle. However, the influence of endometrial preparation on maternal and neonatal health remains unclear. This study aimed to investigate whether the differences between hormone replacement cycle and natural cycle influence perinatal outcomes and risk of congenital anomalies in frozen-thawed blastocyst transfer fetuses or births. Perinatal outcomes and congenital abnormalities were compared between the natural and hormone replacement cycles. According to the timing of ovulation, frozen-thawed blastocyst transfers in the natural cycle were classified into 2 patterns: on day 4.5 (ovulation 4.5) or day 5 (ovulation 5.0) after ovulation. When the serum luteinizing hormone level was not increased on the day of the trigger, a single vitrified-warmed blastocyst transfer was performed on day 7 after the trigger (ovulation 5.0). When the luteinizing hormone level was slightly increased on the day of trigger, single vitrified-warmed blastocyst transfer was performed on day 6 after the trigger (ovulation 5.0). In total, 67,018 cycles (ovulation 4.5, 29,705 cycles; ovulation 5.0, 31,995 cycles; hormone replacement, 5318 cycles) of frozen-thawed blastocyst transfer between January 2008 and December 2017 at Kato Ladies Clinic were retrospectively analyzed. During the study period, embryo cryopreservation was performed using a vitrification method in all cycles. Hormone replacement cycles were associated with a higher occurrence of hypertensive disorders of pregnancy (adjusted odds ratio, 2.16; 95% confidence interval, 1.66-2.81) and placenta accreta (adjusted odds ratio, 4.14; 95% confidence interval, 1.64-10.44) compared with the natural cycle. The risks of cesarean delivery (adjusted odds ratio, 1.93; 95% confidence interval, 1.78-2.18), preterm birth (adjusted odds ratio, 1.55; 95% confidence interval, 1.25-1.93), and low birthweight (adjusted odds ratio, 1.42; 95% confidence interval, 1.18-1.73) were also higher for hormone replacement cycles. No significant difference in the risk of congenital anomalies was observed between the 2 cycles. The risk of hypertensive disorders of pregnancy, placenta accreta, cesarean delivery, preterm delivery, and low birthweight was higher in hormone replacement cycles than in natural cycles, whereas the risk of congenital anomalies was similar between both cycles. Further follow-up is needed to investigate these risks and to explore alternative endometrial preparation methods.

Preparation of Maleimide-Modified Oligonucleotides from the Corresponding Amines Using N-Methoxycarbonylmaleimide.

Oligonucleotide conjugates constitute a versatile tool for research and bioanalytical purposes. Often, such conjugates are prepared by reaction between a thiol on the protein with a maleimide-modified oligonucleotide. Unlike most other chemical handles the maleimide functionality cannot be introduced directly during the solid-phase oligonucleotide synthesis, and therefore the standard method to introduce the maleimide functionality is to react an amino-modified DNA with a heterobifunctional linker containing an activated ester and a maleimide. Here, we present an alternative method for preparation of maleimide and monobromomaleimide-modified oligonucleotides from the corresponding amine using N-methoxycarbonylmaleimide and N-methoxycarbonylbromomaleimide, respectively. In this method, no additional linker is attached to the oligonucleotide, as the maleimide functionality is formed directly on the existing amine. The maleimide can thereby be positioned close to the oligonucleotide, providing a high degree of control over the final construct. The reaction occurs in 30-60 min under alkaline conditions. Maleimide-modified oligonucleotides prepared in this manner were conjugated to bovine serum albumin, and the reaction shows comparable reactivity to the corresponding oligonucleotide modified using the 4-(N-maleimidomethyl)-cyclohexane-1-carboxylate (SMCC) linker.