The development of internal pressure standards for in-house elastic wave velocity measurements in multi-anvil presses

Ultrasonic systems are powerful tools to determine elastic wave velocities of minerals and materials at high pressure and temperature and have been extensively developed in recent decades. However, accurate measurement of sample length is required to convert travel times into wave velocities, limiting their use to synchrotron facilities or room temperature experiments in laboratories. We have made use of a close collaboration between the Bayerisches Geoinstiut and the P61B end-station beamline (PETRA III - DESY) to install ultrasonic systems and develop a novel dual travel time method for in situ pressure determination without the need for synchrotron radiation. Our method relies on the travel times of elastic waves through a reference material; it requires a thermocouple and is non-intrusive, with the reference material replacing the backing plate of the high-pressure assembly. Pressures obtained from this dual travel time method show excellent agreement with those obtained from x-ray diffraction using synchrotron radiation on standard materials. Our novel method enables in situ pressure determination at varying temperatures during in-house ultrasonic interferometry experiments. This allows us not only to determine the elastic behavior of minerals and materials but also to investigate phase diagrams, solidus, or liquidus conditions at varying pressures and temperatures during in-house experiments. During the installation of the pulse-echo ultrasonic system, we identified critical parameters for obtaining reliable data. While these requirements are well-known to experts, this study presents a comprehensive review of the different characteristics of ultrasonic systems, providing user-friendly guidelines for new users installing and operating such systems in high-pressure and high-temperature conditions.

Characterization of Volatile Compounds in Donkey Meat by Gas Chromatography-Ion Mobility Spectrometry (GC-IMS) Combined with Chemometrics

Volatile compounds (VOCs) are an important factor affecting meat quality. However, the characteristic VOCs in different parts of donkey meat remain unknown. Accordingly, this study represents a preliminary investigation of VOCs to differentiate between different cuts of donkey meat by using headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) combined with chemometrics analysis. The results showed that the 31 VOCs identified in donkey meat, ketones, alcohols, aldehydes, and esters were the predominant categories. A total of 10 VOCs with relative odor activity values ≥1 were found to be characteristic of donkey meat, including pentanone, hexanal, nonanal, octanal, and 3-methylbutanal. The VOC profiles in different parts of donkey meat were well differentiated using three- and two-dimensional fingerprint maps. Nine differential VOCs that represent potential markers to discriminate different parts of donkey meat were identified by chemometrics analysis. These include 2-butanone, 2-pentanone, and 2-heptanone. Thus, the VOC profiles in donkey meat and specific VOCs in different parts of donkey meat were revealed by HS-GC-IMS combined with chemometrics, whcih provided a basis and method of investigating the characteristic VOCs and quality control of donkey meat.

Lipase-catalyzed ring-opening polymerization of natural compound-based cyclic monomers

The need for sustainable and environment-friendly materials has led to growing interest in the development of biodegradable polymers based on natural compounds. However, metal-based catalysts used in the polymerization process may cause concerns about the toxicity of the resultant polymers. Therefore, polymers derived from natural compounds and synthesized through the use of green catalysts are highly desirable. Lipase-catalyzed ring-opening polymerization (ROP) of biocompound-based cyclic monomers has emerged as a promising and green strategy for the design and synthesis of such polymers. In this review, we summarize reports on the use of ROP catalyzed by lipase for cyclic monomers derived from natural compounds, including bile acid- and porphyrin-based macrocycles, carbonate-based macrocycles, lactones, and cyclic anhydrides, with an emphasis on ring-closure reactions for the synthesis of cyclic monomers, the types of lipases for the ROP and the choice of reaction conditions (temperature, solvent, reaction time, etc.). Moreover, the current challenges and perspectives for the choice and reusability of lipases, ring-closure versus ring-opening reactions, monomer design, and potential applications are discussed.

Characterization of donkey-meat flavor profiles by GC–IMS and multivariate analysis

The distinctive flavor compounds of donkey meat are unknown. Accordingly, in the present study, the volatile compounds (VOCs) in the meat from SanFen (SF) and WuTou (WT) donkeys were comprehensively analyzed by gas chromatography–ion mobility spectrometry (GC-IMS) combined with multivariate analysis. A total of 38 VOCs, of which 33.33% were ketones, 28.89% were alcohols, 20.00% were aldehydes, and 2.22% were heterocycles, were identified. Ketones and alcohols were significantly more abundant for SF than for WT, whereas aldehydes showed the opposite trend. The donkey meats from the two strains were well differentiated using topographic plots, VOC fingerprinting, and multivariate analysis. A total of 17 different VOCs were identified as potential markers for distinguishing the different strains, including hexanal-m, 3-octenal, oct-1-en-3-ol, and pentanal-d. These results indicate that GC–IMS combined with multivariate analysis is a convenient and powerful method for characterizing and discriminating donkey meat.

P-478 Deleterious influence of cyclophosphamide on primordial follicles derives from increased DNA damage and reduced proliferation in xenotransplanted human ovarian tissue

Study question

What are the acute effects of cyclophosphamide (Cp) on primordial follicles (PrFs) in human ovarian tissue?

Summary answer

Administration of Cp damages PrFs via DNA fragmentation and results in reduced proliferation with no increase in PrF activation markers.

What is known already

Alkylating agents are highly gonadotoxic, and in cases where freezing oocytes, embryos, or ovarian tissue is impractical, a better understanding of the underlying damage mechanism could enable development of fertoprotective approaches (1). Studies from different groups suggest conflicting mechanisms of ovarian damage, with either PrF activation (2) or cell damage and apoptosis (3-4) proposed as drivers of PrF depletion. Few studies have examined this question using human tissue. We performed xenografts using ovarian tissue from a 17-month-old girl to ensure a graft with plentiful PrFs to test the acute effect of Cp.

Study design, size, duration

Cross-sectional study.

We utilized a xenotransplantation model in which human ovarian tissue is co-transplanted with endothelial cells (ECs) into immunocompromised mice (NSG) (5). Three weeks after xenotransplantation, time 0, intraperitoneal (IP) injection of (saline/Cp) was followed by an IP injection of ethynyl-deoxyuridine (Edu), at 0 and 24 hours, followed by 5-chloro-2′-deoxyuridine (CldU), at 48 and 72 hours. Grafts were harvested at 96 hours.

Participants/materials, setting, methods

We co-xenotransplanted human ovarian cortical tissue from a 17-month-old girl, cryopreserved for fertility preservation, into immunocompromised mice. After 3 weeks, Cp (75mg/Kg)/saline was administered IP. Mice were then sequentially injected with EdU, followed by CldU (both at 100mg/kg for 2 days) 24 hours apart. Twenty-four hours later, mice were sacrificed and xenografts were harvested and sectioned. Slides were stained for EdU, CldU, VASA, γ-H2AX, FOXO3a, and 4',6-Diamidino-2-Phenylindole-Dilactate (DAPI) and imaged using a confocal microscope.

Main results and the role of chance

We used anti-VASA staining to evaluate oocyte morphology, confirming that chemotherapy was not sterilizing; we counted 76.5% of morphologically normal PrF in the control group (Ctrl) (130/170) and 35.1% (13/37) in the Cp group. In the Ctrl group, 11% stained positively for DNA fragmentation using anti-γ-H2AX, whereas 43% were positive in the Cp group (p = 0.0073). To evaluate activation, we stained for FOXO3a in the oocyte nucleus. No difference was found between the groups: 52.4% (74/144) versus 44.6% (37/83) in Ctrl versus Cp, respectively. Interestingly, when comparing EdU incorporation, the Ctrl group had higher incorporation at 72%, versus the Cp group with 40% of incorporation (p = 0.0485), and no difference was found with CldU incorporation: Ctrl 22% versus 27% in the Cp group, respectively (P = 0.6960).

Limitations, reasons for caution

We measured acute effects, DNA fragmentation, and proliferation, at five days post-Cp administration; however, this falls short of evaluating processes that appear later (fibrosis and neovascularization). Also, the results may partly stem from the patient’s young age. Repeating the experiment using adult-derived tissue might yield different results.

Wider implications of the findings

A better understanding of both the timeline and underlying mechanisms that contribute to chemotherapy-related gonadotoxicity could diminish the damage and depletion of the ovarian reserve (PrF). These results provide evidence that direct damage to PrFs, and not increased activation, contributes to gonadotoxicity in the acute phase following administration of Cp.

Trial registration number

NA

Comparing the Profiles of Raw and Cooked Donkey Meat by Metabonomics and Lipidomics Assessment

Heat cooking of meat gives it a specific taste and flavor which are favored by many consumers. While the characteristic taste components of chicken, duck, pig, and seafood have been studied, there is a lack of information about the molecular components that give donkey meat its unique taste. Here, the characterization profiles of raw donkey meat (RDM) and cooked donkey meat (CDM) meat by metabonomics and lipidomics. The results showed that a total of 186 metabolites belonging to 8 subclasses were identified in CDM and RDM, including carbohydrates (27.42%), amino acids (17.20%), lipids (13.44%), and nucleotides (9.14%). In total, 37 differential metabolites were identified between CDM and RDM. Among these, maltotriose, L-glutamate, and L-proline might predominantly contribute to the unique umami and sweet taste of donkey meat. Comprehensive biomarker screening detected 9 potential metabolite markers for the discrimination among RDM and CDM, including L-glutamate, gamma-aminobutyric acid, and butane-1, 2, 3, 4-tetrol. Moreover, a total of 992 and 1,022 lipids belonging to 12 subclasses were identified in RDM and CDM, respectively, mainly including triglycerides (TGs) and glycerophospholipids (GPs). Of these lipids, 116 were significantly different between CDM and RDM. The abundances of 61 TGs rich in saturated and monounsaturated fatty acids were retained in CDM, whereas the abundances of 37 GPs rich in polyunsaturated fatty acids were reduced, suggesting that TGs and GPs might be the predominant lipids for binding and generating aroma compounds, respectively. A total of 13 lipids were determined as potential markers for the discrimination among RDM and CDM, including PC(O-16:2/2:0), LPE(22:5/0:0), and PC(P-16:0/2:0). In conclusion, this study provided useful information about the metabolic and lipid profiles of donkey meat which may explain its unique taste and flavor, which could serve as a basis for the development and quality control of donkey meat and its products.

Vegetable Oil-Based Waterborne Polyurethane as Eco-Binders for Sulfur Cathodes in Lithium-Sulfur Batteries

Lithium-sulfur batteries (LSBs) suffer from well-known fast capacity losses despite their extremely high theoretical capacity and energy density. These losses are caused by dissolution of lithium polysulfide (LiPS) in ether-based electrolytes and have become the main bottleneck to widespread applications of LSBs. Therefore, there is a significant need for electrode materials that have a strong adsorption capacity for LiPS. Herein, a waterborne polyurethane (WPUN) containing sulfamic acid (NH₂ SO₃ H) polymer is designed and synthesized as an aqueous-based, ecofriendly binder by neutralizing sulfamic acid with a tung oil-based polyurethane prepolymer. UV-vis spectroscopy shows that the WPUN strongly immobilizes LiPS and thus is an effective inhibitor of the LiPS. Moreover, the WPUN binder has excellent adhesive and mechanical properties that improve the integrity of sulfur cathodes. The WPUN-based cathodes exhibit a significant improvement in their specific capacity and maintain a capacity of 617 mAh g^-1 after 200 cycles at 0.5C. Besides, the LSBs assembled with the WPUN-based cathodes show good rate performance from 0.2C (737 mAh g^-1 ) to 4C (586 mAh g^-1 ), which is significantly higher than that of LSBs assembled with a commercial polymer binder. The structural design of the presented binder provides a new perspective for obtaining high-performance LSBs.

The effect of methylprednisolone pulse therapy in polymyositis/dermatomyositis

The study aim was to assess the effect of corticosteroid (CS) therapy on the clinical and biological features of dermatomyositis (DM) or polymyositis (PM).