Development and Application of Molecularly Imprinted Polymers for the Selective Extraction of Chlordecone from Bovine Serum

The widespread use of chlordecone (CLD), an organochlorine pesticide, until the 1990s to protect banana crops in the French West Indies led to significant pollution of water and soil and, subsequently, of bovine intended for human consumption. Carcasses are submitted to official controls based on perirenal fat CLD determination. In order to allow for pre-slaughter controls, a selective analytical method based on a molecularly imprinted polymer (MIP) associated to the LC/MS-MS method was developed to determine the level of CLD in bovine serum that can be collected before slaughter. Different synthesis conditions were therefore assayed by varying the nature of the monomer and of the porogen, and the most promising MIP in terms of selective retention for CLD (extraction recovery close to 100%) was completely characterized by solid-phase extraction (repeatability of the extraction procedure, of the synthesis, and of the cartridge filling) in pure medium. The capacity of the MIP was determined at 0.13 µmol g−1 of MIP. After application of a spiked bovine serum sample on the MIP, the selective retention was maintained (87 and 21%, respectively, on the MIP and on the corresponding non-imprinted polymer). Moreover, extraction on the MIP led to a cleaner extract compared to those issued from a conventional C18 sorbent.

Нейрофизиологические механизмы решения экспериментальных творческих задач: инсайт и/или критический анализ?

Рассмотрены разные точки зрения на процессы взаимодействия нейронных сетей мозга при селекции информации и принятия решения на основе инсайта или критического анализа идей, сгенерированных при тестировании креативности. Для изучения сочетания разных когнитивных операций в креативности предложены модели BVSR (Blind Variation and Selective Retention) и «GENEPLORE» (Generate and Explore). Анализ возникновения инсайта в экспериментальных исследованиях выполняется с использованием задач на эвристическое мышление, восприятие двойственных фигур, теста отдаленных ассоциаций слов (RAT) или составных отдаленных ассоциаций (CRA). Приведены сведения о наиболее устойчивом ЭЭГ-корреляте инсайта: синхронизации альфа-биопотенциалов и изменениях выраженности и регионарной специфики этого эффекта, обусловленных особенностями креативного задания. Результаты томографических исследований выявили ключевое значение специфичных паттернов «преднастройки» нейронных сетей дефолтной и исполнительной систем и динамики взаимодействия лобных и теменных областей мозга, отражающих разные показатели креативности. Показаны роль критического анализа решения проблемы, модулирующая творческий процесс, и значение тормозных функций в селекции релевантной информации. Включение в поиск решения проблемы противоположных процессов — конвергентного или дивергентного мышления, направленного или дефокусированного и интернального или экстернального внимания — сопровождается временной и структурной реорганизацией активации или торможения в нейронных системах мозга. Ведущими структурами мозга, необходимыми для переключения разных стратегий селекции информации и выбора ответа при решении экспериментальных творческих задач в зависимости от их сложности и содержания, являются префронтальная, цингулярная области коры и гиппокамп.

Selective Retention of Bone Marrow Stromal Cells with Gelatin Sponge for Repair of Intervertebral Disc Defects after Microendoscopic Discectomy: A Prospective Controlled Study and 2-Year Follow-Up

Objective. Discectomy remains the classic procedure for treating lumbar intervertebral disc (IVD) herniation, but the occurrence of defects after discectomy is thought to be an important cause generating recurrent and accelerated IVD degeneration. Previous studies attempted suture of the annulus fissure, but the validity of this technique on restraining the degenerative process is controversial. On the other hand, cell therapies have been shown in multiple clinical and basic studies. Our purpose was to investigate the effectiveness of selective retention of autologous Bone Marrow Stromal Cells (BMSCs) with gelatin sponge in combination with annulus fibrosus suture (AFS) for the repair of IVD defects following mobile microendoscopic discectomy (MMED). Methods. This prospective, two-armed, and controlled clinical study was conducted from December 2016 to December 2018. Written informed consent was obtained from each patient. Forty-five patients with typical symptoms, positive signs of radiculopathy, and obvious lumbar disc herniation observed by MRI were enrolled. Patients were divided into 3 groups with different treating methods: MMED ( n = 15 ), MMED+AFS ( n = 15 ), and MMED+AFS+BMSCs ( n = 15 ). A postoperative 2-year follow-up was performed to evaluate the patient-reported outcomes of VAS, ODI, and SF-36. The improvement rate of VAS and ODI was calculated as latest ‐ preoperative / preoperative to evaluate the therapeutic effect of the three groups. Assessment parameters included Pfirrmann grade, intervertebral disc height (IDH), and disc protrusion size (DPS), as measured by MRI to evaluate the morphological changes. Results. All patients enrolled had a postoperative follow-up at 3, 6, 12, and 24 months. VAS and ODI scores were significantly improved compared to the preoperative status in all three groups with a mean DPS reduction rate over 50%. At the final follow-up, the improvement rate of the VAS score in the MMED+AFS+BMSCs group was significantly higher than the MMED+AFS and MMED groups ( 80.1 % ± 7.6 % vs. 71.3 % ± 7.0 % vs. 70.1 % ± 7.8 % ), while ODI improvement showed a significant change ( 65.6 % ± 8.8 % vs. 59.9 % ± 5.5 % vs. 57.8 % ± 8.1 % ). All participants showed significant improvement in SF-36 PCS and MCS; the differences between each group were not significant. The mean IDH loss rate of the MMED+AFS+BMSCs group was also significantly lower than other groups ( − 17.2 % ± 1.3 % vs. − 27.6 % ± 0.7 % vs. − 29.3 % ± 2.2 % ). The Pfirrmann grade was aggravated in the MMED and MMED+AFS groups while maintained at the preoperative grade in the MMED+AFS+BMSCs group. No adverse events of cell transplantation or recurrence were found in all patients during the postoperative follow-up period. Conclusions. It is feasible and effective to repair lumbar IVD defects using SCR-enriched BMSCs with gelatin sponges, which warrants further study and development as a cell-based therapy for IVD repair.

Evolutionary responses to codon usage of horizontally transferred genes in Pseudomonas aeruginosa: gene retention, amelioration and compensatory evolution

Prokaryote genome evolution is characterized by the frequent gain of genes through horizontal gene transfer (HGT). For a gene, being horizontally transferred can represent a strong change in its genomic and physiological context. If the codon usage of a transferred gene deviates from that of the receiving organism, the fitness benefits it provides can be reduced due to a mismatch with the expression machinery. Consequently, transferred genes with a deviating codon usage can be selected against or elicit evolutionary responses that enhance their integration, such as gene amelioration and compensatory evolution. Within bacterial species, the extent and relative importance of these different mechanisms has never been considered altogether. In this study, a phylogeny-based method was used to investigate the occurrence of these different evolutionary responses in Pseudomonas aeruginosa . Selection on codon usage of genes acquired through HGT was observed over evolutionary time, with the overall codon usage converging towards that of the core genome. Gene amelioration, through the accumulation of synonymous mutations after HGT, did not seem to systematically affect transferred genes. This pattern therefore seemed to be mainly driven by selective retention of transferred genes with an initial codon usage similar to that of the core genes. Additionally, variation in the copy number of tRNA genes was often associated with the acquisition of genes for which the observed variation could enhance their expression. This provides evidence that compensatory evolution might be an important mechanism for the integration of horizontally transferred genes.

Cotton pan-genome retrieves the lost sequences and genes during domestication and selection

BackgroundMillennia of directional human selection has reshaped the genomic architecture of cultivated cotton relative to wild counterparts, but we have limited understanding of the selective retention and fractionation of genomic components.ResultsWe construct a comprehensive genomic variome based on 1961 cottons and identify 456 Mb and 357 Mb of sequence with domestication and improvement selection signals and 162 loci, 84 of which are novel, including 47 loci associated with 16 agronomic traits. Using pan-genome analyses, we identify 32,569 and 8851 non-reference genes lost fromGossypium hirsutumandGossypium barbadensereference genomes respectively, of which 38.2% (39,278) and 14.2% (11,359) of genes exhibit presence/absence variation (PAV). We document the landscape of PAV selection accompanied by asymmetric gene gain and loss and identify 124 PAVs linked to favorable fiber quality and yield loci.ConclusionsThis variation repertoire points to genomic divergence during cotton domestication and improvement, which informs the characterization of favorable gene alleles for improved breeding practice using a pan-genome-based approach.

Tuning the charge of polyelectrolyte complex membranes prepared via aqueous phase separation

Positively and negatively charged membranes are obtained by simply changing the mixing ratio of the polyelectrolytes in a fully aqueous preparation approach. This leads to selective retention of asymmetric salts and a new membrane tuning parameter.