Induction Rate Research Articles

Antileishmanial effects, cellular mechanisms, and cytotoxicity of Elettaria cardamomum essential oil against Leishmania major infection.

Leishmaniasis is an infectious disease with various clinical manifestations. We studied the therapeutic effects of Elettaria cardamomum essential oil (ECEO) against Leishmania major infection. In vitro effects of ECEO against L. major were examined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and macrophage assays. Nitric oxide (NO) production, infection inhibition in macrophages, and the apoptotic activity of ECEO in treated parasites were also measured. By calculating the 50% cytotoxic concentrations (CC50), we studied the cytotoxicity effects of ECEO on human macrophage cells (THP-1). The efficacy of ECEO for improving cutaneous leishmaniasis (CL) lesions in mice (BALB/c) was determined by evaluating the size of lesions and the number of amastigotes before and after four weeks of treatment. The effects of ECEO on liver and kidney function in the tested mice were also evaluated. ECEO dose-dependently (p<0.001) inhibited the viability and the mean number of promastigotes and amastigote forms of L. tropica. Four weeks of treatment with ECEO at the doses of 2.5 and 5 mg/kg/ day significantly (p<0.001) improved the CL lesions and reduced the number of parasites in the infected mice. ECEO significantly increased NO production, apoptosis induction, and infection rate in parasites. The CC50 value for ECEO and MA was 303.4 µg/mL and 835.2 µg/mL, respectively. In the mice receiving ECEO at the doses of 2.5 and 5 mg/kg/day for 28 days, no significant change was reported between the serum level of liver enzymes and kidney factors when compared with the control group. ECEO displayed promising efficacy in parasite reduction in vitro and in the animal model. ECEO can thus be used as an alternative medicine to treat CL.

In Vitro Propagation and Genetic Uniformity Assessment of Manglietiastrum sinicum: A Critically Endangered Magnoliaceae Species.

Manglietiastrum sinicum Y.W. Law is a critically endangered species with great ornamental and commercial value, which urgently requires protection. We tested different combinations of basal media and plant growth regulators to determine (i) the optimal conditions for bud induction and proliferation of explants and (ii) optimal rooting conditions. RAPD- and ISSR-PCR were used to assess the genetic fidelity of regenerated plantlets. Murashige and Skoog medium (MS) supplemented with 0.5 mg/L 6-benzyladenine (BA) and 0.05 mg/L indole-3-butyric acid (IBA) is the optimal medium for bud induction (100% induction). MSM medium (a special basal medium for M. sinicum) was more suitable for the efficient proliferation and rooting of M. sinicum. Maximum bud proliferation rate (446.20%) was obtained on MSM, with 0.4 mg/L BA, 0.5 mg/L kinetin, and 0.06 mg/L IBA, while maximum root induction rate (88.89%) was obtained on MSM supplemented with 0.4 mg/L 1-naphthylacetic acid and 1.0 mg/L IBA with a 7-day initial darkness treatment. The rooted plantlets were transferred to a substrate containing peat soil, perlite, coconut chaff, and bark (volume ratio 2:1:1:1), with a resulting survival rate of 92.2%. RAPD and ISSR markers confirmed the genetic uniformity and stability of regenerated plants.

Establishment of a Highly Efficient In Vitro Regeneration System for Rhododendron aureum

Rhododendron aureum is identified as a vulnerable species in China. The establishment of an in vitro regeneration system assists significantly in species protection. Here, an in vitro regeneration system was developed using both direct and indirect organogenesis pathways. The role of thidiazuron (TDZ) in different developmental stages was also investigated. The leaves of wild-harvested R. aureum plants were used for callus induction after hydroponic cultivation. The optimal formula was found to be woody plant basal medium (WPM) supplemented with 0.5 mg·L−1 TDZ and 0.5 mg·L−1 3-indolebutyric acid (IBA), while the optimal formula for the subculture and induction of adventitious buds was WPM containing 0.1 mg·L−1 TDZ and 0.5 mg·L−1 IBA. The leaves from tissue-cultured seedlings were then used for the induction of bud clusters. An association was observed between the differentiation of bud clusters and the ratio of auxin and cytokinin. The optimal formula for the induction of bud clusters was WPM containing 0.5 mg·L−1 TDZ and 0.1 mg·L−1 IBA, yielding a 50% induction rate and the maximum number of buds. Higher concentrations of TDZ were found to be beneficial for bud proliferation, while a lower concentration was conducive to stem elongation. The optimal formula for subculture was WPM containing 0.1 mg·L−1 TDZ and 0.5 mg·L−1 IBA, while that for stem elongation was WPM supplemented with 0.002 mg·L−1 TDZ and 0.5 mg·L−1 IBA. Only IBA was found to be necessary for rooting, with increased IBA concentrations leading to an increased number of roots and earlier root formation, with larger callus areas; thus, an IBA concentration of 1.0 mg·L−1 was found to be optimal for the rooting of R. aureum. After hardening the seedlings for two days, a substrate composed of vermiculite and peat soil in a 10:1 ratio was identified as a transplantation formula. This system provides directions both for the protection of endangered species and the promotion of industrial development.

Population genomic analysis reveals key genetic variations and the driving force for embryonic callus induction capability in maize

Genetic transformation has been an effective technology for improving the agronomic traits of maize. However, it is highly reliant on the use of embryonic callus (EC) and shows a serious genotype dependence. In this study, we performed genomic sequencing for 80 core maize germplasms and constructed a high-density genomic variation map using our newly developed pipeline (MQ2Gpipe). Based on the induction rate of EC (REC), these inbred lines were categorized into three subpopulations. The low-REC germplasms displayed more abundant genetic diversity than the high-REC germplasms. By integrating a genome-wide selective signature screen and region-based association analysis, we revealed 95.23 Mb of selective regions and 43 REC-associated variants. These variants had phenotypic variance explained values ranging between 21.46 and 49.46%. In total, 103 candidate genes were identified within the linkage disequilibrium regions of these REC-associated loci. These genes mainly participate in regulation of the cell cycle, regulation of cytokinesis, and other functions, among which MYB15 and EMB2745 were located within the previously reported QTL for EC induction. Numerous leaf area-associated variants with large effects were closely linked to several REC-related loci, implying a potential synergistic selection of REC and leaf size during modern maize breeding.

Transcriptome Analysis of Embryogenic and Non-Embryogenic Callus of Picea Mongolica.

Picea mongolica is a rare tree species in China, which is of great significance in combating desertification and improving the harsh ecological environment. Due to the low rate of natural regeneration, high mortality, and susceptibility to pests and cold springs, Picea mongolica has gradually become extinct. At present, somatic embryogenesis (SE) is the most effective method of micro-proliferation in conifers, but the induction rate of embryogenic callus (EC) is low, and EC is difficult to differentiate from non-embryonic callus (NEC). Therefore, the EC and NEC of Picea mongolica were compared from the morphology, histological, physiological, and transcriptional levels, respectively. Morphological observation showed that the EC was white and transparent filamentous, while the NEC was compact and brownish-brown lumpy. Histological analyses showed that the NEC cells were large and loosely arranged; the nuclei attached to the edge of the cells were small; the cytoplasm was low; and the cell gap was large and irregular. In the EC, small cells, closely arranged cells, and a large nucleus and nucleolus were observed. Physiological studies showed significant differences in ROS-scavenging enzymes between the EC and NEC. Transcriptome profiling revealed that 13,267 differentially expressed genes (DEGs) were identified, 3682 were up-regulated, and 9585 were down-regulated. In total, 63 GO terms had significant enrichment, 32 DEGs in plant hormone signal transduction pathway were identified, and 502 different transcription factors (TFs) were characterized into 38 TF families. Meanwhile, we identified significant gene expression trends associated with somatic embryo development in plant hormones (AUX/IAA, YUCCA, LEA, etc.), stress (GST, HSP, GLP, etc.), phenylpropanoid metabolism (4CL, HCT, PAL, etc.), and transcription factors (AP2/ERF, MYB, WOX, etc.). In addition, nine genes were chosen for RT-qPCR, and the results were consistent with RNA-Seq data. This study revealed the changes in morphology, histology, physiology, and gene expression in the differentiation of NEC into EC and laid the foundation for finding the key genes to promote EC formation.

An Assessment of Physical and N6-Cyclohexyladenosine-Induced Hypothermia in Rodent Distal Focal Ischemic Stroke.

Therapeutic hypothermia (TH) mitigates damage in ischemic stroke models. However, safer and easier TH methods (e.g., pharmacological) are needed to circumvent physical cooling complications. This study evaluated systemic and pharmacologically induced TH using the adenosine A1 receptor agonist, N6-cyclohexyladenosine (CHA), with control groups in male Sprague-Dawley rats. CHA was administered intraperitoneally 10 minutes following a 2-hour intraluminal middle cerebral artery occlusion. We used a 1.5 mg/kg induction dose, followed by three 1.0 mg/kg doses every 6 hours for a total of 4 doses, causing 20-24 hours of hypothermia. Animals assigned to physical hypothermia and CHA-hypothermia had similar induction rates and nadir temperatures, but forced cooling lasted ∼6 hours longer compared with CHA-treated animals. The divergence is likely attributable to individual differences in CHA metabolism, which led to varied durations at nadir, whereas physical hypothermia was better regulated. Physical hypothermia significantly reduced infarction (primary endpoint) on day 7 (mean reduction of 36.8 mm3 or 39% reduction; p = 0.021 vs. normothermic animals; Cohen's d = 0.75), whereas CHA-induced hypothermia did not (p = 0.33). Similarly, physical cooling improved neurological function (physical hypothermia median = 0, physical normothermia median = 2; p = 0.008) and CHA-induced cooling did not (p > 0.99). Our findings demonstrate that forced cooling was neuroprotective compared with controls, but prolonged CHA-induced cooling was not neuroprotective.

Interplay of p53 and XIAP protein dynamics orchestrates cell fate in response to chemotherapy

Chemotherapeutic drugs are used to treat almost all types of cancer, but the intended response, i.e., elimination, is often incomplete, with a subset of cancer cells resisting treatment. Two critical factors play a role in chemoresistance: the p53 tumour suppressor gene and the X-linked inhibitor of apoptosis (XIAP). These proteins have been shown to act synergistically to elicit cellular responses upon DNA damage induced by chemotherapy, yet, the mechanism is poorly understood. This study introduces a mathematical model characterising the apoptosis pathway activation by p53 before and after mitochondrial outer membrane permeabilisation upon treatment with the chemotherapy Doxorubicin (Dox). “In-silico” simulations show that the p53 dynamics change dose-dependently. Under medium to high doses of Dox, p53 concentration ultimately stabilises to a high level regardless of XIAP concentrations. However, caspase-3 activation may be triggered or not depending on the XIAP induction rate, ultimately determining whether the cell will perish or resist. Consequently, the model predicts that failure to activate apoptosis in some cancer cells expressing wild-type p53 might be due to heterogeneity between cells in upregulating the XIAP protein, rather than due to the p53 protein concentration. Our model suggests that the interplay of the p53 dynamics and the XIAP induction rate is critical to determine the cancer cells’ therapeutic response.

Symbiotic Variations among Wheat Genotypes and Detection of Quantitative Trait Loci for Molecular Interaction with Auxin-Producing Azospirillum PGPR.

Crop varieties differ in their ability to interact with Plant Growth-Promoting Rhizobacteria (PGPR), but the genetic basis for these differences is unknown. This issue was addressed with the PGPR Azospirillum baldaniorum Sp245, using 187 wheat accessions. We screened the accessions based on the seedling colonization by the PGPR and the expression of the phenylpyruvate decarboxylase gene ppdC (for synthesis of the auxin indole-3-acetic acid), using gusA fusions. Then, the effects of the PGPR on the selected accessions stimulating Sp245 (or not) were compared in soil under stress. Finally, a genome-wide association approach was implemented to identify the quantitative trait loci (QTL) associated with PGPR interaction. Overall, the ancient genotypes were more effective than the modern genotypes for Azospirillum root colonization and ppdC expression. In non-sterile soil, A. baldaniorum Sp245 improved wheat performance for three of the four PGPR-stimulating genotypes and none of the four non-PGPR-stimulating genotypes. The genome-wide association did not identify any region for root colonization but revealed 22 regions spread on 11 wheat chromosomes for ppdC expression and/or ppdC induction rate. This is the first QTL study focusing on molecular interaction with PGPR bacteria. The molecular markers identified provide the possibility to improve the capacity of modern wheat genotypes to interact with Sp245, as well as, potentially, other Azospirillum strains.

Regional practice variation in induction of labor in the Netherlands: Does it matter? A multilevel analysis of the association between induction rates and perinatal and maternal outcomes.

Practice variation in healthcare is a complex issue. We focused on practice variation in induction of labor between maternity care networks in the Netherlands. These collaborations of hospitals and midwifery practices are jointly responsible for providing high-quality maternity care. We explored the association between induction rates and maternal and perinatal outcomes. In a retrospective population-based cohort study, we included records of 184,422 women who had a singleton, vertex birth of their first child after a gestation of at least 37 weeks in the years 2016-2018. We calculated induction rates for each maternity care network. We divided networks in induction rate categories: lowest (Q1), moderate (Q2-3) and highest quartile (Q4). We explored the association of these categories with unplanned caesarean sections, unfavorable maternal outcomes and adverse perinatal outcomes using descriptive statistics and multilevel logistic regression analysis corrected for population characteristics. The induction rate ranged from 14.3% to 41.1% (mean 24.4%, SD 5.3). Women in Q1 had fewer unplanned caesarean sections (Q1: 10.2%, Q2-3: 12.1%; Q4: 12.8%), less unfavorable maternal outcomes (Q1: 33.8%; Q2-3: 35.7%; Q4: 36.3%) and less adverse perinatal outcomes (Q1: 1.0%; Q2-3: 1.1%; Q4: 1.3%). The multilevel analysis showed a lower unplanned caesarean section rate in Q1 in comparison with reference category Q2-3 (OR 0.83; p = .009). The unplanned caesarean section rate in Q4 was similar to the reference category. No significant associations with unfavorable maternal or adverse perinatal outcomes were observed. Practice variation in labor induction is high in Dutch maternity care networks, with limited association with maternal outcomes and no association with perinatal outcomes. Networks with low induction rates had lower unplanned caesarean section rates compared to networks with moderate rates. Further in-depth research is necessary to understand the mechanisms that contribute to practice variation and the observed association with unplanned caesarean sections.

Establishment of PEG-Mediated Transient Gene Expression in Protoplasts Isolated from the Callus of Cunninghamia lanceolata

Cunninghamia lanceolata (C. lanceolata) is an important timber tree species in southern China that requires gene function studies to understand its traits. In this study, we investigated the callus induction rates of immature zygotic embryos from reciprocal hybrids between genotypes B46 and B49. With zygotic embryo development, the callus induction rates showed an increasing trend, followed by a decreasing trend. Moreover, the rate of callus induction in genotype B46 × B49 immature zygotic embryos was greater than in genotype B49 × B46. Callus from C. lanceolata with genotype B46 × B49 was selected as the donor material for protoplast isolation. By using an enzymatic digestion solution containing cellulase, macerozyme, and pectinase, combined with an osmotic stabilizer, we obtained 9.76 × 106 protoplasts/mL with 92.7% viability. We subsequently transformed plasmids into C. lanceolata callus protoplasts and observed the location of the H2B-eYFP fusion protein in the nucleus. To achieve transient transfection of C. lanceolata callus protoplasts, we compared transfection efficiencies at different concentrations of PEG4000, PEG6000, or PEG8000 in a modified MMg solution. We found that 20% (w/v) PEG6000 mediated the transient transfection of C. lanceolata callus protoplasts with a 6.70% efficiency. This study provides a technical foundation for future research on transient transfection and functional analysis of C. lanceolata genes.

Obesity in Pregnant Women and Its Impact on Maternal and Neonatal Morbidity

Obesity in pregnancy is currently a health problem that is associated with increased maternal and neonatal morbidity. Along with the times and lifestyles that are more modern, the incidence of obesity is also increasing. Clinically, obesity is defined as the condition of having excess adipose tissue. Obesity is related to insulin resistance and chronic inflammation. This makes obesity a risk factor for various non-contagious diseases such as cardiovascular disease, hypertension, diabetes mellitus, and cancer. The health consequences of maternal obesity are based on low-grade, chronic (meta-inflammatory) inflammation that occurs as a result of changes in the immune system and proinflammatory cytokines in maternal obesity and pregnancy. Obesity can have a negative impact on maternal, neonatal and labor outcomes. Several maternal complications that can occur due to obesity (BMI 30-34.9) and morbid obesity (BMI ≥ 35) are hypertension during pregnancy (10.2-12.3%), preeclampsia (3-6.3%), gestational diabetes (6.3-9.5%). Risks that can occur to the fetus, such as the occurrence of macrosomia (15.4-17.2%), preterm birth (4-5.5%) and impaired fetal growth (1-0.8%). Maternal obesity is also associated with an increased risk of neural tube defects (NTD) in babies, as well as a higher risk of abortion (1.70-3.11%). Obesity also has an impact on the delivery process. Mothers with obesity have a higher rate of vaginal operative procedures (8.5-11.1%), labor induction and longer duration of labor. The increase in caesarean section deliveries is caused by the occurrence of complications due to maternal obesity, namely the occurrence of preeclampsia, fetal distress, macrosomia, and induction failure.

Pulsed antibiotic treatments of gnotobiotic mice manifest in complex bacterial community dynamics and resistance effects

Bacteria can evolve to withstand a wide range of antibiotics (ABs) by using various resistance mechanisms. How ABs affect the ecology of the gut microbiome is still poorly understood. We investigated strain-specific responses and evolution during repeated AB perturbations by three clinically relevant ABs, using gnotobiotic mice colonized with a synthetic bacterial community (oligo-mouse-microbiota). Over 80days, we observed resilience effects at the strain and community levels, and we found that they were correlated with modulations of the estimated growth rate and levels of prophage induction as determined from metagenomics data. Moreover, we tracked mutational changes in the bacterial populations, and this uncovered clonal expansion and contraction of haplotypes and selection of putative AB resistance-conferring SNPs. We functionally verified these mutations via reisolation of clones with increased minimum inhibitory concentration (MIC) of ciprofloxacin and tetracycline from evolved communities. This demonstrates that host-associated microbial communities employ various mechanisms to respond to selective pressures that maintain community stability.

Development of Specific Molecular and Phenotypic Marker-Based Haploid Inducers in Rice

Doubled haploid (DH) technology is an efficient strategy for producing completely homozygous lines for breeding programs. Mutations in the MATRILINEAL (MTL) phospholipase trigger intraspecific haploid induction in cereals. Although an in vivo haploid induction system based on OsMTL-edited plants has been established in rice (Oryza sativa), DH technology is still limited by other factors, such as haploid identification, which is one of the essential steps required for DH technology. In the study, we addressed this technical challenge by integrating specific molecular and phenotypic markers into rice haploid inducers. We first generated large fragment insertion or deletion mutations within the OsMTL gene and designed a pair of primers flanking the mutational sites to be used as the specific and universal molecular markers between wild-type and Osmtl plants. Next, we screened for hairy leaf as a single dominant trait and integrated it into specific molecular marker-based haploid inducers using the cross and self-cross method. When crossing cytoplasmic male sterile lines with these haploid inducers, we utilized the specific InDel marker and hairy leaf phenotypic marker to identify putative haploids (or double haploids). These putative haploids were further confirmed through ploidy and phenotypic analysis, demonstrating the high efficiency of haploid identification using these markers. The haploid induction rate (HIR) of the developed specific molecular and phenotypic marker-based haploid inducers ranged from 3.7% to 12.5%. We have achieved successful integration of distinct molecular and phenotypic markers into rice haploid inducers. Our advanced marker-based system has significantly enhanced the accuracy of haploid identification, thereby expediting the adoption of DH technology in rice breeding.

Feasibility of laparoscopic radical antegrade modular pancreatosplenectomy (RAMPS) as a standard treatment for distal resectable pancreatic cancer.

Laparoscopic (Lap-) radical antegrade modular pancreatosplenectomy (RAMPS) is an attractive radical procedure that aims to achieve negative posterior retroperitoneal margin in pancreatic ductal adenocarcinoma (PDAC) resections. However, only few institutions are adapting Lap-RAMPS due to the technical difficulties and the lack of supporting evidence for the clinical applications. A retrospective cohort study was performed on consecutive patients who underwent RAMPS for distal resectable PDACs. We analyzed the short- and long-term outcomes including local control and the induction of adjuvant chemotherapy compared between Lap- and Open-RAMPS. Of the 118 RAMPS patients, 43 patients underwent Lap-RAMPS and 75 patients underwent Open-RAMPS. The blood loss was lower (125 vs. 390 mL, p < 0.001), and postoperative hospital stay was shorter (17 vs. 21 days, p = 0.018) in the Lap-RAMPS group. There was no difference in the postoperative complications and no mortality in both groups. R0 resection rate was 100.0% in the Lap-RAMPS and 90.7% in the Open-RAMPS (p = 0.039). Among the patients eligible for adjuvant chemotherapy, the Lap-RAMPS group showed a favorable induction rate (100.0 vs. 89.6%, p = 0.037). Both groups showed a favorable 3-year local recurrence rate (8.7 vs. 10.0%, p = 0.976) and 3-year overall survival (69.8 vs. 71.1%, p = 0.996). The safety and efficacy of Lap-RAMPS were comparable to those of Open-RAMPS in terms of achieving local control and adjuvant chemotherapy induction. A higher early induction of adjuvant chemotherapy is an advantage of minimally invasive surgery.

Assessment of the TRX2p-yEGFP Biosensor to Monitor the Redox Response of an Industrial Xylose-Fermenting Saccharomyces cerevisiae Strain during Propagation and Fermentation.

The commercial production of bioethanol from lignocellulosic biomass such as wheat straw requires utilizing a microorganism that can withstand all the stressors encountered in the process while fermenting all the sugars in the biomass. Therefore, it is essential to develop tools for monitoring and controlling the cellular fitness during both cell propagation and sugar fermentation to ethanol. In the present study, on-line flow cytometry was adopted to assess the response of the biosensor TRX2p-yEGFP for redox imbalance in an industrial xylose-fermenting strain of Saccharomyces cerevisiae during cell propagation and the following fermentation of wheat-straw hydrolysate. Rapid and transient induction of the sensor was recorded upon exposure to furfural and wheat straw hydrolysate containing up to 3.8 g/L furfural. During the fermentation step, the induction rate of the sensor was also found to correlate to the initial ethanol production rate, highlighting the relevance of redox monitoring and the potential of the presented tool to assess the ethanol production rate in hydrolysates. Three different propagation strategies were also compared, and it was confirmed that pre-exposure to hydrolysate during propagation remains the most efficient method for high ethanol productivity in the following wheat-straw hydrolysate fermentations.

Popcorn (Zea mays L. var. Everta) haploids identified by Navajo phenotype and ploidy level.

For popcorn, obtaining and identifying haploids are still challenging steps. We aimed to induce and screen haploids in popcorn using the Navajo phenotype, seedling vigor, and ploidy level. We used the Krasnodar Haploid Inducer (KHI) in crosses with 20 popcorn source germplasms and five maize controls. The field trial design was completely randomized, with three replications. We assessed the efficacy of induction and identification of haploids based on the haploidy induction rate (HIR) and false positive and negative rates (FPR and FNR). Additionally, we also measured the penetrance of the Navajo marker gene (R1-nj). All putative haploids classified by the R1-nj were germinated together with a diploid sample and evaluated for false positives and negatives based on vigor. Seedlings from 14 females were submitted to flow cytometry to determine the ploidy level. The HIR and penetrance were analyzed by fitting a generalized linear model with a logit link function. The HIR of the KHI, adjusted by cytometry, ranged from 0.0 to 1.2%, with a mean of 0.34%. The average FPR from screening based on the Navajo phenotype was 26.2% and 76.4% for vigor and ploidy, respectively. The FNR was zero. The penetrance of R1-nj ranged from 30.8 to 98.6%. The average number of seeds per ear in temperate germplasm (76) was lower than that obtained in tropical germplasm (98). There is an induction of haploids in germplasm of tropical and temperate origin. We recommend the selection of haploids associated with the Navajo phenotype with a direct method of confirming the ploidy level, such as flow cytometry. We also show that haploid screening based on Navajo phenotype and seedling vigor reduces misclassification. The origin and genetic background of the source germplasm influence the R1-nj penetrance. Because the known inducers are maize, developing doubled haploid technology for popcorn hybrid breeding requires overcoming unilateral cross-incompatibility.

Tissue culture and rapid propagation technology for Gentiana rhodantha.

Gentiana rhodantha is a perennial herb of the genus Gentiana (Tourn.) L. This study was novel in establishing a regeneration system of G. rhodantha using young leaves as explants on the Murashige and Skoog (MS) medium supplemented with different plant growth regulators (PGRs). The roots, stems, and leaves of G. rhodantha were used as explants. The effects of the optimal explant disinfection method, type of explant used, concentrations of PGRs added to the culture media on tissue culture, and rapid propagation of G. rhodantha were studied. The results showed that the optimal disinfection method for stems and roots consisted of disinfection using 75% ethanol for 50 s, followed by 4% sodium hypochlorite (NaClO) for 10 min. The optimal disinfection technique for leaves consisted of disinfection using 75% ethanol for 50 s, followed by 4% NaClO for 8 min. Root explant was the most suitable for inducing the callus of G. rhodantha on the MS medium supplemented with different PGRs. The optimal conditions for callus induction included 1.0 mg/L 6-benzylaminopurine (6-BA) and 0.5 mg/L α-naphthalene acetic acid (NAA). The callus induction rate using the root explant reached 94.28%. MS supplemented with 2.0 mg/L 6-BA and 0.1 mg/L NAA was the optimal medium for inducing adventitious shoots from the callus of G. rhodantha. The best medium for propagation and plantlets strengthening was MS supplemented with 0.8 mg/L 6-BA and 0.3 mg/L NAA, and the propagation index was 8.62. MS supplemented with 0.3 mg/L 3-indolebutyric acid was the best culture medium for inducing the rooting of adventitious buds, with the maximum rooting rate reaching up to 100%.

Прийняття рішень із монетарної політики щодо ключової ставки в європейських країнах та їхній вплив на інфляцію

Introduction. For many years central banks around the world kept low rates. In 2021-2022 European countries experienced rising inflation in response to which the European Central Bank, as well as the central banks of countries with their own currencies, raised rates to the highest level in decades. At the same time, the effect of changes in accounting (key) rates turned out to be much weaker than expected. Problem Statement. The research is based on the popular hypothesis that the central bank will raise the key (accounting) rate as a tool to curb inflation. Purpose. To determine the correlation between inflation and the accounting (key) rate of the monetary policy body and approaches to the formation of the composition of bodies that make decisions on the accounting rate. Methods. Economic and statistical methods are used to assess the correlation and volatility of inflation rates and key rates of central banks, comparison, descriptive method, analysis, generalization and induction. Results. A comparative analysis of inflation dynamics in 2022–2023 in European countries and the key rate of central banks was carried out. Countries that are direct participants in the military conflict - Ukraine, Russia, and Belarus - should be considered separately, which is why they are excluded from the analysis. Particular attention is paid to the rationale and procedure for decision-making by monetary policy bodies on revising the key rate. Conclusions. In the euro area, under the conditions of a single policy regarding the key rate, a significant range of inflation rates among countries is allowed in the observation period of 2022-2023 in a wide range. The effect of reducing inflation comes in about 6 months after the key rate increase, however, the impact of non-monetary factors (fluctuations in world prices for oil, gas and grain) may be considered decisive in such a reduction. Accordingly, the discount rate increase has a greater effect not in terms of curbing inflation, but in the context of slowing economic growth. In the countries of the euro zone, inflation has increased and is returning to a moderate level, but the range of fluctuations of its inflation rates is very high. This contradicts the postulates of European market integration. Also, changes in inflation rates are very similar to the dynamics of global energy and food prices. In general, non-monetary factors of inflation remained the main ones, and the effectiveness of the key rate as a tool for reducing inflation in theory seems overestimated. In addition, a comparison of inflation rates and the level of the key rate in a sample of countries produces different ratios: in most countries, inflation exceeds the key rate many times over. Decisions about its level attract attention of market participants, and they are mostly expected (increase, preservation, decrease), but sometimes unexpected situations occur regarding the scale and direction of changes. The decision-making procedure and information disclosure are characterized by a high level of transparency and attention to the consequences and impact on the national economy. In the leading countries of the world, the decision on the level of the discount rate is always made by a collegial body, the composition of which is formed according to different approaches, despite the status of the central bank as independent from political influence.

Photosynthetic induction of the leaves varies among pepper cultivars due to stomatal oscillation

Photosynthetic induction describes a slow response of photosynthetic rate to transient increases in light intensity, which limits crop carbon gain and yields in nature. However, studies related to photosynthetic induction rarely focused on horticultural crops. Here, we investigate the variation in steady-state photosynthetic capacity and photosynthetic induction rate in four popular pepper cultivars in China (sweet pepper TJ-105 and chili peppers CTJ, YJJ-109 and XJ-L2). The results showed that the steady-state photosynthetic rate at a series of light intensities and CO2 concentrations was similar among the four pepper cultivars, however, the photosynthetic induction of the leaves varied widely. TJ-105 showed profound oscillations in photosynthetic rate (A) during photosynthetic induction, while others did not. The oscillations in A were mainly due to oscillations in stomatal conductance (gs), which limited A and caused an 18–25% loss of carbon gain during photosynthetic induction in TJ-105 compared to other cultivars. These results indicate that stomatal oscillations can strongly affect the accuracy of the estimation in steady-state leaf photosynthetic properties. We conclude that dynamic leaf photosynthesis gives a more reliable understanding of crop photosynthesis under the prevailing growth conditions, which is important for selecting or breeding new crop cultivars with improved light use efficiency.

Sacubitril/valsartan reduces susceptibility to atrial fibrillation by improving atrial remodeling in spontaneously hypertensive rats

AimSacubitril/valsartan (Sac/Val, LCZ696), the world's first angiotensin receptor-neprilysin inhibitor (ARNi), has been widely used in the treatment of heart failure. However, the use of Sac/Val in the treatment of atrial fibrillation (AF), especially AF with hypertension, has been less reported. We investigated the effect of Sac/Val on atrial remodeling and hypertension-related AF. MethodsThe AF induction rate and electrophysiological characteristics of spontaneously hypertensive rats (SHRs) treated with Sac/Val or Val were detected by rapid atrial pacing and electrical mapping/optical mapping. The whole-cell patch-clamp and Western blot were used to observe electrical/structural remodeling of atrial myocytes/tissue of rats and atrium-derived HL-1 cells cultured under 40 mmHg in vitro. ResultsSac/Val was superior to Val in reducing blood pressure, myocardial hypertrophy and susceptibility of AF in SHRs. The shorten action potentials duration (APD), decreased L type calcium channel current (ICa,L) and Cav1.2, increased ultrarapid delayed rectified potassium current (Ikur) and Kv1.5 in atrial myocytes/tissue of SHRs could be better improved by Sac/Val, as well as the levels of atrial fibrosis. While the protein expression of angiotensin-converting enzyme-1 (ACE-1), angiotensin, angiotensin II type I AT1 receptor (AT1R) and neprilysin (NEP) were increased, which could be more effective ameliorated by Sac/Val than Val. Furthermore, Val + Sacubitrilat (LBQ657) (an active NEP inhibitor) was also superior to LBQ657 or Val in improving the electrical and structural remodeling of HL-1 cells through inhibiting NEP. ConclusionSac/Val can improve atrial structural and electrical remodeling induced by hypertension and reduce the AF susceptibility by inhibiting RAS and NEP. The above effects of Sac/Val were superior to Val alone.