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In vitro maturation (IVM) and cryopreservation of goat oocytes are important for establishing a valuable genetic bank for domesticated female animals and improving livestock reproductive efficiency. C-Phycocyanin (PC) is a Spirulina extract with antioxidant, antiinflammatory, and radical scavenging properties. However, whether PC has positive effect on goat oocytes IVM or developmental competence after vitrification is still unknown. In this study, we found that first polar body extrusion (n = 293), cumulus expansion index (n = 269), and parthenogenetic blastocyst formation (n = 281) were facilitated by adding 30 μg/mL PC to the oocyte maturation medium when compared with the control groups and that supplemented with 3, 10, 100 or 300 μg/mL PC (P < 0.05). Although PC supplementation did not affect spindle formation or chromosome alignment (n = 115), it facilitated or improved cortical granules migration (n = 46, P < 0.05), mitochondria distribution (n = 39, P < 0.05), and mitochondrial membrane potential (n = 46, P < 10−4). Meanwhile, supplementation with 30 μg/mL PC in the maturation medium could significantly inhibit the reactive oxygen species accumulation (n = 65, P < 10−4), and cell apoptosis (n = 42, P < 0.05). In addition, PC increased the oocyte mRNA levels of GPX4 (P < 0.01), and decreased the mRNA and protein levels of BAX (P < 0.01). Next, we investigated the effect of PC supplementation in the vitrification solution on oocyte cryopreservation. When compared with the those equilibrate in the vitrification solution without PC, recovered oocytes in the 30 μg/mL PC group showed higher ratios of normal morphology (n = 85, P < 0.05), survival (n = 85, P < 0.05), first polar body extrusion (n = 62, P < 0.05), and parthenogenetic blastocyst formation (n = 107, P < 0.05). Meanwhile, PC supplementation of the vitrification solution increased oocyte mitochondrial membrane potential (n = 53, P < 0.05), decreased the reactive oxygen species accumulation (n = 73, P < 0.05), promoted mitochondria distribution (n = 58, P < 0.05), and inhibited apoptosis (n = 46, P < 10−3). Collectively, our findings suggest that PC improves goat oocyte IVM and vitrification by reducing oxidative stress and early apoptosis, which providing a novel strategy for livestock gamete preservation and utilization. • PC promoted oocytes in vitro maturation and embryo development. • PC improved mitochondrial function after oocytes IVM and vitrification. • PC reduced oxidative stress and apoptosis levels after oocytes IVM and vitrification. [ABSTRACT FROM AUTHOR]

[Display omitted] • The prepared SERS substrate Raman detection has an enhancement factor of up to 2.32ⅹ105. • The LSPR of the SERS substrate can be applied to trace detection of fluorescent substances. • The detection limit of PFOA using silver dendrimer SERS substrate was as low as 15.89 ppb. • Providing a simple and low-cost detection method for detecting trace substances of PFOA. Perfluorooctanoic acid (PFOA), a novel organic pollutant, has been shown to be toxic, persistent, bioaccumulative, long-range transportable, and globally prevalent. This article is based on surface enhanced Raman scattering (SERS) spectroscopy analysis technology. The monolayer of SiO 2 was prepared by chemical reduction etching self-assembly method and silver dendrites were grown on it, thus forming the SERS substrate with silver dendrite Metasurface structure with Raman detection enhancement factor up to 2.32 × 105. The prepared silver dendrite Metasurface SERS substrate was applied to the qualitative and quantitative detection of PFOA, with a quantitative detection limit of 15.89 ppb. The results of this paper provide a new, simple, and quick method for the detection of PFOA in the environment. [ABSTRACT FROM AUTHOR]

In oocytes, the cytoplasmic polyadenylation and maternal mRNAs translation is regulated by cis -elements, including polyadenylation signal (PAS) and cytoplasmic polyadenylation element (CPE) in 3ʹ-UTR. Recent studies illustrate non-canonical polyadenylation mechanisms of translational regulation in mouse oocytes, which is different from that in Xenopus oocytes. However, it is still unclear if this regulation in rodent oocytes functions in the domestic animal oocyte. Here, by using sheep as an animal model, we cloned the 3ʹ-UTRs of Cpeb1 or Btg4 and ligated it into the pRK5-Flag- Gfp vector. Variant numbers and positions of PASs and CPEs within the 3ʹ-UTRs were constructed to detect their effects on translational control. After in vitro -transcription and microinjection into sheep fully grown germinal vesicle stage oocytes, the expression efficiency of mRNAs was detected by the GFP and flag expression. Our results show that: (i) PAS located at the proximal end of 3ʹ-UTR can mediate the translation of the maternal mRNAs, as long as they locate far from CPEs; (ii) The proximal PAS has higher efficiency in regulating transcription than the distal one; (iii) increase of PAS number can promote the translational activity more efficiently; (iv) a single CPE located close to PAS (<50 bp) in 3ʹ-UTRs of Cpeb1 or Btg4 could partially repress translation. In 3ʹ-UTRs of Btg4 , two CPEs have a higher inhibitory effect, and three CPEs can completely inhibit mRNA translation. These results confirm the existence of the non-canonical mechanism in domestic animal oocytes. • PASs in the proximal area of 3′-UTR can activate maternal mRNAs translation. • The amount and position of PASs affect the translational activation efficiency. • The location and number of CPEs affect the translational repression efficiency. [ABSTRACT FROM AUTHOR]

Background & Aims: Nucleotides with add‐on interferon treatment (NUC‐IFN) provide significantly higher rates of hepatitis B surface antigen (HBsAg) loss in patients with chronic hepatitis B (CHB). This study aimed to investigate the sustainability of HBsAg loss and the prevention of clinical relapse. Methods: Patients with CHB who achieved HBsAg loss and HBV DNA levels <20 IU/ml after IFN or NUC‐IFN therapy were enrolled and followed up for 96 weeks. The primary outcome was HBsAg negativity without viremia at week 96. Secondary outcomes included virological or clinical relapse and predictors of relapse. Results: 420 patients were included in intention‐to‐treat analysis with 290 and 130 in the IFN and NUC‐IFN groups respectively. At week 96, the intention‐to‐treat analysis revealed similar outcomes between groups, including HBsAg seroreversion (24.83% vs. 23.08%, P =.70), viremia (16.90% vs 13.08%, P =.32) and clinical relapse (11.38% vs 10.00%, P =.68); the per‐protocol analyses also showed HBsAg seroreversion, viremia and clinical relapse in IFN group (15.50%, 6.59% and 0.39%) did not differ from those in NUC‐IFN group (15.25%, 4.24% and 0.85%, P >.05). These outcomes were similar between patients who received entecavir and those who received telbivudine/lamivudine/adefovir before the combination therapy. In NUC‐IFN‐treated patients, fibrosis regression was observed at week 96. Baseline HBsAb negativity was independent predictors of HBsAg sero‐reversion and recurrence of viremia in IFN treated group. Conclusion: NUC‐IFN and IFN therapies are equally effective in achieving sustained functional cure and fibrosis regression. (ClinicalTrials.gov, Number NCT02336399). [ABSTRACT FROM AUTHOR]

Topological defects in graphene induce structural and electronic modulations. Knowing exact nature of broken-symmetry states around the individual atomic defects of graphene is very important for understanding the electronic properties of this material. We investigate structural dependence on localized electronic states in the vicinity of topological defects on a highly oriented pyrolytic graphite (HOPG) surface, using scanning tunneling microscopy and spectroscopy. Several inherent topological defects on the HOPG surface and the local density of states surrounding them are explored, visualized as scattering wave-related () R30° superstructures and honeycomb superstructures. In addition, the superstructures observed near the grain boundary have a much higher decay length at specific sites than that reported previously, indicating far greater electron scattering on the quasi-periodic grain boundary. [ABSTRACT FROM AUTHOR]

In contrast to the homeokinesis of mitosis, asymmetric division of cytoplasm is the conspicuous feature of meiosis in mammalian oocytes. Protein regulator of cytokinesis 1 (PRC1) is an important regulator during mitotic spindle assembly and cytoplasmic division, but its functions in oocyte meiosis and early embryo development have not been fully elucidated. In this study, we detected PRC1 expression and localization and revealed a nuclear, spindle midzone‐related dynamic pattern throughout meiotic and mitotic progressions. Treatment of oocytes with the reagents taxol or nocodazole disturbed the distribution of PRC1 in metaphase II oocytes. Further, PRC1 depletion led to failure of first polar body (PB1) extrusion and spindle migration, aneuploidy and defective kinetochore–microtubule attachment and spindle assembly. Overexpression of PRC1 resulted in PB1 extrusion failure, aneuploidy and serious defects of spindle assembly. To investigate PRC1 function in early embryos, we injected Prc1 morpholino into zygotes and 2‐cell stage embryos. Depletion of PRC1 in zygotes impaired 4‐cell, morula and blastocyst formation. Loss of PRC1 in single or double blastomeres in 2‐cell stage embryos significantly impaired cell division, indicating its indispensable role in early embryo development. Co‐immunoprecipitation showed that PRC1 interacts with polo‐like kinase 1 (PLK1), and functional knockdown and rescue experiments demonstrated that PRC1 recruits PLK1 to the spindle midzone to regulate cytoplasmic division during meiosis. Finally, kinesin family member 4 knockdown downregulates PRC1 expression and leads to PRC1 localization failure. Taken together, our data suggest PRC1 plays an important role during oocyte maturation and early embryonic development by regulating chromosome dynamics and cytoplasmic division. [ABSTRACT FROM AUTHOR]

The aim of this review is to explore the effects of the seminar teaching method versus lecture-based learning (LBL) in the education of medical students by meta-analysis. Data and information available on PubMed, Cochrane Library, EMBASE, MEDLINE, China National Knowledge Infrastructure, WanFang Data, China Science Periodical Database, and Chinese BioMedical were searched and examined from the inception up to January 2020. Randomized controlled trials (RCTs) that investigated the effects of the seminar teaching method versus LBL in medical education were included. A total of 16 RCTs were included, with a total sample size of 1122 medical students. The seminar teaching method significantly improved knowledge scores (SMD = 1.38, 95%CI 0.92–1.84; p < 0.001) and skill scores (SMD = 1.46, 95%CI 1.00–1.91; p < 0.001) and the seminar teaching method significantly improved teaching effects, including active learning ability, learning interest, scientific innovation, and independent thinking ability, expression and communication ability, clinical thinking ability, teamwork, teacher-student interaction, and classroom atmosphere. This meta-analysis showed that the seminar teaching method is an effective method for improving knowledge scores, skill scores, active learning ability, student collaboration, classroom atmosphere, and interaction between teachers and students. [ABSTRACT FROM AUTHOR]

Hatching out from the zona pellucida (ZP) is a crucial step for blastocyst implantation and development. However, it is still unknown whether the location of the hatching site relative to the inner cell mass (ICM) affects embryo implantation and foetal development. Here, we classified hatching blastocysts into three categories, 0° ≤ θ ≤ 30°, 30° < θ ≤ 60°, and 60° < θ ≤ 90°, in which θ is determined based on the relative position of the hatching site to the arc midpoint of the ICM. Non-surgical embryo transfer (NSET) devices were employed to evaluate blastocyst implantation and embryo development. Of 1,827 hatching blastocysts, 43.84%, 30.60%, and 21.67% were categorized as 30° < θ ≤ 60°, 0° ≤ θ ≤ 30°, and 60° < θ ≤ 90°, respectively. Embryos with different hatching sites showed no distinct differences in blastocyst implantation; surrogate female pregnancy; embryo development to term; litter size, or offspring survival, gender, or body weight. Our results indicate that mouse blastocyst hatching site is not randomly distributed. Embryo implantation and development are not correlated with the blastocyst hatching site in mice. Thus, assessment of the blastocyst hatching site should not be recommended to evaluate mouse blastocyst implantation and developmental potential. [ABSTRACT FROM AUTHOR]