Study on Different Shear Performance of Moso Bamboo in Four Test Methods.

Bamboo is recognized as a potential and sustainable green material. The longitudinal-splitting and shear strengths of bamboo are weak but critical to its utilizations. To discuss the different shear performances of bamboo, the shear strength and behaviors of bamboo culm were investigated by four test methods: the tensile-shear, step-shear, cross-shear, and short-beam-shear methods. Then, the different shear performance and mechanisms were discussed. Results indicated that the shear strength was significantly different in the four test methods and was highest in the step-shear-test method but lowest in the tensile-shear-test method. Moreover, the typical load-displacement curves were different across the shear methods but were similar to the curves of the respective loading modes. The axially aligned fiber bundles played an important role in all the shear performances. In the tensile-shear method, specimens fractured at the interface of the bamboo-fiber bundles. However, compress-shear behaviors were a combination of compression and shear. Then, the cross-shear method, in compress-shear, was lower than that of the step-shear method because of oval-shaped bamboo culm sections of different thickness. In the short-beam shear method, the behaviors and shearing characteristics were like bending with the fiber bundle pulled out.

Estrogen valerate pretreatment with the antagonist protocol does not increase oocyte retrieval in patients with low ovarian response: a randomized controlled trial.

STUDY QUESTION: Does luteal phase estrogen valerate pretreatment improve oocyte yield and clinical outcomes in patients with low ovarian response during ovarian stimulation with the antagonist protocol? SUMMARY ANSWER: Pretreatment with oral estrogen valerate from Day 7 after ovulation to Day 2 of the next menstrual cycle did not increase oocyte yield in patients with a low ovarian response compared to no pretreatment. WHAT IS KNOWN ALREADY: Previous studies showed that patients with a normal ovarian response can obtain better clinical outcomes after pretreatment with estrogen in the antagonist protocol. For patients with advanced age and low ovarian response, it remains unclear if estrogen valerate pretreatment with the antagonist protocol yields more oocytes and improves pregnancy outcomes. STUDY DESIGN, SIZE, DURATION: This non-blinded randomized controlled trial (RCT) was conducted between November 2017 and March 2021. Participants were 552 women with low response who requested IVF treatment. The primary endpoint was comparison of the total number of retrieved oocytes between the two groups. The secondary endpoints were the total number of retrieved metaphase II (MII) oocytes, duration and total dosage of recombinant FSH (rFSH), good-quality embryo rate and clinical pregnancy rate. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study was conducted at a reproductive center. The RCT enrolled 552 infertile women with a low ovarian response (according to the Bologna criteria) who were undergoing IVF. In the study group, on Day 7 after ovulation patients were administered oral estrogen valerate (2 mg twice a day) until Day 2 of their next menstruation. Ovary stimulation was performed using rFSH, and a GnRH antagonist (0.25 mg/day) was started when a dominant follicle had a mean diameter ≥13 mm. MAIN RESULTS AND THE ROLE OF CHANCE: No significant difference was observed in the number (mean [SD]) of oocytes retrieved from the estrogen valerate pretreatment and control group (3.2 [2.8] versus 3.4 [2.6], respectively). The treatment difference was -0.18 (95% CI -0.67, 0.32, P = 0.49). No significant differences were observed in the number of MII oocytes (2.9 [2.5] versus 3.1 [2.4], mean difference -0.23, 95% CI (-0.69, 0.23), P = 0.16) and good-quality embryos (1.0 [1.3] versus 1.20 [1.6], mean difference -0.23, 95% CI (-0.50, 0.04), P = 0.19) between the two groups. The duration of rFSH treatment was significantly longer in the estrogen valerate pretreatment group than in the control group (10.3 [2.2] versus 8.6 [2.1] days, mean difference 1.7, 95% CI (1.3, 2.2), P = 0.00), and the total rFSH dosage was significantly higher in the estrogen valerate pretreatment group than in the control group (3081 [680] versus 2548 [649] IU, mean difference 553.7, 95% CI (405.8, 661.6), P = 0.00). The clinical pregnancy rate in the pretreatment group (19.3% [23/119]) was not significantly different from that in the control group (28.7% [43/150]). The mean difference was -0.09, 95% CI (-0.20, 0.01), P = 0.08. LIMITATIONS, REASONS FOR CAUTION: The major limitation was the high dropout rate of patients. Some patients did not return to the hospital for treatment because of predicted low success rates and for economic reasons. In addition, it is possible that the fixed dose of 300 IU rFSH was not sufficient to see differences in oocyte yield between the groups. WIDER IMPLICATIONS OF THE FINDINGS: Estrogen valerate pretreatment with an antagonist protocol did not increase oocyte yield in patients with low ovarian response. Similar to the number of retrieved oocytes, there was no significant difference in clinical pregnancy rate between estrogen pretreatment group and control group. More research is needed on whether patients with low ovarian response need pretreatment and which pretreatment is more appropriate. STUDY FUNDING/COMPETING INTEREST(S): This study was supported in part by a research grant from the Investigator-Initiated Studies Program of MSD (China) Holding Co., Ltd. and Organon (Shanghai) Pharmaceutical Technology Co., Ltd. (Grant number: IIS 56284). The authors declare that they have no competing interests regarding authorship or publication of this study. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT03300518. TRIAL REGISTRATION DATE: 28 September 2017. DATE OF FIRST PATIENT'S ENROLMENT: 15 November 2017.

Biallelic variants in ZFP36L2 cause female infertility characterised by recurrent preimplantation embryo arrest.

BACKGROUND: Recurrent preimplantation embryo developmental arrest (RPEA) is the most common cause of assisted reproductive technology treatment failure associated with identified genetic abnormalities. Variants in known maternal genes can only account for 20%-30% of these cases. The underlying genetic causes for the other affected individuals remain unknown. METHODS: Whole exome sequencing was performed for 100 independent infertile females that experienced RPEA. Functional characterisations of the identified candidate disease-causative variants were validated by Sanger sequencing, bioinformatics and in vitro functional analyses, and single-cell RNA sequencing of zygotes. RESULTS: Biallelic variants in ZFP36L2 were associated with RPEA and the recurrent variant (p.Ser308_Ser310del) prevented maternal mRNA decay in zygotes and HeLa cells. CONCLUSION: These findings emphasise the relevance of the relationship between maternal mRNA decay and human preimplantation embryo development and highlight a novel gene potentially responsible for RPEA, which may facilitate genetic diagnoses.

Homozygous pathogenic variants in ACTL9 cause fertilization failure and male infertility in humans and mice.

Total fertilization failure (TFF) can occur during in vitro fertilization (IVF) treatments, even following intracytoplasmic sperm injection (ICSI). Various male or female factors could contribute to TFF. Increasing evidence suggested that genetic variations in PLCZ1, which encodes 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase zeta-1 (PLCζ), is involved in oocyte activation and is a key male factor in TFF. In the present study, we explored the genetic variants in male individuals that led to TFF. A total of 54 couples with TFF or poor fertilization (fertilization rate < 20%) were screened, and 21 couples were determined to have a male infertility factor by the mouse oocyte activation test. Whole-exome sequencing of these 21 male individuals identified three homozygous pathogenic variants in ACTL9 (actin like 9) in three individuals. ACTL9 variations led to abnormal ultrastructure of the perinuclear theca (PT), and PLCζ was absent in the head and present in the neck of the mutant sperm, which contributed to failed normal calcium oscillations in oocytes and subsequent TFF. The key roles of ACTL9 in the PT structure and TFF after ICSI were further confirmed in an Actl9-mutated mouse model. Furthermore, assisted oocyte activation by calcium ionophore exposure successfully overcame TFF and achieved live births in a couple with an ACTL9 variant. These findings identified the role of ACTL9 in the PT structure and the correct localization of PLCζ. The results also provide a genetic marker and a therapeutic option for individuals who have undergone ICSI without successful fertilization.

[p38/ERK signal pathways regulating the expression of type I collagen and activity of MMP-2 in TGF-beta1-stimulated HLF-02 cells].

OBJECTIVE: To investigate the role of TGF-beta(1)/MAPK signaling pathways in the expression of type I collagen and activity of MMP-2, 9 in human lung fibroblasts. METHODS: Human lung fibroblasts cell line (HLF-02) was cultured and and then stimulated with 10 ng/ml TGF-beta(1) for different time; SB203580 or PD98059 was added into culture medium to block p38 or ERK kinase pathway before incubated with TGF-beta(1); the expression of type I collagen was detected by Western blotting and RT-PCR; zymogram analysis was used to analyze the activity of MMP-2 and MMP-9. RESULTS: (1) In the process of stimulation by TGF-beta(1), the type I collagen mRNA level of 24 h, 48 h and 72 h group was: 1.33 +/- 0.07, 2.46 +/- 0.09 and 2.39 +/- 0.08 respectively; and the type I collagen protein level of 24 h, 48 h and 72 h group was: 114.89 +/- 8.95, 208.16 +/- 6.75 and 211.46 +/- 8.05 respectively; and the activity of MMP-2 of 24 h, 48 h and 72 h group was: 190.33 +/- 5.86, 214.33 +/- 8.39 and 212.67 +/- 11.59 respectively. (2) SB203580 significantly inhibited the TGF-beta(1)-induced expression of type I collagen mRNA, protein and MMP-2 activity (inhibition ratio: 51%, 24% and 20%); (3) PD98059 also significantly attenuated the TGF-beta(1)-induced expression of type I collagen mRNA, protein and MMP-2 activity (inhibition ratio: 42%, 13% and 16%). CONCLUSION: TGF-beta(1) is capable of inducing the expression of type I collagen mRNA and protein and up-regulating MMP-2 activity in HLF-02 cells. p38 and ERK kinase signaling pathways play important role in regulation and control for this process.